Sun and wind produce electricity even when we don’t need it. How can we prevent it from being lost? A gravity battery developed in Switzerland stores renewable energy in heavy blocks of material – an idea that is attracting interest around the world, especially in China.
It is an imposing building without doors or windows. Inside there are 3,500 “bricks” weighing 25 tonnes. A system of elevators and tracks moves them up and down, placing them next to each other, in what looks like a modern 3D Tetris. It is not a new housing concept, but a battery that uses the force of gravity to store and release energy.
The first battery with this technology was connected to the power grid in the Chinese county of Rudong, near Shanghai, in late 2023. “We didn’t imagine that our first plant would be built in China,” Robert Piconi, CEO of Energy Vault, tells SWI swissinfo.ch. The energy storage systems company is based in the US, but it developed and tested its prototype in Switzerland.
In China the environmental imperative to accelerate the country’s decarbonisation – China is the world’s biggest emitter – and current energy policiesExternal link have, however, offered unexpected opportunities for Energy Vault and its innovation. New battery-buildings are already under construction. “We want to help solve the climate crisis,” Piconi says.
Energy storage systems are an essential part of the energy transitionExternal link. Batteries solve one of the main problems of electricity production from renewable sources: volatility. That is, they allow excess electricity generated by the sun or wind to be stored and made available at times of increased demand. They can also help stabilise electrical grids. The challenge is to produce efficient batteries without consuming raw materials and rare metals. And of course, at sustainable costs.