Welcome to Isentropic

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.

The advantages of our system:

  • the lowest cost of any electricity storage device
  • a high round trip efficiency of 72-80% depending on size
  • a small unit size 2MW
  • safe and environmentally inert, using steel, argon and gravel
  • uses no dangerous chemicals or explosive pressures
  • can be installed anywhere and is road transportable
  • has a long life and large number of cycles

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.