What happened?

Energy technology startup Form Energy has closed a $750 million Series G round. The round was led by T. Rowe Price, and the valuation of the company, founded in 2017, passed $2 billion.

The investor list is crowded: Sequoia Capital, Janus Henderson, Franklin Templeton, PEAK6 Investments, Prelude Ventures, Engine Ventures, TPG Rise Climate, Capricorn's Technology Impact Funds, Breakthrough Energy Ventures, Dustin Moskovitz and Cari Tuna, Gigascale Capital, Coatue, Energy Impact Partners, NGP, GE Vernova, Blindspot Ventures and the M&G Catalyst Fund.

The company said it will use the new money to expand manufacturing capacity in West Virginia and to accelerate commercial deployment of its iron-air battery systems.

What the technology does

Form Energy builds long-duration energy storage systems. Its approach aims to store electricity generated from renewable sources such as solar and wind for hours or even days, so the grid can be supplied without interruption when output falls.

The core technology is the iron-air battery. These batteries use oxygen from the air to generate electricity, reversing the process by which iron rusts. With that approach the company aims to build systems that store for longer, and cost less, than conventional short-duration batteries.

Why does it matter?

Long-duration storage targets the best-known gap in renewable energy: what happens when the sun sets and the wind drops. The lithium-ion batteries in wide use today operate on a scale of hours; storage on a scale of days is a different problem standing in front of a grid running entirely on renewable sources.

The customer list is notable in that context: Xcel Energy, Google, Crusoe and FuturEnergy Ireland. That the list includes a technology company and a data centre operator alongside a utility is a signal about where electricity demand is coming from.

The size of the number

The company has a commercial order backlog of roughly 80 gigawatt-hours. That represents capacity contracted but not yet delivered — one of the more concrete indicators that a startup's product has moved past the laboratory stage.

Form Energy was founded by Mateo Jaramillo, Yet-Ming Chiang, Ted Wiley, William Woodford and Marco Ferrara.

In figures

  • Round size: $750 million, Series G
  • Lead investor: T. Rowe Price
  • Valuation: above $2 billion
  • Order backlog: roughly 80 gigawatt-hours
  • Customers: Xcel Energy, Google, Crusoe, FuturEnergy Ireland
  • Founded: 2017

What is not settled

The announcement did not state how much of the backlog will be delivered on what schedule. Independent data on the long-term performance of iron-air technology at grid scale is also limited; the real test for systems like these is how much efficiency they lose over charge and discharge cycles repeated across years.