The first liquid-air energy storage (LAES) plant in the US — a 50MW-plus “cryobattery” with eight hours of storage (400MWh) — is to be built in the state of Vermont by the technology’s pioneer, Highview Power, and developer Encore Renewable Energy.
The project will be the first of many LAES facilities that privately-owned UK-based Highview is planning to develop in the country, and will be the first commercial development of the new wave of Baldies (build-anywhere long-duration intermittent-energy storage) technologies in the US, beating competitors such as Siemens Gamesa and Google spin-off Malta.
The northern Vermont facility — able to store energy for weeks at a time — will enable more wind and solar power to reach customers on an overloaded part of the local grid known as the Sheffield-Highgate Export Interface, where renewable energy is often curtailed against the wishes of policymakers, generators and customers.
“In addition to supplying clean, reliable and cost-efficient energy storage, the facility… [will] stabilise the regional electrical grid, and ensure future energy security during storms and other disruptions,” the co-developers said in a statement. The plant will also have the ability to provide “market arbitrage, frequency management, reserve and grid constraint management services”.
No date has been revealed for construction or completion of the project.
Highview’s technology works by cooling air down to -196°C, shrinking its volume by a factor of 700, and storing it in low-pressure vacuum-insulated steel tanks — the kind that houses liquefied natural. When this cryogenically frozen liquid air is exposed to ambient temperatures, it turns back into a gas and rapidly expands, with the rush of air from this 700-fold expansion directly driving an electricity-generating turbine.
The company’s LAES system is thought to be cheaper than lithium-ion battery solutions. Highview chief executive Javier Cavada told Recharge in July that a 100MW system would have a levelized cost of storage (LCOS) of just over $100/MWh. By comparison, a new pumped-hydro plant would have an LCOS of $152-198 per MWh, with a comparable lithium-ion system costing $285-581/MWh, according to analyst Lazard.
The technology has been proven in the field at a 5MW/15MWh grid-connected pilot project near Manchester, northwest England, and the first commercial unit, a 50MW/250MWh plant is due to be begin construction in northern England in the first half of 2020.