Regulatory Matters (Tables)

9 Months Ended

Sep. 30, 2011

Regulatory Matters [Abstract]

Summary of PPFAC and PGA Rates

	2011									2010
	June -			April -						June			April -
	September			May			First Quarter			September			May			First Quarter
TEP
PPFAC		0.53			0.53			0.09			0.09			0.09			0.18
CTC(1)		(0.53	)		(0.53	)		(0.09	)		(0.09	)		(0.09	)		(0.18	)
Total PPFAC Rate		—			—			—			—			—			—
UNS Electric		(0.88	)		0.08			0.08			(0.28	)		(1.06	)		(1.06	)
UNS Gas		—			—			—			(8.00	)		(8.00	)		(8.00	)

⁽¹⁾ Competition Transition Charge

Changes in PPFAC related accounts and impacts on revenue and expense

	At September			At December			Nine Months Ended
	30, 2011			31, 2010			September 30, 2011
									Reduction to
									Fuel and
									Purchased
							Increase to		Power
	Asset (Liability)						Revenue		Expense
	-Millions of Dollars-
PPFAC — Fixed CTC Revenue to be Refunded (current)	$	(5	)	$	(36	)	$	31
PPFAC (current and non-current)		59			54				$	5