Finland plans world’s largest seasonal heat storage facility

Finland

VANTAA, April 9, 2024 – Finland’s Vantaa Energy plans to build a 90-GWh underground thermal energy storage facility, set to be the world’s largest on completion in 2028, the company said on Monday.

The Varanto facility, which will be more than 1 million cubic metres in size and located in the city of Vantaa, could heat a medium-sized Finnish city year-round, the company said.

It will be the world’s largest “by all standards,” around double the size of New York City’s Madison Square Garden arena.

Its design involves storing heat as water heated to 140 degrees Celsius in underground caverns, to be used to heat buildings via the district heating network whenever needed.

Nordic countries face a large gap in difference between heat consumption in the summer and winter, with summer peak load comprising only a tenth of that seen in winter.

Photo courtesy of Vantaa Energy.