Nature of Operations and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Revision Impact to Statements of Income

The revisions noted above impacted UNS Energy’s statements of income as shown in the tables below:

	UNS Energy
	Year Ended				Year Ended
	December 31, 2011				December 31, 2010
	As Reported		As Revised		As Reported		As Revised
	-Thousands of Dollars-
Income Statement
Electric Wholesale Sales	$	163,159	$	132,346	$	151,962	$	123,943
Total Operating Revenues		1,509,515		1,478,702		1,453,966		1,425,947
Purchased Energy		307,423		276,610		307,288		279,269
Total Fuel and Purchased Energy		634,345		603,532		584,263		556,244
Total Operating Expenses		1,227,843		1,196,995		1,156,852		1,128,833

	UNS Energy 2012 Three Months Ended
	March 31,				June 30,				September 30,
	As Reported		As Revised		As Reported		As Revised		As Reported		As Revised
	-Thousands of Dollars
Income Statement
Electric Wholesale Sales	$	37,104	$	33,538	$	28,684	$	24,381	$	32,494	$	28,836
Purchased Energy		63,276		59,790		51,376		48,203		60,238		57,085
Total Fuel and Purchased Energy		134,276		130,790		151,328		148,155		175,687		172,534
Total Operating Expenses		284,479		280,984		299,112		295,932		330,852		327,700

	UNS Energy 2011 Three Months Ended
	March 31,				June 30,				September 30,				December 31,
	As Reported		As Revised		As Reported		As Revised		As Reported		As Revised		As Reported		As Revised
	-Thousands of Dollars
Income Statement
Electric Wholesale Sales	$	40,914	$	35,438	$	38,744	$	35,331	$	41,847	$	32,818	$	41,654	$	28,759
Purchased Energy		78,274		71,685		66,336		61,804		88,734		79,343		74,079		63,778
Total Fuel and Purchased Energy		146,579		139,990		155,539		151,007		182,766		173,376		149,461		139,159
Total Operating Expenses		299,946		293,357		298,383		293,852		327,187		317,796		302,327		291,990

	UNS Energy
	Six Month Period Ended								Nine Month Period Ended
	June 30, 2012				June 30, 2011				September 30, 2012				September 30, 2011
	As Reported		As Revised		As Reported		As Revised		As Reported		As Revised		As Reported		As Revised
	-Thousands of Dollars
Income Statement
Electric Wholesale Sales	$	65,787	$	57,919	$	79,658	$	70,769	$	98,282	$	86,755	$	121,506	$	103,587
Total Operating Revenues		686,044		679,384		714,439		703,318		1,123,305		1,113,492		1,165,387		1,144,875
Purchased Energy		114,653		107,993		144,610		133,489		174,891		165,078		233,344		212,832
Total Fuel and Purchased Energy		285,605		278,945		302,118		290,997		461,292		451,479		484,885		464,373
Total Operating Expenses		583,590		576,916		598,330		587,209		914,428		904,616		925,518		905,005
Operating Income(1)		102,454		102,468		116,109		116,109		208,877		208,876		239,869		239,869

(1) Includes immaterial reclassifications from Operating Expense to Other Expense to conform with current year presentation.

AFUDC Rates

The average AFUDC rates on regulated construction expenditures are included in the table below:

	2012			2011			2010
TEP		7.22	%		6.72	%		6.65	%
UNS Gas		7.95	%		8.32	%		8.19	%
UNS Electric		7.89	%		8.18	%		8.22	%

Summary of Average Annual Depreciation Rates for All Utility Plants

Below are the summarized average annual depreciation rates for all utility plant.

	TEP			UNS Gas			UNS Electric
2012		3.22	%		2.69	%		3.99	%
2011		3.14	%		2.84	%		4.02	%
2010		3.16	%		2.83	%		4.35	%