TNW
Summary
A “metal sock” in the ground stuffed full of hydrogen. Vats of scorching sand. Huge weights moving very, very slowly up and down old mineshafts. Is this the future of energy?
This menagerie of strange machines and heat-retaining vessels is poised to emerge across Europe as the continent seeks ways of storing the surplus energy produced by renewables. The UK, for example, wasted half a billion pounds’ worth of wind energy in 2021 because it had nowhere to store it. Without such storage, electricity must be used at the very moment it is generated.
In an industrial corner of Kankaanpää, Finland, a town home to around 12,000 people, there is a seven metre-tall, dark grey silo full of sand. Sand that can store energy in the form of heat.
“Our year-round efficiency is about 90% for the system, so 10% losses, which is obviously quite good,” says Tommi Eronen, chief executive and co-founder of Polar Night Energy, an eight-people-strong startup that’s raised €1.25 million to date. Eronen described how the sand, heated to 600˚C using surplus electricity, will stay hot for months on end thanks to insulation lining the walls of the steel container. Pipes filled with hot air run through the sand in order to transfer heat in or out.
This sand battery is connected to a heat exchanger, says Eronen, so that operators can transfer thermal energy to district heating systems or, in possible future versions of the technology, turbines for electricity generation.
Continue Reading
#News#DistrictHeating