The Salmisaari power plant in central Helsinki produced heat and electricity for the country's capital, also emitting carbon dioxide (CO2) that contributes to deadly climate change.

As a result of the closure, Helen's yearly CO2 emissions will decrease by an estimated 50 percent compared to 2024 levels and Helsinki's total emissions will drop by 30 percent, the energy company said in a statement.

Calling it "the end of the era of coal" and a step towards both cleaner and more self-sufficient energy production, the closure of the power plant also meant that Finland's total emissions will fall by nearly two percent compared to last year.

"Giving up coal is a concrete step towards Helen's clean, self-sufficient and affordable energy production," the company's chief executive officer Olli Sirkka said.

In 2022, 64 percent of the company's district heating production still originated from burning coal -- which was delivered by ships to Helsinki.

Now that smoke has stopped billowing from the plant's chimney, the company's emissions in 2025 will amount to 20 percent of what its total emissions had been in 1990, the company said.

However, a coal reserve would be kept in storage to be used "if necessary".

Meanwhile some companies in the Nordic country still use small amounts of coal for energy production.

Finland has decided that the use of coal in energy production will be banned as of May 1, 2029.