Eos Energy Enterprises vs. Plug Power: Which Energy Storage Pioneer Is a Better Buy in 2026?

As the global transition toward renewable energy accelerates, the race to capture market share in storage and delivery is intensifying. Deciding between Eos Energy Enterprises (NASDAQ:EOSE) and Plug Power (NASDAQ:PLUG) is a choice between two distinct technologies.

Eos Energy Enterprises specializes in zinc-based long-duration battery systems designed for utility and industrial applications. Plug Power focuses on building an end-to-end green hydrogen ecosystem, from fuel production to powering heavy machinery. Both companies are scaling rapidly but face different financial hurdles as they attempt to reach long-term profitability in the clean energy market.

The case for Eos Energy Enterprises

Eos Energy Enterprises designs zinc-based battery systems and is carving out a niche within industrial stocks. In its latest annual report, the company noted that two customers accounted for nearly 52% and 19% of revenue. Customer concentration like this adds a layer of risk to the business, though it highlights the scale of its current utility-level partnerships.

In FY 2025, revenue reached about $114.2 million, representing a roughly 632% increase over the previous year. The company reported a net loss of approximately $970 million for the period. This performance follows a net loss of nearly $686 million in fiscal 2024 as the company continues to invest heavily in its manufacturing capabilities.

As of its December 2025 balance sheet, the debt-to-equity ratio is approximately negative 1.0x, indicating total liabilities exceed shareholder equity. The current ratio, which measures the ability to pay short-term obligations with short-term assets, is nearly 4.9x. Free cash flow, which is cash from operations minus capital expenditures, was roughly negative $265.0 million in FY 2025.

The case for Plug Power

Plug Power builds an integrated green hydrogen ecosystem, deploying over 74,000 fuel cell systems globally. In its latest annual report, the company disclosed that Walmart Inc. (NASDAQ:WMT) was its largest customer, representing approximately a quarter of revenue. Such high customer concentration adds a layer of risk to the enterprise as it navigates the high costs of hydrogen infrastructure.

In FY 2025, revenue reached about $709.9 million, which is a roughly 13% increase from the prior year. The company recorded a net loss of approximately $1.6 billion for the same period. This trend follows a net loss of roughly $2.1 billion in fiscal 2024, showing a slight narrowing of losses even as the top line remains volatile.

As of its December 2025 balance sheet, the debt-to-equity ratio is approximately 1.0x, meaning total debt is roughly equal to shareholder equity. The current ratio is close to 2.3x. Free cash flow was approximately negative $662 million during FY 2025, reflecting the massive capital intensity required to build and operate hydrogen production facilities.

Risk profile comparison

Eos Energy Enterprises faces significant legal challenges from securities fraud class action lawsuits filed in 2026. These suits allege the company made misleading disclosures about its production ramp-up and quality issues at its Turtle Creek facility. The business also contends with competition from larger energy storage providers like Fluence Energy (NASDAQ:FLNC) and remains sensitive to changes in government subsidies.

Plug Power is currently defending against multiple federal securities fraud lawsuits regarding its financial performance and Department of Energy loan status. The company suspended activities related to that loan program in November 2025, creating uncertainty about its path to low-cost capital. It also faces intense competition from established giants like GE Vernova (NYSE:GEV) while managing a complex supply chain for materials like iridium.

Valuation comparison

Eos Energy Enterprises is cheaper based on Forward P/E and earnings estimates, whereas Plug Power has a lower P/S ratio using sales over the past twelve months.

Valuation metrics include sourcing from Financial Modeling Prep (FMP) and may differ from other data providers.

Which stock would I buy in 2026?

The current fiscal year, 2026, looks to be a major step forward for Eos Energy Enterprises. The business has already sold more products through the first half of the year than it did in all of 2025, shipping $126 million of gear to clients.

The longer term should be much greater, too. Management says it has nearly $25 billion of business pipeline, meaning proposed energy storage developments Eos could bid on, and an $807 million backlog, which are firm orders for the company's products. 2026 revenue is expected to more than double.

Recently, Eos scored a high-profile deal to support the PJM grid after joining with Alphabet Inc (NASDAQ:GOOG) and MN8 Energy on a solar energy storage project in West Virginia.

Similarly, Plug Power's fuel cells run on clean-burning hydrogen, though creating hydrogen is often done in a process fueled by natural gas. Still, Plug Power sits firmly in the renewable energy niche, benefiting from many countries' moves toward green (non-fossil-fuel-derived) hydrogen. It is also benefiting from the datacenter boom and from restored tax credits that make its systems more affordable to deploy.

For fiscal 2026, revenue growth is pretty good, with Wall Street analyst consensus predicting a nearly 15% increase to $812 million. The net loss is seen narrowing to about $580 million.

Both businesses offer investors a way to play the rise in demand for power storage brought about by AI data center demand and the need for storage for renewable energy production. Eos, with its lower forward P/E and similar P/S ratio, seems to be the better bet for long-term investors.

Brendan Coffey has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Alphabet, Fluence Energy, GE Aerospace, GE Vernova, and Walmart. The Motley Fool has a disclosure policy.