High oil and gas prices are making pellet-fired boilers particularly attractive. More and more consumers are opting for this alternative which is both economical and environment-friendly. Buderus and Junkers are both offering special pellet-fired boilers in response to the growing demand.

Wood pellets are pure biomass, consisting of waste from the wood-processing industry. They are produced by forcing sawdust and wood chips under high pressure through a die without any chemical additives to form cylindrical rods and then cutting them to the desired length. It’s a straightforward process.

Wood pellets are now available throughout Germany, after Austria and Scandinavia in particular had done the initial work to develop and popularise this technology. The fuel is delivered to the house as conveniently and cleanly as fuel oil. A tanker pumps the pellets through a hose into the storage room or bunker. If you only require relatively small quantities, it is also possible to buy pellets in bags. Since these small cylinders have a high energy density, the annual requirement for a family home is no more than about nine cubic metres. The feed to the heating system is also very simple as modern pellet-fired systems work almost fully automatically. A suction system or an electrically powered spiral conveyor transports the material which is then ideal for "trickling" into the burner.

The sums add up: wood pellets have a calorific value of almost five kilowatt-hours per kilogram. The energy content of two kilograms of pellets corresponds to that of one litre of fuel oil. Two kilograms cost 0.32 euro including VAT. In rough figures, pellets, whose price is very stable, are therefore currently half the price of fuel oil. Around 6,000 kilograms of pellets are enough to supply a family home heated averagely with a heat requirement of ten kilowatts for a whole year – at a price of approx. 960 euro. Although the purchase cost of a pellet-fired boiler is higher than that of conventional oil- or gas-fired systems, the bottom line is that the investment costs including the chimney reconstruction which is usually necessary pay are recovered in five to eight years. The grants payable to private users by the state to assist with the purchase costs are included in this analysis.

But heating with wood pellets not only saves money, it also helps cut environmental pollution. Pellets are obtained exclusively from waste, meaning that no tree has to be felled to produce this fuel. Wood is also a renewable energy source; in other words its energy balance is CO2-neutral. Neutral means that, on combustion, the wood releases as much carbon dioxide as it absorbed while growing – and as it would release by degrading naturally. In the combustion of fossil fuels such as oil and gas, by contrast, carbon dioxide that has been locked up for millions of years is released which increases the CO2 levels in the atmosphere.

Incidentally, the German Federal Office of Economics and Export Control supports the installation of pellet-fired heating systems in private homes with grants of 1,500 euro or more, depending on the heat output. And KfW Förderbank offers a number of loans to cover the rest of the capital cost. More information is available at www.bafa.de and www.kfw.de.