SunEdison Interconnects Europe's Largest Single Operating PV Solar Power Plant

Construction and Interconnection Completed in Nine Month Period

BELTSVILLE, Maryland, November 23, 2010 - SunEdison, a leading worldwide solar energy services provider and a
subsidiary of MEMC Electronic Materials (NYSE: WFR), has successfully
interconnected a 70 megawatt (MW) photovoltaic (PV) power plant in Northeast
Italy, near the town of Rovigo. The deployment, which is now the largest
single-operating PV solar power plant in Europe, was completed and
interconnected in a nine-month time period.

(Photo: photos.prnewswire.com/prnh/20101123/NY06576 )

The Rovigo solar power plant was acquired by First Reserve through a
previously announced joint venture between First Reserve Corporation and
SunEdison. First Reserve recently announced the execution of a euro 260M
project finance facility for the project with some of the leading European
banks, including Banco Santander, Unicredit Corporate Banking, Dexia Crediop,
Natixis, Societe Generale and Credit Agricole. SunEdison, a minority investor
in the joint venture with First Reserve, will manage the ongoing operations
and maintenance of the Rovigo plant.

"With construction completion in less than one year, we believe this
deployment signifies a new milestone for the industry and will become the
standard for future mega projects," said Carlos Domenech, President of
SunEdison. "SunEdison has once again demonstrated its capabilities and
expertise in developing large-scale solar projects while helping government
agencies promote renewable energy initiatives."

"SunEdison has proved it is highly efficient and reliable as a leader in
executing large scale solar projects like Rovigo," commented Mark Florian,
Managing Director of First Reserve Energy Infrastructure. "We are proud to
add this flagship project to our energy infrastructure portfolio and look
forward to developing new opportunities for our joint venture with SunEdison
in the future. The combination of a strong regulatory environment, a stable
tariff regime and reliable solar exposure are attractive characteristics for
the Italian solar market."

"The deployment of the Rovigo project within this timeframe was made
possible thanks to the commitment of our project partners and local and
regional authorities," said Pancho Perez, General Manager of SunEdison EMEA.
"This project is a fine example of SunEdison's commitment to the continued
development of the solar PV sector in Italy and the EMEA."

In a letter to Carlos Domenech, the Italian Minister for Economic
Development, Paolo Romani, congratulated SunEdison's achievement. The
Minister referred to the challenges of energy supply in Italy and the
project's importance to economic growth and success.

The Rovigo solar plant will create significant environmental benefits
over its expected lifetime. In its first year of operation alone, the system
is expected to generate enough energy to power more than 16,500 homes and
prevent the emission of more than 40,000 tons of CO(2), equivalent to the
removal of 8,000 cars from the road.

About SunEdison

SunEdison is a global provider of solar-energy services. The company
develops, finances, installs and operates distributed power plants using
proven photovoltaic technologies, delivering fully managed, predictably
priced solar energy services for its commercial, government and utility
customers. In 2009, SunEdison delivered more kilowatt hours (kWh) of energy
than any other solar services provider in North America. For more information
about SunEdison, please visit www.sunedison.com.

About MEMC

MEMC is a global leader in the manufacture and sale of wafers and related
intermediate products to the semiconductor and solar industries. The company
has been a pioneer in the design and development of silicon wafer
technologies for 50 years. With R&D and manufacturing facilities in the U.S.,
Europe, and Asia, MEMC enables the next generation of high-performance
semiconductor devices and solar cells. Through its SunEdison division, MEMC
is also a developer of solar power projects and North America's largest solar
energy services provider. MEMC's common stock is listed on the New York Stock
Exchange under the symbol "WFR" and is included in the S&P 500 Index. For
more information about MEMC, please visit www.memc.com.

About First Reserve

First Reserve is the world's leading private equity firm in the energy
industry, making both private equity and infrastructure investments
throughout the energy value chain. For more than 25 years, it has invested
solely in the global energy industry, and has developed an unparalleled
franchise, utilizing its broad base of specialized energy industry knowledge
as a competitive advantage. First Reserve invests strategically across a wide
range of energy industry sectors, developing a portfolio that is diversified
across the energy value chain, backing talented management teams and building
value by building companies. Further information is available at
www.firstreserve.com.

About the First Reserve Joint Venture

In May 2010, First Reserve and SunEdison announced the creation of a
joint venture for the acquisition of SunEdison's photovoltaic projects. This
partnership is one of the largest investment vehicles to exclusively fund
photovoltaic solar power created to date, with the prospect of long-term
ownership of the assets across several key geographies.

Forward-Looking Statements

Certain matters discussed in this press release are forward-looking
statements, including our belief that this deployment signifies a new
milestone for the industry and will become the standard for future mega
projects to come; and that in its first year of operation alone, the system
is expected to generate enough energy to power more than 16,500 homes and
prevent the emission of more than 40,000 tons of CO(2), equivalent to the
removal of 8,000 cars from the road. Such statements involve certain risks
and uncertainties that could cause actual results to differ materially from
those in the forward-looking statements. Potential risks and uncertainties
include delays or unforeseen difficulties with respect to the closing of the
long-term debt financing by First Reserve; the timely availability of
required permits and authorizations for projects from governmental entities
and third parties; changes in applicable regulatory requirements and
incentives for production of solar power; general business and economic
conditions, including seasonality of the industry; and other risks described
in MEMC's filings with the Securities and Exchange Commission, including its
Form 10-K for the 2009 fiscal year and its quarterly reports on Form 10-Q for
the first, second and third quarters of 2010. These forward-looking
statements represent MEMC's and SunEdison's judgment as of the date of this
release. MEMC and SunEdison disclaim, however, any intent or obligation to
update these forward-looking statements.

Media: Bill Michalek, Director, Corporate Communications, MEMC Electronic Materials, Inc., +1-636-474-5443 or Virginia Amador, Head of Marketing EMEA, SunEdison, vamador at sunedison.com; Investors/Analysts: Kurt Bruenning, Treasurer, MEMC Electronic Materials, Inc., +1-636-474-5925; First Reserve: Michael Henman of Cubitt Consulting, +44-0-20-7367-5100, michael.henman at cubitt.com or Caroline Harris of CJP Communications, +1-212-279-3115; ext. 222, charris at cjpcom.com