Long-duration energy storage
Non-lithium systems such as iron-air (100-hour), zinc batteries and compressed-air storage for multi-hour to multi-day shifting
3 leading companies in long-duration energy storage, one segment of energy storage — Battery cells and grid or behind-the-meter storage. 108 GW was added worldwide in 2025, up 40% on 2024 (IEA).
new market segment · researched 2026-11-14
Battery cellsUtility-scale battery storageLong-duration energy storageStorage system integrators & software
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Leading long-duration energy storage companies
3 companies, with the scale each source states. Scale is the whole company's unless the row says otherwise.
| Company | Where | What they do | Scale |
|---|---|---|---|
| Form Energy ↗ | Somerville, MA, United States since 2017 | Iron-air batteries that store electricity for 100 hours. Its plant is in Weirton, WV. Reported 2026 deals: Google, 30 GWh; Crusoe, 12 GWh. | — |
| Eos Energy Enterprises EOSE ↗ | Pittsburgh, PA, United States | Zinc-based battery storage systems for grid use; a non-lithium alternative | revenue: 114.2 USD millions (2025) ↗ |
| Hydrostor ↗ | Toronto, ON, Canada since 2010 | Compressed-air energy storage, a long-duration, non-battery technology. It has a facility in Goderich, ON. | — |
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The energy storage market
The whole market this segment sits in.
installed capacity (annual battery storage additions, utility-scale + behind-the-meter) · world108
↗GW · 2025
Growth, segments, risks and every company in energy storage →
Quick answers
- What is long-duration energy storage?
- Non-lithium systems such as iron-air (100-hour), zinc batteries and compressed-air storage for multi-hour to multi-day shifting. It is one segment of the energy storage market.
- Who are the leading long-duration energy storage companies?
- Form Energy (United States), Eos Energy Enterprises (United States), Hydrostor (Canada).
- Which long-duration energy storage companies are publicly traded?
- Eos Energy Enterprises (EOSE).
- Which Canadian companies are in long-duration energy storage?
- Hydrostor, Toronto, ON.
- How big is the energy storage market?
- For the whole energy storage market, not this segment alone: installed capacity (annual battery storage additions, utility-scale + behind-the-meter) (world) 108 GW, 2025 — International Energy Agency.