BALTIMORE, Oct. 1 -- Constellation Energy (NYSE: CEG) today announced that its wholesale origination and risk management subsidiary, Constellation Energy Commodities Group, Inc., has signed a second long-term power purchase agreement with Horizon Wind Energy, a company owned by Energias de Portugal (EDP), for power produced at the Twin Groves wind farm outside of Bloomington, Ill.

The agreement covers approximately 99 megawatts, representing roughly half of the emissions-free generating capacity produced by 120 turbines at Twin Groves' Phase 1. The 18-year contract will run through 2025. Twin Groves Phase I commenced operations in April 2007.

On July 25, 2007 the companies entered into a similar 18-year agreement for the entire 198 megawatts to be produced by 120 turbines at Twin Groves's Phase II. Construction is underway at Phase II and expected to be completed in early 2008. The contract term for the Phase II agreement commences when the project is completed and producing power.

The Twin Groves wind farm is located in eastern McLean County, Ill., and interconnected to the regional PJM interconnection power grid.

Constellation Energy said the agreement will allow the company, which has been a leading competitive energy supplier in Illinois since 1999, to acquire a long-term source of renewable power in the state and will help meet growing customer demand for green power products.

Constellation Energy, a FORTUNE 200 company with 2006 revenues of $19.3 billion, is the nation's largest competitive supplier of electricity to large commercial and industrial customers and the nation's largest wholesale power seller. Constellation Energy also manages fuels and energy services on behalf of energy intensive industries and utilities. It owns a diversified fleet of 78 generating units located throughout the United States, totaling approximately 8,700 megawatts of generating capacity. The company delivers electricity and natural gas through the Baltimore Gas and Electric Company (BGE), its regulated utility in Central Maryland.

Horizon Wind Energy develops, constructs, owns, and operates wind farms throughout the United States. Having developed more than 1000 MW of wind farms operating in Illinois, Texas, Minnesota, Iowa, Pennsylvania, Oklahoma, New York, Washington, and Costa Rica, Horizon is currently developing a portfolio of more than 9000 MW in a dozen states and expects to bring nearly 1000 MW online in 2007. Horizon Wind Energy is owned by Energias de Portugal, S.A., a major Portuguese utility.