Does Finland have a sand battery?

Finland begs to differ. This month saw the Nordic nation launch the world's first commercial "sand battery". About 230 kilometres north-west of Helsinki, in the town of Kankaanpää, homes, offices and the public swimming pool are being heated by thermal energy stored in a 7-metre steel container filled with 100 tonnes of sand.

Where will Neoen's new lithium-ion battery plant be located?

The facility will be located close to Lappeenranta in the south-east of the country. Following on from the Hornsdale Power Reserve in Australia, Azur stockage in France and Albireo Power Reserve in El Salvador, this first roll-out of lithium-ion stationary batteries in Finland underpins Neoen’s leadership in battery-based grid services.

Are lithium batteries good for sand?

Lithium batteries work well for specific applications, explains Markku, but aside from their environmental issues and expense, they cannot take in a huge amount of energy. Grains of sand, it turns out, are surprisingly roomy when it comes to energy storage.

How much energy can a battery store?

It can store up to 8 megawatt-hours of energy, which is the capacity of a large, grid-scale lithium battery. The project was the work of Finnish startup Polar Night Energy and a local Finnish utility Vatajankoski. Markku Ylönen and Tommi Eronen began working on the battery idea when they were at university. (Supplied: Polar Night Energy)

Can a sand battery store more energy than a chemical battery?

There are of course limitations, experts note. "A sand battery stores five to 10 times less energy [per unit volume] than traditional chemical batteries," says Dan Gladwin from the department of electronic and electrical engineering at the University of Sheffield in the UK.

Does Finland need a district heating system?

"It's very useful in Finland where we have cold winters and need heating pretty much from September to May, [due to] an average annual temperature of under 10C (50F)," she says, adding that half of Finland's 5.5 million people are connected to a district heating network.