Segment Information

6 Months Ended

Jun. 30, 2011

Segment Information [Abstract]

Segment Information

13.Segment Information

We assess our business on a regional basis due to the impact on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors impacting supply and demand. At June30, 2011, our reportable segments were West (including geothermal), Texas, North (including Canada and the assets purchased in the Conectiv Acquisition) and Southeast. We continue to evaluate the optimal manner in which we assess our performance including our segments and future changes may result.

Commodity Margin includes our power and steam revenues, sales of purchased power and physical natural gas, capacity revenue, REC revenue, sales of surplus emission allowances, transmission revenue and expenses, fuel and purchased energy expense, fuel transportation expense, RGGI compliance and other environmental costs, and cash settlements from our marketing, hedging and optimization activities including natural gas transactions hedging future power sales that are included in mark-to-market activity, but excludes the unrealized portion of our mark-to-market activity and other revenues. Commodity Margin is a key operational measure reviewed by our chief operating decision maker to assess the performance of our segments.

The tables below show our financial data for our segments for the periods indicated (in millions). Our North segment information for the three and six months ended June30, 2011, includes the financial results of the assets we acquired from Conectiv, with no similar revenues and expenses included for the three and six months ended June30, 2010. See Note 2 for further information about our Conectiv Acquisition.

	Three Months Ended June 30, 2011
	West		Texas		North		Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	466	$	646	$	324	$	197		$	—		$	1,633
Intersegment revenues		1		5		5		40			(51	)		—
Total operating revenues	$	467	$	651	$	329	$	237		$	(51	)	$	1,633
Commodity Margin	$	236	$	128	$	179	$	59		$	—		$	602
Add: Mark-to-market commodity activity, net and other revenue(1)		11		27		—		—			(9	)		29
Less:
Plant operating expense		116		63		47		41			(6	)		261
Depreciation and amortization expense		42		35		33		22			(1	)		131
Sales, general and other administrative expense		8		13		6		6			1			34
Other operating expenses(2)		11		3		9		2			(5	)		20
Lossfrom unconsolidated investments in power plants		—		—		2		—			—			2
Income (loss) from operations		70		41		82		(12	)		2			183
Interest expense, net of interest income														190
(Gain) loss on interest rate derivatives, net														37
Debt extinguishment costs and other (income) expense, net														8
Loss before income taxes and discontinued operations													$	(52	)

	Three Months Ended June 30, 2010
	West		Texas			North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	525	$	552		$	134		$	219		$	—		$	1,430
Intersegment revenues		1		6			1			21			(29	)		—
Total operating revenues	$	526	$	558		$	135		$	240		$	(29	)	$	1,430
Commodity Margin	$	258	$	128		$	79		$	68		$	—		$	533
Add: Mark-to-market commodity activity, net and other revenue(1)		10		(10	)		3			(9	)		(6	)		(12	)
Less:
Plant operating expense		88		78			23			31			(7	)		213
Depreciation and amortization expense		50		40			19			27			(1	)		135
Sales, general and other administrative expense		11		16			22			2			(1	)		50
Other operating expenses(2)		12		(5	)		7			(1	)		8			21
(Income) from unconsolidated investments in power plants		—		—			(6	)		—			—			(6	)
Income (loss)from operations		107		(11	)		17			—			(5	)		108
Interest expense, net of interest income																220
(Gain) loss on interest rate derivatives, net																(8	)
Debt extinguishment costs and other (income) expense, net																8
Lossbefore income taxes and discontinued operations															$	(112	)

	Six Months Ended June 30, 2011
	West		Texas			North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	1,065	$	1,096		$	595		$	376		$	—		$	3,132
Intersegment revenues		4		10			13			85			(112	)		—
Total operating revenues	$	1,069	$	1,106		$	608		$	461		$	(112	)	$	3,132
Commodity Margin	$	469	$	195		$	314		$	113		$	—		$	1,091
Add: Mark-to-market commodity activity, net and other revenue(1)		16		(33	)		4			(4	)		(15	)		(32	)
Less:
Plant operating expense		203		143			92			74			(13	)		499
Depreciation and amortization expense		88		65			66			45			(2	)		262
Sales, general and other administrative expense		19		23			12			11			1			66
Other operating expenses(2)		19		3			16			3			(3	)		38
(Income) from unconsolidated investments in power plants		—		—			(7	)		—			—			(7	)
Income (loss) from operations		156		(72	)		139			(24	)		2			201
Interest expense, net of interest income																378
(Gain) loss on interest rate derivatives, net																146
Debt extinguishment costs and other (income) expense, net																108
Loss before income taxes and discontinued operations															$	(431	)

	Six Months Ended June 30, 2010
	West		Texas		North			Southeast		Consolidation and Elimination			Total
Revenues from external customers	$	1,190	$	1,079	$	257		$	418	$	—		$	2,944
Intersegment revenues		5		10		2			44		(61	)		—
Total operating revenues	$	1,195	$	1,089	$	259		$	462	$	(61	)	$	2,944
Commodity Margin	$	471	$	235	$	131		$	126	$	—		$	963
Add: Mark-to-market commodity activity, net and other revenue(1)		18		86		—			13		(14	)		103
Less:
Plant operating expense		178		162		45			59		(13	)		431
Depreciation and amortization expense		103		76		39			56		(3	)		271
Sales, general and other administrative expense		26		16		25			6		(1	)		72
Other operating expenses(2)		29		2		15			2		(1	)		47
(Income) from unconsolidated investments in power plants		—		—		(13	)		—		—			(13	)
Incomefrom operations		153		65		20			16		4			258
Interest expense, net of interest income														399
(Gain) loss on interest rate derivatives, net														3
Debt extinguishment costs and other (income) expense, net														13
Loss before income taxes and discontinued operations													$	(157	)

_________

(1) Mark-to-market commodity activity represents the unrealized portion of our mark-to-market activity, net, included in operating revenues and fuel and purchased energy expense on our Consolidated Condensed Statements of Operations.

(2) Excludes $2 million and $5 million of RGGI compliance and other environmental costs for the three months ended June 30, 2011 and 2010, respectively, and $4 million and $5 million for the six months ended June 30, 2011 and 2010, respectively, which are included as a component of Commodity Margin.