Exhibit 99.1

Atlantic Power Corporation Releases First Quarter 2012 Results

BOSTON, MASSACHUSETTS — May 7, 2012 /PRNewswire/ -- Atlantic Power Corporation (NYSE: AT) (TSX: ATP) (“Atlantic Power” or the “Company”) today announced its results for the three months ended March 31, 2012. All amounts are in U.S. dollars unless otherwise indicated. Please see “Regulation G Disclosures” attached to this news release for an explanation and US GAAP reconciliation of the terms “Project Adjusted EBITDA” and “Cash Available for Distribution” as used in this news release.

Highlights

·                  Project Adjusted EBITDA increased by $56.9 million, or 158%, from the comparable period

·                  Acquired a 99% interest in Canadian Hills Wind, an approximate 300 MW wind power project in Oklahoma, and closed construction financing in March; construction commenced in April

·                  Announced agreement with Primary Energy Recycling Corporation (“PERC”) in February, in which they agreed to purchase Atlantic Power’s 14.3% interest in Primary Energy Recycling Holdings (“PERH”)

“Thanks to our transformative acquisition of Capital Power Income, LP (the “Partnership”) last year, we are benefiting from being a much larger company that owns and operates more than half of its projects,” said Barry Welch, President & CEO.  “We are building on the momentum of our recent growth initiatives and continue to deliver long-term value to our many stakeholders.  Our commercial development team is benefiting from increased interest on the part of development companies to partner on a variety of late-stage development projects, and from passive equity partners focused on leveraging our operating expertise.  Canadian Hills is a perfect example where we are deploying capital in an accretive acquisition that has added significant value to the Company.  We are also considering opportunities to rationalize any non-core assets in our portfolio given our scale and primary business focus.”

Operating Performance

Project Adjusted EBITDA, including earnings from equity investments, increased by $56.9 million, or 158%, to $92.9 million for the quarter ended March 31, 2012 compared to $36.0 million for the same period in 2011, primarily due to contributions from the 18 projects added to Atlantic Power’s portfolio when it acquired the Partnership, including: $9 million from Curtis Palmer; $6.4 million from Williams Lake; and $5.4 million from Tunis.

Aggregate power generation in MWhs for the three months ended March 31, 2012 increased approximately 138% from the comparable 2011 period primarily due to increased generation from the newly acquired Partnership projects.  Weighted average availability of Atlantic Power’s projects increased by 2.7% to 96.3% for the quarter ended March 31, 2012, compared to the same period in 2011.

Cash Available for Distribution

For the three months ended March 31, 2012, Cash Available for Distribution increased by $43.2 million compared to the same period in 2011, primarily due to an increase in working capital associated with the Ontario plants acquired in the Partnership acquisition as well as reducing the Company’s combined foreign currency forward positions as a result of the acquisition.  The payout ratio for the quarter ended March 31, 2012 was 55% compared to 114% for the same prior year period.  Due to the timing of numerous working capital adjustments and the cash payments associated with the Company’s corporate level interest payments, the Company’s payout ratio will fluctuate from quarter to quarter.  For example, the interest payments on its $460 million Senior Notes are due semi-annually (May and November) and will impact the payout ratio in the second and fourth quarters.

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The calculation of Cash Available for Distribution (in both US$ and Cdn$) and a summary of Project Adjusted EBITDA by segment for the quarters ended March 31, 2012 and 2011 are attached to this news release. [In addition, a summary of Project Adjusted EBITDA by project for the quarter ended March 31, 2012 is attached to this news release.]

Canadian Hills

In March, the Company closed on a $310 million non-recourse, project-level construction financing facility, for its 99% ownership interest in Canadian Hills Wind, which includes a $290 million construction loan and a $20 million, 5-year letter of credit facility.  The construction loan is structured to be repaid by tax equity investments, which we are actively pursuing, when the project commences commercial operations.  Atlantic Power is committed to investing approximately $180 million of equity (net of financing costs) following the funding of the construction financing.  The project began construction in April and we anticipate that the Project will begin commercial operations by the fourth quarter of 2012.  The Company expects approximately $16 to $19 million in cash distributions from the project for each full year of operations through 2020, after which time the Company expects distributions to increase.

Commercial Developments

In February, Atlantic Power entered into an agreement with Primary Energy Recycling Corporation whereby PERC will purchase the Company’s 14.3% common membership interests in PERH for approximately $24 million, plus a management agreement termination fee of approximately $6.1 million for a total price of $30.1 million.  The transaction remains subject to financing as well as pricing adjustment or termination under certain circumstances, and is expected to close in the second quarter of 2012.

In February, the Chambers project received a favorable ruling from the Superior Court of New Jersey in Salem County related to a summary judgment motion on liability related to the suit the project filed against DuPont regarding its performance under the energy services agreement. The court’s decision included a description of the pricing methodology that is consistent with the project’s position.  In April, the court issued its written opinion which ordered DuPont to pay Chambers $15.7 million (Atlantic’s share, $6.8 million) in damages and an estimated approximately $10.6 million (Atlantic’s share, $4.2 million) in additional interest and true-up charges.  Additional details on the suit can be found in the Company’s filings.

In March, Path 15 filed a formal settlement agreement establishing a revenue requirement at $28.8 million with the Administrative Law Judge for her review and certification to FERC for approval.  All of the parties in the rate case either support or do not oppose the settlement agreement.  Path 15 expects an order approving the settlement from FERC during the second quarter of 2012.

Outlook

Based on actual performance to date and projections for the remainder of the year, Atlantic Power expects to receive distributions from its projects in the range of $250 to $265 million for the full year 2012. The Company expects overall levels of operating cash flows in 2012 to be improved over 2011 levels due primarily to full year contributions from the Partnership assets and increased distributions from Selkirk following the final payment of its non-recourse, project-level debt by mid-2012. These increased operating cash flows in 2012, in addition to the smaller and final $1 million management termination fee to ArcLight and one-time realized gains from the termination of a portion of aggregate foreign currency forward contracts from the combined company, are expected to result in a significant increase in cash available for distribution from 2011.  Atlantic Power continues to anticipate a 2012 payout ratio of approximately 90% to 97%, subject to the financial performance of its projects.

Investor Conference Call and Webcast

A telephone conference call hosted by Atlantic Power’s management team will be held on Tuesday, May 8, 2012 at 10:00 AM ET. The telephone numbers for the conference call are: U.S. Toll Free: 1-877-317-6789; Canada Toll Free: 1-866-605-3852; International Toll: +1 412-317-6789.  The Conference Call will also be broadcast over Atlantic Power’s website. Please call or log in 10 minutes prior to the call. The

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telephone numbers to listen to the conference call after it is completed (Instant Replay) are U.S. Toll Free: 1-877-344-7529; International Toll: +1-412-317-0088. Please enter conference call number 10012731.  The conference call will also be archived on Atlantic Power’s website.

About Atlantic Power

Atlantic Power is a leading publicly traded, power generation and infrastructure company with a well diversified portfolio of assets in the United States and Canada. The Company’s power generation projects sell electricity to utilities and other large commercial customers under long-term power purchase agreements, which seek to minimize exposure to changes in commodity prices.  The net generating capacity of the Company’s projects is approximately 2,140 MW, consisting of interests in 31 operational power generation projects across 11 states and 2 provinces and an 84-mile, 500 kilovolt electric transmission line located in California.  In addition, the Company has one 53 MW biomass project under construction in Georgia and one approximate 300 MW wind project under construction in Oklahoma.  Atlantic Power also owns a majority interest in Rollcast Energy, a biomass power plant developer in Charlotte, NC.  Atlantic Power is incorporated in British Columbia, headquartered in Boston and has offices in Chicago, Toronto, Vancouver and San Diego.

The Company’s corporate strategy is to increase the value of the company through accretive acquisitions in North American markets while generating stable, contracted cash flows from its existing assets to sustain its dividend payout to shareholders.  The Company’s dividend is currently paid monthly at an annual rate of Cdn$1.15 per share.

Atlantic Power has a market capitalization of approximately $1.6 billion and trades on the New York Stock Exchange under the symbol AT and on the Toronto Stock Exchange under the symbol ATP.  For more information, please visit the Company’s website at www.atlanticpower.com or contact:

Atlantic Power Corporation 
Amanda Wagemaker, Investor Relations
(617) 977-2700 
info@atlanticpower.com

Copies of financial data and other publicly filed documents get filed on SEDAR at www.sedar.com or on EDGAR at www.sec.gov/edgar.shtml under “Atlantic Power Corporation” or on the Company’s website.

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Cautionary Note Regarding Forward-looking Statements

To the extent any statements made in this news release contain information that is not historical, these statements are forward-looking statements within the meaning of Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the U.S. Securities Exchange Act of 1934, as amended and under Canadian securities law (collectively, “forward-looking statements”).

Certain statements in this news release may constitute “forward-looking statements”, which reflect the expectations of management regarding the future growth, results of operations, performance and business prospects and opportunities of our Company and our projects.  These statements, which are based on certain assumptions and describe our future plans, strategies and expectations, can generally be identified by the use of the words “may,” “will,” “project,” “continue,” “believe,” “intend,” “anticipate,” “expect” or similar expressions that are predictions of or indicate future events or trends and which do not relate solely to present or historical matters.  Examples of such statements in this press release include, but are not limited, to statements with respect to the following:

·     The expectation that distributions from our projects will be in the range of $250 million to $265 million for the full year 2012;

·     The expectation that overall levels of operating cash flows in 2012 will be improved over actual 2011 levels;

·     The expectation that the payout ratio in 2012 will be approximately 90% to 97%;

·     The expectation that the PERH transaction will close in the second quarter of 2012;

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·     The expectation that Canadian Hills will achieve commercial operation by the fourth quarter of 2012;

·     The expectation that Canadian Hills will provide between $16 and $19 million in cash distributions for each full year through 2020, after which time the Company expects distributions to increase; and

·     The expectation that Path 15 will receive an order approving the settlement from FERC during the second quarter of 2012.

Forward-looking statements involve significant risks and uncertainties, should not be read as guarantees of future performance or results, and will not necessarily be accurate indications of whether or not or the times at or by which such performance or results will be achieved.  Please refer to the factors discussed under “Risk Factors” in the Company’s periodic reports as filed with the Securities and Exchange Commission from time to time for a detailed discussion of the risks and uncertainties affecting our Company.  Although the forward-looking statements contained in this news release are based upon what are believed to be reasonable assumptions, investors cannot be assured that actual results will be consistent with these forward-looking statements, and the differences may be material.  These forward-looking statements are made as of the date of this news release and, except as expressly required by applicable law, the Company assumes no obligation to update or revise them to reflect new events or circumstances.  The financial outlook information contained in this news release is presented to provide readers with guidance on the cash distributions expected to be received by the Company and to give readers a better understanding of the Company’s ability to pay its current level of distributions into the future.  Readers are cautioned that such information may not be appropriate for other purposes.

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Atlantic Power Corporation

Consolidated Balance Sheets (in thousands of U.S. dollars)

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Atlantic Power Corporation

Consolidated Statements of Operations (in thousands of U.S. dollars, except per share amounts)

(Unaudited)

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Atlantic Power Corporation

Consolidated Statements of Cash Flows (in thousands of U.S. dollars)

(Unaudited)

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Regulation G Disclosures

Cash Available for Distribution is not a measure recognized under U.S. generally accepted accounting principles (“GAAP”) and does not have a standardized meaning prescribed by GAAP.  Management believes Cash Available for Distribution is a relevant supplemental measure of the Company’s ability to earn and distribute cash returns to investors.  A reconciliation of Cash Flows from Operating Activities to Cash Available for Distributions is provided below.  Investors are cautioned that the Company may calculate this measure in a manner that is different from other companies.

Project Adjusted EBITDA is defined as project income plus interest, taxes, depreciation and amortization (including non-cash impairment charges) and changes in fair value of derivative instruments.  Project Adjusted EBITDA is not a measure recognized under GAAP and is therefore unlikely to be comparable to similar measures presented by other issuers and does not have a standardized meaning prescribed by GAAP.  Management uses Project Adjusted EBITDA at the Project-level to provide comparative information about project performance.  A reconciliation of Project Adjusted EBITDA to project income is provided on the following page. Investors are cautioned that the Company may calculate this measure in a manner that is different from other issuers.

Atlantic Power Corporation

Cash Available for Distribution

(In thousands of U.S. dollars, except as otherwise stated)

(Unaudited)

(1)               Cash Available for Distribution is not a recognized measure under GAAP and does not have any standardized meaning prescribed by GAAP. Therefore, this measure may not be comparable to similar measures presented by other companies. See “Supplementary Non-GAAP Financial Information” above.

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Atlantic Power Corporation

Project Adjusted EBITDA by Segment (in thousands of U.S. dollars)

(Unaudited)

Atlantic Power Corporation

Project Adjusted EBITDA by Project (those contributing more than $4,000) (in thousands of U.S. dollars)

(Unaudited)

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