v2.4.0.6

Equity compensation plans (Tables)

12 Months Ended

Dec. 31, 2012

Equity compensation plans

Schedule of changes in LTIP notional units

		Units			Grant Date Weighted-Average Fair Value per Unit
Outstanding at December 31, 2009			471,280		$	7.30
Granted			305,112			13.29
Additional shares from dividends			46,854			9.54
Vested and redeemed			(222,265	)		7.94
Outstanding at December 31, 2010			600,981			10.28
Granted			216,110			14.02
Additional shares from dividends			36,204			11.04
Forfeitures			(103,991	)		11.55
Vested and redeemed			(263,523	)		9.40
Outstanding at December 31, 2011			485,781			11.49
Granted			233,752			14.67
Additional shares from dividends			38,667			13.43
Forfeitures			(28,932	)		13.63
Vested and redeemed			(236,733	)		10.18
Outstanding at December 31, 2012			492,535		$	13.88

Schedule of assumptions for calculation of simulated total shareholder return under the Monte Carlo model

		December 31, 2012			December 31, 2011
Weighted average risk free rate of return			0.05 - 0.28	%		0.15 - 0.28	%
Dividend yield			10.10	%		7.90	%
Expected volatility—Atlantic Power			22.49	%		22.20	%
Expected volatility—peer companies			11.9 - 97.1	%		17.3 - 112.9	%
Weighted average remaining measurement period			1.39 years			0.87 years

X

- Definition

Tabular disclosure of the significant assumptions used during the year to estimate the fair value of equity-based payment instruments, excluding stock (or unit) options, including, but not limited to: (a) expected term of equity instruments, (b) expected volatility of the entity's shares and peer entities, (c) expected dividends, (d) risk-free rate(s).

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- Definition

Tabular disclosure of share-based compensation plans that may be presented in a single table for outstanding, vested and expected to vest, and exercisable awards. The information that may be disclosed in this table may include, but is not limited to, number of shares, weighted average exercise price, weighted average remaining contractual life, and aggregate intrinsic value.

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