Soluna Holdings, Inc

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and

Stockholders of Soluna Holdings, Inc. and Subsidiaries

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Soluna Holdings, Inc. and Subsidiaries (the Company) as of December 31, 2025 and 2024, and the related consolidated statements of operations, changes in equity, and cash flows for each of the years in the two-year period ended December 31, 2025, and the related notes (collectively referred to as the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the years in the two-year period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. 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 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 consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting, but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits 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 audits 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 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 consolidated 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 consolidated 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 consolidated 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.

Fair value of Warrants

Description of the Matter

As discussed in Note 12 to the consolidated financial statements, the Company had a total of approximately 30.6 million common stock warrant shares outstanding as of December 31, 2025. The Company uses option pricing models to estimate the fair value of the warrants using various market-based inputs.

We identified the fair value measurement of the warrants as a critical audit matter. Specifically, there was a high degree of subjectivity and judgment in evaluating the determination of the expected volatility inputs used in the option pricing models for the warrants. Historical, implied, and peer group volatility levels provide a range of possible expected volatility inputs and the fair value estimates for the warrants are sensitive to the expected volatility inputs.

How We Addressed the Matter in Our Audit

The primary procedures we performed to address this critical audit matter included gaining an understanding of certain internal controls over the Company’s process to measure the fair value of the warrants. This included understanding of controls related to the evaluation of observable market information used in the determination of the expected volatility inputs. We didn't test the operating effectiveness of these controls. We obtained and evaluated the underlying warrant agreements and traced the inputs into the fair value calculation. We also involved our firm’s valuation professionals with specialized skills and knowledge, who assisted in:

•evaluating the expected volatility inputs by comparing them against our separately derived shadow calculation of volatility; and

•developing a shadow calculation of value of the warrants using our separately derived volatility and comparing it to the value calculated by the Company.

Going Concern Assessment

Description of the Matter

As discussed in Note 1 to the consolidated financial statements, the Company incurred recurring operating losses, had negative cash flows from operations, and has significant outstanding debt and commitments for capital expenditures. These conditions raised substantial doubt about the Company’s ability to continue as a going concern within one year after the issuance of the consolidated financial statements.

Management evaluated these conditions and developed plans to alleviate the substantial doubt, including securing additional debt and equity financing and, if necessary, implementing cost reduction initiatives.

We identified the evaluation of the Company’s ability to continue as a going concern as a critical audit matter due to the significant judgment involved in assessing the feasibility and sufficiency of management’s plans, particularly regarding projected cash flows and access to financing.

How We Addressed the Matter in Our Audit

Our audit procedures related to this matter included, among others:

•Evaluating management's going concern assessment in accordance with relevant accounting standards.

•Assessing the reasonableness of key assumptions used in cash flow forecasts including timing of projected debt and equity financing, revenue projections, margins and timing of expenditures.

•Inspecting agreements related to new financing arrangements.

•Testing the mathematical accuracy of the forecast model.

•Assessing the Company's historical accuracy in forecasting results.

•Evaluating whether management's plans, including additional financing, were probable of being effectively implemented.

/s/UHY LLP

We have served as the Company’s auditor since 2021.

Albany, New York

March 27, 2026