
<PAGE>   1

     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MARCH 8, 2001

                                                     REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------

                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------

                              CALPINE CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<S>                              <C>                              <C>
            DELAWARE                           4911                          77-0212977
 (STATES OR OTHER JURISDICTIONS    (PRIMARY STANDARD INDUSTRIAL           (I.R.S. EMPLOYER
                OF
 INCORPORATION OR ORGANIZATION)    CLASSIFICATION CODE NUMBERS)       IDENTIFICATION NUMBERS)
</TABLE>

                          50 WEST SAN FERNANDO STREET
                           SAN JOSE, CALIFORNIA 95113
                                 (408) 995-5115
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                                PETER CARTWRIGHT
      CHAIRMAN, PRESIDENT AND CHIEF EXECUTIVE OFFICER, CALPINE CORPORATION
                          50 WEST SAN FERNANDO STREET
                           SAN JOSE, CALIFORNIA 95113
                                 (408) 995-5115
 (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)

                                   COPIES TO:

                                BRUCE C. BENNETT
                              COVINGTON & BURLING
                          1330 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10019
                                 (212) 841-1000

        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
   From time to time after the effective date of this Registration Statement.

     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box:  [ ]

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, please check the following box:  [X]

     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering:  [ ] __________

     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering:  [ ] __________

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box:  [ ]

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<S>                                 <C>               <C>                   <C>                      <C>
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
                                                        PROPOSED MAXIMUM       PROPOSED MAXIMUM
       TITLE OF EACH CLASS            AMOUNT TO BE     OFFERING PRICE PER     AGGREGATE OFFERING         AMOUNT OF
  OF SECURITIES TO BE REGISTERED       REGISTERED             UNIT                   PRICE           REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------
Common Stock, par value $.001 per
  share, of Calpine
  Corporation(1)..................     31,259,193          $44.70(2)           $1,397,285,924(2)         $349,500
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
</TABLE>

(1) Includes certain preferred stock purchase rights (the "Rights") associated
    with shares of the Common Stock of Calpine Corporation. Until the occurrence
    of certain prescribed events, none of which have occurred, the Rights are
    not exercisable, are evidenced by the certificate representing the Common
    Stock and will be transferred along with and only with the Common Stock.

(2) Estimated solely for the purpose of determining the registration fee in
    accordance with Rule 457(c) under the Securities Act based upon the average
    of the high and low prices of Calpine's Common Stock as reported on The New
    York Stock Exchange on March 5, 2001.

     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>   2

        THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED.
        WE MAY NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED
        WITH THE SECURITIES AND EXCHANGE COMMISSION RELATING TO THESE SECURITIES
        IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER TO SELL THESE SECURITIES
        AND IS NOT SEEKING AN OFFER TO BUY THESE SECURITIES IN ANY STATE WHERE
        THE OFFER OR SALE IS NOT PERMITTED.

                   SUBJECT TO COMPLETION, DATED MARCH 8, 2001

PROSPECTUS

                            Up to 31,259,193 Shares

                              CALPINE CORPORATION

                                  Common Stock
                          (Par Value $.001 per share)

     This prospectus relates to the shares of common stock of Calpine
Corporation, a Delaware corporation, issuable upon exchange or redemption of the
exchangeable shares of Calpine Canada Holdings Ltd., an Alberta corporation and
an indirect wholly-owned subsidiary of Calpine, which we call Calpine Canada in
this prospectus. The exchangeable shares are being issued to the former
shareholders of Encal Energy Ltd., an Alberta corporation, in connection with
our acquisition of Encal. Each exchangeable share may be exchanged for one share
of our common stock, plus all payable and unpaid dividends, if any, on a share
of our common stock. Because the shares of our common stock offered by this
prospectus will be issued only in exchange for, or upon the redemption of, the
exchangeable shares, we will not receive any cash proceeds from this offering.

     Up to 8,711,315 shares of the common stock offered hereby may be resold by
the selling holder named in this prospectus following our issuance of common
stock to such selling holder in exchange for, or upon redemption of, its
exchangeable shares. The selling holder will receive all of the proceeds from
the sale of the securities and will pay all expenses incident to the offer and
sale of the common stock, including any underwriting discounts and selling
commissions applicable to any sale. The selling holder and any broker-dealers,
agents or underwriters that participate in the distribution of the securities
may be deemed to be "underwriters" within the meaning of the Securities Act, and
any commission received by them and any profit on the resale of the securities
purchased by them may be deemed to be underwriting commission or discounts under
the Securities Act.

     We are paying all expenses of registration incurred in connection with this
offering.

     Calpine's common stock is traded on The New York Stock Exchange under the
symbol "CPN." On February 28, 2001, the last reported sales price of the common
stock on that exchange was $44.49. Unless otherwise indicated, all dollar
references in this prospectus are to U.S. dollars.

     INVESTING IN CALPINE'S COMMON STOCK INVOLVES RISKS. SEE "RISK FACTORS" ON
PAGE 7.

     NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE
ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

               The date of this prospectus is             , 2001.
<PAGE>   3

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                              PAGE
                                                              ----
<S>                                                           <C>
The Company.................................................    1
Risk Factors................................................    7
Where You Can Find More Information.........................    8
Forward-Looking Statements..................................    9
Use of Proceeds.............................................   10
Selling Holder..............................................   10
Plan of Distribution........................................   11
Description of Our Capital Stock............................   16
Income Tax Considerations...................................   19
Legal Matters...............................................   28
Independent Auditors........................................   28
</TABLE>

                           -------------------------

     This document is called a prospectus and is part of a registration
statement that we filed with the Securities and Exchange Commission (the "SEC")
using a "shelf" registration or continuous offering process.

     The registration statement containing this prospectus, including the
exhibits to the registration statement, provides additional information about us
and the securities offered under this prospectus. The registration statement,
including the exhibits, can be read at the SEC web site or at the SEC offices
mentioned under the heading "Where You Can Find More Information."

     You should rely only on the information incorporated by reference or
provided in this prospectus. We have not authorized anyone to provide you with
different information. We are not making an offer or soliciting a purchase of
these securities in any jurisdiction in which the offer or solicitation is not
authorized or in which the person making the offer or solicitation is not
qualified to do so or to anyone to whom it is unlawful to make the offer or
solicitation. You should not assume that the information in this prospectus or
the prospectus supplement is accurate as of any date other than the date on the
front of the document.

     The prospectus incorporates business and financial information about us
that is not included in or delivered with the document. YOU MAY REQUEST AND
OBTAIN THIS INFORMATION FREE OF CHARGE BY WRITING OR TELEPHONING US AT THE
FOLLOWING ADDRESS: CALPINE CORPORATION, 50 WEST SAN FERNANDO STREET, SAN JOSE,
CALIFORNIA 95113, ATTENTION: LISA M. BODENSTEINER, ASSISTANT SECRETARY,
TELEPHONE: (408) 995-5115.

     Unless we have indicated otherwise, references in this prospectus to
"Calpine," "we," "us," and "our" or similar terms are to Calpine Corporation and
its consolidated subsidiaries.

                                        i
<PAGE>   4

                                  THE COMPANY

     We are a leading independent power company engaged in the development,
acquisition, ownership and operation of power generation facilities and the sale
of electricity predominantly in the United States. We have experienced
significant growth in all aspects of our business over the last five years.
Currently, we own interests in 50 power plants having a net capacity of 5,849
megawatts. We also have 25 gas-fired projects under construction having a net
capacity of 14,028 megawatts and have announced plans to develop 35 gas-fired
power plants with a net capacity of 15,142 megawatts, including the Calgary
Energy Centre, a 300 megawatt combined-cycle, gas-fired power plant to be
located in Calgary, Alberta. Upon completion of the projects under construction,
we will have interests in 74 power plants located in 21 states having a net
capacity of 19,877 megawatts. Of this total generating capacity, 96% will be
attributable to gas-fired facilities and 4% will be attributable to geothermal
facilities.

     As a result of our expansion program, our revenues, EBITDA, earnings and
assets have grown significantly over the last five years, as shown in the table
below.

<TABLE>
<CAPTION>
                                                                             COMPOUND ANNUAL
                                                      1995         1999        GROWTH RATE
                                                    --------    ----------   ---------------
                                                    (DOLLARS IN MILLIONS)
<S>                                                 <C>         <C>          <C>
Total Revenue.....................................   $132.1      $  847.7          59%
EBITDA............................................     74.2         351.5          48%
Net Income........................................      7.4          95.1          89%
Total Assets......................................    554.5       3,991.6          64%
</TABLE>

     Since our inception in 1984, we have developed substantial expertise in all
aspects of the development, acquisition and operation of power generation
facilities. We believe that the vertical integration of our extensive
engineering, construction management, operations, fuel management and financing
capabilities provides us with a competitive advantage to successfully implement
our acquisition and development program and has contributed to our significant
growth over the past five years.

                                        1
<PAGE>   5

CAPITALIZATION

     The following table sets forth, as of September 30, 2000, (1) the actual
consolidated capitalization of Calpine; and (2) the consolidated capitalization
of Calpine as adjusted to reflect the net effect of the purchase of the Dighton,
Tiverton and Rumford facilities from Energy Management, Inc., the leveraged
lease transactions of the Tiverton and Rumford facilities, the application of
the proceeds from the pass through certificates for the Tiverton and Rumford
financing, the acquisition of SkyGen Energy, LLC, the acquisition of TriGas
Exploration, Inc., the acquisition of Power Systems Mfg., the sale of $1.15
billion of our 8 1/2% Senior Notes due 2011 and the issuance of our common stock
offered hereby. This table is not adjusted to reflect the business combination
with Encal (other than the issuance of the common stock offered hereby), as such
adjustment would require information regarding the business of Encal that will
not be available until Encal has provided us with its fiscal year 2000 audited
financial information. We will file an amendment to this registration statement
when such information is available adjusting this table to reflect the business
combination with Encal. The adjustments do not reflect normal day-to-day
operations. This table should be read in conjunction with the consolidated
financial statements and related notes thereto incorporated by reference in this
prospectus.

<TABLE>
<CAPTION>
                                                                 SEPTEMBER 30, 2000
                                                              ------------------------
                                                                ACTUAL     AS ADJUSTED
                                                              ----------   -----------
                                                                    (UNAUDITED)
                                                                   (IN THOUSANDS,
                                                               EXCEPT SHARE AMOUNTS)
<S>                                                           <C>          <C>
LONG-TERM DEBT:
  Notes payable, net of current portion.....................  $   55,374   $   55,374
  Project financing, net of current portion.................     361,188      861,849
  Senior notes..............................................   2,551,750    3,701,750
  Capital lease obligation, net of current portion..........     207,941      207,941
                                                              ----------   ----------
     Total long-term debt...................................   3,176,253    4,826,914
                                                              ----------   ----------
Company-obligated mandatorily redeemable convertible
  preferred securities of subsidiary trusts.................   1,122,828    1,122,828
Minority interests..........................................      40,118       38,364
                                                              ----------   ----------
STOCKHOLDERS' EQUITY:
  Preferred stock, $.001 par value:
     10,000,000 shares authorized; no shares outstanding,
       actual and as adjusted...............................          --           --
                                                              ----------   ----------
  Common stock, $.001 par value:
     500,000,000 shares authorized, 279,426,248 shares
       outstanding, actual; and 314,186,973 shares
       outstanding, as adjusted(1)..........................         279          283
  Additional paid-in capital................................   1,563,699    1,686,162
  Retained earnings.........................................     428,872      428,872
  Accumulated other comprehensive loss......................        (891)        (891)
                                                              ----------   ----------
     Total stockholders' equity.............................   1,991,959    2,114,426
                                                              ----------   ----------
     Total capitalization...................................  $6,331,158   $8,102,532
                                                              ==========   ==========
</TABLE>

-------------------------
(1) We have calculated the number of shares of our common stock to be offered
    hereby based upon the maximum number of shares that could be issuable in
    connection with the business combination with Encal, which presumes a price
    of $28.00 per share for our common stock. On February 28, 2001, the last
    reported sales price of our common stock on the NYSE was $44.49. The actual
    number of shares issuable in connection with the business combination with
    Encal will be finally determined based on a weighted average price for our
    common stock over a period ending three trading days prior to the Encal
    shareholders' meeting to vote on the business combination.

                                        2
<PAGE>   6

THE MARKET

     The power industry represents the third largest industry in the United
States, with an estimated end-user market of over $225 billion of electricity
sales in 1999 produced by an aggregate base of power generation facilities with
a capacity of approximately 785,000 megawatts. In response to increasing
customer demand for access to low-cost electricity and enhanced services, new
regulatory initiatives have been and are continuing to be adopted at both the
state and federal level to increase competition in the domestic power generation
industry. The power generation industry historically has been largely
characterized by electric utility monopolies producing electricity from old,
inefficient, high-cost generating facilities selling to a captive customer base.
Industry trends and regulatory initiatives have transformed the existing market
into a more competitive market where end users purchase electricity from a
variety of suppliers, including non-utility generators, power marketers, public
utilities and others.

     There is a significant need for additional power generating capacity
throughout the United States, both to satisfy increasing demand and to replace
old and inefficient generating facilities. Due to environmental and economic
considerations, we believe this new capacity will be provided predominantly by
gas-fired facilities. We believe that these market trends will create
substantial opportunities for efficient, low-cost power producers that can
produce and sell energy to customers at competitive rates.

     In addition, as a result of a variety of factors, including deregulation of
the power generation market, utilities, independent power producers and
industrial companies are disposing of power generation facilities. To date,
numerous utilities have sold or announced their intentions to sell their power
generation facilities and have focused their resources on the transmission and
distribution business segments. Many independent producers operating a limited
number of power plants are also seeking to dispose of their plants in response
to competitive pressures, and industrial companies are selling their power
plants to redeploy capital in their core businesses.

STRATEGY

     Our strategy is to continue our rapid growth by capitalizing on the
significant opportunities in the power market, primarily through our active
development and acquisition programs. In pursuing our growth strategy, we
utilize our management and technical knowledge to implement a fully integrated
approach to the acquisition, development and operation of power generation
facilities. This approach uses our expertise in design, engineering,
procurement, finance, construction management, fuel and resource production and
acquisition, operations and power marketing, which we believe provides us with a
competitive advantage. The key elements of our strategy are as follows:

     - Development of new and expansion of existing power plants. We are
       actively pursuing the development of new and expansion of our existing
       highly efficient, low-cost, gas-fired power plants to replace old and
       inefficient generating facilities and meet the demand for new generation.

     - Acquisition of power plants. Our strategy is to acquire power generating
       facilities that meet our stringent criteria, provide significant
       potential for revenue, cash flow and earnings growth and provide the
       opportunity to enhance the operating efficiencies of the plants.

     - Enhancement of existing power plants. We continually seek to maximize the
       power generation and revenue potential of our operating assets and
       minimize our operating and maintenance expenses and fuel costs.

RECENT DEVELOPMENTS

     ACQUISITIONS AND OTHER TRANSACTIONS. On December 15, 2000, we completed the
acquisition of strategic power assets from Dartmouth, Massachusetts-based Energy
Management, Inc. ("EMI") for approximately $145 million (a cash payment of $100
million and the issuance of shares of our common stock with a value at closing
of approximately $45 million) and the assumption of project financing. We
acquired from EMI the remaining interests in three recently-constructed
combined-cycle power generating

                                        3
<PAGE>   7

facilities located in Dighton, Massachusetts, Tiverton, Rhode Island, and
Rumford, Maine, as well as Calpine-EMI Marketing LLC, a joint marketing venture
between Calpine and EMI.

     On December 19, 2000, we completed leveraged lease transactions in which we
sold the Tiverton, Rhode Island, and Rumford, Maine facilities (purchased from
EMI) to a single owner lessor for $466.7 million, which then leased the
facilities back to our Tiverton and Rumford subsidiaries. We have fully and
unconditionally guaranteed all of the obligations of the Tiverton and Rumford
subsidiaries under the leases and other lease documents related to their lease
of the facilities from the owner lessor. The owner lessor paid the purchase
price for the facilities through an equity investment and by issuing notes. The
notes were purchased by a pass through trust created by the Tiverton and Rumford
subsidiaries. The purchase of the notes was financed by the private placement by
the pass through trust of $366.0 million in 9.00% pass through certificates due
July 15, 2018.

     On February 7, 2001, we announced the signing of a 10-year, $4.6 billion
fixed-price contract with the California Department of Water Resources to
provide electricity to the State of California. We committed to sell up to 1,000
megawatts of electricity, with initial deliveries of 200 megawatts starting
October 1, 2001, and increasing to 1,000 megawatts by January 1, 2004. This
contract will continue through 2011. The electricity will be sold directly to
the State's Department of Water Resources on a 24-hour, 7-day-a-week basis.

     On February 8, 2001, we announced our plans to acquire all of the common
shares of Encal Energy Ltd. ("Encal"), a Calgary, Alberta-based natural gas and
petroleum exploration and development company, through a stock-for-stock
exchange in which Encal shareholders will receive Cdn. $12.00 per share in
Calpine common equivalent shares (called "exchangeable shares" in this
prospectus) of our subsidiary, Calpine Canada, based on an exchange ratio to be
determined prior to closing. The aggregate value of the transaction is
approximately U.S. $1.2 billion, including the assumed indebtedness of Encal.
With the addition of Encal's assets, which currently produce approximately 230
million cubic feet of gas equivalent ("mmcfe") per day, net of royalties, our
net production is expected to increase to 390 mmcfe per day in North America,
enough to fuel approximately 2,300 megawatts of our power fleet. The
Registration Statement of which this prospectus is a part is being filed with
the SEC in order to register the shares of our common stock that will be
issuable on exchange of the exchangeable shares issued in connection with our
business combination with Encal and to allow for resales of such common stock by
a selling holder who is an affiliate of Encal.

     On February 15, 2001, the Company completed a public offering of $1.15
billion of its 8 1/2% Senior Notes due 2011. The senior notes earn interest at
8 1/2% per year, payable semi-annually, and mature on February 15, 2011.

     On February 28, 2001, we announced the signing of two additional long-term
power sales contracts with the California Department of Water Resources.
Pursuant to the first contract, a $5.2 billion, 10-year fixed-price contract, we
committed to sell up to 1,000 megawatts of electricity. Initial deliveries of
200 megawatts are scheduled to begin July 1, 2001, with deliveries increasing to
1,000 megawatts as early as July 2002, depending upon when our new California
energy centers have entered into commercial operation. This contract will
continue through 2011. The electricity will be sold directly to the State's
Department of Water Resources on a 24-hour, 7-day-a-week basis. Pursuant to the
second contract, a $3.1 billion 20-year contract, we committed to sell up to 495
megawatts of peaking electricity generation, which is electricity produced
during high power demand periods. Initial deliveries of 90 megawatts are
scheduled to begin in August 2001, with deliveries increasing up to 495
megawatts as early as August 2002, depending on when eleven new California
peaking generating units we have proposed have entered commercial operation.
This contract will continue through 2021.

     PROJECT DEVELOPMENT AND CONSTRUCTION. On February 12, 2001, we announced
that the Florida Public Service Commission approved a joint application filed by
Calpine and Seminole Electric Cooperative, Inc., under which Calpine will build
the Osprey Energy Center to supply electric power to help meet Seminole's
members' power needs.

                                        4
<PAGE>   8

     FOURTH QUARTER 2000 EARNINGS. On February 6, 2001, we announced earnings
for the quarter and year ended December 31, 2000.

     Net income was $107.7 million for the quarter ended December 21, 2000,
representing a 250% increase compared to net income of $30.8 million for the
fourth quarter of 1999. Diluted earnings per share rose 183% to $0.34 per share
for the quarter, from $0.12 per share for the same period in 1999. Revenue for
the quarter increased 304%, from $247.5 million a year ago to $1.0 billion.
EBITDA increased 138% to $263.1 million for the quarter compared to $110.6
million a year ago.

     For the year ended December 31, 2000, net income, before extraordinary
charge, was $324.7 million, an increase of 238% compared to $96.2 million in
1999. Diluted earnings per share, before extraordinary charge, rose 158% to
$1.11 per share, compared to $0.43 per share in 1999. Revenue for the year was
$2.3 billion, an increase of 171% compared to $847.7 million a year ago. EBITDA
for the 2000 fiscal year rose 135% to $825.9 million, from $351.5 million in
1999. Total assets at December 31, 2000 were $9.7 billion, up 143% from $4.0
billion at December 31, 1999.

     Financial results for both the three and twelve months ended December 31,
2000 benefited primarily from the execution of our strategy to acquire and build
low-cost power generation facilities around the United States in key markets
where supply is insufficient to meet the rising demand for power and from the
continued optimization of these assets through our vertically integrated
organization.

     CALIFORNIA POWER MARKET. The deregulation of the California power market
has produced significant unanticipated results in the past year. The
deregulation froze the rates that utilities can charge their retail and business
customers in California and prohibited the utilities from buying power on a
forward basis, while wholesale power prices were not subjected to limits.

     In the past year, a series of factors have reduced the supply of power to
California, which has resulted in wholesale power prices that have been
significantly higher than historical levels. Several factors contributed to this
increase. These included:

     - significantly increased volatility in prices and supplies of natural gas;

     - an unusually dry fall and winter in the Pacific Northwest, which reduced
       the amount of available hydroelectric power from that region (typically,
       California imports a portion of its power from this source);

     - the large number of power generating facilities in California nearing the
       end of their useful lives, resulting in increased downtime (either for
       repairs or because they have exhausted their air pollution credits and
       replacement credits have become too costly to acquire on the secondary
       market); and

     - continued obstacles to new power plant construction in California which
       deprived the market of new power sources that could have, in part,
       ameliorated the adverse effects of the foregoing factors.

     As a result of this situation, two major California utilities that are
subject to the retail rate freeze, including Pacific Gas & Electric ("PG&E"),
have faced wholesale prices that far exceed the retail prices they are permitted
to charge. This has led to significant underrecovery of costs by these
utilities; and they have been widely reported to be facing the prospect of
insolvency. As a consequence, these utilities have defaulted under a variety of
contractual obligations, including payment obligations to power generators. PG&E
has defaulted on payment obligations to us.

     As this situation has deteriorated, California and the federal government
have taken steps to restore a predictable and reliable power market to the
State. Recently, California adopted legislation permitting it to issue long-term
revenue bonds to provide funding for wholesale purchases of power. The bonds
will be repaid with the proceeds of payments by retail customers over time. The
California State Department of Water Resources sought bids for long-term power
supply contracts. We successfully bid in that auction, and recently announced
that we had signed a significant long-term power supply contract with California
(see "The Company -- Recent Developments -- Acquisitions and Other
Transactions").

                                        5
<PAGE>   9

     We have historically sold power to PG&E, which is one of the California
utilities that is subject to the rate freeze. We are currently selling power to
PG&E pursuant to long-term qualifying facility (or "QF") contracts, which are
subject to federal regulation under Public Utility Regulatory Policies Act of
1978, as amended (16 U.S.C. sec. 796 et seq.) We have continued to honor our
contractual obligations to this utility under our QF contracts. To date, we have
refrained from pursuing our remedies with respect to PG&E's default. We have
been actively involved with the California utilities, the California
legislature, and other interested parties to develop legislation designed to
stabilize energy prices through the application of a long-term energy pricing
methodology (for a five-year period) in place of the short-term pricing
methodology currently utilized under the QF contracts. With greater stability of
energy prices under the QF contracts and the implementation of recent
legislation that shifts the purchase of some of the wholesale power needs to the
state of California, PG&E's ability to make payments on past due amounts will be
substantially enhanced. We also expect further legislation to enable the
California utilities to finance over a longer term the difference between the
wholesale prices that have been paid and the retail prices they received during
last fall and into this winter. We believe that this should further enhance
PG&E's ability to make payment of all past due amounts. While management cannot
predict the timing or ultimate outcome of this process, it believes that
legislation reflecting these agreements will be enacted in the near term.

                          PRINCIPAL EXECUTIVE OFFICES

     Our principal executive offices are located at 50 West San Fernando Street,
San Jose, California 95113. Our telephone number is (408) 995-5115, and our home
page on the world wide web is at http://www.calpine.com. The contents of our
website are not part of this prospectus.

                                        6
<PAGE>   10

                                  RISK FACTORS

     Investing in our common stock involves risk. In addition to the risk
factors described in our Annual Report on Form 10-K for the year ended December
31, 1999, which is incorporated by reference in this prospectus, you should
carefully consider the risk factors described below, in addition to the other
information contained or incorporated by reference in this prospectus, before
making an investment decision. The risks and uncertainties described below and
incorporated by reference are not the only risks we face. Additional risks and
uncertainties not presently known to us or that we currently deem immaterial may
impair our business operations.

                     RISKS RELATING TO EXCHANGEABLE SHARES

THE EXCHANGE OF YOUR EXCHANGEABLE SHARES IS GENERALLY TAXABLE.

     Based on the tax laws as of the date of this prospectus, the exchange or
redemption of exchangeable shares is generally a taxable event in Canada and may
be a taxable event in the U.S. Your tax consequences depend on a number of
factors, including your residency and whether the shares are exchanged or
redeemed.

THE MARKET PRICE OF OUR COMMON STOCK MAY BE LESS THAN THE MARKET PRICE OF THE
EXCHANGEABLE SHARES.

     Our common stock trades on The New York Stock Exchange and the exchangeable
shares are expected to trade on The Toronto Stock Exchange. We do not plan to
list our common stock or the exchangeable shares on any other exchanges.
Although the market prices on the NYSE and TSE should reflect equivalent value,
there can be no assurances that the market price of our common stock will be
identical, or even similar, to the market prices of the exchangeable shares.

OUR COMMON STOCK WILL BE FOREIGN PROPERTY FOR CANADIAN TAX PURPOSES.

     You may be required to limit your investment in our common stock or risk
incurring penalties under the Income Tax Act (Canada) if you are:

     - a registered pension plan;

     - a registered retirement savings plan;

     - a registered retirement income fund;

     - a registered education savings plan (you should consult your own tax
       advisor as additional considerations may arise as a result of the
       acquisition of the Ancillary Rights (defined below under "Income Tax
       Considerations -- Certain United States Federal Income Tax
       Considerations -- Ancillary Rights and Call Rights") to the exchangeable
       shares);

     - a deferred profit sharing plan; or

     - among some other classes of tax-exempt person.

     So long as the exchangeable shares are listed on a prescribed Canadian
stock exchange, which exchanges include the TSE, and Calpine Canada maintains a
substantial presence in Canada, the exchangeable shares will be qualified
investments for these plans or persons and will not be foreign property under
the Income Tax Act (Canada). Our common stock will, however, be foreign property
for these plans or persons. These plans or persons must limit their investment
in our common stock or risk incurring penalties under the Income Tax Act
(Canada).

                                        7
<PAGE>   11

                 CERTAIN RISKS RELATING TO INDUSTRY CONDITIONS

THE CURRENT ISSUES IN THE CALIFORNIA POWER MARKET COULD ADVERSELY AFFECT OUR
PERFORMANCE.

     As described in "The Company -- Recent Developments -- California Power
Market," the California power market is currently in a state of disarray. Two of
the three major utilities in California have been widely reported to be facing
the prospect of insolvency, including Pacific Gas & Electric, which is a
customer of ours. State and federal regulators and legislators, along with the
major participants in the market and consumer groups, are attempting to resolve
this situation, but the ultimate result of this effort is not yet known. We are
actively involved in all aspects of this regulatory, legislative and contractual
effort. While we cannot predict the outcome of this very fluid process, or the
ultimate impact any such outcome will have upon us, management believes that the
resolution of this problem will not have a material adverse effect on our
results of operations or financial condition.

                      WHERE YOU CAN FIND MORE INFORMATION

     We file annual, quarterly and current reports, proxy statements and other
information with the SEC. You may obtain any document we file with the SEC at
the SEC's public reference rooms in Washington, D.C., Chicago, Illinois and New
York, New York. You may obtain information on the operation of the SEC's public
reference facilities by calling the SEC at 1-800-SEC-0330. You can request
copies of these documents, upon payment of a duplicating fee, by writing to the
SEC at its principal office at 450 Fifth Street, N.W., Washington, D.C.
20549-1004. Our SEC filings are also accessible through the Internet at the
SEC's Web site at http://www.sec.gov.

     The SEC permits us to "incorporate by reference" into this prospectus the
information in documents we file with it, which means that we can disclose
important information to you by referring you to those documents. The
information incorporated by reference is considered to be a part of this
prospectus, and later information that we file with the SEC will update and
supersede this information. We incorporate by reference the documents listed
below and any future filings made with the SEC under Section 13(a), 13(c), 14 or
15(d) of the Securities Exchange Act of 1934, as amended, until the offering is
otherwise terminated:

     - Calpine's Annual Report on Form 10-K for the year ended December 31,
       1999;

     - Calpine's Quarterly Reports on Form 10-Q for the quarters ended March 31,
       2000, June 30, 2000 and September 30, 2000;

     - Calpine's Current Reports on Form 8-K dated January 26, 2000, February 3,
       2000, March 6, 2000, March 30, 2000, May 18, 2000, June 26, 2000, July
       24, 2000, July 25, 2000, October 26, 2000 and February 6, 2001; and

     - The description of Calpine's common stock contained in Calpine's
       Registration Statement on Form 8-A (File No. 001-12079), filed with the
       SEC on August 20, 1996, pursuant to Section 12 of the Securities Exchange
       Act.

     If you request a copy of any or all of the documents incorporated by
reference, then we will send to you the copies you requested at no charge.
However, we will not send exhibits to such documents, unless such exhibits are
specifically incorporated by reference in such documents. You should direct
requests for such copies to Calpine Corporation, 50 West San Fernando Street,
San Jose, California 95113, attention: Lisa M. Bodensteiner, Assistant
Secretary, telephone: (408) 995-5115.

     We have filed with the SEC a registration statement on Form S-3 under the
Securities Act, covering the securities described in this prospectus. This
prospectus does not contain all of the information included in the registration
statement. Any statement made in this prospectus concerning the contents of any
contract, agreement or other document is only a summary of the actual contract,
agreement or other document. If we have filed any contract, agreement or other
document as an exhibit to the registration statement, you should read the
exhibit for a more complete understanding of the document or matter involved.
Each statement regarding a contract, agreement or other document is qualified in
its entirety by reference to the actual document.

                                        8
<PAGE>   12

                           FORWARD-LOOKING STATEMENTS

     Some of the statements contained in this prospectus and incorporated by
reference into this prospectus are forward-looking statements within the meaning
of Section 27A of the Securities Act and Section 21E of the Securities Exchange
Act and are subject to the safe harbor created by the Private Securities
Litigation Reform Act of 1995. These statements include declarations regarding
our or our management's intents, beliefs or current expectations. In some cases,
you can identify forward-looking statements by terminology such as "may,"
"will," "should," "expects," "plans," "anticipates," "believes," "estimates,"
"predicts," "potential," or "continue" or the negative of such terms or other
comparable terminology. Any forward-looking statements are not guarantees of
future performance and actual results could differ materially from those
indicated by the forward-looking statements. Forward-looking statements involve
known and unknown risks, uncertainties, and other factors that may cause our or
our industry's actual results, levels of activity, performance, or achievements
to be materially different from any future results, levels of activity,
performance, or achievements expressed or implied by such forward-looking
statements.

     Among the important factors that could cause actual results to differ
materially from those indicated by such forward-looking statements are:

     - the information is of a preliminary nature and may be subject to further
       adjustment,

     - the possible unavailability of financing,

     - risks related to the development, acquisition, construction and operation
       of power plants,

     - the impact of electricity and gas price fluctuations,

     - the impact of curtailment of power plant generation due to constrained
       transmission capacity or other causes,

     - the seasonal nature of our business,

     - start-up risks,

     - general operating risks,

     - dependence on third parties,

     - risks associated with international investments,

     - risks associated with the power marketing business,

     - changes in government regulation,

     - availability of natural gas,

     - the effects of competition,

     - dependence on senior management,

     - volatility in our stock price,

     - fluctuations in quarterly results and seasonality,

     - the recent disarray of the of the California power market, which has led
       to various efforts by federal, state and local regulators and government
       officials to remedy this situation. This is an ongoing process, the
       outcome of which cannot be predicted. However, it is possible that any
       such outcome will include changes in government regulations, business and
       contractual relationships or other factors that could materially
       adversely affect the Company, and

     - other risks identified from time to time in our reports and registration
       statements filed with the SEC, including the risk factors identified in
       "Risk Factors" and in our Annual Report on Form 10-K for the year ended
       December 31, 1999, which is incorporated by reference in this prospectus.

                                        9
<PAGE>   13

     Although we believe that the expectations reflected in the forward-looking
statements are reasonable, we cannot guarantee future results, levels of
activity, performance, or achievements. Moreover, neither we nor any other
person assumes responsibility for the accuracy and completeness of such
statements. We are under no duty to update any of the forward-looking statements
after the date of this prospectus to conform such statements to actual results.

                                USE OF PROCEEDS

     Because the shares of our common stock will be issued in exchange for
exchangeable shares, we will not receive any cash proceeds upon the issuance of
our common stock. In the case of resales by the selling holder, the selling
holder will receive all of the net proceeds of the resales. We will not receive
any of the proceeds of such resales.

                                 SELLING HOLDER

     The selling holder may from time to time offer and sell pursuant to this
prospectus any or all of the shares of common stock listed below that are issued
to such selling holder in exchange for, or upon redemption of, such selling
holder's exchangeable shares. The selling holder may also elect not to sell any
common stock held by it. The term "selling holder" refers to the holder listed
below. Only those shares of common stock listed below may be offered for resale
by the selling holder pursuant to this prospectus.

     The selling holder may offer and sell, from time to time following our
issuance of common stock to the selling holder in exchange for, or upon
redemption of, such selling holder's exchangeable shares, any or all of its
common stock listed below by using this prospectus. Because the selling holder
may offer all or only some portion of the common stock listed in the table, no
estimate can be given as to the amount or percentage of these shares of common
stock that will be held by the selling holder upon termination of this offering.
In addition, the selling holder may have sold, transferred or otherwise disposed
of all or a portion of its exchangeable shares since the date on which it
provided the information regarding its ownership of the exchangeable shares, and
thus its right to obtain the common stock included herein.

     The following table sets forth information as of February 28, 2001 with
respect to the number of shares of common stock beneficially owned by the
selling holder, assuming exchange or redemption of all of the selling holder's
exchangeable shares, that may be offered for the selling holder's account
pursuant to this prospectus. We prepared the table based on information supplied
to us by the selling holder.

<TABLE>
<CAPTION>
                                             NUMBER OF SHARES OF                              NUMBER OF SHARES OF
                                                COMMON STOCK                                     COMMON STOCK
                                             BENEFICIALLY OWNED         NUMBER OF SHARES      BENEFICIALLY OWNED
            SELLING HOLDER               PRIOR TO THE OFFERING(1)(2)   BEING OFFERED(1)(2)   AFTER THE OFFERING(1)
            --------------               ---------------------------   -------------------   ---------------------
<S>                                      <C>                           <C>                   <C>
Ontario Teachers' Pension Plan
  Board(3).............................           8,711,315                 8,711,315                  0
</TABLE>

-------------------------
(1) Beneficial ownership is determined in accordance with the rules of the SEC
    and generally includes voting or investment power with respect to
    securities. The selling holder has sole voting and sole investment power
    with respect to all shares beneficially owned, subject to community property
    laws, where applicable. For purposes of this table, we have assumed all of
    the selling holder's exchangeable shares will be exchanged or redeemed for
    shares of our common stock and that the selling holder will offer and sell
    all of the shares of our common stock it receives upon the exchange of its
    exchangeable shares, however, the selling holder may offer and/or sell less
    than all of such shares of common stock.

(2) The actual number of shares of common stock that will be beneficially owned
    and that will be offered by the selling holder shall be finally determined
    prior to the meeting of Encal's shareholders to vote upon the business
    combination, pursuant to a formula based upon a weighted average price for
    our common stock over a certain period, the United States-Canada exchange
    rate and a per share price for Encal common stock of Cdn. $12.00 per share.
    For purposes of this table, we have assumed a Calpine share price of $28.00
    (the price below which the combination agreement related to the

                                        10
<PAGE>   14

    business combination with Encal may be terminated) and a United
    States-Canadian exchange rate of Cdn. $1.00 to U.S. $.6527, which was the
    rate in effect on February 28, 2001 as reported by the Federal Reserve
    Board.

(3) As of February 28, 2001, Ontario Teachers' Pension Plan Board was the
    beneficial owner of approximately 28% of the common stock of Encal and
    accordingly is expected to be the beneficial owner of approximately 28% of
    the exchangeable shares, assuming that its ownership remains the same at the
    time that the business combination with Encal is consummated.

     To our knowledge, other than its stock ownership described in the above
table, the selling holder has had no position, office or material relationship
with Calpine or any of its predecessors or affiliates within the past three
years.

                              PLAN OF DISTRIBUTION

                            DISTRIBUTION BY CALPINE

     Our common stock may be issued to you in several ways:

     - You have the right to exchange or cause the redemption of your
       exchangeable shares. You may require an exchange by us or redemption by
       Calpine Canada of your exchangeable shares for our common stock. These
       rights are called your:

      - exchange put rights; and

      - retraction rights;

     - Automatic exchange or redemption. Upon the occurrence of a specified
       triggering event, you will be required to exchange your exchangeable
       shares for our common stock. These rights arise automatically upon the
       occurrence of triggering events, and are called:

      - the automatic redemption right;

      - the liquidation right; and

      - the automatic exchange right;

     - We may exercise our call rights.  Our call rights permit us to require an
       exchange of exchangeable shares for our common stock if you exercise your
       retraction rights or in any circumstance where Calpine Canada would
       redeem your exchangeable shares. The exchange may be made between you and
       one of our subsidiaries that we will designate, other than Calpine
       Canada. We plan to exercise our call rights, when available, and
       currently foresee no circumstances under which we would not exercise our
       call rights. We expect that you will receive our common stock through an
       exchange with one of our subsidiaries, as opposed to a redemption by
       Calpine Canada or through us, of your exchangeable shares for our common
       stock. While the consideration received upon an exchange with another of
       our subsidiaries or a redemption by Calpine Canada will be the same, the
       tax consequences will be substantially different. These call rights are
       called our:

      - retraction call rights;

      - liquidation call rights; and

      - redemption call rights.

YOUR RIGHTS TO EXCHANGE OR REDEEM YOUR SHARES

     We will grant your exchange put right described below to a Canadian trust
company, as trustee, for the benefit of the holders of the exchangeable shares.
You also have the right to retract any or all of your exchangeable shares.

     YOUR EXCHANGE PUT RIGHT. You may require us to exchange all or any part of
your exchangeable shares for an equivalent number of shares of our common stock,
plus all dividends on our common stock then

                                        11
<PAGE>   15

payable but unpaid. You may exercise your exchange put right by presenting to
the trustee, at its principal offices in Calgary, Alberta or Toronto, Ontario:

     - written notice;

     - a certificate or certificates representing the exchangeable shares you
       desire to have us exchange; and

     - other documents and instruments as provided in the voting and exchange
       trust agreement among us, Calpine Canada and the trustee.

     An exchange pursuant to this right will be completed not later than the
close of business on the third business day following receipt by the trustee of
the items listed above. The notice you provide to the trustee will be
irrevocable unless the exchange is not completed in accordance with the terms of
the voting and exchange trust agreement.

     YOUR RETRACTION RIGHTS. Subject to applicable law and our retraction call
right, you are entitled at any time to retract, or require Calpine Canada to
redeem, any or all of your exchangeable shares and to receive an equal number of
shares of our common stock plus all dividends on our common stock then payable
but unpaid. You may retract by presenting to the trustee or Calpine Canada:

     - a certificate or certificates representing the number of exchangeable
       shares you desire to retract; and

     - a duly executed retraction request:

      - specifying the number of exchangeable shares you desire to retract;

      - stating the retraction date on which you desire to have Calpine Canada
        redeem your shares, which must be between five and ten business days
        from the date of delivery of the request; and

      - acknowledging our overriding retraction call right to purchase all but
        not less than all of the retracted shares directly from you and that the
        retraction request will be deemed to be a revocable offer by you to sell
        the retracted shares to us or to another subsidiary designated by us in
        accordance with our retraction call right on the terms and conditions
        described below.

     Calpine Canada will promptly notify us upon receipt of a retraction
request. In order to exercise our retraction call right, we must notify Calpine
Canada of our determination to do so within two business days of our receipt of
notification. If we deliver the call notice within two business days, and you
have not revoked your retraction request, Calpine Canada will not redeem the
retracted shares and we will purchase or cause to be purchased from you the
retracted shares on the retraction date. If we do not timely deliver the call
notice and you have not revoked your retraction request, Calpine Canada will
redeem the retracted shares on the retraction date. In the event that we do
exercise our retraction call right, the closing of the purchase and sale of the
retracted shares pursuant to the retraction call right will be deemed to occur
as at the close of business on the retraction date, and no redemption by Calpine
Canada of the retracted shares will take place on the retraction date.

     You may withdraw your retraction request by giving notice in writing to
Calpine Canada before the close of business on the business day before your
retraction date. If you withdraw your retraction request, your offer to sell the
shares to us will be deemed to have been revoked. If, as a result of liquidity
or solvency requirements or other provisions of applicable law, Calpine Canada
is not permitted to redeem all the exchangeable shares you desire to retract,
Calpine Canada will redeem only those exchangeable shares you have tendered as
would be permitted by applicable law.

     If any of your exchangeable shares are not redeemed by Calpine Canada as a
consequence of applicable law or purchased by us, you will be deemed to have
required us to purchase your unretracted shares in exchange for an equal number
of shares of our common stock, plus the amount of all of our dividends, payable
and unpaid, on the retraction date or as soon as practicable thereafter pursuant
to your exchange put right.

                                        12
<PAGE>   16

AUTOMATIC RIGHTS

     THE AUTOMATIC REDEMPTION RIGHT. Subject to applicable law and our
redemption call rights, on an automatic redemption date, Calpine Canada will
redeem all of the then outstanding exchangeable shares in exchange for an equal
number of shares of our common stock, plus all dividends on our common stock
then payable but unpaid. Notwithstanding any proposed redemption of the
exchangeable shares, our redemption call rights give us the overriding right to
acquire, or to cause one of our other subsidiaries to acquire, on an automatic
redemption date all but not less than all of the outstanding exchangeable shares
in exchange for an equal number of shares of our common stock, plus the amount
of all of our dividends, payable and unpaid.

     An automatic redemption date is the first to occur of:

     - the date selected by the Calpine Canada board of directors, if the
       selected date is later than the first anniversary of the closing of our
       acquisition of Encal;

     - the date selected by the Calpine Canada board of directors, if less than
       5% of the number of exchangeable shares issuable at the closing of our
       acquisition of Encal, other than exchangeable shares held by us and
       entities owned or controlled by us, are outstanding;

     - the date on which the share purchase rights issued pursuant to our rights
       agreement separate from our common stock and become exercisable (for a
       description of our rights plan, see "Description of Our Capital
       Stock -- Anti-Takeover Effects of Provision of the Certificate of
       Incorporation, Bylaws, Rights Plan and Delaware Laws -- Rights Plan");

     - the business day prior to the record date for any meeting or vote of the
       Calpine Canada shareholders to consider any matter in which the holders
       of exchangeable shares would be entitled to vote as Calpine Canada
       shareholders, but, except as described in the bullet immediately below,
       excluding certain meetings or votes regarding certain changes to the
       rights, privileges, restrictions or conditions of the exchangeable shares
       requiring the approval of the holders of the exchangeable shares; and

     - the business day following the day on which the holders of exchangeable
       shares fail to take the necessary action at a meeting or other vote of
       holders of exchangeable shares, if and to the extent the action is
       required, to approve or disapprove, as applicable, any change to, or in
       the rights of the holders of, the exchangeable shares, if the approval or
       disapproval, as applicable, of the change would be required to maintain
       the economic and legal equivalence of the exchangeable shares and our
       common stock.

     At least 45 days before an automatic redemption date (or as soon as
reasonably practicable after Calpine Canada has knowledge of the occurrence of
an automatic redemption date, if not known 45 days before the automatic
redemption date) or before a possible automatic redemption date which may result
from a failure of the holders of the exchangeable shares to take a necessary
action as described in the bullet immediately above, Calpine Canada shall
provide you with written notice of the proposed redemption or possible
redemption of the exchangeable shares by Calpine Canada or the purchase of the
exchangeable shares by us pursuant to our redemption call right, as the case may
be. In the case of a possible automatic redemption date, the notice will be
given contingently and will be withdrawn if the contingency does not occur.

     THE LIQUIDATION RIGHT. Subject to our liquidation call right, in the event
of the liquidation, dissolution or winding-up of Calpine Canada or any other
distribution of assets of Calpine Canada among its shareholders for the purpose
of winding-up its affairs, you will be entitled to receive for each exchangeable
share one share of Calpine common stock, together with all dividends on our
common stock then payable but unpaid.

     THE AUTOMATIC EXCHANGE RIGHT. In the event of a Calpine liquidation event,
we will be deemed to have purchased each outstanding exchangeable share and you
will be deemed to have sold your exchangeable shares to us for an equal number
of shares of Calpine common stock, plus the equivalent amount of all

                                        13
<PAGE>   17

Calpine dividends, payable and unpaid, immediately prior to the effective time
of the Calpine liquidation event.

     A Calpine liquidation event is:

     - any determination by our board to institute voluntary liquidation,
       dissolution or winding-up proceedings of Calpine or to effect any other
       distribution of our assets among our shareholders for the purpose of
       winding-up our affairs; or

     - the earlier of receipt of notice of, and our otherwise becoming aware of,
       any threatened or instituted claim or other proceeding with respect to
       the involuntary liquidation, dissolution or winding-up of Calpine or to
       effect any other distribution of our assets among our shareholders for
       the purpose of winding-up our affairs.

OUR CALL RIGHTS

     In the circumstances described below, we will have overriding call rights
to acquire your exchangeable shares by delivering an equal number of shares of
our common stock, plus all dividends on our common stock then payable but
unpaid. DIFFERENT CANADIAN FEDERAL INCOME TAX CONSEQUENCES MAY ARISE DEPENDING
UPON WHETHER WE EXERCISE OUR CALL RIGHTS OR WHETHER YOUR EXCHANGEABLE SHARES ARE
REDEEMED BY CALPINE CANADA. See "Income Tax Considerations -- Canadian Federal
Income Tax Considerations." We have the right to cause one of our other
subsidiaries (other than Calpine Canada) to exercise the overriding call rights
in our place by purchasing your exchangeable shares and delivering the common
shares of our common stock and other consideration that you are entitled to
receive. In any circumstance where we are required to purchase your exchangeable
shares, we may cause this separate Canadian subsidiary to acquire from us and
deliver to you the shares of our common stock. In either case, the tax
consequences of the exchange to you will be substantially identical.

     OUR RETRACTION CALL RIGHT. If you request the redemption by Calpine Canada
of your exchangeable shares, you will be deemed to offer your exchangeable
shares to us, and we will have an overriding retraction call right to acquire
(or cause one of our other subsidiaries to acquire) all, but not less than all,
of the exchangeable shares that you have requested Calpine Canada to redeem in
exchange for an equal number of shares of our common stock, plus all dividends
on our common stock then payable but unpaid.

     OUR LIQUIDATION CALL RIGHT. We will be granted an overriding liquidation
call right, in the event of and notwithstanding a proposed liquidation,
dissolution or winding-up of Calpine Canada or any other distribution of the
assets of Calpine Canada among its shareholders for the purpose of winding-up
its affairs, to acquire (or cause one of our other subsidiaries to acquire) all,
but not less than all, of the exchangeable shares then outstanding in exchange
for an equal number of shares of our common stock, plus all dividends on our
common stock then payable and unpaid. Upon the exercise of our liquidation call
right, you will be obligated to transfer your exchangeable shares to us (or to a
subsidiary that we designate). The acquisition of all of the outstanding
exchangeable shares upon the exercise of our liquidation call right will occur
on the effective date of the voluntary or involuntary liquidation, dissolution
or winding-up of Calpine Canada.

     OUR REDEMPTION CALL RIGHT. We have an overriding redemption call right to
acquire (or cause one of our other subsidiaries to acquire) on an automatic
redemption date all, but not less than all, of the exchangeable shares then
outstanding in exchange for an equal number of shares of our common stock, plus
all dividends on our common stock then payable but unpaid, and, upon the
exercise of our redemption call right, you will be obligated to transfer your
shares to us (or to a subsidiary that we designate).

     If we exercise one or more of our call rights, we will directly issue our
common stock to you and will become the holder of your exchangeable shares, or
we will cause one of our other subsidiaries (other than Calpine Canada) to
deliver our common stock to you and it will become the holder of your
exchangeable shares. We or, if applicable, our subsidiary, will not be entitled
to exercise any of the voting rights attached to your exchangeable shares. If we
decline to exercise our call rights when available, we will be required to issue
our common stock as Calpine Canada directs, including to Calpine Canada, which
will,

                                        14
<PAGE>   18

in turn, transfer our common stock to you in consideration for the return and
cancellation of your exchangeable shares. In the event we do not exercise our
call rights when applicable and instead deliver our common stock as Calpine
Canada directs, you would receive the same consideration, but the Canadian tax
consequences will be substantially different. See "Income Tax
Considerations -- Canadian Federal Income Tax Considerations." However, we
anticipate that we will exercise our call rights, when available, and currently
foresee no circumstances under which we would not exercise our call rights. In
addition, we do not anticipate any restriction or limitation on the number of
exchangeable shares we or our subsidiary would acquire upon the exercise of our
call rights.

                         DISTRIBUTION BY SELLING HOLDER

     Following our distribution of common stock to the selling holder as
described above, the selling holder may offer and sell such common stock from
time to time directly to purchasers. Alternatively, the selling holder may from
time to time offer those shares of common stock to or through underwriters,
broker-dealers or agents, who may receive compensation in the form of
underwriting discounts, concessions or commissions from the selling holder or
the purchasers of the common stock for whom they act as agents. The selling
holder and any underwriters, broker-dealers or agents that participate in the
distribution of the common stock may be deemed to be "underwriters" within the
meaning of the Securities Act, and any profit on the sale of such common stock
and any discounts, commissions, concessions or other compensation received by
any such underwriter, broker-dealer or agent may be deemed to be underwriting
discounts and commissions under the Securities Act.

     The selling holder's common stock may be sold from time to time in one or
more transactions at fixed prices, at prevailing market prices at the time of
sale, at varying prices determined at the time of sale or at negotiated prices.
The sale of the common stock may be effected in transactions, which may involve
crosses or block transactions:

     - on any national securities exchange or quotation service on which the
       common stock may be listed or quoted at the time of sale,

     - in the over-the-counter market,

     - in transactions otherwise than on such exchanges or in the
       over-the-counter market, or

     - through the writing and exercise of options.

     At the time a particular offering of the common stock is made by the
selling holder, such selling holder must provide a copy of this prospectus,
which sets forth the name of the selling holder and the aggregate amount of
common stock being offered. A prospectus supplement will also be distributed at
the time a particular offering is made, setting forth additional information, if
any, concerning terms of the offering, including the name or names of any
underwriters, broker-dealers or agents, any discounts, commissions and other
terms constituting compensation from the selling holder and any discounts,
commissions or concessions allowed or reallowed to be paid broker-dealers.

     To comply with the securities laws of certain jurisdictions, if applicable,
the common stock will be offered or sold in such jurisdictions only through
registered or licensed brokers or dealers. In addition, in certain jurisdictions
the common stock may not be offered or sold unless it has been registered or
qualified for sale in such jurisdictions or any exemption from registration or
qualification is available and is complied with.

     The selling holder and any other person participating in such distribution
will be subject to applicable provisions of the Securities Exchange Act and the
rules and regulations under the Securities Exchange Act, which provisions may
limit the timing of purchases and sales of any of the common stock by the
selling holder. This may affect the marketability of the offered shares of
common stock.

     We have borne all fees and expenses incurred in connection with the
registration of the common stock. The selling holder will pay all expenses
incident to the offer and sale of the common stock, including broker's
commissions and underwriting discounts and commissions, if any.

                                        15
<PAGE>   19

                        DESCRIPTION OF OUR CAPITAL STOCK

     Our authorized capital stock consists of 500,000,000 shares of common
stock, $.001 par value, and 10,000,000 shares of preferred stock, $.001 par
value. The following summary is qualified in its entirety by the provisions of
our certificate of incorporation and bylaws, which have been incorporated by
reference or attached as exhibits to the Registration Statement of which this
prospectus constitutes a part. The information provided below reflects the 2 for
1 split of our common stock that became effective on October 7, 1999, the 2 for
1 split of our common stock that became effective on June 8, 2000 and the 2 for
1 split of our common stock that became effective on November 14, 2000.

COMMON STOCK

     The holders of common stock are entitled to one vote per share on all
matters to be voted upon by the stockholders. Subject to preferences that may be
applicable to any outstanding preferred stock, the holders of common stock are
entitled to receive ratably such dividends, if any, as may be declared from time
to time by the board of directors out of legally available funds. See "Dividend
Policy." In the event of our liquidation, dissolution or winding up, the holders
of common stock are entitled to share ratably in all assets remaining after
payment of liabilities, subject to prior liquidation rights of preferred stock,
if any, then outstanding. The common stock has no preemptive or conversion
rights or other subscription rights. There are no redemption or sinking fund
provisions applicable to the common stock. All shares of common stock to be
outstanding upon the redemption or exchange of the exchangeable shares will be
fully paid and non-assessable. Pursuant to a rights agreement entered into in
June of 1997, our shares of common stock outstanding prior to the occurrence of
events specified in the rights agreement have certain preferred share purchase
rights, which are set forth in more detail in the rights agreement incorporated
by reference as an exhibit to the Registration Statement of which this
prospectus constitutes a part. See "-- Anti-Takeover Effects of Provisions of
the Certificate of Incorporation, Bylaws, Rights Plan and Delaware Law -- Rights
Plan."

PRICE RANGE OF COMMON STOCK

     Our common stock is traded on The New York Stock Exchange under the symbol
"CPN." Public trading of the common stock commenced on September 20, 1996. Prior
to that, there was no public market for the common stock. The following table
sets forth, for the periods indicated, the high and low sale price per share of
the common stock on The New York Stock Exchange.

<TABLE>
<CAPTION>
                                                            HIGH        LOW
                                                           -------    -------
<S>                                                        <C>        <C>
1998
First Quarter............................................  $ 2.313    $ 1.594
Second Quarter...........................................    2.657      2.157
Third Quarter............................................    2.688      2.141
Fourth Quarter...........................................    3.453      2.196
1999
First Quarter............................................  $ 4.672    $ 3.157
Second Quarter...........................................    7.375      4.391
Third Quarter............................................   11.969      6.852
Fourth Quarter...........................................   16.375     10.633
2000
First Quarter............................................  $30.750    $16.094
Second Quarter...........................................   35.219     18.125
Third Quarter............................................   52.250     32.250
Fourth Quarter...........................................   52.969     32.250
2001
First Quarter (through February 28, 2001)................  $48.800    $29.000
</TABLE>

                                        16
<PAGE>   20

     As of February 28, 2001, there were approximately 602 holders of record of
our common stock. On February 28, 2001, the last sale price reported on The New
York Stock Exchange for our common stock was $44.49 per share.

DIVIDEND POLICY

     We do not anticipate paying any cash dividends on our common stock in the
foreseeable future because we intend to retain our earnings to finance the
expansion of our business and for general corporate purposes. In addition, our
ability to pay cash dividends is restricted under our indentures and our other
debt agreements. Future cash dividends, if any, will be at the discretion of our
board of directors and will depend upon, among other things, our future
operations and earnings, capital requirements, general financial condition,
contractual restrictions and such other factors as the board of directors may
deem relevant.

PREFERRED STOCK

     As of February 28, 2001, there were no shares of preferred stock
outstanding. Our board of directors has the authority, without further vote or
action by our stockholders, to issue from time to time up to 10,000,000 shares
of preferred stock in one or more series, and to fix the rights, preferences,
privileges, qualifications, limitations and restrictions granted to or imposed
upon any wholly unissued shares of undesignated preferred stock, including
without limitation dividend rights, if any, voting rights, if any, and
liquidation and conversion rights, if any. Our board of directors has the
authority to fix the number of shares constituting any series and the
designations of such series without any further vote or action by our
stockholders. Our board of directors, without stockholder approval, can issue
preferred stock with voting and conversion rights which could adversely affect
the voting power of the holders of our common stock. The issuance of preferred
stock may have the effect of delaying, deferring or preventing a change in
control of our company, or could delay or prevent a transaction that might
otherwise give our stockholders an opportunity to realize a premium over the
then prevailing market price of our common stock.

     Our board of directors has authorized the issuance of up to 500,000 shares
of Series A Participating Preferred Stock, par value $.001 per share, pursuant
to a rights plan adopted by our board of directors on June 5, 1997. On February
28, 2001, no shares of our participating preferred stock were outstanding. A
description of the rights plan and the participating preferred stock is set
forth under "-- Anti-Takeover Effects of Provisions of the Certificate of
Incorporation, Bylaws, Rights Plan and Delaware -- Rights Plan," below.

     A series of preferred stock, consisting of one share, will be designated as
special voting preferred stock, having a par value of $.001 per share and a
liquidation preference of $.01. Except as otherwise required by law or our
certificate of incorporation, the one share of special voting preferred stock
will possess a number of votes for the election of directors and on all other
matters submitted to a vote of our stockholders equal to the number of
outstanding exchangeable shares from time to time not owned by us or any entity
controlled by us. The holders of our common stock and the holder of the special
voting preferred stock will vote together as a single class on all matters on
which holders of our common stock are eligible to vote. In the event of our
liquidation, dissolution or winding-up, all outstanding exchangeable shares will
automatically be exchanged for shares of our common stock, and the holder of the
special voting preferred stock will not be entitled to receive any assets
available for distribution to our stockholders. The holder of the special voting
preferred stock will not be entitled to receive dividends. The share of special
voting preferred stock will be issued to a Canadian trust company, as trustee
under a voting and exchange trust agreement among us, Calpine Canada and the
trustee. At such time as the one share of special voting preferred stock has no
votes attached to it because there are no exchangeable shares outstanding not
owned by us or an entity controlled by us, the share of special voting preferred
stock will be canceled.

                                        17
<PAGE>   21

ANTI-TAKEOVER EFFECTS OF PROVISIONS OF THE CERTIFICATE OF INCORPORATION, BYLAWS,
RIGHTS PLAN AND DELAWARE LAW

CERTIFICATE OF INCORPORATION AND BYLAWS

     Our certificate of incorporation and bylaws provide that our board of
directors is classified into three classes of directors serving staggered,
three-year terms. The certificate of incorporation also provides that directors
may be removed only by the affirmative vote of the holders of two-thirds of the
shares of our capital stock entitled to vote. Any vacancy on the board of
directors may be filled only by vote of the majority of directors then in
office. Further, the certificate of incorporation provides that any business
combination (as therein defined) requires the affirmative vote of the holders of
two-thirds of the shares of our capital stock entitled to vote, voting together
as a single class. The certificate of incorporation also provides that all
stockholder actions must be effected at a duly called meeting and not by a
consent in writing. The bylaws provide that our stockholders may call a special
meeting of stockholders only upon a request of stockholders owning at least 50%
of our capital stock. These provisions of the certificate of incorporation and
bylaws could discourage potential acquisition proposals and could delay or
prevent a change in control of our company. These provisions are intended to
enhance the likelihood of continuity and stability in the composition of the
board of directors and in the policies formulated by the board of directors and
to discourage certain types of transactions that may involve an actual or
threatened change of control of our company. These provisions are designed to
reduce our vulnerability to an unsolicited acquisition proposal.

     The provisions also are intended to discourage certain tactics that may be
used in proxy fights. However, such provisions could have the effect of
discouraging others from making tender offers for our shares and, as a
consequence, they also may inhibit fluctuations in the market price of our
shares that could result from actual or rumored takeover attempts. Such
provisions also may have the effect of preventing changes in our management.

     Rights Plan. On June 5, 1997, we adopted a stockholders' rights plan to
strengthen our ability to protect our stockholders. The rights plan is designed
to protect against abusive or coercive takeover tactics that are not in the best
interests of Calpine or its stockholders. To implement the rights plan, we
declared a dividend of one preferred share purchase right for each outstanding
share of our common stock held on record as of June 18, 1997, and directed the
issuance of one preferred share purchase right with respect to each share of our
common stock that shall become outstanding thereafter until the rights become
exercisable or they expire as described below. Each right initially represents a
contingent right to purchase, under certain circumstances, one one-thousandth of
a share, called a "unit," of our Series A Participating Preferred Stock, par
value $.001 per share, at a price of $80.00 per unit, subject to adjustment. The
rights become exercisable and trade independently from our common stock upon the
public announcement of the acquisition by a person or group of 15% or more of
our common stock, or ten days after commencement of a tender or exchange offer
that would result in the acquisition of 15% or more of our common stock. Each
unit purchased upon exercise of the rights will be entitled to a dividend equal
to any dividend declared per share of common stock and will have one vote,
voting together with the common stock. In the event of our liquidation, each
share of the participating preferred stock will be entitled to any payment made
per share of common stock.

     If we are acquired in a merger or other business combination transaction
after a person or group has acquired 15% or more of our common stock, each right
will entitle its holder to purchase at the right's exercise price a number of
the acquiring company's shares of common stock having a market value of twice
the right's exercise price. In addition, if a person or group acquires 15% or
more of our common stock, each right will entitle its holder (other than the
acquiring person or group) to purchase, at the right's exercise price, a number
of fractional shares of our participating preferred stock or shares of our
common stock having a market value of twice the right's exercise price.

     The rights expire on June 18, 2007, unless redeemed earlier by us. We can
redeem the rights at a price of $.01 per right at any time before the rights
become exercisable, and thereafter only in limited circumstances.

                                        18
<PAGE>   22

DELAWARE ANTI-TAKEOVER STATUTE

     We are subject to Section 203 of the Delaware General Corporation Law,
which, subject to certain exceptions, prohibits a Delaware corporation from
engaging in any business combination with any interested stockholder for a
period of three years following the date that such stockholder became an
interested stockholder, unless: (1) prior to such date, the board of directors
of the corporation approved either the business combination or the transaction
that resulted in the stockholder becoming an interested stockholder; (2) upon
consummation of the transaction that resulted in the stockholder becoming an
interested stockholder, the interested stockholder owned at least 85% of the
voting stock of the corporation outstanding at the time the transaction
commenced, excluding for purposes of determining the number of shares
outstanding those shares owned (x) by persons who are directors and also
officers and (y) by employee stock plans in which employee participants do not
have the right to determine confidentially whether shares held subject to the
plan will be tendered in a tender or exchange offer; or (3) on or subsequent to
such date, the business combination is approved by the board of directors and
authorized at an annual or special meeting of stockholders, and not by written
consent, by the affirmative vote of at least 66 2/3% of the outstanding voting
stock that is not owned by the interested stockholder.

     Section 203 defines business combination to include: (1) any merger or
consolidation involving the corporation or any of its direct or indirect
majority-owned subsidiaries and the interested stockholder; (2) any sale,
transfer, pledge or other disposition of 10% or more of the assets of the
corporation or any of its direct or indirect majority-owned subsidiaries
involving the interested stockholder; (3) subject to certain exceptions, any
transaction that results in the issuance or transfer by the corporation or any
of its direct or indirect majority-owned subsidiaries of any stock of the
corporation or that subsidiary to the interested stockholder; (4) any
transaction involving the corporation or any of its direct or indirect
majority-owned subsidiaries that has the effect of increasing the proportionate
share of the stock of any class or series of the corporation or that subsidiary
beneficially owned by the interested stockholder; or (5) the receipt by the
interested stockholder of the benefit of any loans, advances, guarantees,
pledges or other financial benefits provided by or through the corporation or
any of its direct or indirect majority-owned subsidiaries. In general, Section
203 defines an interested stockholder as any entity or person beneficially
owning 15% or more of the outstanding voting stock of the corporation and any
entity or person affiliated with or controlling or controlled by such entity or
person.

                           INCOME TAX CONSIDERATIONS

                   CANADIAN FEDERAL INCOME TAX CONSIDERATIONS

     In the opinion of Macleod Dixon LLP, our Canadian counsel, the following is
a fair and adequate summary of the material Canadian federal income tax
considerations generally applicable under the Income Tax Act (Canada) (the
"Canadian Income Tax Act)" if you hold exchangeable shares or acquire our common
stock on the exchange of exchangeable shares and if, for purposes of the
Canadian Income Tax Act, you deal with us at arm's length and hold your
exchangeable shares and will hold our common stock as capital property. This
discussion does not apply to you if you are a "financial institution", as
defined in the Canadian Income Tax Act, and are therefore subject to the
mark-to-market provisions of the Canadian Income Tax Act.

     The exchangeable shares and our common stock will generally be considered
to be capital property to you unless the shares are held by you in the course of
carrying on a business of buying and selling similar securities or the shares
are acquired in a transaction considered to be an adventure in the nature of
trade. If you are a resident of Canada and the exchangeable shares might not
otherwise qualify as capital property, you may be entitled to obtain this
qualification by making the irrevocable election provided under subsection 39(4)
of the Canadian Income Tax Act. If you do not hold your exchangeable shares or
will not hold our common stock as capital property, you should consult your own
tax advisors for information and advice having regard to your particular
circumstances.

                                        19
<PAGE>   23

     This summary is based on the current provisions of the Canadian Income Tax
Act and regulations thereunder, the current provisions of the Convention Between
the United States of America and Canada with Respect to Taxes on Income and on
Capital, signed September 26, 1980, as amended, (the "Canada-U.S. Tax
Convention") and our counsel's understanding of the current published
administrative practices of the Canada Customs and Revenue Agency (the "CCRA").
This summary takes into account all specific proposals to amend the Canadian
Income Tax Act and regulations that have been publicly announced by the Minister
of Finance (Canada) prior to the date hereof and assumes that all of these
proposed amendments will be enacted in their present form. No assurances can be
given that any proposed amendments will be enacted in the form proposed, if at
all. Except for the foregoing, this summary does not take into account or
anticipate any changes in law, whether by legislative, administrative or
judicial decision or action, nor does it take into account provincial,
territorial or foreign income tax legislation or considerations which may differ
from the Canadian federal income tax considerations described below. No advance
income tax ruling has been sought or obtained from the CCRA to confirm the tax
consequences of any of the transactions relating to the exchangeable shares or
the acquisition of our common stock on the exchange of exchangeable shares.

     For purposes of the Canadian Income Tax Act, all amounts otherwise
denominated in United States dollars relating to the acquisition, holding or
disposition of our common stock, including dividends, adjusted cost base amounts
and proceeds of disposition, must be converted into Canadian dollars based on
the prevailing United States dollar exchange rate generally at the time these
amounts arise.

     THIS SUMMARY IS OF A GENERAL NATURE ONLY AND IS NOT INTENDED TO BE, AND
SHOULD NOT BE CONSTRUED TO BE, LEGAL, BUSINESS OR TAX ADVICE TO YOU. THEREFORE,
YOU SHOULD CONSULT YOUR OWN TAX ADVISORS WITH RESPECT TO YOUR PARTICULAR
CIRCUMSTANCES.

SHAREHOLDERS RESIDENT IN CANADA

     The following portion of this summary will apply to you if, for the
purposes of the Canadian Income Tax Act and any applicable income tax treaty or
convention, you are resident or deemed to be resident in Canada at all relevant
times. This summary does not apply to you if we are or will be a "foreign
affiliate" of you as defined in the Canadian Income Tax Act.

REDEMPTION OF EXCHANGEABLE SHARES

     On a redemption (including a retraction) of your exchangeable shares by
Calpine Canada, you will be deemed to have received a dividend equal to the
amount, if any, by which the redemption proceeds exceed the paid-up capital of
the exchangeable shares so redeemed. For these purposes, the redemption proceeds
will be the fair market value of our common stock received from Calpine Canada
at the time of the redemption plus the amount, if any, of all payable and unpaid
dividends on the exchangeable shares paid on the redemption. The taxation of
dividends received on the exchangeable shares is described below. We anticipate
that we will exercise our call rights, when available, and currently foresee no
circumstances under which exchangeable shares would be redeemed by Calpine
Canada.

     On a redemption (including a retraction) of your exchangeable shares, you
will also be considered to have disposed of your exchangeable shares, but the
amount of the deemed dividend, described above, will be excluded in computing
your proceeds of disposition for purposes of computing any capital gain or
capital loss arising on the disposition. If you are a corporation, in some
circumstances, the amount of any such deemed dividend may be treated as proceeds
of disposition and not as a dividend. The taxation of capital gains and capital
losses is described below.

EXCHANGE OF EXCHANGEABLE SHARES WITH US

     On an exchange of your exchangeable shares with us or one of our Canadian
subsidiaries for our common stock, you will generally realize a capital gain (or
a capital loss) equal to the amount by which the proceeds of disposition of your
exchangeable shares, net of any reasonable costs of disposition, exceed
                                        20
<PAGE>   24

(or are less than) the adjusted cost base to you of the exchangeable shares
immediately before the exchange. For these purposes, the proceeds of disposition
will be the fair market value at the time of the exchange of our common stock
which you receive (plus any other amounts received by you as part of the
exchange). The taxation of capital gains and capital losses is described below.

DIVIDENDS ON EXCHANGEABLE SHARES

     If you are an individual, dividends received or deemed to be received on
the exchangeable shares will be included in computing your income, and will be
subject to the gross-up and dividend tax credit rules normally applicable to
taxable dividends received from a corporation resident in Canada.

     If you are a corporation other than a "specified financial institution", as
defined in the Canadian Income Tax Act, dividends received or deemed to be
received on the exchangeable shares normally will be included in your income and
be deductible in computing your taxable income.

     The exchangeable shares will be "term preferred shares", as defined in the
Canadian Income Tax Act. Consequently, if, you are a "specified financial
institution", as defined in the Canadian Income Tax Act, a dividend received on
the exchangeable shares will be deductible in computing your taxable income only
if:

          1. you did not acquire the exchangeable shares in the ordinary course
     of carrying on your business; or

          2. at the time the dividend is received, the exchangeable shares are
     listed on a prescribed stock exchange in Canada (which currently includes
     the TSE) and you, either alone or together with persons with whom you do
     not deal at arm's length, do not receive (or be deemed to receive)
     dividends in respect of more than 10% of the issued and outstanding
     exchangeable shares.

     In addition, to the extent that a deemed dividend arises on the redemption
of the exchangeable shares by Calpine Canada, the dividend may be deductible by
specified financial institutions in accordance with the exceptions outlined
above. If you are a specified financial institution, you should consult your own
tax advisors.

     If you are a "private corporation", as defined in the Canadian Income Tax
Act, or any other corporation resident in Canada and controlled or deemed to be
controlled by or for the benefit of an individual or a related group of
individuals, you may be liable under Part IV of the Canadian Income Tax Act to
pay a refundable tax of 33 1/3% of any dividends received or deemed to be
received on your exchangeable shares to the extent that these dividends are
deductible in computing your taxable income.

     If you are throughout the relevant taxation year a "Canadian-controlled
private corporation", as defined in the Canadian Income Tax Act, you may be
liable to pay an additional refundable tax of 6 2/3% on your "aggregate
investment income" for the year which will include dividends or deemed dividends
that are not deductible in computing taxable income.

     If you are a corporation, the amount of any capital losses arising from a
disposition or deemed disposition of exchangeable shares may be reduced by the
amount of any dividends received or deemed to have been received by you on the
exchangeable shares to the extent and under circumstances prescribed by the
Canadian Income Tax Act. Similar rules may apply where you are a corporation and
a member of a partnership or a beneficiary of a trust that owns these shares.

ACQUISITION AND DISPOSITION OF OUR COMMON STOCK

     The cost of our common stock received on a retraction, redemption or
exchange of exchangeable shares will be equal to the fair market value of such
exchangeable shares at the time of that event, and will be averaged with the
adjusted cost base of any other shares of our common stock held by you at that
time as capital property. A disposition or deemed disposition of our common
stock by you will generally result in the realization of a capital gain (or a
capital loss) equal to the amount by which the proceeds of disposition, net of
any reasonable costs of disposition, exceed (or are less than) the adjusted cost
base to

                                        21
<PAGE>   25

you of these shares immediately before the disposition. The taxation of capital
gains and capital losses is described below.

DIVIDENDS ON OUR COMMON STOCK

     Dividends on our common stock will be included in your income for the
purposes of the Canadian Income Tax Act. If you are an individual, you will not
be subject to the gross-up and dividend tax credit rules in the Canadian Income
Tax Act applicable to dividends received from corporations resident in Canada.
If you are a corporation, you will be required to include these dividends in
computing your income and generally will not be entitled to deduct the amount of
these dividends in computing your taxable income.

     A shareholder that is throughout the relevant taxation year a
"Canadian-controlled private corporation", as defined in the Canadian Income Tax
Act, may be liable to pay an additional refundable tax of 6 2/3% of its
"aggregate investment income" for the year which will include these dividends.

     If there is United States non-resident withholding tax on any dividends you
receive on our common stock, you will generally be eligible for foreign tax
credit or deduction treatment where applicable under the Canadian Income Tax
Act.

TAXATION OF CAPITAL GAINS AND CAPITAL LOSSES

     One-half of any capital gain realized on a disposition or deemed
disposition of exchangeable shares or our common stock must be included in your
income for the year of the disposition. You generally may be able to deduct
one-half of any capital losses against one-half of any capital gains realized in
the year of the disposition. Any capital losses in excess of capital gains in
the year of the disposition may generally be carried back and deducted against
net capital gains (capital gains less capital losses) up to three taxation years
or carried forward indefinitely, to the extent and in the circumstances
prescribed in the Canadian Income Tax Act.

     Capital gains realized by an individual or trust, other than certain
trusts, may give rise to alternative minimum tax under the Canadian Income Tax
Act.

     A shareholder that is throughout the relevant taxation year a
"Canadian-controlled private corporation", as defined in the Canadian Income Tax
Act, may be liable to pay an additional refundable tax of 6 2/3% on its
"aggregate investment income" for the year which will include an amount in
respect of taxable capital gains.

FOREIGN PROPERTY INFORMATION REPORTING

     With some exceptions, any taxpayer resident in Canada in the year is a
"specified Canadian entity", as defined in the Canadian Income Tax Act. If you
are a specified Canadian entity for a taxation year or fiscal period and the
total cost amount of "specified foreign property", which would include our
common stock and the exchangeable shares, at any time in the year or fiscal
period exceeds C$100,000, you will be required to file an information return for
the year or period disclosing prescribed information, your cost amount, any
dividends received in the year, and any gains or losses realized in the year, in
respect of the specified foreign property. You should consult your own advisors
about whether you must comply with these rules with respect to the ownership of
our common stock or the exchangeable shares.

SHAREHOLDERS NOT RESIDENT IN CANADA

     The following portion of this summary will apply to you only if, for
purposes of the Canadian Income Tax Act and any applicable tax treaty or
convention, you will not be resident or deemed to be resident in Canada at any
time while you hold exchangeable shares or our common stock, and if you will not
use or hold the exchangeable shares or our common stock in the course of
carrying on a business (including an insurance business) in Canada and, except
as specifically discussed below, if those shares do not constitute "taxable
Canadian property" to you as defined in the Canadian Income Tax Act.
                                        22
<PAGE>   26

     The exchangeable shares will generally not be taxable Canadian property to
you at a particular time provided that these shares are listed on a prescribed
stock exchange (which includes the TSE) and you, separately or together with
persons with whom you do not deal at arm's length, have not owned (or had under
option) 25% or more of the issued shares of any class or series of the capital
stock of Calpine Canada or Encal at any time within five years preceding the
particular time. Our common stock will generally not constitute taxable Canadian
property to you.

     Provided the exchangeable shares or our common stock are not taxable
Canadian property to you, you will not be subject to tax under the Canadian
Income Tax Act on the exchange of exchangeable shares for our common stock
(except to the extent the exchange gives rise to a deemed dividend as discussed
below), or on the sale or other disposition of exchangeable shares or our common
stock.

     Dividends paid or deemed to be paid on the exchangeable shares will be
subject to non-resident withholding tax under the Canadian Income Tax Act at the
rate of 25%, although this rate may be reduced under the provisions of an
applicable income tax treaty or convention. For example, under the Canada-U.S.
Tax Convention, the rate of non-resident withholding tax is generally reduced to
15% in respect of dividends paid to a person who is the beneficial owner thereof
and who is resident in the United States for purposes of the convention.

     A holder whose exchangeable shares are redeemed by Calpine Canada (either
under redemption rights or pursuant to retraction rights) will be deemed to
receive a dividend equal to the amount, if any, by which the redemption proceeds
exceed the paid-up capital of the exchangeable shares at the time the
exchangeable shares are redeemed. For these purposes, the redemption proceeds
will be the fair market value of our common stock received from Calpine Canada
at the time of the redemption plus the amount, if any, of all payable and unpaid
dividends on the exchangeable shares paid on the redemption. Any deemed dividend
will be subject to non-resident withholding tax as described in the preceding
paragraph. However, we anticipate that we will exercise our call rights, when
available, and currently foresee no circumstances under which exchangeable
shares would be redeemed by Calpine Canada.

            CERTAIN UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

     The following discussion of the principal United States federal income tax
consequences of the receipt, ownership and disposition of exchangeable shares is
the opinion of Covington & Burling, who acted as United States counsel to
Calpine in connection with our business combination with Encal. This discussion
is based, in part, on certain representations and agreements made by Calpine,
and the assumption that such representations were, as of the date made and as of
the effective time of the business combination (the "Effective Time"), true and
correct, that such agreements will be complied with and that the business
combination will be consummated in accordance with the combination agreement and
plan of arrangement relating to the business combination.

     This discussion is based on the United States Internal Revenue Code of
1986, as amended (the "U.S. Code"), United States Treasury regulations, proposed
and final, issued thereunder, and judicial and administrative interpretations of
the U.S. Code and regulations, in each case as in effect and available as of the
date of this prospectus. These income tax laws, regulations and interpretations,
however, may change at any time, and any change could be retroactive to the date
of this prospectus. These income tax laws and regulations are also subject to
various interpretations, and the United States Internal Revenue Service (the
"IRS") or the United States courts could later disagree with the explanations or
conclusions contained in this summary.

     No statutory, judicial or administrative authority exists that directly
addresses the United States federal income tax consequences of the receipt and
ownership of instruments comparable to the exchangeable shares. Consequently,
the United States federal income tax treatment of the receipt of exchangeable
shares and the exchange of exchangeable shares for shares of Calpine common
stock is not certain. No advance ruling has been sought or obtained from the IRS
regarding the tax consequence of any of the transactions described herein and
there can be no assurance that the IRS would not challenge

                                        23
<PAGE>   27

the conclusions contained in the discussion below, or, if challenged, that a
court would not agree with the IRS.

     As used herein, a "United States Holder" is a beneficial owner of Encal
common shares, exchangeable shares or Calpine common stock, as the case may be,
that, for United States federal income tax purposes, is: (1) a citizen or
individual resident of the United States, (2) a corporation created or organized
in or under the laws of the United States, or of any political subdivision
thereof, (3) an estate or other entity the income of which is includible in its
gross income for United States federal income tax purposes without regard to its
source or (4) a trust if a court within the United States is able to exercise
primary supervision over the administration of such trust and one or more United
States persons have the authority to control all substantial decisions of the
trust. A "non-United States Holder" is a beneficial owner who, for United States
federal income tax purposes, is a non-resident alien individual, a foreign
corporation, or a foreign estate or trust. If a partnership (including for this
purpose any entity treated as a partnership for United States federal income tax
purposes) is a beneficial owner of the Encal common shares, the exchangeable
shares or Calpine common stock, as the case may be, the treatment of a partner
in the partnership will generally depend upon the status of the partner and upon
the activities of the partnership. A Holder that is a partnership and partners
in such partnership should consult their tax advisers about the United States
federal income tax consequences of receiving, holding and disposing of Encal
common shares, exchangeable shares or Calpine common stock. This summary assumes
that neither Encal nor Calpine Canada is a "foreign personal holding company" or
a "passive foreign investment company" for United States federal income tax
purposes. This discussion does not address persons subject to special provisions
of United States federal income tax law, such as tax-exempt organizations,
financial institutions, insurance companies, broker-dealers, persons having a
"functional currency" other than the United States dollar, holders who hold
Encal common shares, exchangeable shares or Calpine common stock, as the case
may be, as part of a hedge, straddle, wash sale, synthetic security, conversion
transaction or other integrated investment, and holders of Encal common shares,
exchangeable shares or Calpine common stock, as the case may be, who acquired
their interests through the exercise of employee stock options or otherwise as
compensation for services. This discussion is limited to Holders who hold Encal
common shares as a capital asset and who will hold exchangeable shares and
Calpine common stock, as the case may be, as a capital asset.

     This discussion does not address aspects of United States taxation other
than United States federal income taxation under the U.S. Code, nor does it
address all aspects of United States federal income taxation that may be
applicable to a particular Holder in light of the Holder's particular
circumstances. Accordingly, all Holders are urged to consult their own tax
advisors with respect to the United States federal income tax consequences to
them of the receipt, ownership and disposition of exchangeable shares and
Calpine common stock, as the case may be, in light of their particular
circumstances. In addition, this discussion does not address the United States
state or local tax consequences or the foreign tax consequences of the business
combination on the receipt, ownership and disposition of the exchangeable shares
or Calpine common stock.

     HOLDERS ARE URGED TO CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE UNITED
STATES FEDERAL, STATE AND LOCAL TAX CONSEQUENCES, THE FOREIGN TAX CONSEQUENCES
AND THE NON-TAX CONSEQUENCES OF THE BUSINESS COMBINATION, INCLUDING THE RECEIPT,
OWNERSHIP AND DISPOSITION OF EXCHANGEABLE SHARES, CALPINE COMMON STOCK AND
ANCILLARY RIGHTS (AS DEFINED BELOW) AND CALL RIGHTS (AS DEFINED BELOW).

UNITED STATES HOLDERS

RECEIPT OF EXCHANGEABLE SHARES

     Although the matter is not free from doubt, Calpine and Calpine Canada
intend to take the position that the receipt of the exchangeable shares is a
taxable event for United States federal income tax purposes and that United
States Holders who exchange Encal common shares for exchangeable shares

                                        24
<PAGE>   28

should recognize gain or loss. As a result, a United States Holder should
recognize gain or loss measured by the difference, if any, between the fair
market value of the consideration received in exchange for the United States
Holder's Encal common shares (i.e., the fair market value of the exchangeable
shares received together with the amount of cash received in lieu of fractional
shares, if any, or pursuant to the exercise of dissenters' rights) and the
United States Holder's tax basis in the Encal common shares exchanged for that
consideration. A United States Holder's tax basis in the exchangeable shares
received should equal the fair market value of such shares at the Effective
Time, and the holding period for such shares should begin on the day after the
Effective Time. Any gain or loss recognized upon an exchange of Encal common
shares will generally be United States source income, will be capital gain or
loss and will be long-term capital gain or loss if the United States Holder's
holding period for the Encal common shares exchanged is more than one year at
the Effective Time.

     There can be no assurance that the IRS will not attempt to recharacterize
the receipt of the exchangeable shares as a tax-free transaction. If the IRS
were to successfully assert such a characterization: (i) United States Holders
would recognize gain (but not loss) with respect to any cash received for
fractional shares or pursuant to the exercise of dissenters' rights (as
described below); (ii) the tax basis of the exchangeable shares received by a
United States Holder would generally equal the tax basis of the Encal common
shares surrendered, reduced by the amount of cash received in respect of such
Encal common shares and increased by the amount of gain recognized on the
receipt of the exchangeable shares; and (iii) the holding period of the
exchangeable shares received by a United States Holder would include the holding
period of the Encal common shares exchanged therefor.

ANCILLARY RIGHTS AND CALL RIGHTS

     Encal shareholders who receive exchangeable shares will also receive the
"Ancillary Rights," which comprise the liquidation right, the automatic exchange
right and your voting rights under the voting and exchange trust agreement. See
"Plan of Distribution" and "Description of Our Capital Stock -- Preferred
Stock." In addition, Encal shareholders who receive exchangeable shares may be
deemed to grant the "Call Rights," which comprise the liquidation call right,
the redemption call right and the retraction call right, which are each
described in "Plan of Distribution." Calpine and Calpine Canada believe that the
Ancillary Rights received and any Call Rights deemed to be granted by Encal
shareholders generally will have only nominal value and, therefore, that neither
their receipt or grant, as the case may be, nor the lapse of any Call Rights,
should result in any material United States federal income tax consequences,
although the value of such rights could vary depending on the circumstances of a
particular Encal shareholder. It is possible, however, that the Service could
take the position that the Ancillary Rights and the Call Rights have greater
than nominal value. In such event, the receipt of Ancillary Rights and the lapse
of any Call Rights could generate taxable income or loss of more than a nominal
amount. Such gain or loss should be capital gain or loss to the United States
Holder. United States Holders should consult their tax advisors with respect to
the potential tax consequences of the receipt of the Ancillary Rights and the
grant of the Call Rights pursuant to the business combination.

EXCHANGE OF EXCHANGEABLE SHARES

     There is no authority directly addressing the proper characterization of
instruments similar to the exchangeable shares together with the associated
Ancillary Rights and Call Rights or the exchange of exchangeable shares for
Calpine common stock (including an exchange upon the occurrence of an automatic
redemption date). As a result, the consequences to a United States Holder of
such an exchange are unclear.

     A United States Holder may be justified in taking the position that the
exchangeable shares should be treated as stock of Calpine for United States
federal income tax purposes and therefore that the exchange of the exchangeable
shares for Calpine common stock is not a taxable event. If a United States
Holder takes such a position, the aggregate tax basis of the Calpine common
stock received pursuant to the exchange would equal the United States Holder's
aggregate tax basis in the exchangeable shares and the holding period of the
Calpine common stock received by such Holder would include the holding period of
                                        25
<PAGE>   29

the exchangeable shares surrendered in the exchange. Calpine and Calpine Canada
intend to take the position that the exchangeable shares, together with the
Ancillary Rights and the Call Rights, represent stock of Calpine.

     Alternatively, if the exchangeable shares are characterized as representing
an equity interest in Calpine Canada for United States federal income tax
purposes, a United States Holder who exchanges its exchangeable shares for
shares of Calpine common stock generally would recognize gain or loss. Such gain
or loss would be measured by the difference, if any, between the fair market
value of the shares of Calpine common stock at the time of the exchange and the
United States Holder's tax basis in the exchangeable shares surrendered, and
would generally be capital gain or loss, except with respect to any declared but
unpaid dividends on the exchangeable shares. Under this alternative
characterization, a United States Holder's tax basis in the shares of Calpine
common stock received would be equal to the fair market value of such shares at
the time of the exchange and the holding period for such shares would begin on
the day after the exchange. However, even if the exchangeable shares are
characterized as representing an equity interest in Calpine Canada, under
certain limited circumstances, the exchange by a United States Holder of
exchangeable shares for Calpine common stock may be characterized as a tax-free
transaction. Whether an exchange by a particular United States Holder would be
tax-free will depend upon the facts and circumstances existing at the time of
the exchange and cannot be accurately predicted at the date of this prospectus.

     For United States federal income tax purposes, gain recognized on the
exchange of exchangeable shares for shares of Calpine common stock generally
will be treated as United States source gain, except that, under the terms of
the Canada-U.S. Tax Convention, such gain may be treated as sourced in Canada.
Any Canadian tax imposed on the exchange may be available as a credit against
United States federal income taxes, subject to applicable limitations. A United
States Holder that is ineligible for a foreign tax credit with respect to any
Canadian tax paid may be entitled to a deduction therefor in computing United
States taxable income.

DISTRIBUTIONS ON THE EXCHANGEABLE SHARES

     Calpine Canada and Calpine intend to treat dividends, if any, received by a
United States Holder with respect to the exchangeable shares as dividends from
Calpine. A United States Holder of exchangeable shares generally will be
required to include in gross income as ordinary income dividends paid on the
exchangeable shares to the extent paid out of the earnings and profits of
Calpine. Such dividends paid in Canadian dollars will be includible in the
income of a United States Holder in a United States dollar amount calculated by
reference to the exchange rate in effect on the date the dividends are deemed
received. United States Holders should consult their own tax advisors regarding
the treatment of any foreign currency gain or loss on any Canadian dollars
received which are not converted into United States dollars on such date.

     Alternatively, it is possible that the IRS could take the position that any
dividends received by a United States Holder with respect to the exchangeable
shares are dividends from Calpine Canada. If the IRS were successful in
asserting this position, any dividends paid on the exchangeable shares out of
Calpine Canada's earnings and profits would be treated as foreign source
dividend income and would generally not be eligible for the dividends received
deduction allowed to corporate shareholders under the U.S. Code.

     Under the terms of the Canada-U.S. Tax Convention, distributions with
respect to the exchangeable shares received by United States Holders would be
subject to Canadian withholding tax at a rate of 15% irrespective of any
position the IRS may take. Subject to certain limitations of United States
federal income tax law, a United States Holder should generally be entitled to
either a credit against its United States federal income tax liability or a
deduction in computing United States taxable income for Canadian income taxes
withheld from distributions with respect to the exchangeable shares. The use of
a credit may, however, be limited or precluded entirely if the United States
Holder has no income that is treated as non-United States source income for
United States federal income tax purposes.

                                        26
<PAGE>   30

DISSENTING SHAREHOLDERS

     A United States Holder who exercises the right to dissent from the business
combination will recognize gain or loss on the exchange of such Holder's Encal
common shares for cash in an amount equal to the difference between the amount
of cash received (other than amounts, if any, which are or are deemed to be
interest for United States federal income tax purposes, which amounts will be
taxed as ordinary income) and such Holder's basis in its Encal common shares.
Such gain or loss generally will be United States source income, will be capital
gain or loss if the Encal common shares were held as capital assets at the
Effective Time and will be long-term capital gain or loss if the United States
Holder's holding period for the Encal common shares is more than one year at
such time.

NON-UNITED STATES HOLDERS

     The following discussion is applicable to a non-United States Holder.

RECEIPT, EXCHANGE OR OTHER DISPOSITION OF EXCHANGEABLE SHARES AND CALPINE COMMON
STOCK

     Subject to the discussion below under "-- Foreign Investment in Real
Property Tax Act," a non-United States Holder generally will not be subject to
United States federal income tax on any gain realized on the receipt of
exchangeable shares in exchange for Encal common shares, on the sale or exchange
of the exchangeable shares, or on the sale or exchange of shares of Calpine
common stock, unless (i) such gain (A) in the absence of an applicable tax
treaty, is effectively connected with a trade or business of the non-United
States Holder in the United States, or (B) if a tax treaty applies, is
attributable to a permanent establishment maintained by the non-United States
Holder in the United States or (ii) unless an applicable tax treaty provides
otherwise the non-United States Holder is an individual who holds the Encal
common shares, the exchangeable shares or the Calpine common stock, as the case
may be, as a capital asset and is present in the United States for 183 days or
more in the taxable year of disposition, and certain other conditions are
satisfied.

DISTRIBUTIONS ON THE EXCHANGEABLE SHARES AND CALPINE COMMON STOCK

     Because Calpine intends to treat the dividends, if any, paid to non-United
States Holders in respect of the exchangeable shares as dividends from Calpine,
such amounts will generally be subject to United States withholding tax at a
rate of 30% for United States federal income tax purposes. In general, dividends
received by a non-United States Holder with respect to Calpine common stock that
are not effectively connected with the conduct by such Holder of a trade or
business in the United States will also be subject to United States withholding
tax at a rate of 30 percent. The withholding rate may be reduced by an
applicable income tax treaty in effect between the United States and the
non-United States Holder's country of residence (currently 15%, generally, on
dividends paid to residents of Canada under the Canada-U.S. Tax Convention).

FOREIGN INVESTMENT IN REAL PROPERTY TAX ACT

     Notwithstanding the discussion above, under the Foreign Investment in Real
Property Tax Act of 1980 ("FIRPTA"), gain or loss recognized by a non-United
States Holder on the sale or exchange of Calpine common stock, as well as any
gain or loss recognized on the sale or exchange of exchangeable shares (if such
shares are treated by the IRS as representing stock of Calpine), will be subject
to United States federal income tax as if such gain or loss were effectively
connected with a United States trade or business if such shares are treated as
"United States real property interests" ("USRPIs") (as defined below) and the
non-United States Holder is a greater than 5% shareholder.

     A USRPI generally includes any interest (other than an interest solely as a
creditor) in a "United States real property holding corporation" (a "USRPHC").
exchangeable shares and Calpine common stock will be USRPIs unless it is
established under specific procedures that Calpine is not (and was not for the
prior five-year period) a USRPHC. A corporation is a USRPHC if the fair market
value of its interests in United States real property equals or exceeds 50% of
the sum of the fair market value of all of
                                        27
<PAGE>   31

its interests in real property and all of its other assets used or held for use
in a trade or business (as defined in applicable regulations). Calpine cannot
give any assurance as to whether it is, at any time within the past five years
it has been, or will in the future become a USRPHC.

     If it is determined that Calpine is, has been in the past five years or in
the future becomes, a USRPHC, so long as Calpine's stock is regularly traded on
an established securities market, an exemption should apply, except with respect
to a non-United States Holder whose beneficial and/or constructive ownership of
common stock in Calpine exceeds 5% of the total fair market value of the total
outstanding exchangeable shares and the Calpine common stock. This exception
should apply to both the Calpine common stock and to the exchangeable shares.
Any investor that may approach or exceed the 5% ownership threshold discussed
above, either alone or in conjunction with related persons, should consult its
own tax advisor concerning the United States tax consequences that may result. A
non-United States Holder who sells or otherwise disposes of exchangeable shares
or Calpine common stock may be required to inform its transferee whether such
shares constitute a United States real property interest.

     The foregoing discussion of the possible application of the FIRPTA rules to
non-United States Holders is only a summary of certain material aspects of these
rules. Because the United States federal income tax consequences to a non-United
States Holder under FIRPTA may be significant and are complex, non-United States
Holders are urged to discuss those consequences with their tax advisors.

BACKUP WITHHOLDING AND INFORMATION REPORTING

UNITED STATES HOLDERS

     Payments of dividends made on, or the proceeds of the sale or other
disposition of, the exchangeable shares and shares of Calpine common stock, as
the case may be, may be subject to information reporting and United States
federal backup withholding tax at the rate of 31% if the recipient of such
payment fails to supply an accurate taxpayer identification number or otherwise
fails to comply with applicable United States information reporting or
certification requirements. Any amount withheld from a payment to a United
States Holder under the backup withholding rules is allowable as a credit
against the Holder's United States federal income tax, provided that the
required information is furnished to the IRS.

NON-UNITED STATES HOLDERS

     A non-United States Holder may be required to comply with certification
procedures to establish that the Holder is not a United States person in order
to avoid backup withholding tax requirements with respect to distributions on
the exchangeable shares and shares of Calpine common stock, as the case may be.
In addition, Calpine must report annually to the IRS and to each non-United
States Holder the amount of any dividends paid to and the tax withheld with
respect to, such Holder, regardless of whether any tax was actually withheld.
Copies of these information returns may also be made available under the
provisions of a specific treaty or agreement to the tax authorities of the
country in which the non-United States Holder resides.

                                 LEGAL MATTERS

     The validity of the shares of our common stock issuable hereunder will be
passed upon for us by Covington & Burling, New York, New York. Certain U.S.
federal income tax matters have been passed upon by Covington & Burling, and
certain Canadian federal income tax matters have been passed upon by Macleod
Dixon LLP, Calgary, Canada.

                              INDEPENDENT AUDITORS

     Calpine's financial statements incorporated by reference in this prospectus
and elsewhere in this registration statement have been audited by Arthur
Andersen LLP, independent public accountants, as indicated in their reports with
respect thereto, and are included herein in reliance upon the authority of said
firm as experts in giving such reports.

                                        28
<PAGE>   32

                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

     The following table sets forth the costs and expenses payable by Calpine in
connection with issuance and distribution of the securities being registered.
All amounts are estimates subject to future contingencies except the SEC
registration statement filing fee.

<TABLE>
<S>                                                           <C>
SEC registration statement filing fee.......................  $349,500
Accounting fees and expenses................................    75,000
Legal fees and expenses.....................................    50,000
Printing fees...............................................    75,000
Transfer agent fees.........................................     5,000
Miscellaneous...............................................    15,500
                                                              --------
  Total.....................................................  $570,000
                                                              ========
</TABLE>

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Section 145 of the General Corporation Law of the State of Delaware (the
"Delaware Law") empowers a Delaware corporation to indemnify any persons who
are, or are threatened to be made, parties to any threatened, pending or
completed legal action, suit or proceedings, whether civil, criminal,
administrative or investigative (other than action by or in the right of such
corporation), by reason of the fact that such person was an officer or director
of such corporation, or is or was serving at the request of such corporation as
a director, officer, employee or agent of another corporation or enterprise. The
indemnity may include expenses (including attorneys' fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in
connection with such action, suit or proceeding, provided that such officer or
director acted in good faith and in a manner he reasonably believed to be in or
not opposed to the corporation's best interests, and, for criminal proceedings,
had no reasonable cause to believe his conduct was unlawful. A Delaware
corporation may indemnify officers and directors in an action by or in the right
of the corporation under the same conditions, except that no indemnification is
permitted without judicial approval if the officer or director is adjudged to be
liable to the corporation in the performance of his duty. Where an officer or
director is successful on the merits or otherwise in the defense of any action
referred to above, the corporation must indemnify him against the expenses which
such officer or director actually and reasonably incurred.

     In accordance with Delaware Law, the certificate of incorporation of
Calpine contains a provision to limit the personal liability of the directors of
Calpine for violations of their fiduciary duty. This provision eliminates each
director's liability to Calpine or its stockholders for monetary damages except
(i) for any breach of the director's duty of loyalty to Calpine or its
stockholders, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware Law providing for liability of directors for unlawful payment of
dividends or unlawful stock purchases or redemptions, or (iv) for any
transaction from which a director derived an improper personal benefit. The
effect of this provision is to eliminate the personal liability of directors for
monetary damages for actions involving a breach of their fiduciary duty of care,
including any such actions involving gross negligence. The certificate of
incorporation further provides that, if the Delaware Law is amended to further
reduce the liability of a corporation's directors for breaches of fiduciary
duty, then a director of Calpine shall not be liable for any such breach to the
fullest extent permitted by the law as so amended.

     Article Ten of the bylaws of Calpine provides for indemnification of the
officers and directors of Calpine to the fullest extent permitted by applicable
law.

     Calpine has entered into indemnification agreements with its directors and
officers. These agreements provide substantially broader indemnity rights than
those provided under the Delaware Law and Calpine's

                                       II-1
<PAGE>   33

bylaws. The indemnification agreements are not intended to deny or otherwise
limit third-party or derivative suits against Calpine or its directors or
officers, but if a director or officer were entitled to indemnity or
contribution under the indemnification agreement, the financial burden of a
third-party suit would be borne by Calpine, and Calpine would not benefit from
derivative recoveries against the director or officer. Such recoveries would
accrue to the benefit of Calpine but would be offset by Calpine's obligations to
the director or officer under the indemnification agreement. In addition, the
directors of Calpine are insured under officers and directors liability
insurance policies.

ITEM 16. EXHIBITS

<TABLE>
<CAPTION>
    EXHIBIT
    NUMBER                             DESCRIPTION
    -------                            -----------
    <C>        <S>
      *2.1     Combination Agreement, dated as of February 7, 2001, by and
               between Calpine Corporation and Encal
      *2.2     Form of Plan of Arrangement Under Section 186 of the
               Business Corporations Act (Alberta) (included as Exhibit A
               to Exhibit 2.1) Involving and Affecting Encal and the
               Holders of its Common Shares and Options
      *3.1     Amended and Restated Certificate of Incorporation of Calpine
               Corporation
      *3.2     Certificate of Correction of Calpine Corporation
      +3.3     Certificate of Designation of Series A Participating
               Preferred Stock of Calpine Corporation(a)
      *3.4     Amended Certificate of Designation of Series A Participating
               Preferred Stock of Calpine Corporation
      +3.5     Amended and Restated By-laws of Calpine Corporation(b)
      *4.1     Form of Exchangeable Share Provisions and Other Provisions
               to Be Included in the Articles of Calpine Canada Holdings
               Ltd. (included as Exhibit B to Exhibit 2.1)
      *4.2     Form of Support Agreement between Calpine Corporation and
               Calpine Canada Holdings Ltd. (included as Exhibit C to
               Exhibit 2.1)
      +4.3     Rights Agreement, dated as of June 5, 1997, between Calpine
               Corporation and First Chicago Trust Company of New York, as
               Rights Agent(a)
      *5.1     Opinion of Covington & Burling
      *8.1     Opinion of Covington & Burling as to certain U.S. tax
               matters
      *8.2     Opinion of Macleod Dixon LLP as to certain Canadian tax
               matters
      *9.1     Form of Voting and Exchange Trust Agreement between Calpine
               Corporation, Calpine Canada Holdings Ltd. and a Canadian
               trust company, as trustee (included as Exhibit D to Exhibit
               2.1)
     *23.1     Consent of Arthur Andersen LLP, independent public
               accountants
     *23.2     Consent of Covington & Burling
     *23.3     Consent of Macleod Dixon LLP
    ++24.1     Power of Attorney of Officers and Directors of Calpine
               Corporation (set forth on the signature pages of this
               Registration Statement)
</TABLE>

-------------------------
 *  To be filed by amendment.

 +  Previously filed or incorporated by reference.

 ++  Filed herewith.

(a) Incorporated by reference to Calpine's Registration Statement on Form 8-A
    filed with the SEC on June 18, 1997 and amended by Calpine's Registration
    Statement on Form 8-A/A filed with the SEC on June 24, 1997 (File No.
    001-12079).

(b) Incorporated by reference to Calpine's Annual Report on Form 10-K dated
    December 31, 1999 and filed on February 29, 2000 (File No. 001-12079).

                                       II-2
<PAGE>   34

ITEM 17. UNDERTAKINGS

     The undersigned registrant hereby undertakes:

          (1) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this registration statement to include
     any material information with respect to the plan of distribution not
     previously disclosed in the registration statement or any material change
     to such information in the registration statement.

          (2) That, for the purpose of determining any liability under the
     Securities Act of 1933, each such post-effective amendment shall be deemed
     to be a new registration statement relating to the securities offered
     therein, and the offering of such securities at that time shall be deemed
     to be the initial bona fide offering thereof.

          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.

          (4) If the registrant is a foreign private issuer, to file a
     post-effective amendment to the registration statement to include any
     financial statements required by Rule 3-19 of this chapter at the start of
     any delayed offering or throughout a continuous offering. Financial
     statements and information otherwise required by Section 10(a)(3) of the
     Act need not be furnished, provided, that the registrant includes in the
     prospectus, by means of a post-effective amendment, financial statements
     required pursuant to this paragraph (a)(4) and other information necessary
     to ensure that all other information in the prospectus is at least as
     current as the date of those financial statements. Notwithstanding the
     foregoing, with respect to registration statements on Form F-3, a
     post-effective amendment need not be filed to include financial statements
     and information required by Section 10(a)(3) of the Act or Rule 3-19 of
     this chapter if such financial statements and information are contained in
     periodic reports filed with or furnished to the Commission by the
     registrant pursuant to Section 13 or Section 15(d) of the Securities
     Exchange Act of 1934 that are incorporated by reference in the Form F-3.

     The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934, (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     The undersigned registrant hereby undertakes to deliver or cause to be
delivered with the prospectus, to each person to whom the prospectus is sent or
given, the latest annual report, to security holders that is incorporated by
reference in the prospectus and furnished pursuant to and meeting the
requirements of Rule 14a-3 under Rule 14c-3 under the Securities Exchange Act of
1934; and, where interim financial information required to be presented by
Article 3 of Regulation S-X is not set forth in the prospectus, to deliver, or
cause to be delivered to each person to whom the prospectus is sent or given,
the latest quarterly report that is specifically incorporated by reference in
the prospectus to provide such interim financial information.

     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the SEC such indemnification is against
public policy as expressed in the Securities Act of 1933 and is, therefore,
unenforceable. In the event that a claim for indemnification against such
liabilities (other than the payment by the registrant of expenses incurred or
paid by a director, officer or controlling person of the registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such
                                       II-3
<PAGE>   35

indemnification by them is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

     The undersigned registrant hereby undertakes that:

     (1) For purposes of determining any liability under the Securities Act of
1933, the information omitted from the form of prospectus filed as part of this
registration statement in reliance upon Rule 430A and contained in a form of
prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or 497(h)
under the Securities Act shall be deemed to be part of this registration
statement as of the time it was declared effective.

     (2) For the purpose of determining any liability under the Securities Act
of 1933, each post-effective amendment that contains a form of prospectus shall
be deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

                                       II-4
<PAGE>   36

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing this Registration Statement on Form S-3 and has duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized in the City of San Jose, State of
California, on this 8th day of March, 2001.

                                          CALPINE CORPORATION

                                          By:       /s/ ANN B. CURTIS

                                            ------------------------------------
                                                       Ann B. Curtis
                                                  Executive Vice President
                                                and Chief Financial Officer

                               POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS:

     That the undersigned officers and directors of Calpine Corporation do
hereby constitute and appoint Peter Cartwright and Ann B. Curtis, and each of
them, the lawful attorney and agent or attorneys and agents with power and
authority to do any and all acts and things and to execute any and all
instruments which said attorneys and agents, or either of them, determine may be
necessary or advisable or required to enable Calpine Corporation to comply with
the Securities and Exchange Act of 1934, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement on Form S-3. Without limiting the
generality of the foregoing power and authority, the powers granted include the
power and authority to sign the names of the undersigned officers and directors
in the capacities indicated below to this Registration Statement or amendments
or supplements thereto, and each of the undersigned hereby ratifies and confirms
all that said attorneys and agents, or either of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

     IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated opposite the name.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Registration Statement on Form S-3 has been signed below by the following
persons on behalf of the Registrant and in the capacities and on the dates
indicated.

<TABLE>
<CAPTION>
                     SIGNATURE                                     TITLE                     DATE
                     ---------                                     -----                     ----
<S>                                                    <C>                               <C>

               /s/ PETER CARTWRIGHT                      Chairman, President, Chief      March 8, 2001
---------------------------------------------------    Executive Officer and Director
                 Peter Cartwright

                 /s/ ANN B. CURTIS                       Executive Vice President,       March 8, 2001
---------------------------------------------------     Chief Financial Officer and
                   Ann B. Curtis                                  Director

             /s/ CHARLES B. CLARK, JR.                 Vice President and Controller,    March 8, 2001
---------------------------------------------------       Chief Accounting Officer
               Charles B. Clark, Jr.

               /s/ JEFFREY E. GARTEN                              Director               March 8, 2001
---------------------------------------------------
                 Jeffrey E. Garten
</TABLE>

                                       II-5
<PAGE>   37

<TABLE>
<CAPTION>
                     SIGNATURE                                     TITLE                     DATE
                     ---------                                     -----                     ----
<S>                                                    <C>                               <C>

               /s/ MICHAEL P. POLSKY                              Director               March 8, 2001
---------------------------------------------------
                 Michael P. Polsky

                /s/ SUSAN C. SCHWAB                               Director               March 8, 2001
---------------------------------------------------
                  Susan C. Schwab

              /s/ GEORGE J. STATHAKIS                             Director               March 8, 2001
---------------------------------------------------
                George J. Stathakis

                /s/ JOHN O. WILSON                                Director               March 8, 2001
---------------------------------------------------
                  John O. Wilson

               /s/ V. ORVILLE WRIGHT                              Director               March 8, 2001
---------------------------------------------------
                 V. Orville Wright
</TABLE>

                                       II-6
<PAGE>   38

                               INDEX TO EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT
NUMBER                             DESCRIPTION
-------                            -----------
<C>        <S>
  *2.1     Combination Agreement, dated as of February 7, 2001, by and
           between Calpine Corporation and Encal
  *2.2     Form of Plan of Arrangement Under Section 186 of the
           Business Corporations Act (Alberta) (included as Exhibit A
           to Exhibit 2.1) Involving and Affecting Encal and the
           Holders of its Common Shares and Options
  *3.1     Amended and Restated Certificate of Incorporation of Calpine
           Corporation
  *3.2     Certificate of Correction of Calpine Corporation
  +3.3     Certificate of Designation of Series A Participating
           Preferred Stock of Calpine Corporation(a)
  *3.4     Amended Certificate of Designation of Series A Participating
           Preferred Stock of Calpine Corporation
  +3.5     Amended and Restated By-laws of Calpine Corporation(b)
  *4.1     Form of Exchangeable Share Provisions and Other Provisions
           to Be Included in the Articles of Calpine Canada Holdings
           Ltd. (included as Exhibit B to Exhibit 2.1)
  *4.2     Form of Support Agreement between Calpine Corporation and
           Calpine Canada Holdings Ltd. (included as Exhibit C to
           Exhibit 2.1)
  +4.3     Rights Agreement, dated as of June 5, 1997, between Calpine
           Corporation and First Chicago Trust Company of New York, as
           Rights Agent(a)
  *5.1     Opinion of Covington & Burling
  *8.1     Opinion of Covington & Burling as to certain U.S. tax
           matters
  *8.2     Opinion of Macleod Dixon LLP as to certain Canadian tax
           matters
  *9.1     Form of Voting and Exchange Trust Agreement between Calpine
           Corporation, Calpine Canada Holdings Ltd. and a Canadian
           trust company, as trustee (included as Exhibit D to Exhibit
           2.1)
 *23.1     Consent of Arthur Andersen LLP, independent public
           accountants
 *23.2     Consent of Covington & Burling
 *23.3     Consent of Macleod Dixon LLP
++24.1     Power of Attorney of Officers and Directors of Calpine
           Corporation (set forth on the signature pages of this
           Registration Statement)
</TABLE>

-------------------------
 *  To be filed by amendment.

 +  Previously filed or incorporated by reference.

 ++  Filed herewith.

(a) Incorporated by reference to Calpine's Registration Statement on Form 8-A
    filed with the SEC on June 18, 1997 and amended by Calpine's Registration
    Statement on Form 8-A/A filed with the SEC on June 24, 1997 (File No.
    001-12079).

(b) Incorporated by reference to Calpine's Annual Report on Form 10-K dated
    December 31, 1999 and filed on February 29, 2000 (File No. 001-12079).
