A trans-disciplinary team, coordinated by international design and innovation office CRA-Carlo Ratti Associati, has developed the finalist proposal for the Helsinki Energy Challenge. Titled Hot Heart, the project is based on an archipelago of heat-storing basins with the dual function of storing thermal energy and serving as a hub for recreational activities. The “islands” will also be home to tropical forests and ecosystems from around the world, giving the Finnish capital additional public space and a new educational attraction.
Located off the coast of Helsinki, Hot Heart will be the largest infrastructural facility of its kind. The project consists of a set of 10 cylindrical basins, each measuring 225 meters in diameter. They collectively can hold up to 10 million cubic meters of water. The system functions like a giant thermal battery: low- or negative-cost renewable energy is converted into heat, stored in the tanks and withdrawn into the city’s heat distribution channels during the winter.
Hot Heart was developed as part of the Helsinki Energy Challenge organized by the municipality of Helsinki to accelerate the city’s transition towards carbon-neutrality in heating by 2030. The project is also highly adaptable and could be replicated by other cities with similar climatic characteristics pursuing sustainable heating solutions. In addition to its thermal storage properties, Hot Heart doubles as an accessible recreational venue.
Four of the 10 hot water reservoirs are enclosed in transparent domes containing the “Floating Forests” – tropical ecosystems from the world’s key rainforest zones naturally heated by the basins underneath. The “Floating Forests” provide visitors with a place to socialize and enjoy the sunlight, even in the harsh Nordic winter, thanks to the use of powerful Sun-like LED Technology. They create a unique public space for local residents and provide an attraction to international travelers.
CRA worked with an international group of consulting and manufacturing firms and energy optimization experts to develop the project’s central concept: using seawater heat pumps to convert wind, solar and other forms of power into heat, which is stored in Hot Heart’s reservoirs. The system, operated by artificial intelligence, synchronizes the production and consumption of thermal energy, which helps stabilize the national energy grid in relation to fluctuating supply.
The whole system is expected to cover the entire heating needs of Helsinki, estimated at 6,000 GWh, by the end of the decade, all without any carbon emissions and at an estimated cost 10% lower than today. Having just won the Helsinki Energy Challenge, Hot Heart is planned to enter the master planning phase in 2021 and projected to be fully implemented in 2028. Source by CRA-Carlo Ratti Associati.
- Location: Helsinki, Finland
- Architect: CRA-Carlo Ratti Associati
- CRA team: Carlo Ratti, James Schrader (Project Manager), Alberto Benetti, Federica Busani, Rui Guan, Stephanie Lee, Juan Carlos Romero and Chenyu Xu
- Renderings by CRA graphic team: Gary di Silvio, Pasquale Milieri, Gianluca Zimbardi
- General Engineering: Ramboll
- Climate Engineering: Mika Kovanen, Kreetta Manninen Transsolar
- Demand Management Engineering: Monika Schulz, Thomas Auer, Danfoss Leanheat®
- Technology Partner for Sustainability and Energy Efficiency: Oddgeir Gudmundsson, Jukka Aho, Juho Nermes, Lauri Leppä, Nico Klecka, Schneider Electric
- Financial Analysis: Jani Vahvanen, OP Financial Group
- Lightweight Structural Engineering: schlaich bergermann partner
- Communications Partner: Mike Schlaich, Boris Reyher, Squint/Opera
- Year: 2021
- Images: Courtesy of CRA-Carlo Ratti Associati