Pumped Heat Electricity Storage (PHES) is a new technology developed by Isentropic, which promises to be the cheapest and most convenient way to store and recover electricity.
The shift to renewable and nuclear energy is challenging the power supply industry worldwide due to the intermittency of renewable sources and the inflexibility of nuclear energy. A solution is needed to store and recover electrical energy to prevent disruptions to the electricity supply.
The critical issue is the cost of energy storage. Storing hot and cold is the cheapest way to store energy and is well understood. Our system transforms electrical energy into a temperature difference between two volumes of crushed mineral material. The system then efficiently recovers electricity from that temperature difference.
We can achieve a levelized cost of storage (LCOS) of less than $35/MWh stored. We believe this to be the lowest price of any storage technology - including pumped hydro.
Our eight years of R & D have validated our performance predictions on three prototype machines and a utility-scale storage machine is currently under development.
The Energy Technologies Institute (ETI) has provided project funding and an equity investment, together totalling £14m ($22m). We are using the funding to develop a 1.5MW/6MWh electricity storage unit, which will be deployed on a UK primary substation owned by Western Power Distribution in the Midlands region.