Qualified Dividends for U.S. holders

U.S. individual or other non-corporate taxpayers should be eligible for the reduced rate of tax currently applicable to "qualified dividends" provided that the investor meets the holding period and any other requirements.

The Company's common share dividend is subject to a 15% withholding tax for U.S. holders. U.S. individuals holding shares in taxable accounts may be eligible to receive a credit on their U.S. income tax return for this withholding tax. U.S. individuals holding the Company's common shares in Individual Retirement Accounts ("IRAs") may be exempt from withholding tax pursuant to the Canada – U.S. Income Tax Convention.

For U.S. individual or other non-corporate taxpayers, dividends received from the common share portion of Atlantic Power Corporation's Income Participating Securities ("IPSs") should be eligible for the reduced rate of tax currently applicable to "qualified dividends," provided that the investor meets the holding period and any other requirements. The Company's IPSs were exchanged for new common shares on November 27, 2009.

This notice for U.S. holders has been updated as of December 1, 2009 and may not reflect subsequent changes in tax law, regulations or procedural rules. Taxpayers should always seek their own independent qualified professionals regarding the tax consequences to them of purchasing or owning IPSs or common shares of The Company.

Eligible Dividends for Canadian Resident Individuals

Canadian resident individuals who receive "eligible dividends" in 2006 and subsequent years will be entitled to an enhanced gross-up and dividend tax credit, resulting in a reduction of income taxes otherwise payable on those dividends. Atlantic Power Corporation has designated that all of its dividends paid in 2006 are "eligible dividends" for these purposes.

Atlantic Power Corporation also advises that all of its dividends will be designated as "eligible dividends" for 2007 and subsequent years, unless indicated otherwise.

Taxpayers should always seek their own independent qualified professionals regarding the tax consequences to them of purchasing or owning IPSs or common shares of The Company.