UK firm promises high density pumped hydro revolution

A new system based on pumped hydro generation promises to vastly increase capacity to store and release energy generated from renewables, providing a more environmentally-friendly alternative to batteries.

The breakthrough in the system being developed by start-up RheEnergise is a bespoke fluid with a density 2.5 times that of water. The company says this opens up a huge number of potentially suitable sites.

Electricity supply has always faced the problem of dealing with a mismatch between supply and demand. In the past huge coal-fired power stations were designed to run for long periods at a constant output and could not easily respond to peaks and troughs in demand. One method devised to address this was pumped hydro storage, in which water is pumped into a dam at off-peak times, and then released to generate hydro-electricity and balance the grid when needed. But because of the need for high heads of water to generate the necessary power it was limited to mountainous sites in Scotland and Wales.