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 |

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- 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). + References No definition available. + Details
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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. + References No definition available. + Details
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