– its new bioplant generates heat for almost 100,000 people

Together with the City of Espoo, Espoo-based energy company Fortum is committed to making district heating production carbon-neutral in Espoo, Kauniainen and Kirkkonummi by 2025. The new bio-heating facility built in Kivenlahti, Espoo,Finland, is a big step towards the goal: it replaced one of the two coal-fired units in the Suomenoja power plant. The replaced coal unit was permanently decommissioned in spring 2020.

“The new bioplant in Kivenlahti is a significant part of our Espoo Clean Heat program, where we replace fossil energy sources with smart and flexible solutions, including bioenergy, utilization of waste heat, and geothermal energy,” states Olli Heinonen, Fortum’s project manager.

The Kivenlahti bioplant is the largest plant supplied by KPA Unicon Oy to date. The Unicon Renefluid fluidized bed boiler has a fuel output of about 49 megawatts, but due to a flue gas condenser and heat pump technology, the plant can produce up to 58 megawatts of heat for the grid at best. On an annual basis, that means about 350 gigawatt hours, which is enough heat for nearly 100,000 people.

“According to our calculations, the new plant will increase the share of energy produced from biomass in the Espoo district heating network by about 60 percent. The carbon dioxide emissions will decrease by about 90,000 tons per year. For us, this project proved our ability to supply plants of this size, and it opened up a whole new market,” says Ilkka Linnas, project manager of KPA Unicon.

Citizens as neighbors

The Kivenlahti bioplant is located very close to a residential area, which is why special attention was paid to curbing plant noise, environmental impacts and local emissions.

“We have had an active dialogue with the City. In addition, we carried out noise modeling, and the noise has also been minimized with technical solutions and equipment placement. KPA Unicon has designed the layout of the plant and, for example, the air intakes, in such a way that the noise and sounds are directed away from the neighborhood,” says Heinonen.

The plant produces district heat from wood-based biomass, which consists mainly of fractions unsuitable for industry: forest residue chips and clean recycled wood. Energy sources come from the capital area and its surroundings. This will significantly reduce the supply of imported fossil fuels.

On average, 32 trucks—about half of which are fuel transports to the new plant—visit the plant site every day. In addition to the new biomass boiler plant, there are also two pellet-fired boilers at the plant site. According to Heinonen, transports are not made during the weekend.

“The new plant has two silos, and when the plant operates at full capacity, the two full silos can fuel the plant for about 2.5–3 days, depending on the quality of the fuel. Fuel transports are generally carried out on weekdays from 6 am to 10 pm.”