AT&T Enlists SunEdison to Add 2MW of Solar Power in California by 2011

Trade Street site in San Diego, first of 6 California based solar power installations to be activated.

AT&T* and SunEdison announced that SunEdison, a leading worldwide solar energy services provider and subsidiary of MEMC Electronic Materials (NYSE: WFR), will expand AT&T's national solar initiative by activating a new roof top solar power installation in San Diego. San Diego Mayor Jerry Sanders as well as executives from AT&T and SunEdison were on hand to officially flip the switch on the solar power system. In addition to this installation in San Diego, AT&T has contracts with SunEdison to deploy five other solar power installations in California by the second quarter of 2011, equating to approximately 2 megawatts (MW) of total solar capacity for all six sites. The additional California solar deployments will be located in Dunnigan, Commerce, Mojave, Santa Ana and West Sacramento.

The solar power installation in San Diego is a 296 kW rooftop mounted photovoltaic system that will generate an estimated 420,000 kWh of energy in its first year of operation alone. Over 20 years, the power installation will generate more than 7.7 million kWh of energy – enough energy to power more than 720 US homes for one year. The environmental attributes associated with the solar power installation will avoid more than 8 million pounds of carbon dioxide during the initial 20 years of operation – the equivalent of taking more than 800 cars off the road according to SunEdison projections.

“Partnerships such as this one between AT&T and SunEdison show why San Diego continues to be the national leader in solar energy,” said San Diego Mayor Jerry Sanders. “Our residents and businesses have embraced clean energy, which not only benefits our environment, but also our region's economy.”

The program is made possible through a strategic power purchase agreement (PPA) between SunEdison and AT&T under which SunEdison will construct, monitor and maintain an additional five solar power installations in California. In return, AT&T will buy the energy produced from the solar systems to offset their grid demand. Once activated, the six systems will total an estimated 2 megawatts of solar capacity and will generate over 3.2 million kWh of energy within the first year of operation. According to SunEdison projections, the environmental attributes associated with the six systems will avoid an estimated 62 million pounds of CO2 over 20 years of operation.

“We are continually seeking opportunities to add renewable energy resources to power our business operations, and this agreement provides more sustainable solutions for our energy needs in California,” said John Schinter, director of energy, AT&T.

"SunEdison makes solar a reality for commercial clients throughout the world," said Brian Jacolick, general manager, Americas for SunEdison. “Through smart design, proven technologies and our strong financing capabilities, SunEdison helps clients like AT&T realize the benefits solar energy offers. “

AT&T recently released its 2009 Citizenship and Sustainability Report highlighting the company's progress toward up to $865 million in multi-year commitments for important education, environmental and volunteerism programs that help strengthen communities and stimulate economic growth. For more information about AT&T's sustainability efforts, please visit www.att.com/sustainability or www.att.com/csr.

*AT&T products and services are provided or offered by subsidiaries and affiliates of AT&T Inc. under the AT&T brand and not by AT&T Inc.

About SunEdison
SunEdison is a global provider of solar-energy services. The company develops, installs, finances and operates distributed power plants using proven photovoltaic technologies, delivering fully managed, predictably priced solar energy services for its commercial, government and utility customers. 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. MEMC 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.