Thursday, November 02, 2006

Keep warm this winter the green way...

...and invest in a wood burning stove.



It might seem like a technological step backwards, but today's wood burning stoves are mean, green heating machines. With the carbon neutrality of wood as a fuel, a clean, efficient stove can make expensive heating bills a thing of the past.

Wood is a renewable fuel: more can easily be grown. And while burning wood releases carbon into the atmosphere - just like fossil fuels - that carbon is taken back out again when new plant growth occurs. This means that wood is a carbon-neutral fuel (provided, of course, that the amount of wood burnt is equalled by new wood growth). With increasing gas and electricity prices, this makes wood an increasingly attractive way to provide heating and hot water at a domestic level.

There are two main types of wood burning stove: the conventional 'old fashioned' type in which you burn wood or wood chips, and the more high-tech wood pellet burning stoves.
Wood pellets are made from waste material such as sawdust and grain husks, which is
compressed into small pellets. Most pellet stoves involve some sort of computer control, which dtermines the flow of fuel into the burner; ensuring maximum efficiency. This higher complexity means that pellet stoves tend to be more expensive than wood chip stoves - a few thousand pounds compared to a few hundred. However, pellet stoves have many more advantages.
The stoves are more efficient, release far less pollution (such as toxic carbon monoxide and large particulate matter), and leave far less waste residue after burning. The residue from both wood chip and pellet stoves can be used as fertilizer in the garden.
The advantage of wood chip stoves is that the fuel is more readily available. Waste wood is plentiful, available from tree management in parks and as waste from industrial processes. Quite often it is free for the taking! Pellets, on the other hand, must be bought specially and quite often supply can be a problem. Pellet stoves also require a supply of electricity to run the pellet feed mechanism.
Both types of stove can be used in a variety of ways. They can be used to provide heat directly, or as a fuel for boilers for central heating, or as a combination of the two - the stove would be connected to a back-boiler which would provide hot water.
You could even go further and get an integrated range cooker stove. Very traditional!
Stove design has also come a long way - many modern designs are available as well as traditional ones; some would not look out of place in a minimalist's apartment.


Images from Stoves Online


Last, but not least, there are grants available for the purchasing and installation of both wood chip and pellet burners on both the domestic and community scales.
On the domestic scale, funding is available as follows:
Automated wood chip or pellet stoves (single room heaters) £75/kW up to a maximum of £600 per installation
Automated wood chip or pellet boilers (ie whole house wet central heating systems) £85 per kW up to a maximum grant of £1100 per system.

This site has a good explanation of wood as a fuel, and contains some energy values and efficiencies for the more technical minded.

As a brief aside: avoid electrical fan heaters! These operate at very high wattages, and can rack up your electricity bills something terrible...

More informtation here and here about wood as a fuel and the relative costs.

Read more...