<SEC-DOCUMENT>0001279569-17-002345.txt : 20171207
<SEC-HEADER>0001279569-17-002345.hdr.sgml : 20171207
<ACCEPTANCE-DATETIME>20171206212128
ACCESSION NUMBER:		0001279569-17-002345
CONFORMED SUBMISSION TYPE:	6-K
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20171206
FILED AS OF DATE:		20171207
DATE AS OF CHANGE:		20171206

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TRANSALTA CORP
		CENTRAL INDEX KEY:			0001144800
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		6-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15214
		FILM NUMBER:		171243404

	BUSINESS ADDRESS:	
		STREET 1:		110 12TH AVE SW BOX 1900 STATION M
		STREET 2:		CALGARY ALBERTA T2P 2MI
		CITY:			CALGARY
		STATE:			A0
		ZIP:			T2P2M1
		BUSINESS PHONE:		403-267-4724

	MAIL ADDRESS:	
		STREET 1:		110-12TH AVENUE SW
		CITY:			CALGARY ALBERTA CANADA
		STATE:			A0
		ZIP:			T2P2M1
</SEC-HEADER>
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<FILENAME>transalta6k.htm
<DESCRIPTION>FORM 6-K
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<P STYLE="font: bold 14pt Times New Roman, Times, Serif; margin: 0 0 24pt; text-align: center"><FONT STYLE="font-size: 10pt">&nbsp;</FONT><FONT STYLE="font-size: 14pt">UNITED
STATES</FONT><BR>
<FONT STYLE="font-size: 14pt">SECURITIES AND EXCHANGE COMMISSION</FONT><BR>
<FONT STYLE="font-size: 12pt">Washington, D.C. 20549</FONT></P>

<P STYLE="font: 14pt Times New Roman, Times, Serif; margin: 0 0 24pt; text-align: center"><FONT STYLE="font-size: 18pt"><B>FORM
6-K</B></FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 24pt; text-align: center"><FONT STYLE="font-size: 12pt"><B>REPORT
OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934</B></FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 24pt"><FONT STYLE="font-size: 10pt">For the month of December 2017</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: center"><FONT STYLE="font-size: 24pt"><B>TRANSALTA
CORPORATION</B></FONT></P>

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<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: center"><FONT STYLE="font-size: 10pt">(Translation
of registrant&rsquo;s name into English)</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: center"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: center"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center"><FONT STYLE="font-size: 10pt"><B>110-12<SUP>th
</SUP>Avenue S.W., Box 1900, Station &ldquo;M&rdquo;, Calgary, Alberta, T2P 2M1</B></FONT></P>

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<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt">(Address
of principal executive offices)</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt">&nbsp;&nbsp;</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-size: 10pt">I<FONT STYLE="font-family: Times New Roman, Times, Serif">ndicate
by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.</FONT></FONT></P>

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    <TD STYLE="width: 50%; text-align: center"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Form 20-F &#9744;</FONT></TD>
    <TD STYLE="width: 50%; text-align: center"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Form 40-F &#9746;</FONT></TD></TR>
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<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Indicate
by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ____</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Indicate
by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ____</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt"></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt"></P>

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<P STYLE="font: 11pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><B>I</B></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">The
document listed below as Exhibit 99.1 to this Form 6-K is a copy of the Registrant&rsquo;s news release dated December 6, 2017
announcing &ldquo;TransAlta Announces Accelerated Transition to Clean Energy&rdquo;.</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&nbsp;</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0; text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">This
news release is being furnished, not filed, and will not be incorporated by reference into any registration statement filed by
TransAlta Corporation under the Securities Act of 1933, as amended.</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt 40.5pt; text-align: justify; text-indent: 0in"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&nbsp;</FONT></P>

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    <TD STYLE="width: 15%; padding-right: 5.4pt; padding-bottom: 12pt; padding-left: 5.4pt; font: 12pt Times New Roman, Times, Serif; text-indent: 0in"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">99.1</FONT></TD>
    <TD STYLE="width: 85%; padding-right: 5.4pt; padding-left: 5.4pt; font: 12pt Times New Roman, Times, Serif; text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&ldquo;TransAlta
    Announces Accelerated Transition to Clean Energy&rdquo;</FONT></TD></TR>
</TABLE>
<P STYLE="font: 12pt Times New Roman, Times, Serif; margin: 0 0 12pt 40.5pt; text-indent: 0in"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&nbsp;</FONT></P>



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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&nbsp;&nbsp;</FONT></P>

<P STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0; text-align: center; margin-bottom: 0"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">&nbsp;</FONT></P>

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<P STYLE="font: 14pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-align: center"><FONT STYLE="font-size: 10pt"><B>Signatures</B></FONT></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0 0 24pt">Pursuant to the requirements of the Securities Exchange
Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.</P>

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    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD COLSPAN="2"><FONT STYLE="font-size: 10pt"><B>TransAlta Corporation</B></FONT></TD></TR>
<TR STYLE="vertical-align: top; text-align: left">
    <TD STYLE="width: 52%"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="width: 5%"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="width: 43%"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD></TR>
<TR STYLE="vertical-align: top; text-align: left">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD><FONT STYLE="font-size: 10pt">By:</FONT></TD>
    <TD STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 10pt"><I>/s/ Donald Tremblay</I></FONT></TD></TR>
<TR STYLE="vertical-align: top; text-align: left">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD></TD>
    <TD><FONT STYLE="font-size: 10pt">Donald Tremblay</FONT></TD></TR>
<TR STYLE="vertical-align: top; text-align: left">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD><FONT STYLE="font-size: 10pt">Chief Financial Officer</FONT></TD></TR>
</TABLE>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0 0 24pt">Date: December 6, 2017</P>



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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0in"><B>EXHIBIT INDEX</B></P>

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    <TD STYLE="width: 15%; padding-right: 5.4pt; padding-bottom: 12pt; padding-left: 5.4pt; font: 12pt Times New Roman, Times, Serif; text-indent: 0in"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">99.1</FONT></TD>
    <TD STYLE="width: 85%; padding-right: 5.4pt; padding-left: 5.4pt; font: 12pt Times New Roman, Times, Serif; text-align: justify"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Press
    release dated December 6, 2017 announcing &ldquo;TransAlta Announces Accelerated Transition to Clean Energy&rdquo;</FONT></TD></TR>
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0 0 12pt; text-indent: 0in">&nbsp;</P>

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<P STYLE="margin: 0; text-align: right"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt"><B>Exhibit 99.1</B></FONT></P>

<P STYLE="margin: 0; text-align: right"><FONT STYLE="font: 8pt Arial, Helvetica, Sans-Serif"><B>&nbsp;</B></FONT></P>

<P STYLE="margin: 0; text-align: right"><FONT STYLE="font: 8pt Arial, Helvetica, Sans-Serif"><B></B></FONT></P>

<P STYLE="font: 12pt Arial, Helvetica, Sans-Serif; margin: 0pt 0 12pt"><B>&nbsp;</B></P>

<P STYLE="font: 12pt Arial, Helvetica, Sans-Serif; margin: 0pt 0 12pt"></P>

<P STYLE="font: 12pt Arial, Helvetica, Sans-Serif; margin: 0pt 0 12pt"><B>TransAlta Announces Accelerated Transition to Clean Energy</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">CALGARY, Dec. 6, 2017 /CNW/ - TransAlta Corporation (&quot;TransAlta&quot;
or the &quot;Company&quot;) (TSX: TA; NYSE: TAC) announced today that its Board of Directors has approved additional elements in
the Company's strategy to accelerate its transition to gas and renewables generation.&nbsp; These elements include:</P>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 12pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Entering into a letter of intent with Tidewater Midstream
and Infrastructure Ltd. (&quot;Tidewater&quot;) to construct a 120 kilometre natural gas pipeline from Tidewater's Brazeau River
Complex to TransAlta's generating units at Sundance and Keephills to eventually supply the Company with up to 340 million cubic
feet of gas per day; </FONT></TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 12pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Accelerating the conversion of Sundance Units 3 to
6 and Keephills Units 1 and 2 from coal-fired generation to gas-fired generation in the 2021 to 2022 timeframe, a year earlier
than originally planned.&nbsp; The coal-fired plants operated by TransAlta, once converted to gas, are anticipated to be able to
run through to 2031 to 2039 &ndash; a significant lengthening of their asset lives; and </FONT></TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 12pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Mothballing temporarily a combination of Sundance
units in 2018 and 2019 to ensure that two Sundance coal units can operate at high capacity utilizations with lower costs through
the period to 2020 when additional power will be needed in the Alberta market.&nbsp; Sundance Units 3 to 6 will re-enter the market
starting in 2020 as the demand for electricity rises.&nbsp; </FONT></TD></TR></TABLE>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">Details on the Company's Brazeau Pumped Storage Project, which
is a key cornerstone of its gas and renewables strategy, are also provided. The Company expects dispatchable renewable resources
to be valuable in a future where carbon emitting plants will mostly provide back up to low cost intermittent renewable resources.&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">The Company also provided its 2018 annual guidance today,
which is discussed below. &nbsp;&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">&quot;We continue to position TransAlta as a leader in clean
power generation and our strategy dramatically improves our competitive position and our ability to generate strong cash flow over
the long term,&quot; said Dawn Farrell, President and Chief Executive Officer. &quot;Our asset base in Alberta is poised to ensure
that we can provide low cost, clean, reliable and firm electricity to customers.&quot;&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B>Gas Supply for Conversions and Accelerated Coal-to-Gas
Conversion Schedule</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">As announced earlier today, TransAlta has entered into a letter
of intent with Tidewater for the construction of a 120 kilometre pipeline from their Brazeau River Complex to TransAlta's Sundance
and Keephills facilities.&nbsp;&nbsp; The pipeline will provide initial capacity of 130 million cubic feet of gas per day by 2020,
and have expansion capability to 340 million cubic feet of gas per day.&nbsp; The initial capacity will support fuel blending,
using a fuel combination of coal and gas for generation, which will reduce the marginal cost as well as emissions.&nbsp; TransAlta
will have the option to invest up to 50 percent in the pipeline, which, if exercised, would reduce the costs associated with the
tolling agreement.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">The decision to work with Tidewater advances the timeframe
for the construction of a pipeline and permits the acceleration of plant conversions.&nbsp; As a result, and given the clarity
provided by the draft coal-to-gas conversion rules proposed by the Government of Canada, the Company has determined to accelerate
the conversion of Sundance Units 3 to 6 and Keephills Units 1 and 2 from coal-fired generation to gas-fired in the 2021 to 2022
timeframe, a year earlier than originally planned.&nbsp; TransAlta remains of the view that having at least two pipelines supplying
natural gas would reduce operational risks and continues to advance discussions with other parties to construct additional pipelines
to meet the remaining gas supply requirements for the facilities.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">Although not yet finalized, the Government of Canada has proposed
coal-to-gas conversion rules that would extend the life of TransAlta's gas conversion units by five-to-ten years past their federal
end of coal life, depending on their CO<SUB>2</SUB> emissions profile.&nbsp; The proposed rules would see the life of TransAlta's
entire coal-fired fleet extended by an aggregate of approximately 75 years.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">In addition to the extending of their operating lives, the
benefits of converting units to gas generation include: (i) significantly lowering carbon intensities, emissions, and costs; (ii)
significantly lowering operating and sustaining capital costs; and (iii) increasing operating flexibility.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B>Sundance Operations in the 2018 to 2020 Timeframe</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">The Board of Directors have approved the following;</P>

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<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Sundance Unit 3, will be temporarily mothballed on
April 1, 2018 for a period of up to two years; </FONT></TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 12pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Sundance Unit 5, will be temporarily mothballed on
April 1, 2018 for a period of up to one year; and </FONT></TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 12pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 12pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 4.5pt"></TD><TD STYLE="width: 18pt"><FONT STYLE="font-family: Symbol; font-size: 10pt">&#183;</FONT></TD><TD><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 10pt">Sundance Unit 4, will be temporarily mothballed on
April 1, 2019 for a period of up to two years.</FONT></TD></TR></TABLE>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">The decision to mothball selected units ensures that the remaining
units operate at strong capacity utilization factors which ensure competitive cost structures.&nbsp; Sundance Unit 3, Sundance
Unit 4 and Sundance Unit 5 comprise 368 MW, 406 MW and 406 MW, respectively, of the 2,141 MW Sundance power plant.&nbsp; TransAlta
maintains the flexibility to return mothballed units to service when market fundamentals support the addition of their generation.&nbsp;
The mothballing of the units will also assist TransAlta in its preparations for converting the units to gas.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">On April 19, 2017, the Company announced that it would retire
Sundance Unit 1 and mothball Sundance Unit 2, effective January 1, 2018.&nbsp; Sundance Unit 2 will also be available to return
to service in 2020.&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B>Brazeau Pumped Storage</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">Brazeau Hydro is an existing power station on the North Saskatchewan
River location north-west of Edmonton.&nbsp; The facility currently produces 355 MW of power under a power purchase arrangement
(&quot;PPA&quot;) with the Balancing Pool. The PPA expires at the end of 2020.&nbsp; Brazeau Pumped Storage is a development project,
at Brazeau Hydro, that would create up to 900 MW of additional generation and storage capability. The facility would utilize the
existing footprint to generate power under conditions of strong demand and store power when supply resources outpace demand. It
is particularly competitive for ensuring that low cost, intermittent wind and solar generation resources can be stored for use
in high demand periods.&nbsp; The Company is developing the project in anticipation of a requirement over time to replace baseload
thermal resources with dispatchable renewable resources in the Alberta market.&nbsp; The project, if it were to win a long-term
contract in a future competitive call, could be ready for service as early as 2025.&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B>2018 Outlook</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">For 2018, we expect our annual free cash flow (&quot;FCF&quot;)
to be in-line with our 2017 expected annual FCF, despite the expiry of the Sundance A PPA, the early termination of the Sundance
B PPA and Sundance C PPA, and the termination of our Solomon contract in Australia. We have already received approximately $400
million for the early termination of the Solomon contract and we are expecting to receive in excess of $200 million from the Balancing
Pool for the early termination of the Sundance B PPA and Sundance C PPA.&nbsp; As a result, we have accelerated our debt reduction
plan and will have additional financial flexibility over the next three years.&nbsp; The PPA terminations have provided increased
operational flexibility and enables optimization of the Sundance power plant.&nbsp; This optimization results in significant reductions
in operating costs as well as sustaining and productivity capital, which we expect will be in the range of $215 to $235 million.&nbsp;&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">The outlook assumes an average price of $50-60/MWh in Alberta
and that the Sundance merchant units will run between 65 to 75% in 2018.&nbsp;&nbsp; The following table outlines TransAlta's financial
targets for 2018:</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Arial, Helvetica, Sans-Serif">
<TR STYLE="vertical-align: bottom">
    <TD STYLE="border-bottom: black 1pt solid; padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt"><B>Measure</B></FONT></TD>
    <TD STYLE="border-bottom: black 1pt solid; padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt"><B>Target</B></FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Comparable EBITDA<SUP>(1)</SUP></FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$950 million to $1,050 million</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">FFO<SUP>(1)</SUP></FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$725 million to $800 million</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">FCF <SUP>(1)</SUP>&nbsp;&nbsp; </FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$275 million to $350 million</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Dividend</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$0.16 per share, 13 to 17 per cent payout of Comparable FCF</FONT></TD></TR>
</TABLE>
<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><I><U>Range of key power price assumptions</U></I>:</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Arial, Helvetica, Sans-Serif">
<TR STYLE="vertical-align: bottom">
    <TD STYLE="border-bottom: black 1pt solid; padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt"><B>Market</B></FONT></TD>
    <TD STYLE="border-bottom: black 1pt solid; padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt"><B>Power Prices ($/MWh)</B></FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Alberta Spot </FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$50 to $60</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Alberta Contracted</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$35 to $40</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Mid-C Spot (US$)</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$20 to $25</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Mid-C Contracted (US$)</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$47 to $53</FONT></TD></TR>
</TABLE>
<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><I><U>Other assumptions relevant to 2018 outlook:</U></I></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Arial, Helvetica, Sans-Serif">
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Sustaining Capital</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">$215 million to $235 million</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Canadian Coal Capacity Factor</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">65% to 75%</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Hydro/Wind Resource</FONT></TD>
    <TD STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">Long term average</FONT></TD></TR>
<TR STYLE="vertical-align: bottom">
    <TD COLSPAN="2" STYLE="padding: 1.5pt"><FONT STYLE="font-family: Arial, Helvetica, Sans-Serif; font-size: 8pt">(1)&nbsp; These items are not defined under IFRS. Presenting these items provides management and investors with the ability to evaluate earnings trends more readily in comparison with prior periods' results. Refer to the Funds from Operations and Free Cash Flow, Discussion of Segmented Comparable Results, and Earnings and Other Measures on a Comparable Basis sections of TransAlta's 2017 third quarter management discussion and analysis for additional information.</FONT></TD></TR>
</TABLE>
<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B>Investor Day</B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">TransAlta will be hosting an Investor Day at 9:30am ET on
Wednesday, December 6<SUP>th</SUP>, 2017 during which our executive team will discuss the announcements above.&nbsp; A link to
the presentation and live webcast will be available on the Investors section of TransAlta's website at http://www.transalta.com/investors/events-and-presentations.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B><I>About TransAlta Corporation:</I></B>&nbsp;</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><I>TransAlta owns, operates and develops a diverse fleet of
electrical power generation assets in Canada, the United States and Australia with a focus on long-term shareholder value. We provide
municipalities, medium and large industries, businesses and utility customers clean, affordable, energy efficient, and reliable
power. Today, we are one of Canada's largest producers of wind power and Alberta's largest producer of hydro-electric power. For
over 100 years, TransAlta has been a responsible operator and a proud community-member where its employees work and live. TransAlta
aligns its corporate goals with the UN Sustainable Development Goals and we have been recognized by CDP (formerly Climate Disclosure
Project) as an industry leader on Climate Change Management. We are also proud to have achieved the Silver level PAR (Progressive
Aboriginal Relations) designation by the Canadian Council for Aboriginal Business. </I></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><I>For more information about TransAlta, visit our web site
at transalta.com.</I></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><B><I>Forward-Looking Statements&nbsp; </I></B></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0"><I>This news release contains forward-looking statements and
forward-looking information within the meaning of applicable securities laws. The use of any of the words &quot;expect&quot;, &quot;anticipate&quot;,
&quot;continue&quot;, &quot;estimate&quot;, &quot;may&quot;, &quot;will&quot;, &quot;project&quot;, &quot;should&quot;, &quot;propose&quot;,
&quot;plans&quot;, &quot;intends&quot; and similar expressions are intended to identify forward-looking information or statements.
More particularly, and without limitation, this news release contains forward-looking statements and information relating to: the
mothballing of Sundance Units 3, 4 and 5; the expected value of dispatchable renewable resources, such as the Brazeau Pumped Storage
project; that carbon emitting plants are expected to primarily provide back up to low cost intermittent renewable resources in
the future; the expectation that mothballing a combination of Sundance units in 2018 and 2019 will allow the two operating Sundance
coal units to operate at high capacity utilizations to 2020, when additional power is expected to be needed in the Alberta market;
the conversion to gas-fired generation of Sundance Units 3 to 6 and Keephills Units 1 to 2, including the timing thereof; the lengthening
of the coal-fired plants lives, once converted to gas, to 2031 to 2039; the expected gas supply required for converted units and
the construction by Tidewater of a 120 kilometre pipeline to TransAlta's Sundance and Keephills facilities with a capacity of 130
million cubic feet of gas per day by 2020 and expansion capability to 340 million cubic feet of gas per day; the terms of any definitive
agreement with Tidewater, including the option to invest up to 50 percent in the pipeline; the anticipated benefits of converting
units to gas; the Government of Canada's proposed coal-to-gas conversion rules expected to extend the life of TransAlta's coal
units by five-to-ten years past their federal end of coal life, depending on their emissions profile; the life of TransAlta's coal-fired
fleet to be extended by an aggregate of approximately 75-years; the benefits of converting coal-fired generating units to gas-fired
generating units; the construction and development of the Brazeau Pumped Storage project, including that such project &nbsp;would
create up to 900 MW of additional hydro and storage capability, the timing for when such project could come on-line, the competitiveness
of such project, and the anticipated Alberta provincial requirement to replace baseload thermal generation with dispatchable renewable
resources; the 2018 outlook, including 2017 expected annual FCF and 2018 financial targets; amounts to be received from the Balancing
Pool in connection with the termination of the Sundance B and Sundance C PPAs; increased asset optimization; reductions in operating
costs and sustaining and productivity capital in the range of $215 to $235 million; and the 2018 dividend amounts and payout ratio.
These statements are based on TransAlta's belief and assumptions based on information available at the time the assumptions were
made. These statements are subject to a number of risks and uncertainties that may cause actual results to differ materially from
those contemplated by the forward-looking statements. Some of the factors that could cause such differences include: legislative
or regulatory developments, including as it pertains to the Alberta capacity market; the Federal and/or Provincial governments
not implementing legislation or regulations facilitating the conversion from coal generation to gas generation; the Federal and/or
Provincial governments adopting different carbon prices rules; changes in economic and competitive conditions; inability to secure
natural gas supply and the construction of a natural gas pipeline on terms satisfactory to the Company; the introduction of disruptive
sources of energy or capacity; changes in the price for natural gas and electricity, including expected pricing in Alberta and
Mid-C; decreased demand for energy or capacity; Canadian coal capacity factors and hydro and wind resources being lower than expected;
availability of financing; and other risk factors contained in the Company's annual information form and management's discussion
and analysis. Readers are cautioned not to place undue reliance on these forward-looking statements or forward-looking information,
which reflect TransAlta's expectations only as of the date of this news release. The purpose of the financial outlooks contained
in this news release are to give the reader information about management's current expectations and plans and readers are cautioned
that such information may not be appropriate for other purposes. TransAlta disclaims any intention or obligation to update or revise
these forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.</I></P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">Note: All financial figures are in Canadian dollars unless
otherwise indicated.</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">SOURCE TransAlta Corporation</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">View original content: http://www.newswire.ca/en/releases/archive/December2017/06/c8180.html</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">%CIK: 0001144800</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 0"><B>For further information: </B>Investor Inquiries: Sally Taylor,
Manager, Investor Relations, Phone: 1-800-387-3598 in Canada and U.S., Email: investor_relations@transalta.com; Media Inquiries:
Amber Goulard, Senior Advisor, Communications, Phone: Toll-free media number: 1-855-255-9184, Email: ta_media_relations@transalta.com</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">CO: TransAlta Corporation</P>

<P STYLE="font: 10pt Arial, Helvetica, Sans-Serif; margin: 9.75pt 0">CNW 06:00e 06-DEC-17</P>



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