Despite the pessimism that has dominated the market since the election of President Donald Trump, renewable energy is not dead. Regardless of what happens in the United States, European countries are still moving toward ambitious clean energy goals. The EU alone is expected to build an average of 22 gigawatts of new wind power each year between 2024 and 2030. The growing deployment of wind and solar will also benefit other technologies, including new energy storage methods such as liquid air.
Definitions of long-term energy storage (LDES) vary, but typically refer to technologies that can store electricity for periods ranging from eight hours to weeks or months. This capability has long existed with pumped storage power plants (or water batteries), which use electricity to push water from one reservoir to a second reservoir during times of overproduction. Water is then released from the upper reservoir through a turbine to generate electricity as needed. However, the geographic limitations of water batteries have led to increased interest in other LDES technologies.
Enter liquid-air energy storage without such geographic limitations. It works by using electricity during periods of abundant wind and solar power to purify, dry, and cool the air until it liquefies. Liquid air is stored in an insulated tank. When electricity is needed, it is pumped at high pressure, reheated, and expanded to produce high-pressure gas that powers a turbine.
The UK government-owned Wealth Fund and FTSE 100 electricity company Centrica this summer took part in a £300m funding round to support the construction of a liquid air energy plant due to open in 2026 near Manchester in northwest England. .
Once completed, the power plant will have a storage capacity of 300 MWh (megawatt hours) and generate 50 megawatts of electricity, making it the largest facility of its kind in the world. Rio Tinto and Goldman Sachs Power Trading are among the syndicates supporting the project, which is being developed by private company Highview Power. Highview is also planning four more larger liquid air plants, including one in Scotland.
However, like many LDES technologies, liquid-air energy storage is expensive. Broadly speaking, storage costs can be around £500 per kilowatt-hour for first-of-its-kind projects. Lithium-ion batteries, by comparison, cost about 300 pounds per KWh.
The UK government is proposing a “cap and floor” revenue mechanism once a plant is operational to encourage more facilities. LDES developers have been campaigning for this for a long time. However, if liquid-air energy storage moves into the mainstream, there will still be pressure to significantly reduce costs.
nathalie.thomas@ft.com
