It sounds like magic but it is real – a plan to store cheap night-time wind energy in the form of liquid air.
Here is how: you use the off-peak electricity to compress and cool air in a tank, so it becomes a freezing liquid.
When demand peaks, you warm the liquid back into a gas, and as that expands it drives a turbine to create more electricity.
The technology, created by a backyard inventor, is about to hit the big time.
It has been tried at small scale but now the firm behind it, Highview, has announced that a grid-scale 50MW plant will be built in the north of England on the site of a former conventional power plant.