
                                                                   Exhibit 99.1

  ECD Announces Expansion of NiMH Battery License to Cobasys and Restructuring
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           of Relationship with ChevronTexaco Technology Ventures
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      Rochester Hills, Mich., Dec. 3, 2004 ? Energy Conversion Devices, Inc.
(ECD Ovonics) (NASDAQ:ENER) announced today that, as part of its focus on its
core businesses, it is entering into a series of agreements with ChevronTexaco
Technology Ventures LLC (CTTV), a subsidiary of ChevronTexaco Corporation
(ChevronTexaco) (NYSE:CVX), and Cobasys LLC (Cobasys), the 50-50 Ovonic nickel
metal hydride (NiMH) battery manufacturing joint venture between CTTV and Ovonic
Battery Company, Inc. (Ovonic Battery), a subsidiary of ECD Ovonics, to expand
the scope of licenses granted to Cobasys at the time of the formation of the
joint venture in July 2001.

      In consideration of the expanded license, revised joint venture agreements
and the collateralization of certain obligations, ECD Ovonics, through its
subsidiary Ovonic Battery, will receive an option to purchase the 4,376,633
shares of ECD common stock currently owned by a subsidiary of ChevronTexaco. The
option is exercisable at $4.55 per share and expires on November 1, 2005. In
addition, CTTV will transfer to ECD its interest in Texaco Ovonic Hydrogen
Systems LLC (TOHS) in consideration of relieving CTTV of any continuing
obligations to fund TOHS. The transaction will increase ECD Ovonics' operating
income in the quarter ended December 31, 2004 by approximately $77 million as a
result of this one-time, non-cash event.

      The 4,376,633 shares of ECD common stock subject to the option represent
approximately 17% of the currently issued and outstanding shares. ECD Ovonics
believes that the option arrangement will provide it with value and added
flexibility in its activities to secure additional capital required for its
future growth.

      The agreement also provides a mechanism for additional funding from CTTV
to continue Cobasys' expansion. CTTV will be entitled to a priority right of
repayment for providing the additional funding. ECD Ovonics and CTTV will each
continue to own a 50 percent interest in Cobasys, subject to adjustment under
certain circumstances.

      Cobasys presently develops, manufactures and markets advanced Ovonic NiMH
battery systems for transportation, telecommunication and uninterruptible power
supply applications. One objective of the agreements is the expansion of the
Ovonic Battery license to Cobasys to provide an opportunity for Cobasys to take
advantage of the growing interest in NiMH batteries and enable it to address a
full range of battery opportunities for military, homeland security, load
leveling, stationary power and other prismatic battery applications.

      Robert Stempel, Chairman and CEO of ECD Ovonics, said, "This agreement
provides Cobasys with the technology rights and a means for additional financial


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resources to capitalize on the significant commercial opportunities for its
proprietary battery solution systems in a wide range of markets."

      Thomas Neslage, President and CEO of Cobasys, commented, "This agreement
is an important next step in our pursuit of becoming a world-class NiMH energy
solutions company to meet the needs of our customers."

      The hydrogen business unit will be renamed Ovonic Hydrogen Systems LLC. It
will focus on continuing to commercialize small portable metal hydride storage
systems that have current and near-term market applications while continuing to
develop and commercialize ECD Ovonics' proprietary reversible solid metal
hydride-based low-pressure hydrogen storage systems for longer term stationary,
transportation and infrastructure applications.

      ECD will hold a conference call on Monday, December 6, 2004, at 11:00 a.m.
(Eastern Time) to review and discuss the expansion of the Ovonic NiMH battery
license to Cobasys and restructuring of the relationship with ChevronTexaco
Technology Ventures. Individuals wishing to participate in the conference should
call (877) 858-2512 or (706) 634-1291. A live webcast of the conference call
will be available online at http://www.ovonic.com/investor or through the
Company's web site at www.ovonic.com. A replay of the call will be available
through December 8, 2004, until 3:00 p.m. ET, at (800) 642-1687 or (706)
645-9291. Callers should use conference ID # 2647447 to access the conference
call and the replay.

About ECD Ovonics:
ECD Ovonics is the leader in the synthesis of new materials and the development
of advanced production technology and innovative products. It has invented,
pioneered and developed its proprietary, enabling technologies in the fields of
energy and information leading to new products and production processes based on
amorphous, disordered and related materials. ECD Ovonics' proprietary advanced
information technologies include Ovonic phase-change electrical memory, Ovonic
phase-change optical memory and the Ovonic Threshold Switch. The Company's
portfolio of alternative energy solutions includes Ovonic thin-film
continuous-web amorphous solar cells, modules, panels and systems for generating
solar electric power; Ovonic NiMH batteries; Ovonic hydride storage materials
capable of storing hydrogen in the solid state for use as a feedstock for fuel
cells or internal combustion engines or as an enhancement or replacement for any
type of hydrocarbon fuel; and Ovonic fuel cell technology. ECD Ovonics designs
and builds manufacturing machinery that incorporates its proprietary production
processes, maintains ongoing research and development programs to continually
improve its products and develops new applications for its technologies. ECD
Ovonics holds the basic patents in its fields. More information on ECD Ovonics
is available on www.ovonic.com.

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Contacts:
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Ghazaleh Koefod, Investor Relations           Bruce MacDonald, Liebler!MacDonald
Dick Thompson, Media Relations                248.283.1039
Energy Conversion Devices, Inc.
248.293.0440

