The international architecture firm CRA-Carlo Ratti Associati led a multidisciplinary design team in creating the winning proposal for an infrastructure facility for the Helsinki Energy Challenge. In addition to CRA, the design team included Ramboll, Transsolar, Danfoss Leanheat, Schneider Electric, OP Financial Group, schlaich bergermann partner, and Squint/Opera. The municipality of Helsinki — Finland’s capital — organized the challenge as part of its efforts to transition to carbon-neutral heating by 2030.
Dubbed Hot Heart, the facility will be located off the coast of Helsinki and will comprise an archipelago of 10 thermally insulated “islands.” These islands will be 225 m diameter, enclosed, heat-storing basins. Four of these basins will have rooftop bubbles, resembling greenhouse domes.
The domes, which will be heated by the tanks beneath them, will host tropical forests and ecosystems from around the world, serving as an educational and recreational attraction.
The archipelago will hold up to 10 million cu m of water. Seawater heat pumps will convert wind and solar power to heat, which will be stored in the basins and then withdrawn for use in the city’s heat distribution channels, according to material distributed by CRA.
“Production of renewable energy is getting cheaper, but storage is still extremely expensive,” said Carlo Ratti, the founding partner and chair of CRA, in a company press release. “Our idea is to use the giant ‘thermal batteries’ to store energy when prices are at low or even negative levels and extract it when required by the district heating system when demand is high.
“In addition, Hot Heart offers a unique experience, bringing the natural and artificial worlds together,” Ratti said. “It is inspired by the Finnish concept of Jokamiehen Oikeudet, which could be translated as ‘every person’s right’: the right to reflect and unwind while peacefully enjoying nature.”
Artificial intelligence will control the system’s inputs and outputs to help stabilize the national energy grid, according to the architects. The archipelago is expected to furnish the city’s entire district heating network — estimated at 6,000 GWh annually — by 2030 and to do so with no carbon emissions and for a cost that is estimated to be 10% lower than the cost of today’s heating.
This article first appeared in the July/August issue of Civil Engineering as "The Heat Is On."