Exhibit 12b

Tucson Electric Power Company

Computation of Ratio of Earnings to Fixed Charges

	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010*		Dec. 31, 2009*		Dec. 31, 2008*			Dec. 31, 2007*		Dec. 31, 2006*
	- Thousands of Dollars -
Fixed Charges:
Interest on Long-Term Debt	$	49,858	$	42,378	$	36,226	$	47,456		$	50,230	$	51,422
Other Interest (1)		1,127		433		1,571		1,367			4,538		6,436
Interest on Capital Lease Obligations		44,874		52,534		53,670		57,252			64,477		72,556
Estimated Interest Portion of Rental Expense		795		72		106		130			160		188
Total Fixed Charges	$	96,654	$	95,417	$	91,573	$	106,205		$	119,405	$	130,602
Net Income	$	85,334	$	108,260	$	90,688	$	7,206		$	55,591	$	67,306
Add (Deduct):
(Income) Losses from Equity Investees		—		—		—		(1,381	)		—		(320	)
Income Taxes		52,000		59,936		54,220		12,729			36,940		42,845
Total Fixed Charges		96,654		95,417		91,573		106,205			119,405		130,602
Total Earnings before Taxes and Fixed Charges	$	233,988	$	263,613	$	236,481	$	124,759		$	211,936	$	240,433
Ratio of Earnings to Fixed Charges		2.421		2.763		2.582		1.175			1.775		1.841

* As revised. See Note 1 to the financial statements for more information.

(1) Excludes recognition of Allowance for Borrowed Funds Used During Construction.