Hot Heart: An innovative project that will decarbonise Helsinki’s heating

In addition to distributing heat without any carbon emissions, Hot Heart will offer citizens and tourists tropical forests and hot water pools

Last week, the Mayor of Helsinki Jan Vapaavuori announced the four Award Winners of the Helsinki Energy Challenge: HIVE, Beyond Fossils, Smart Salt City, and The Hot Heart. The challenge tasked teams with finding a solution to one question: “How can we decarbonise the heating of Helsinki, using as little biomass as possible?”

While all four teams found innovative solutions to this problem, the Hot Heart project received particular praise and attention.

No carbon emissions

The Hot Heart system comprises of 10 cylindrical reservoirs of 225m diameter. These reservoirs will be filled with approximately 10 million cubic metres of hot water. To do this, Hot Heart will first use energy from existing renewable sources, converting them into heat using seawater heat pumps. Then, it will store this thermal energy in the reservoirs for when it is needed.

Finally, the reservoirs will be connected to Helsinki’s existing district heating system in order to distribute heat across the city at lower prices, without any carbon emissions. On its website, the Helsinki Energy Challenge explains that by the end of the decade, Hot Heart expects to cover the full heating demand of the city (6,000 GWh).

Tourist attraction

In addition to decarbonising the city’s heating, the project will also attract tourists as four of the ten cylinders will house all-year tropical forests and hot water pools at sea. Taking this idea further, the Hot Heart system will also perfectly embody various elements of Finnish Culture: islands, nature, etc.

The Hot Heart project aims to become known as “the Helsinki model” by 2028. In other words, it hopes that by the end of the decade, other countries will be able to apply the system to their own cities in order to benefit from its numerous advantageous features.

The Hot Heart project video (Carlo Ratti Associati)

This project has been developed by a diverse and multidisciplinary team as Carlo Ratti Associati (Italy) collaborated with Ramboll (Finland), Transsolar (Germany), Danfoss/Leanheat (Finland), Schneider Electric (Finland), OP (Finland), Schlaich Bergermann Partner (Germany) and Squint/Opera (UK).