In 2004 the share of bio-fuels in the Group’s own energy production was 62.5%, a slight increase from 61.5% in 2003. In absolute terms the total use of bio-fuels has increased by 6 000 TJ. The most important sources of bio-fuel are black liquor, bark and fibrous sludge.

Power plants under construction at Skoghall Mill and Kvarnsveden Mill will increase the share of bio-fuels. Kabel Mill and its local energy supplier have jointly built a new bio-fuel power plant, which started operations in December 2004.

Major investments are by no means the only way to increase the use of bio-fuels. Smaller steps also matter, particularly when they are continuous and systematic. At Veitsiluoto Mill, for instance, a new bark press was installed in 2004, improving the dry content and energy value of the bark bio-fuel. Bark and wood residual handling was also improved at Celbi Mill. At Sachsen Mill new equipment has been installed for storing and conveying substitute fuels that can be used instead of natural gas in the residue boiler.

In a large company like Stora Enso, it is also possible to channel bio-fuel to other units, if there is a surplus in one mill. A new example of such a scheme comes from Oulu Mill, which uses excess bark from Kemijärvi Pulp Mill.

Bio-fuels already account for some 63% of Stora Enso's total annual fuel consumption of 221 400 TJ (215 300 TJ in 2003). Combined heat and power production covers 32% of the Group's total electricity consumption of 24.4 TWh.