Segment Information

9 Months Ended

Sep. 30, 2011

Segment Information [Abstract]

Segment Information

10. Segment Information

PSCo has the following reportable segments: regulated electric utility, regulated natural gas utility and all other.

· PSCo's regulated electric utility segment generates, transmits and distributes electricity in Colorado. In addition, this segment includes sales for resale and provides wholesale transmission service to various entities in the U.S. Regulated electric utility also includes PSCo's commodity trading operations.

· PSCo's regulated natural gas utility segment transports, stores and distributes natural gas in portions of Colorado.

· Revenues from operating segments not included above are below the necessary quantitative thresholds and are therefore included in the all other category. Those primarily include steam revenue, appliance repair services and nonutility real estate activities.

Operating results from the regulated electric utility and regulated natural gas utility serve as the primary basis for the chief operating decision maker to evaluate the dual performance of PSCo. The accounting policies of the segments are the same as those described in Note 1 to the consolidated financial statements included in PSCo's Annual Report on Form 10-K for the year ended Dec. 31, 2010. These segments are managed separately because the revenue streams are dependent upon regulated rate recovery which is separately determined for each segment.

Asset and capital expenditure information is not provided for PSCo's reportable segments because as an integrated electric and natural gas utility, PSCo operates significant assets that are not dedicated to a specific business segment, and reporting assets and capital expenditures by business segment would require arbitrary and potentially misleading allocations which may not necessarily reflect the assets that would be required for the operation of the business segments on a stand-alone basis.

To report income from continuing operations for regulated electric utility and regulated natural gas utility segments the majority of costs are directly assigned to each segment. However, some costs, such as common depreciation, common O&M expenses and interest expense are allocated based on cost causation allocators. A general allocator is used for certain general and administrative expenses, including office supplies, rent, property insurance and general advertising.

	Regulated		Regulated			All		Reconciling			Consolidated
(Thousands of Dollars)	Electric		Natural Gas			Other		Eliminations			Total
Three Months Ended Sept. 30, 2011
Operating revenues from external customers	$	933,490	$	122,672		$	7,772	$	-		$	1,063,934
Intersegment revenues		53		(18	)		-		(35	)		-
Total revenues	$	933,543	$	122,654		$	7,772	$	(35	)	$	1,063,934
Net income (loss)	$	143,702	$	(4,219	)	$	1,235	$	-		$	140,718
Three Months Ended Sept. 30, 2010
Operating revenues from external customers	$	849,707	$	101,203		$	4,060	$	-		$	954,970
Intersegment revenues		25		3			-		(28	)		-
Total revenues	$	849,732	$	101,206		$	4,060	$	(28	)	$	954,970
Net income	$	125,978	$	664		$	31,449	$	-		$	158,091

Nine Months Ended Sept. 30, 2011
Operating revenues from external customers	$	2,387,434	$	725,593	$	28,454	$	-		$	3,141,481
Intersegment revenues		237		201		-		(438	)		-
Total revenues	$	2,387,671	$	725,794	$	28,454	$	(438	)	$	3,141,481
Net income	$	276,218	$	27,320	$	4,828	$	-		$	308,366
Nine Months Ended Sept. 30, 2010
Operating revenues from external customers	$	2,346,962	$	733,380	$	24,621	$	-		$	3,104,963
Intersegment revenues		157		107		-		(264	)		-
Total revenues	$	2,347,119	$	733,487	$	24,621	$	(264	)	$	3,104,963
Net income	$	248,701	$	45,877	$	25,448	$	-		$	320,026