Long-duration energy storage

Hydrogen

This hydrogen microgrid is the first of its kind. Is it a good idea?

Energy Vault, Plug Power, and PG&E partnered on a project that replaces diesel generators with fuel cells to provide backup power for a small town in California.

By Julian Spector . 11 August 2025

white industrial boxes against a sunset — This hydrogen microgrid should keep the power on in Calistoga, California. (Energy Vault)

Long-duration energy storage

Used EV batteries could upend the race for long-duration storage

Redwood Materials says second-life batteries are the cheapest form of long-duration storage. If true, battery startups are in trouble — and renewables are in luck.

By Julian Spector . 6 August 2025
Energy storage

Redwood Materials built record grid storage project using old EV batteries

The EV battery recycler determined it could make good money by repurposing old battery packs for the grid, and found an eager data center customer.

By Julian Spector . 2 July 2025
Batteries

Could this 1980s battery design unlock long-term clean energy storage?

Utility Southern Co. will install Inlyte's iron-salt long-duration battery, tech the startup has updated for the era of renewables and data center demand.

By Julian Spector . 7 May 2025
Long-duration energy storage

The biggest grid storage project using old batteries is online in Texas

Startup Element Energy set out to prove that second-life batteries could deliver cheaper energy storage safely and at scale.

By Julian Spector . 21 November 2024
Long-duration energy storage

Form Energy raises $405M for its 100-hour iron-air batteries

The long-duration energy storage startup has raised a total of $1.2 billion. Form is expanding its West Virginia factory and working on its first deployments now.

By Jeff St. John . 9 October 2024
Long-duration energy storage

Form Energy set to build world’s biggest battery in Maine

The long-duration storage pioneer won DOE grant money to construct a massive iron-air battery intended to help a strained pocket of the New England grid.

By Julian Spector . 15 August 2024
Clean energy manufacturing

Clean energy factories, thermal storage get boost from new tax credits

The IRS just released rules on incentives for clean energy manufacturers that make stuff in the U.S. Long-duration storage and thermal batteries could benefit the most.

By Julian Spector . 15 December 2023
Podcast

What do you do with a 100-hour battery?

Form Energy’s Mateo Jaramillo argues that utilities can use multiday storage to do more than balance intermittent renewables.

Play

By Shayle Kann . 46 min . 14 December 2023
Energy storage

Will this startup finally crack the code on flow battery tech?

Germany's CMBlu just pulled in a 100-million-euro investment, is ramping up manufacturing and has contracts with major utilities. Can it succeed where others have failed?

By Julian Spector . 13 November 2023
Long-duration energy storage

Why Energy Vault went from disrupting batteries to selling them

The buzzy startup raised a record $110M back in 2019 to transform grid storage with novel long-duration tech, but now it's embracing industry favorite lithium-ion.

By Julian Spector . 16 October 2023