A team in the United Kingdom has started work on what the BBC reports is the world’s first facility to store energy as highly compressed air.
An artist's impression of Highview's planned energy storage facility
The 50 megawatt plant will take excess power from wind farms (the UK is the Saudia Arabia of wind energy) and use it to store ordinary air at pressures so great that it will become a liquid. Then, during periods of peak demand, they’ll warm the stored air up and use it to power a turbine that pumps electricity back into the grid.
Inventor Peter Dearman says the system is between 60 and 70 percent efficient. That’s worse than a battery, but he predicted they’ll be able to easily scale the system by adding more tank volume. “Batteries are really great for short-term storage,” Dearman told the broadcaster. “But they are too expensive to do long-term energy storage. That’s where liquid air comes in.”
Also, unlike batteries, liquid air storage does not create a demand for minerals which may become increasingly scarce as the world moves towards power systems based on variable renewable electricity.
“It’s very exciting,” he told the BBC. “We need many different forms of energy storage - and I’m confident liquid air will be one of them.”
Work is beginning on what is thought to be the world's first major plant to store energy in the form of liquid air. It will use surplus electricity from wind farms at night to compress air so hard that it becomes a liquid at -196 Celsius. Then when there is a peak in demand in a day or a month, the liquid air will be warmed so it expands. The resulting rush of air will drive a turbine to make electricity, which can be sold back to the grid.
The system was devised by Peter Dearman, a self-taught backyard inventor from Hertfordshire, and it has been taken to commercial scale with a £10m grant from the UK government. He is now a passive shareholder in Highview, one of the firms building the 50MW plant near Manchester that will store enough power for roughly 50,000 homes for five hours.