Startup Heats Crushed Rocks To Store Renewable Energy

By Ariel Grossman, NoCamels November 08, 2022 2 minutes

Brenmiller Energy has developed a unique storage system for excess renewable energy, in which steam heats up crushed rocks and can be stored for hours (Photo: Courtesy)

An Israeli company has installed its system for storing excess renewable energy at a power plant in Italy.

Brenmiller Energy stores the energy by sending steam through pipes to heat crushed rocks.

The accumulated heat is then released when needed, to heat pressurized water and generate steam for electricity.

Its thermal energy storage (TES) solution is now at a power plant in Tuscany run by Italian multinational power company Enel.

The system can store up to 24 MWh of clean heat at a temperature of about 550°C for five hours, providing critical resiliency to the power plant and reducing reliance on fossil fuels.

The problem is that with many renewables, it costs more to store the electricity, making it less economical than using fossil fuels. This system makes power plants more flexible.

The collaboration between Enel and Brenmiller came about as part of an Italian-Israeli protocol aimed at accelerating cooperation between Israeli companies and large Italian industries. The project was partly financed by the Israeli Innovation Authority, which supported Brenmiller with 1 million euros in financing.

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“Our TES system at Enel’s Santa Barbara power plant in Tuscany is the first-ever system of its kind to provide utility-scale thermal energy storage and offers commercial and industrial users a viable path towards decarbonization,” said Avi Brenmiller, Chairman and CEO of Brenmiller Energy.

“The TES also makes it possible to add additional renewables to the grid with greater reliability. We believe the success of this moment reflects the types of innovative collaborations needed to transition the global economy away from its heavy, albeit lessening, dependence on fossil fuels, and towards a 100 per cent clean, flexible, and affordable energy grid.”

Ernesto Ciorra, Head of Innovation at Enel, said: “This solution makes renewables more reliable, flexible and resilient and can be used to decarbonize sectors that need heat at high temperatures.

“Furthermore, it does not involve any use of rare materials and can be made using stones available in every part of the planet, so it is scalable in a sustainable way everywhere.

“We thank the colleagues of the Tel Aviv hub for having found it and our Italian colleagues for having implemented it, thanks also to the financial support deriving from the collaboration between the Italian and Israeli governments.”