A reliable electricity system based almost wholly on renewables is not just a lot of hot air, it’s a lot of cold air.
UK based Highview Power’s solution to the intermittency of green sources of power is cryogenic technology relying on chilled air.
Using off peak energy, air is turned into liquid at close to minus 200 degrees centigrade and stored until it’s needed. When renewable power drops off because the wind stops blowing or the sun isn’t shining, the air is allowed to heat up. As it expands 700 times to reach ambient temperatures it drives turbines which power up the system.
Highview, which has recently announced plans for a 50 MW liquid air plant in the north of England, says its technology has reached a new record on costs for large scale power storage. It claims whole life or levelised cost of storage (LCOS) of £110/MWh for a 10-hour, 200 MW/2 GWh system.
Currently 90% of power storage around the world depends on pumped hydro, such as the Turlough Hill plant in the Wicklow Mountains.
While the idea of using liquid air for energy storage was published in academic papers in the 1970’s, the process on which the technology works was invented a hundred years ago by French engineer Georges Claude.
