Wärtsilä is supplying two BioPower moudularised power plants for wood fuelled combined heat and power production at Finnforest Corporation’s Vilppula and Renko sawmills. The new plants use the rotating conical grate biomass burning technology that Wärtsilä ­ up until recently exclusively a reciprocating engine specialist ­ now owns through its acquisition of Sermet. The Finnforest order represents an important step for Wärtsilä in its strategy of moving into the market for small standardised biomass plants.

The Vilppula and Renko sawmills are the largest business units in Finnforest’s Solid Wood division. The Vilppula sawmill is the largest in Europe. Finnforest Corporation, owned by the Metsäliitto Group, is Europe’s biggest wood group with net sales of EUR 1.8 billion.

At the Vilppula sawmill, Wärtsilä will construct a BioPower 5 heat and power plant, in addition to a BioEnergy heat only plant. In total the electrical output will be 2.9 MW and the total heat output 22.5 MW. Together the plants will produce over 70 per cent of the electricity needed and 100 per cent of the heat required to dry wood at the sawmill, they will also provide all the heat required for the town of Vilppula.

The plant at the Renko sawmill, a BioPower 2, will be smaller in scale, electrical output 1.3 MW and 8 MW of heat. It will produce the majority of the heat needed in the drying processes at the sawmill and approximately 50 per cent of the electricity required by the sawmill.

The fuel used at Vilppula and Renko will be byproducts of the sawing process, primarily bark and sawdust. The power plants are due to enter operation in the autumn of this year.

Performance data for the BioPower 2 and BioPower 5 cogeneration units offered by Wärtsilä are shown in the table, left, the Finnforest BioPower units being of the HW type.