A Swiss company is busily preparing the site for what it claims will become the world’s biggest battery. This system will use redox-flow chemistry, and it will be able to deliver as much electricity as a nuclear power station for 24 hours.
This output corresponds to supplying 1 million households for 5 hours, or 210,000 households for 24, according to the company. The scale of this project is quite mind-boggling, compared to what we have encountered before.
More About The Scale of The Battery
The company is currently excavating a 27-meter-deep pit (88 feet) with a footprint of two football pitches. The battery that will go there will be able to store up to 1.2 gigawatt hours of electricity in a few milliseconds, and release it at the same astonishing rate.
If all goes well, the world’s biggest battery should commission in 2029, and generate 300 jobs. This includes the battery, associated data center, laboratories and offices.
How the World’s Biggest Battery Will Work

Redox flow batteries, as a class, store their energy in liquid electrodes, unlike the solid ones in our sealed gel lead-acid batteries you can trust. A pair of two huge tanks will hold the electrodes deep overground.
While above the battery, stacks of multitudes of cells will convert the stored chemical energy to the electricity grid customers use. When the world’s biggest battery needs to recharge, this process reverses, and the cells convert fresh renewable electricity to chemical energy.
Connecting the Flow Battery to The Grid
The national high-voltage utility Swiss Grid, will connect to the world’s biggest redox flow battery when it is up and running. “Large batteries can store energy when there is a lot of it, and release it when it is needed.” the utility explains.
“So in the future, with wind production that will fluctuate according to the weather, having this flexibility can help stabilize the grid.” It could also reduce the risk of power outages, and meet escalating demand from data centers.

More Information
Aqueous Redox Flow Battery Could Be The Key
Flow Batteries for Long Energy Storage
Preview Image: World’s Biggest Flow Battery