A Town in Finland Is Heated Using a Sand Battery

A small town in Finland has adopted a rather intriguing method for heating. The system operates neither on coal nor on natural gas. Instead, tons of sand are heated inside a colossal silo. This heat is then distributed into the town's district heating network, effectively turning the humble sand into a giant battery of sorts.In the town of Pornainen in Finland, a system has been established that operates with a sand battery developed by Polar Night Energy. The concept is actually quite straightforward. When excess electricity is generated from sources like wind and solar, this energy is converted into heat instead of being directly consumed. The electrically heated air is circulated through sand or similar solid material within a silo.In this way, the sand can heat up to levels of 500-600°C and is able to store the energy as heat for a long time. While traditional batteries store electricity chemically, this system retains energy in the form of heat. When needed, the heat stored in the sand is transferred to hot water or a district heating line.The sand battery in Pornainen has been connected to Loviisan Lämpö's district heating network. According to Polar Night Energy, the facility provides 1 megawatt of thermal power and has a storage capacity of 100 megawatt hours. The company states that this system is ten times larger than the first sand battery that was launched in Kankaanpää in 2022, signifying that the technology has evolved beyond being merely a laboratory idea or a small-scale experiment.According to a field impression by Interesting Engineering set for 2026, the battery in Pornainen contains 2,000 tons of material. When fully charged, the system reaches temperatures of 500-600°C, providing flexibility to the town, particularly during periods of rising energy prices. In countries like Finland, where winters are long and harsh, the ability to store excess renewable energy for later use as heat becomes increasingly crucial.One of the most striking impacts of the sand battery in Pornainen is its ability to reduce fossil fuel usage. According to data from Polar Night Energy, the system is projected to decrease the annual carbon dioxide equivalent emissions in the local heating network by approximately 160 tons. This signifies a staggering drop of about 70% in the town's regional heating-related climate emissions.Moreover, the town's heating system is expected to completely cease its use of oil, while the consumption of wood chips is anticipated to decrease by approximately 60%. A noteworthy aspect of this system is its independence from rare or expensive materials. Solid materials like sand or crushed stone can retain high temperatures and thus function as an energy reservoir. Consequently, the sand battery is seen as a practical solution to one of the biggest challenges of renewable energy - storage.

They Are Heating The Whole Town With Sand Heated To 600 Degrees

Excess electricity is being stored in sand as heat.

The system has escalated from a minor trial to a town-wide scale.

The town is expected to phase out its use of oil.

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