The City of Helsinki has announced the winners of its million-euro Helsinki Energy Challenge.
An international jury selected four winners out of ten finalists at an awards ceremony that marked the end of the year-long challenge.
The competition attracted 252 proposals from teams based in 35 countries. The winning solutions all focused on the city s district heating system, which accounts for more than half of Helsinki s carbon emissions.
The city has committed to becoming carbon neutral by 2035.
Two of the winning concepts, HIVE and The Hot Heart, would use water from the Baltic sea as a source of carbon-free warmth and energy storage for Helsinki s heating needs.