This acquisition builds on the utility’s plans to invest nearly $5bn in affordable clean energy projects over six years.

According to Exelon, the purchase price for the power plant is $305m, as adjusted for working capital, and the company expects that the transaction will be accretive to free cash flow beginning in 2012.

The acquisition also eliminates an existing power purchase agreement between Exelon and Wolf Hollow to buy 350MW of the plant’s output through 2023.

Exelon chairman and CEO John Rowe said the purchase of Wolf Hollow is another step in growing Exelon’s clean energy portfolio, an increasingly valuable asset as forthcoming US Environmental Protection Agency clean air rules spur a transition to a cleaner, lower-emission energy supply.