An overlooked technology for nearly 50 years, the first liquid air energy storage facility is finally set to power up in 2026. It’s hoping to compete with grid-scale lithium batteries and hydro to store clean power, and reduce the need to fall back on fossil fuels.
As the world’s use of renewable electricity soars, surpassing coal for the first time, the need to store that energy when the Sun isn’t shining and the wind isn’t blowing is growing in step. While some turn to grid-scale lithium batteries and others to pumped hydro, a small but growing industry is convinced there’s a better solution still: batteries that rely on air.
Near the village of Carrington in north-west England, the foundations are being laid for the world’s first commercial-scale liquid air energy storage facility. The site will eventually become an array of industrial machinery and a number of large storage tanks, filled with air that has been compressed and cooled so much it has become a liquid, using renewable energy surplus to demand. The stored energy can be discharged later when demand exceeds supply.
If the project succeeds, more will follow. The site’s developers Highview Power are confident that liquid air energy storage will make it easier for countries to replace fossil fuels with clean renewable energy – though at present, the technology is expensive. But as the need for clean energy storage surges, they’re betting the balance will tip in favour of liquid air.
Switching to renewable energy is essential if the world is to cut greenhouse gas emissions and avoid the worst impacts of climate change. But doing so poses challenges for electricity grids.
Power plants that burn fossil fuels like coal and gas can be turned on and off largely at will, offering a predictable supply of electricity that can be matched to demand. In contrast, renewables are intermittent. This means there is sometimes there isn’t enough electricity being generated, risking power cuts, and sometimes there is too much – such as on very windy days – which could damage the grid.
A big part of the solution is to store the surplus energy so that it can be released when it’s needed. This helps ensure a reliable supply and minimises the risk of damage to the grid. As renewable use has ramped up, it has become increasingly important to build up grid-scale storage capacity, says Shaylin Cetegen, a chemical engineer at the Massachusetts Institute of Technology (MIT), who studies energy storage systems.
For decades, the main form of energy storage has been pumped hydro. Surplus electricity is used to pump water uphill, where it sits behind a dam. When energy is needed, the water is allowed to flow through turbines, generating electricity. In 2021, the world had 160 gigawatts of pumped hydro capacity.
More recently, as demand for energy storage has risen, large-scale battery storage systems have been built. This is happening quickly, and accelerating. According to the International Energy Agency, grid-scale battery storage grew from 1GW in 2013 to over 80GW in 2023, with over 40GW added in 2023 alone.
Liquid air energy storage, by contrast, is a relatively new technology on the block. The basic idea has been around since 1977, but it received little attention until this century. (BBC)
