English word pellet – means ball, little ball – is the common name for wood granules, whose production was started in seventies in USA and Canada.
A new type of fuel was developed, that enables wood and its waste to be burnt In the boilers with automatic feeding to the combustion chamber. Advantages of the pellets as an ecological fuel were quickly noticed in Scandinavian countries and Austria, Germany and Denmark, where sale of pellets increases every year by 30 – 40%. Following the above, the number of pellet manufacturers is continuously increased, which resulted in stabilization of pellet prices in the entire European Union.
This fuel has the calorific value of approx. 17 MJ/kg, its moisture content ranges from 8 to 12%, ash content up to 0.5 %. Granules are packed in 16 and 25kg bags or big-bags.
Local factories, as well as large fuel concerns are engaged in the pellet distribution in Europe, which demonstrates that it is important and perceived by all as alternative to other types of fuels. Replacement in the combustion process of: coal, oil or gas with pellets has a significant influence on emission of carbon dioxide, sulphur oxides and others into the atmosphere. The big advantage of pellet combustion is small amount of harmless ash (that can be even dumped in the garden).
Pellets have high energy content of min. 4.9 KWh/kg. The equivalent of 1000 l of oil is 2000kg, that is 3.2 m3 of pellets. In the case of a typical single family house, the annual requirement for oil is 2000 l, which corresponds to approx. 4 t of pellets.
Savings connected with switching to pellet heating may even reach 60-65% of annual heating costs. With the increase in fuel oil and gas prices, there is an increase in interest in pellets as the fuel to be burnt in the central heating boilers.