In five years’ time, heating for the inhabitants of the towns of Jõhvi and Ahtme in north-east Estonia will be based on peat and woodchips and produced together with power. As a result, Estonia will be able to reduce CO2 emissions by 200,000 tons a year.

Estonia must live up to the EU’s environmental directives, and the only realistic option for the region’s 53-year-old oil shale plant is to replace it with a new combined heating and power plant. Local district heating company Kohtla-Järve Soojus, in collaboration with its co-owner the Estonian electricity supply company Eesti Energia, has therefore decided to build a biomass based CHP plant.

The proposed plant also accords well with Estonia’s declared political goal of increasing electricity production based on sustainable energy sources.

Environmentally difficult to deal with

"Oil shale has a number of disadvantages,” explains COWI project manager Thomas Engberg Pedersen, who has analysed the income basis for the area and completed a financial analysis. “The calorific value of oil shale is low so large quantities must be burned, which in turn produces polluting ash equal to about half the original quantity of shale."

However, Estonia still hopes that in future the country can continue to use oil shale in its larger power plants, in part because it is a naturally occurring fuel and full cessation of production would place many mining jobs at risk.

"But in order to meet the EU's environmental directives, Estonia must either implement environmental improvements at its oil shale plants or consider replacing oil shale with other, more environmentally friendly fuels," adds Thomas Engberg Pedersen.

"In this particular case, which involves a medium-sized plant, at present it would be prohibitively expensive to establish a new oil shale plant with the requisite environmental measures in place. Therefore the decision was taken to opt for alternative sources of fuel."

Published: 10.11.2004
By: Christina Tækker, cht@cowi.com