Helsinki Energy is considering the possibility of using wood chips as fuel in one of the furnaces of the Hanasaari power plant, which now burns coal.
The move would be one way in which Helsinki could come closer to reaching its climate policy goals.
In January Helsinki agreed to a target under which 20 per cent of the city's energy would come from renewable sources by 2020.
Hanasaari currently has two coal-burning furnaces which produce both electricity and district heat. One of the furnaces produces about ten per cent of the city's total energy production.
The new biomass furnace would be set up alongside one of the coal units. The old coal furnace would be kept in reserve in case of possible shortages of biological fuel.
Pekka Manninen, director of Helsinki Energy, notes that the plans are still in an early stage.
For instance, it remains to be decided where the wood chips or pellets would be stored, where they would be bought from, and whether or not there is enough of the raw material available on the market.
Suggestions by politicians that the City of Helsinki set up a wood pellet factory of its own is not among the immediate plans of Helsinki Energy.
"Our starting point is that commercial players will deliver the fuel", Manninen says.
The price also remains open. Previously it has been calculated that converting the whole Hanasaari power plant to bio-energy would cost EUR 300 million.
The company has no idea of what a biomass furnace would cost. In any case the building would have to be expanded.
Helsinki's heavy reliance on coal and natural gas has come under criticism in recent years by environmentalists and even by Prime Minister Matti Vanhanen (Centre). Pekka Manninen insists that a wood-burning unit in Hanasaari would not be an about-face in the company's attitude.
"We have been going in this direction all the time. The goals that came in January mean that we will have to plan bigger and stronger measures."
Helsinki Energy is increasing its use of wind energy, and experiments are continuing in mixing biological fuel - wood chips or pellets - with coal in existing power plant furnaces.