# Metal-air batteries: Impact and additionality

Could week-long batteries finally retire backup gas plants?

Source page: https://www.materialinsights.org/energy/e_metal_air/sg-impact/

What this tab covers The impact and additionality lens: what it displaces on the grid, who gains and who bears the burden along the supply chain, and what happens at end of life.

Multi-day iron-air storage is one of the few battery options aimed at replacing gas plants kept for rare low-renewable weeks. It is still pre-commercial at utility scale, and India's interest lies mainly in aluminium-air.

#### Grid decarbonisation versus fossil displacement
Favourable

Lithium-ion shifts solar by a few hours; a 100-hour store can cover multi-day weather events, the role now played by gas peakers and coal reserves. That makes iron-air potentially high-additionality, but only once systems run at scale. The first utility system, 1.5 MW / 150 MWh at Great River Energy's Cambridge, Minnesota, peaking plant, was originally due by end 2025; in Oct 2026 MIT Technology Review put it at 2027. The Georgia Power project was agreed in 2023 at 15 MW / 1,500 MWh, when Form said it could come online as early as 2026; no start of operation had been reported by late 2026.^[1](https://www.technologyreview.com/2026/10/06/1145020/2026-climate-tech-companies-to-watch-form-energy-iron-batteries/amp/)^[2](https://www.energy-storage.news/100-hour-ldes-battery-technologies-from-form-noon-and-ore-how-do-they-compare/)^[3](https://www.energy-storage.news/form-energy-signs-definitive-agreement-for-100-hour-iron-air-bess-with-georgia-power/)^[15](https://greatriverenergy.com/what-we-do/cambridge-energy-storage-project)
 Great River Energy system 1.5 MW / 150 MWh; target slipped from end 2025 to 2027^[1](https://www.technologyreview.com/2026/10/06/1145020/2026-climate-tech-companies-to-watch-form-energy-iron-batteries/amp/)^[15](https://greatriverenergy.com/what-we-do/cambridge-energy-storage-project) Georgia Power project 15 MW / 1,500 MWh^[3](https://www.energy-storage.news/form-energy-signs-definitive-agreement-for-100-hour-iron-air-bess-with-georgia-power/) Duration versus lithium-ion 100 h vs about 8-12 h nameplate^[2](https://www.energy-storage.news/100-hour-ldes-battery-technologies-from-form-noon-and-ore-how-do-they-compare/)

#### Just transition and local community impact
Mixed

Form's factory is on the former Weirton Steel site in West Virginia, a coal and steel state, with 2 GWh a year of capacity. In India, IOC Phinergy (Indian Oil and Phinergy of Israel) has been preparing aluminium-air manufacturing, with Hindalco agreeing to make aluminium plates and recycle used aluminium, a model framed around cutting battery imports. Aluminium smelting is energy-intensive, so the carbon benefit depends on the power used in smelting and recycling.^[1](https://www.technologyreview.com/2026/10/06/1145020/2026-climate-tech-companies-to-watch-form-energy-iron-batteries/amp/)^[6](https://autocarpro.in/news/indian-oils-aluminium-air-battery-manufacturing-jv-readies-itself-for-manufacturing-rollout--113826)^[7](https://www.hindalco.com/media/press-releases/hindalco-phinergy-and-iop-partner-revolutionary-aluminium-air-batteries-evs-and-energy-storage)^[16](https://www.energy-storage.news/iron-air-us-ldes-startup-form-energy-secures-us750-million-series-g-financing/)
 Form factory capacity 2 GWh a year^[1](https://www.technologyreview.com/2026/10/06/1145020/2026-climate-tech-companies-to-watch-form-energy-iron-batteries/amp/)

#### Circular economy and end of life
Favourable

Iron and steel are among the most recycled materials, and Form says its batteries are designed with abundant and recyclable raw materials. Aluminium-air depends on recycling by design: used aluminium goes back to the smelter to make new plates, which Hindalco has agreed to do in India. Zinc-air button cells are a small but dispersed waste stream covered by EU portable battery collection rules.^[3](https://www.energy-storage.news/form-energy-signs-definitive-agreement-for-100-hour-iron-air-bess-with-georgia-power/)^[6](https://autocarpro.in/news/indian-oils-aluminium-air-battery-manufacturing-jv-readies-itself-for-manufacturing-rollout--113826)^[7](https://www.hindalco.com/media/press-releases/hindalco-phinergy-and-iop-partner-revolutionary-aluminium-air-batteries-evs-and-energy-storage)

#### Sources

1. [15 Climate Tech Companies to Watch 2026: Form Energy (6 Oct 2026)](https://www.technologyreview.com/2026/10/06/1145020/2026-climate-tech-companies-to-watch-form-energy-iron-batteries/amp/) MIT Technology Review, 2026
2. [100-hour LDES battery technologies from Form, Noon and Ore: how do they compare? (cites Form presentations and a LinkedIn commentator)](https://www.energy-storage.news/100-hour-ldes-battery-technologies-from-form-noon-and-ore-how-do-they-compare/) Energy-Storage.news, 2025
3. [Form Energy signs definitive agreement for 100-hour iron-air BESS with Georgia Power](https://www.energy-storage.news/form-energy-signs-definitive-agreement-for-100-hour-iron-air-bess-with-georgia-power/) Energy-Storage.news, 2023
4. [Indian Oil's aluminium-air battery manufacturing JV readies itself for manufacturing rollout](https://autocarpro.in/news/indian-oils-aluminium-air-battery-manufacturing-jv-readies-itself-for-manufacturing-rollout--113826) Autocar Professional, 2023
5. [Hindalco, Phinergy and IOP partner on revolutionary aluminium-air batteries for EVs and energy storage (press release, 18 Jul 2022)](https://www.hindalco.com/media/press-releases/hindalco-phinergy-and-iop-partner-revolutionary-aluminium-air-batteries-evs-and-energy-storage) Hindalco Industries, 2022
6. [Cambridge Energy Storage Project (project page)](https://greatriverenergy.com/what-we-do/cambridge-energy-storage-project) Great River Energy, 2025
7. [Iron-air US LDES startup Form Energy secures US$750 million Series G financing (Aug 2026)](https://www.energy-storage.news/iron-air-us-ldes-startup-form-energy-secures-us750-million-series-g-financing/) Energy-Storage.news, 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_metal_air/index.md)
- [Overview](https://www.materialinsights.org/energy/e_metal_air/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_metal_air/correlation/index.md)
- [Science and technology](https://www.materialinsights.org/energy/e_metal_air/sg-sci/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_metal_air/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_metal_air/sg-econ/index.md)
- [What to track](https://www.materialinsights.org/energy/e_metal_air/tracking/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_metal_air/links/index.md)