PLUG POWER INC

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the stockholders and the Board of Directors of Plug Power Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Plug Power Inc. and subsidiaries (the “Company”) as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive loss, stockholders’ equity, and cash flows, for each of the two years in the period ended December 31, 2023, and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022 and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 29, 2024 expressed an adverse opinion on the Company’s internal control over financial reporting because of material weaknesses.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters

The critical audit matters communicated below are matters arising from the current-period audit of the financial statements that were communicated or required to be communicated to the audit committee and that (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

Inventories – Reserves – Refer to Notes 2 and 7 to the financial statements

The Company establishes inventory reserves against excess, obsolete, and damaged goods and records its inventory at the lower of cost or net realizable value. As a part of this process, the Company reviews all contracts related to product lines with projected negative margins that are expected to be sold at a loss in the future, which serves as the basis for the lower of cost or net realizable value adjustment. The Company’s estimate of the reserves utilizes certain inputs and involves judgment. The Company evaluates excess and obsolescence and lower of cost or net realizable value inventory reserves on a quarterly basis and, as necessary, reserves inventory based upon a variety of factors, including historical usage, forecasted usage and sales, product obsolescence, anticipated selling price, and anticipated cost to complete to determine product margin and other factors. Reserve balances are included within inventory, net, on the balance sheet. The reserve for excess and obsolete inventory and lower of cost or net realizable value as of December 31, 2023, was $85.2 million.

We identified the inventory reserves as a critical audit matter because of judgments made by management in determining the reserves. Evaluating the reasonableness of the Company’s reserves required a high degree of auditor judgment and an increased extent of audit effort.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to inventory reserves included the following, among others:

Loss accrual for service contracts — Refer to Note 2 of the financial statements

The Company records an accrual for loss contracts if the sum of expected costs of providing maintenance services for fuel cell systems and related infrastructure exceeds the related unearned net revenues over the remaining contract term. The Company recorded an accrual for loss contracts of $137.9 million as of December 31, 2023. Maintenance costs are estimated in determining the accrual for loss contracts based upon current service cost levels.

We identified the evaluation of maintenance cost projections in the accrual for loss contracts related to service as a critical audit matter. A high degree of auditor judgment was required to evaluate the expected remaining service costs required to fulfill the related customer maintenance contracts. Changes in the expected costs of providing maintenance services could have had a significant effect on the amount of the recorded accrual for loss contracts.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related toLoss Accrual for Service Contracts included the following, among others:

/s/ Deloitte & Touche LLP

Rochester, NY

February 29, 2024

We have served as the Company’s auditor since 2022.

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors

Plug Power Inc.:

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated statement of operations, comprehensive loss, stockholders’ equity, and cash flows of Plug Power Inc. and subsidiaries (the Company) for the year ended December 31, 2021, and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the results of its operations and its cash flows for the year ended December 31, 2021, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated financial statements based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. Our audit included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audit provides a reasonable basis for our opinion.

/s/ KPMG LLP

We served as the Company’s auditor from 2001 to 2022.

Albany, New York

March 1, 2022