Exhibit 99.3

Unaudited Pro Forma Combined Financial Statements

The Unaudited Pro Forma Combined Financial Statements, or the pro forma financial statements, combine the historical consolidated financial statements of Pattern Energy Group Inc. (“Pattern Energy”) and the statements of Lost Creek Wind Finco, LLC (“Lost Creek Finco”) and Lincoln County Wind Project Holdco, LLC (“Lincoln County Holdco”), to illustrate the effect of the acquisition of such entities (the “Acquisition”) and the acquisition of the Class A Shares of Lost Creek Finco, which will be purchased for $35 million pursuant to a purchase agreement (the “Lost Creek Tax Equity Buyout”). The pro forma financial statements were based on, and should be read in conjunction with, the:

The historical audited consolidated statements of operations of Lost Creek Finco and its subsidiaries and Lincoln County Holdco and its subsidiary for the year ended March 31, 2015 have been combined with Pattern Energy’s audited consolidated statement of operations for the year ended December 31, 2014 in the Unaudited Pro Forma Combined Statement of Operations.

The historical consolidated financial statements have been adjusted in the pro forma financial statements to give effect to pro forma events that are (1) directly attributable to the Acquisition, including the Lost Creek Tax Equity Buyout, (2) factually supportable and (3) with respect to the pro forma statements of operations, expected to have a continuing impact on the combined results. The Unaudited Pro Forma Combined Statements of Operations, for the year ended December 31, 2014 and for the three months ended March 31, 2015, give effect to the Acquisition as if it occurred on January 1, 2014. The Unaudited Pro Forma Combined Balance Sheet, as of March 31, 2015, gives effect to the Acquisition as if it occurred on March 31, 2015.

As described in the accompanying notes, the pro forma financial statements have been prepared using the acquisition method of accounting under U.S. GAAP and the regulations of the Securities and Exchange Commission. The purchase price for the Acquisition is allocated to the assets acquired and liabilities assumed based upon their estimated fair values as of the date of the Acquisition. The initial accounting for the Acquisition is not complete because the evaluation necessary to assess the fair values of certain net assets acquired is still in process. The provisional amounts are subject to revision until the evaluations are completed to the extent that additional information is obtained about the facts and circumstances that existed as of the Acquisition date. Accordingly, the pro forma purchase price adjustments are preliminary, subject to future adjustments, and have been made solely for the purpose of providing the pro forma financial statements presented herewith. Differences between these preliminary estimates and the final acquisition accounting may occur and these differences could have a material impact on the accompanying pro forma financial statements and Pattern Energy’s future results of operations and financial position.

The pro forma financial statements have been presented for informational purposes only and are not necessarily indicative of what the combined company’s results of operations and financial position would have been had the Acquisition been completed on the dates indicated. Pattern Energy could incur significant costs to integrate the business. The pro forma financial statements do not reflect the cost of any integration activities or benefits that may result from synergies that may be derived from any integration activities. In addition, the pro forma financial statements do not purport to project the future results of operations or financial position of the combined company.

Unaudited Pro Forma Combined Statement of Operations

For the Three Months Ended March 31, 2015

Unaudited Pro Forma Combined Statement of Operations

For the Twelve Months Ended December 31, 2014

Unaudited Pro Forma Combined Balance Sheet

As of March 31, 2015

Notes to the Unaudited Pro Forma Combined Financial Statements

Note 1. Pro Forma Adjustments

(a) Represents an adjustment to reflect $67.0 million cash utilized to fund a portion of the Acquisition purchase price for the Class B Shares of Lost Creek Finco and Lincoln County Holdco, the remainder of the purchase price was funded through the use of a $175.0 million draw on an existing Pattern Energy revolving credit agreement, described in note (g). Additionally, represents an adjustment to reflect $35.0 million cash utilized to fund the entire acquisition purchase price for the Lost Creek Tax Equity Buyout.

(b) Represents an adjustment to reflect property, plant and equipment at its estimated fair value, excluding the fair value of the acquired power purchase agreements (“PPAs”), on the date of the Acquisition. The estimated fair value was determined using an income approach. The estimate is preliminary, subject to change and could vary materially from the actual adjustment at the date of the Acquisition. The fair value adjustment to property, plant and equipment, has resulted in an increase of approximately $7.6 million in annual depreciation expense, primarily to conform with Pattern Energy’s accounting policy which uses a shorter depreciable life, as compared to WCG’s accounting policy. Refer to Note (p).

(c) Represents an adjustment to remove unamortized deferred financing fees of the acquired entities as the debt was revalued under acquisition accounting.

(d) Represents an adjustment to reflect the Lincoln County Holdco deferred transmission upgrade refund at its estimated fair value on the date of the Acquisition. The estimate is preliminary, subject to change and could vary materially from the actual adjustment at the date of the Acquisition.

(e) Represents an adjustment to record the intangible asset and liability value associated with the acquired power purchase agreements (“PPAs”). The estimated fair value was determined using an income approach. The estimated remaining terms of the PPAs range from 15 to 17 years. The fair value adjustment to intangible assets and liabilities has resulted in an increase in annual amortization expense of approximately $3.0 million. Refer to Note (o).

(f) Represents an adjustment to remove the current portion of the financial liability representing the Class A Shares of Lost Creek Finco. Additionally, represents an adjustment to remove the carrying value of the Lincoln County Holdco derivatives which were not assumed in the Acquisition.

(g) Represents an adjustment to reflect $175.0 million draw on an existing Pattern Energy revolving credit agreement utilized to fund a portion of the Acquisition purchase price for the Class B Shares of Lost Creek Finco and Lincoln County Holdco. Adjustments were made in the Pro Forma Statement of Operations to reflect the estimated increase in interest expense related to these borrowings.

(h) Represents an adjustment to remove the Lincoln County Holdco project debt which was not assumed in the Acquisition. Additionally, represents the fair value adjustment to Lost Creek Finco’s long-term debt based on preliminary estimates of fair value based on market rates for similar project-level debt.

(i) Represents an adjustment to remove the Lost Creek Finco unamortized deferred income related to 1603 Government Grant received in June, 2010. In a business combination, the acquirer recognizes a liability related to deferred revenue only to the extent that the deferred revenue represents a legal performance obligation assumed by the acquirer.

(j) Represents an adjustment to reflect the Lost Creek Tax Equity Buyout. Additionally, represents the adjustment to reclassify Lost Creek Finco’s asset retirement obligation liability to be consistent with Lincoln County Holdco and Pattern Energy.

(k) Represents an adjustment to reflect asset retirement obligation liabilities at their estimated fair value on the date of the Acquisition. The estimate is preliminary, subject to change and could vary materially from the actual adjustment at the date of the Acquisition.

Notes to the Unaudited Pro Forma Combined Financial Statements

(l) Represents an adjustment to remove the carrying value of the Lincoln County Holdco derivatives and accrued interest related to debt which were not assumed in the Acquisition.

(m) Represents an adjustment to remove Lost Creek Finco and Lincoln County Holdco member’s equity.

(n) Represents an adjustment to reflect Lincoln County Holdco’s noncontrolling interest at its estimated fair value on the date of the Acquisition.

(o) Represents additional amortization expense resulting from the intangible asset and liability value associated with the acquired PPAs. The remaining terms of the PPAs range from 15 to 17 years. The estimated fair value for intangible assets and liabilities are preliminary, subject to change and could vary materially from the actual adjustment on the date of the Acquisition.

(p) Represents the increase in accretion expense resulting from the revaluation of the asset retirement obligations and the increase in depreciation expense resulting from the fair value adjustment to property, plant and equipment, has resulted in an increase of approximately $7.6 million in annual depreciation expense, primarily to conform with Pattern Energy’s accounting policy which uses a shorter depreciable life, as compared to WCG’s accounting policy.

(q) Represents an adjustment to remove amortization expense of Lost Creek Finco’s deferred income related to 1603 Government Grant received in June, 2010.

(r) Represents an adjustment to remove interest expense related to Lincoln County Holdco’s project debt which was not assumed in the Acquisition. Additionally, represents the adjustment to remove amortization expense of Lost Creek Finco’s and Lincoln County Holdco’s deferred financing fees, the adjustment to increase interest expense related to the debt incurred to finance the Acquisition, an increase of interest expense related to purchase accounting fair value adjustments for the Lost Creek Finco debt assumed, the adjustment to reflect losses on derivatives that were deemed not to meet the effectiveness requirements under business combination re-assessment per ASC 815 and the adjustment to remove interest accretion expense related to the financial liability representing the Class A Shares of Lost Creek Finco, which will be purchased for $35.0 million pursuant to a purchase agreement.

(s) Represents an adjustment to remove the tax benefits allocated to the carrying value of the financial liability representing the Class A Shares of Lost Creek Finco, which will be purchased for $35.0 million pursuant to a purchase agreement.

(t) Pro forma Income tax provision (benefit) represents management’s assumption that pro forma net deferred tax assets would have been fully offset by a valuation allowance and thus no pro forma adjustments to Income tax provision (benefit) would result from the Acquisition.

(u) Represents an adjustment to remove the non-recurring transaction costs directly related to the Acquisition reflected in the historical financial statements of Pattern Energy.

Notes to the Unaudited Pro Forma Combined Financial Statements

Note 2. Basis of Pro Forma Presentation

The Unaudited Pro Forma Combined Statements of Operations, for the year ended December 31, 2014 and for the three months ended March 31, 2015, give effect to the Acquisition as if it occurred on January 1, 2014. The Unaudited Pro Forma Combined Balance Sheet, as of March 31, 2015, gives effect to the Acquisition as if it occurred on March 31, 2015.

The pro forma financial statements have been derived from the historical financial statements of Pattern Energy, Lost Creek Finco and Lincoln County Holdco that are included elsewhere in this filing. Assumptions and estimates underlying the pro forma adjustments are described in the accompanying notes, which should be read in connection with the pro forma financial statements.

The pro forma financial statements were prepared using the acquisition method of accounting under U.S. GAAP. Acquisition accounting requires, among other things, that most assets acquired and liabilities assumed be recognized at fair value as of the acquisition date. Because acquisition accounting is dependent upon certain valuations and other studies that must be completed subsequent to the Acquisition date, there is not currently sufficient information for a definitive measurement. Therefore, the pro forma financial statements are preliminary and have been prepared solely for the purpose of providing unaudited pro forma financial information. Differences between these preliminary estimates and the final acquisition accounting will occur and these differences could have a material impact on the accompanying pro forma financial statements and Pattern Energy’s combined future results of operations and financial position. The Acquisition is reflected in the pro forma financial statements as being accounted for based on the accounting guidance for business combinations. Under the acquisition method, the total estimated purchase price is calculated as described in Note 3 to the pro forma financial statements. In accordance with accounting guidance for business combinations, the assets acquired and the liabilities assumed have been measured at fair value. The fair value measurements use estimates based on key assumptions of the Acquisition, including prior acquisition experience, benchmarking of similar acquisitions and historical and current market data. The pro forma adjustments included herein may be revised as additional information becomes available and as additional analyses are performed. The final purchase price allocation will be determined after the Acquisition is completed and the final amounts recorded for the Acquisition may differ materially from the information presented in these pro forma financial statements.

The Unaudited Pro Forma Combined Financial Statements do not reflect any cost savings from operating efficiencies or synergies that could result from the Acquisition.

For the purpose of measuring the estimated fair value of the assets acquired and liabilities assumed, as reflected in the pro forma financial statements, we have applied the accounting guidance for fair value measurements, which defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

Note 3. Preliminary Purchase Price Allocation

The allocation of the preliminary purchase price to the fair values of assets acquired and liabilities assumed includes pro forma adjustments to reflect the fair values of Lost Creek Finco’s and Lincoln County Holdco’s assets and liabilities, and the Lost Creek Tax Equity Buyout, at the Acquisition date. The final allocation of the purchase price could differ materially from the preliminary allocation used for the Unaudited Pro Forma Combined Balance Sheet primarily because power market prices, interest rates and other valuation variables will fluctuate over time and be different at the time of completion of the Acquisition compared to the amounts assumed in the pro forma adjustments. The following is a summary of the fair value of net assets acquired: