Pornainen made headlines with the world’s largest sand battery
Here it is, right in front of us, the facility that houses the world’s largest sand battery. We walked a couple of blocks from the Pornainen municipal hall, following in the footsteps of Mayor Antti Kuusela.
For Kuusela, the tour is almost a routine, as the sand battery attracts attention as far away as Central Europe. The day before, he presented the plant to German journalists.
The sand battery is interesting because it makes energy production climate-friendly and efficient, and above all, it promotes circular economy.
Kuusela says that thanks to the new battery, the district heating network in Pornainen will be able to completely phase out oil. The use of wood chips will be reduced by about 60 percent, and the wood chip plant will remain as a backup power plant. The plant can be used during peaks in heat consumption, but so far, there has been no need for it.
Thanks to the battery, carbon dioxide emissions will be reduced by 70 percent.
The Best Inventions of the year in Time magazine
The world’s largest sand battery (power 1 MW and storage capacity 100 MWh) was developed by Finnish startup Polar Night Energy, whose name now stands in large letters on the wall of the heating plant next to Loviisan Lämpö, the local district heating company.
The sand battery was put into use in previous summer and has been working well ever since.
How did it find its way here, to a municipality of 5,000 inhabitants in Uusimaa?
Kuusela says that he had just started as mayor of Pornainen in 2022 when his phone rang and Mikko Paajanen, CEO of Loviisan Lämpö, had something to discuss.
Paajanen wanted to know what the opinion in Pornainen would be if a district heating plant powered by wind energy were to be built next to a chip-fired bioenergy plant. It would be connected to the world’s largest sand battery, storing electricity that would in turn be purchased during low-priced hours on the spot market.
“Private equity investor CapMan had proposed a trial to Loviisan Lämpö, in which an industrial-scale sand battery would be installed in Pornainen. The battery would become part of Loviisan Lämpö’s district heating network,” Kuusela explains.
Elisa Industriq, on the other hand, would optimize the system using artificial intelligence to ensure efficient operation in line with the electricity market.
The mayor thought the pilot sounded excellent, and it was also well received by the municipal council.
Pornainen has since gained widespread international recognition, as the battery and its location were highlighted when Time magazine(Will be opened in a new window, You are transferring to another service) recently listed the 100 best inventions of the year. The sand battery represented the green energy category in the list.
Tulikivi’s surplus turned into battery sand
Kuusela praises the municipality’s forward-looking attitude. Even before he took office, Pornainen had conducted an energy audit to identify ways in which the municipality could increase its use of renewable energy. It was decided that climate issues would be given considerable weight in the municipality’s own investments.
The municipality was involved in the sand battery project from the outset, as the benefits are significant. A large proportion of the municipality’s own buildings are heated by district heating.
Kuusela says that the sand battery is also a good example of circular economy. It utilises surplus soapstone aggregate from Tulikivi, a well-known fireplace manufacturer, to store renewable energy.
Although this battery in Pornainen is referred to as a “sand battery,” in practice it contains 2,000 kilotons of soapstone that has been crushed to a suitable grain size. The tonnage corresponds to approximately one thousand soapstone stoves.
Battery storage of thermal energy is needed to make energy systems more flexible.
Kuusela says that the sand battery is a good concrete example of the municipality’s desire to be environmentally smart and a pioneer of sustainable development in the Helsinki-Uusimaa Region.
“Sand batteries enable cost-effective and safe storage of renewable energy. This model can be applied to other municipalities as well,” says Kuusela.
The municipality’s residents are pleased, as they receive cleanly produced district heating at a stable price. If heat was produced as before using oil and wood chips, it would be more difficult to predict the price, and the price would most likely rise – and be a bad option in terms of the climate.
Circular economy companies to Pornaisten Portti
Another good example of the municipality’s sustainability efforts, alongside the sand battery, is the Pornaisten Portti industrial area, Kuusela mentions. The area is being developed specifically as a hub for circular economy and clean energy companies. Discussions are currently underway regarding the area’s own district heating network.
The municipality is doing its part to create conditions for companies to undertake smart energy and material pilots.
Pornainen is also taking very concrete action on climate change. Energy efficiency and low emissions are a self-evident requirement in municipal construction and renovation projects. In the future multi-purpose hall, the number of solar panels will be maximised, and the hall will be heated using the new sand battery.
In the soon to be renovated school energy efficient solutions have been included already in the tendering process.
The municipality is doing its part to create conditions for companies to undertake smart energy and material pilots.
Sustainable also from an economic perspective
Achieving carbon neutrality requires widespread cooperation. To meet the region’s ambitious goal of carbon neutrality by 2030, transportation needs to be involved as well.
In Pornaisten, as in Finland and the rest of the world, the adoption of electric cars has been slower than expected. Small municipalities also lack the resources for efficient public transport.
Transportation is therefore a big question mark when it comes to achieving the goal in Pornainen.
Nevertheless, ambition is needed. Kuusela quotes the municipality’s vision, which emphasises sustainability and a clean transition.
He points out that Pornainen’s vision aligns well with the Helsinki-Uusimaa Regional Programme, which also emphasises environmental values, climate resilience, circular economy and renewable energy.
Kuusela says that there is no need to justify working towards sustainability and the clean transition in Pornainen, at least not to municipal policymakers or companies participating in tenders and procurements.
“Nowadays, it is understood that working for the environment and nature with sustainable life cycle solutions is also economically sustainable.”
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