A UK technology company has unveiled a “cryogenic” energy storage system that it says can store gigawatt-hours (GWh) of renewable energy at half the cost of lithium-ion batteries.

Highview Power says its scaleable zero-emissions CRYOBattery technology, which uses liquid air as its storage medium, could potentially replace natural-gas peaker plants that help to balance the grid.

A 10-hour, 200MW/1.2GWh system offers a levelised cost of storage of $140/MWh, the company says. By comparison, analyst Lazard puts the price of a similar lithium-ion gas-peaker replacement facility at $285-581 per MWh.

“Other locatable, long-duration energy storage technologies — such as Lithium-ion — typically offer a range of 4-8 hours of storage, whereas Highview Power’s CRYOBattery offers multiple gigawatt hours of storage, representing weeks’ worth of storage, not just hours or days,” said the company.

And unlike equivalent pumped-hydro storage plants, CRYOBattery systems could be sited anywhere.

“This makes replacing gas peaker power plants with a combination of solar, wind, and energy storage a viable reality and truly sets the stage for a future where 100% of the world’s electricity comes from clean energy sources,” said Highview chief executive Javier Cavada.

“As more and more renewables are added to the grid, long-duration, giga-scale energy storage is the necessary foundation to make these intermittent sources of power reliable enough to become baseload. Not only does our CRYOBattery deliver this reliability and allow scalability — it is proven, cost-effective, and available today.”

On Wednesday, the technology won the ﻿Ashden Award for Energy Innovation﻿.

Other companies are working on build-anywhere GWh-scale energy-storage systems, including Siemens Gamesa, which recently completed installation of its hot-rock thermal storage pilot project in Hamburg.

Siemens Gamesa hopes the pilot will be able to store power for weeks at a time at a cost of €100 ($113) per MWh, with future costs determined by the price of electricity used to heat its volcanic rocks (which later drive a steam turbine to generate energy).