Medium Duration Storage Endures Woes, While Form’s Long Duration Grows, and Lithium Overflows

Why It Matters

Form Energy’s scaling demonstrates that multi‑day storage can become commercially viable, potentially reshaping grid decarbonization, while the cash woes of EOS and ESS signal heightened risk for medium‑duration non‑lithium technologies amid falling lithium costs.

Key Takeaways

• Form Energy secured a 300 MW/30 GWh iron‑air battery for Google
• Project valued near $1 billion, implying ~$33/kWh before credits
• EOS and ESS face cash shortages and minimal 2025 revenue
• Lithium storage prices dropping below $80/kWh challenge non‑lithium players

Pulse Analysis

The long‑duration storage market is at a crossroads as lithium‑ion solutions continue to undercut traditional iron‑based systems. While four‑hour batteries average just under $80/kWh globally, aggressive cost reductions and new tax incentives are driving lithium prices even lower, threatening the niche occupied by medium‑duration manufacturers. This price pressure forces companies like EOS and ESS to reevaluate product roadmaps and seek fresh capital, highlighting the volatility of the non‑lithium segment.

Form Energy’s recent partnership with Google to deploy a 300 MW/30 GWh iron‑air battery in Minnesota illustrates a different trajectory. Valued at roughly $1 billion, the deal translates to an estimated $33/kWh before accounting for the Inflation Reduction Act’s 45 $/kWh storage tax credit and other incentives, effectively lowering the delivered cost. The project consumes 60% of Form’s West Virginia plant capacity, accelerating its plan to reach 500 MW annual output by 2028 and positioning the firm to meet its long‑term $20/kWh ambition if economies of scale materialize.

Conversely, EOS and ESS are grappling with liquidity constraints that limit their ability to compete. ESS posted a $63.4 million loss in 2025 with only $1.6 million in revenue, prompting a $15 million cash raise after its bank balance fell to $1 million. EOS, while slightly better funded, still missed revenue targets. Their struggles underscore the broader market reality: without significant cost breakthroughs or policy support, medium‑duration, non‑lithium storage faces an uphill battle against increasingly affordable lithium alternatives. Investors and utilities must weigh the trade‑offs between emerging multi‑day technologies and the proven, price‑competitive lithium options that dominate today’s storage deployments.