How Helsinki ditched coal in just 2 years

A few years ago, if you turned on the heat in an apartment in Helsinki, the energy typically came from coal. But the city’s power company shut down one coal plant in 2023, and the remaining one closed this week—four years earlier than a target set by the national government.

“Within two years, we have completely phased out coal,” says Olli Sirkka, CEO of Helen, the power company, which is a subsidiary of the city.

The city has one of the world’s biggest district heating systems, with a network of underground pipes filled with hot water that deliver heat to buildings. It takes a huge amount of energy to run. One large chunk of that now comes from wind power, which has more than doubled in Finland since 2020. Helsinki is now building the world’s largest heat pump, which will send heat to 30,000 homes when it starts running in 2026. At the site of one of the closed coal plants, the city is also building a new facility that will capture heat from the Baltic Sea.

Some of the energy also now comes from wood pellets, which Helsinki is using temporarily as it transitions completely away from combustion. (Wood helped replace natural gas from Russia after the invasion of Ukraine, but isn’t a good long-term solution. Burning it still produces CO2, it puts pressure on forests, and it’s more expensive than other alternatives; Finland plans to phase it out completely by 2040.) Helsinki also uses some hydro and nuclear power, and as much waste heat as possible. That includes capturing heat from local data centers and wastewater.