Form Energy secures $450 million in funding for long duration ‘rust’ battery

Form Energy has raised US$450 million from investors including ArcellorMittal, bringing the multi-day battery startup’s total investment to date to US$800 million.

The tech company announced the successful Series E funding round yesterday, led by TPG Rise Climate, an impact investing platform for alternative asset manager TPG’s TPG Rise fund, which itself closed in April with US$7.3 billion to invest.

Form Energy is developing and commercialising a novel battery technology based on iron and air, with which it is targeting applications that require 100 hours of energy storage, possibly even more.

The basic principle behind it is the reversible oxidation, aka rusting, of iron as the battery discharges, while applying electrical current to it as it charges converts the rust back to iron, emitting only oxygen. That means it could enable renewable energy to be a direct replacement for fossil fuels on the grid, helping energy suppliers ride out quiet periods of wind and solar PV generation.

The company’s first pilot project was announced in 2020, with Form set to supply a 1MW battery system with up to 150 hours duration to Great River Energy, a Minnesota utility aiming to radically lower its dependence on coal. Discussions were also said to be underway with Georgia Power for a potential pilot with the southern US utility a few months ago too.

At the recent RE+ 2022 clean energy industry event in Anaheim, California, Form Energy senior business development manager Molly Bales appeared in a panel discussion on long-duration energy storage and its role in the market. Bales noted that while there will be a need for diverse storage technologies on the modern electricity grid, including shorter duration and diurnal (daily) storage playing roles to help balance the grid, Form Energy’s technology aims to answer a different value proposition around resiliency and reliability for utilities with a need for multi-day use cases.

Form’s Series E round was oversubscribed and follows a 2021 Series D round that raised US$240 million, US$40 million more than the company was aiming for. ArcellorMittal invested US$25 million into that Series D and followed up with a further US$17.5 million participation in the latest round.

Previous articleGM Defense selected to develop battery prototype for military use
Next articleInvinity Energy sells battery system to provide power in US