In a bid to combat the challenges of cold polar winters, Finland is set to introduce an industrial-scale ‘sand battery’ boasting impressive power and thermal energy capacities. Developed by Polar Night Energy, this groundbreaking technology promises to revolutionize energy storage and utilization in the region.

The new sand battery, approximately 10 times larger than its pilot predecessor operational since 2022, presents a clever concept. Essentially, it comprises a sizable steel silo filled with sand or a similar solid material, heated via a buried heat exchanger at its core. This process utilizes surplus electricity from the grid, particularly during renewable energy spikes, making it an environmentally friendly solution.

Capable of storing energy for extended periods with minimal loss, the sand battery serves as a reservoir of heat, ready for extraction when needed. While conversion back into electricity is feasible, the optimal approach, according to Polar Night, is to utilize the heat directly.

In Finland’s frosty climate, integrating the sand battery into the local district heating system proves highly advantageous. Managed by Loviisan Lämpö, the battery will undergo trials in the district heating network of the Finnish municipality of Pornainen. Towering at 13 meters tall and 15 meters wide, the new sand battery boasts a formidable output power of 1 MW and a storage capacity of 100 MWh, catering to the community’s winter heat demands for up to a week, and a month’s worth during summer.

The environmental benefits are equally impressive, with an anticipated reduction of approximately 160 tonnes of carbon dioxide emissions annually, representing nearly a 70% decrease in emissions from the district heating system. Furthermore, the sand utilized in the battery is sourced sustainably, derived from crushed soapstone, a byproduct of local industry known for its superior heat conductivity.

While sand batteries may find limited application beyond areas utilizing district heating, they present a valuable addition to the arsenal of climate change mitigation strategies. Alongside other grid-scale storage options like lithium-ion, gravity, molten salt, iron-air, or flow batteries, sand batteries contribute to a diversified approach crucial in addressing the challenges of climate change.

Polar Night Energy anticipates completing construction and testing of the new sand battery within approximately 13 months, marking a significant milestone in Finland’s quest for sustainable energy solution.

By Impact Lab