Wood pellets are a clean, CO2-neutral and convenient fuel, mostly produced from sawdust and wood shavings, compressed under high pressure using no glue or other additives.Burning wood pellets for heat and power has become common across central and northern Europe and yields considerable environmental and economic, benefits. With a rapidly growing share of the market, they are a key technology for increasing biomass utilization in Europe and beyond, especially in the heating sector. Pellets are also an excellent way of using local resources, a concrete contribution to CO2 reduction.
A number of different systems are suitable for using wood pellets these include:
Pellet stoves: These are often modern appliances in an attractive design where bagged pellets are normally used. They are ideal for milder climates or as a heating source additional to an electric, gas or oil heating system. The largest market for these in Europe is Italy.
Pellet boilers: These are fully automatic central heating systems for residential heating with bulk delivery of pellets. In parts of Europe, pellets are usually delivered by a special tanker truck and blown into storage systems. The pellet boilers are connected to the pellet storage by an auger or Archimedes screw (mechanical fuel feeding system) or a suction system (pneumatic system) from which the pellets are transported automatically into the boiler. No manual work is necessary for the fuel supply, making such systems as user-friendly as a gas or oil-fired heating system – the heat distribution system within the building is typically water-based.
Well developed markets for pellet central heating systems are found in Austria, Germany, Sweden and France. While the investment costs for such systems are about 30% higher than for an oil-fired heating system, fuel costs are considerably lower and there is a good return on investment.
Utility-scale boilers: In northern European countries, such as Sweden or Denmark, pellets are also used to fire biomass district heating or combined heat and power (CHP) plants. A growing market is also co-firing, whereby pellets are used to partially substitute coal in large power plants – for example in Belgium, the Netherlands and the UK.
Modern pellet stoves and pellet boilers require pellets of a high quality. Austria was the first country to adopt a pellet standard (the Austrian ÖNORM M 7135) which helped the market development tremendously; from the offset, only pellets of a clearly defined quality were available, allowing boiler manufacturers to develop very low-emission appliances.
Several other European countries followed by introducing quality standards for wood pellets (such as the German DIN plus standard). And, currently, a European standard is under development, with its adoption anticipated for 2009. In addition, with an increase of global trade, a world-wide certification for the sustainable production of pellets will become increasin
