Winter is coming: time to start using carbon-free technology
A Finnish company, Polar Night Energy (PNE), has developed a huge thermal battery, consisting of a 100-ton silo filled with normal construction sand heated to temperatures close to 500°C using surplus renewable energy.
Sand is a very efficient medium for storing heat, which it maintains for long periods, allowing the silo to remain at temperatures close to 500°C for several months. In the case of the heating coil built by PNE, the system is also powered by excess heat evacuated from a nearby data center.
When energy prices are higher or when renewable energy generation is not possible, as in the long Nordic winter, the battery can discharge the hot air, which is used to heat water for homes in the town of Kankaanpää, where the company is located, as well as the local swimming pool. Efficiency decreases significantly when the heat is used to generate electricity again, but since heat is a fundamental energy need, the solution is extremely useful.
Such solutions, originally designed by a pulp mill in another Finnish city, Tampere, are attracting attention in Finland due to the war in Ukraine and the country’s recent decision to join NATO. Finland traditionally received most of its natural gas from Russia, but Moscow has now cut off supplies in retaliation for joining the alliance, raising…
