One-Quarter of Listed BESS Manufacturers Fall Into Financial Distress zone in Sinovoltaics Ranking

Lausanne, Switzerland – May 26, 2026 – Financial performance across the BESS sector is increasingly diverging by business model according to the second edition of the Energy Storage Manufacturer Ranking report released by Sinovoltaics. Diversified electrical-infrastructure groups are strengthening, while independent storage and long-duration specialists are sliding toward financial distress, with nearly one in four publicly listed manufacturers now in the distress zone.

The report tracks the Altman Z-Score, a widely used indicator of financial distress risk, which classifies companies as Green (2.6 or above), Grey (1.1 to below 2.6), or Red (below 1.1). As of March 2026, the 63 listed companies are split across the three tiers: 26 in the safe zone, 21 in the grey zone, and 16 in the distress zone.

The result appears more closely linked to business model than to geography or company size. The strongest performers are diversified electrical and grid-infrastructure groups, likely benefiting from grid expansion and rising power demand from data centers. Hyundai Electric posted the sharpest gain, lifting its Z-Score from 1.83 to 9.02; ABB, Eaton, Delta Electronics, GE Vernova, and a recovering Siemens Energy also moved higher. For these firms, storage is only one part of a broad electrification portfolio, giving them more stability than companies focused mainly on storage.

Financial pressure is concentrated in two areas. Solar-linked inverter specialists declined significantly, with Hoymiles falling from 25.17 to 3.59, SolarEdge from 6.25 to 0.18, and Enphase from 7.64 to 3.02, in line with the post-2022 slowdown in rooftop solar demand. Financial pressure is even more severe among pure-play and long-duration energy storage (LDES) developers. ESS Tech (iron flow) recorded a Z-Score of minus 26.22, Eos Energy (zinc-bromine) minus 5.90, and Stem minus 4.41, while Microvast, CBAK, and Invinity also reported negative scores. Powin has filed for Chapter 11 (the US bankruptcy process that lets a company keep operating while it restructures its debts), and NHOA Energy is delisting.

Two caveats matter for interpretation. The Altman Z-Score was designed for established manufacturers and can fluctuate significantly for asset-light or pre-scale technology firms, so the LDES figures are best read as directional rather than as precise forecasts; Eos Energy, for instance, ranged from above 17 to below minus 20 within the period. Several scores also reflect a parent company rather than its storage division, including Saft (TotalEnergies), Sonnen (Shell), and Faradion (Reliance Industries).

"The key issue for buyers is not just whether some pure-play BESS companies are under financial pressure, but what that means for long-term warranty support," said Arthur Claire, Director of Technology. "A 15-year performance warranty is only as credible as the balance sheet behind it. Developers and lenders should treat manufacturer financial health as a core part of supplier due diligence. If current trends continue, further consolidation among independent storage companies appears likely over the next 12 to 18 months."

Edition 2 also reflects a substantial methodology revision. Twenty-two companies were removed from the first edition because they are not BESS manufacturers, a group spanning lithium miners, battery-production equipment makers, automakers without a shipping storage product, and consumer-battery firms. The revised edition features 63 companies and 11 privately held manufacturers. Several of these, such as Huawei Digital Power, Hithium, Envision AESC, and REPT Battero, command significant market share in BESS manufacturing, but because they are privately held, they do not publish the financial data needed to calculate an Altman Z-Score. China and Hong Kong S.A.R. account for 31 of the listed names and most of the private group, highlighting how much of the global BESS supply chain is now concentrated in privately held Chinese manufacturers. Tesla remains the top-ranked manufacturer, although its trend indicator points down.

The Altman Z-score is a financial model that combines profitability, leverage, liquidity, solvency and activity ratios into a single composite indicator of financial health. A score above 2.6 is considered safe, a score between 1.1 and 2.6 is classified as grey, and a score below 1.1 is associated with elevated bankruptcy risk over the following two years. Scores below zero indicate severe financial distress.

The full report is available on Sinovoltaics’ website and is intended for use by project developers, EPC contractors, investors, financiers and procurement professionals evaluating supplier bankability and long-duration warranty risk in BESS projects. Sinovoltaics’PV Module Manufacturer and PV Inverter Manufacturer Ranking Reports are also available on the company’s website.

About Sinovoltaics
Since 2010, Sinovoltaics, a Dutch-German Battery Energy Storage (BESS) and solar photovoltaic (PV) technical compliance and quality assurance service firm, has been a pioneer in the BESS and solar photovoltaic industries. With innovative software solutions such as SELMA® (Sinovoltaics EL Mass Analysis) software, and BESSential (100% Battery Pack Analysis), Sinovoltaics’ mission is to eliminate all photovoltaic and BESS product defects, enabling investors and the world to succeed with minimal investment risks.    

Sinovoltaics’ services include quality assurance inspections, factory audits, Environmental, Social, and Governance (ESG) reporting, and traceability audits for utility-scale solar and BESS developers and investors. The company maintains a global presence with offices in Switzerland, the United States, Hong Kong, Mainland China and Vietnam, as well as factory inspection and audit teams strategically located in China, Vietnam, Türkiye, Thailand, India and other key manufacturing bases.

Media Contact
Rasa Jakaitis
Media Manager
rasa@sinovoltaics.com
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Lithuania

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