Subterranean power store planned in salt caverns

Plans have been drawn up to create a renewable power battery in underground salt caverns.

Energy firm Storelectric has acquired hundreds of acres of land at Seal Sands, near Billingham, on Teesside and wants to take electricity from green sources and store it as compressed air.

The project - Teesside Compressed Air Energy Storage (TeesCAES) - which aims to increase the output from sources of renewable power, has won provisional approval from the energy regulator Ofgem.

Storelectric's executive director Tallat Azad said the scheme would stop potential energy going to waste and aid the "green transition to net zero emissions".

Windfarms and solar panels can be switched off at times of low demand as the energy grid cannot use their generated energy.

Azad said: "We really need to make sure we can continue to deploy renewable energy to meet the green transition to net zero emissions.

"What we do is take that renewable energy when it is not needed and store it underground in salt caverns."

He said the technology was like holding a balloon which had been blown up but not tied.

"If you can't put a knot in the balloon, it will just fly away," he said.

"That is essentially the energy we are storing underground.

"When it's needed we release it, it goes through a turbine then back into the grid."

Industrial salt caverns are found all over the world and used to store oil and gas, having been formed by injecting water into deep layers of salt.

There are about 110 caverns on Teesside, believed to be big enough to hold enough water to fill 200 Olympic swimming pools.

Professor Nash Dawood, of Teesside University's new zero industrial innovation centre, said compressed air technology could provide an alternative to traditional battery storage.

He said: "Batteries have been used but the whole life cycle is not that great, because after a few years they have to be dismantled - salt caverns are a really exciting place."

Storelectric also has land at Wilton and hopes to store hydrogen underground as well as compressed air.

TeesCAES has been given "minded to" approve status by Ofgem's Long Duration Storage scheme.

A final decision on the projects will be supported is expected in the autumn.

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