Environmental Developments (Tables)

12 Months Ended

Dec. 31, 2012

Environmental Developments [Abstract]

Estimated costs of retrofitting plants

Based on work to date, the estimated costs of retrofitting the Midwest Generation plants are as follows:

Unit	Remaining Cost (in millions)			Unit	Remaining Cost (in millions)
Joliet 6		$	75	Waukegan 7		$	59
Joliet 7		111		Waukegan 8		64
Joliet 8		124		Will County 3		104
Powerton 5		127		Will County 4		90
Powerton 6		69