A schematic of the CES pilot project in operation at Scotland's Slough Heat & Power plant (Image: Highview Power Storage)
Balancing demand for energy with timely production is a juggling act that is particularly relevant to renewable sources such as wind and solar. Because the wind isn't always blowing and the sun isn't always shining, the energy produced by these systems needs to be stored efficiently so it can be used when it's needed. While some scientists are looking into storing such energy by converting it to natural gas, Britain's Highview Power Storage has its own approach, which is already in use in a pilot project. In a nutshell, the company is storing excess energy as liquid air.