Biomass boilers have been around for centuries, mainly as wood burning stoves. Now they pack a new punch as a carbon neutral way of generating heat, helping reduce the amount of harmful carbon emissions.
In the last few years it became impossible to get away from the hype about green technologies versus fossil fuel technologies. Solar panels, solar thermal and wind turbines have ruled the headlines with major projects undertaken around the world. However, let us not forget the humble wood burning stove. Although not as flashy as a gleaming white wind turbine rotating at a steady speed over a green hill or a high-tech solar photovoltaic cell generating electricity out of simple sun light, the wood burning stove has some important benefits to bring to the table.
In order to fairly evaluate biomass boilers, it is important to explain how they work. Biomass boilers burn wood, which is an organic fuel (hence the bio-fuel label), rather than fossil fuels that come from the ground (oil, gas, coal). The boilers burn untreated wood (such as logs, wood chips) and treated wood (most common being wood pallets).
Wood pallets are the most efficient of the wood fuel types. They are made from sawdust which is compressed at high pressure into small pallets (roughly the size of AAA batteries). They are made from by-products of local carpentries, joinery workshops and sawmills. The high pressure compression removes moisture and increases their output to weight ratio, meaning you need less fuel to get the same amount of heat. Another benefit is that they don't leave as much residue on the burner due to full burning reaction.
Fossil fuels are normally associated with global warming and climate change. When fossil fuels are burned (e.g. natural gas in your domestic boiler), they release CO2 as part of their natural chemical reaction. This gas was captured within the fuel for millions of years in underground deposits. By burning it now, we release this gas into the atmosphere. Biomass boilers are considered to be carbon neutral heating technologies, because they only release CO2 that was captured by the plant during its growth years, thus not bringing new CO2 into the global equation.
Before installing a biomass boiler it important to consider a few aspects of this technology:
* Wood supplier - it is much easier to run a biomass boiler if you have a local sawmill or carpentry workshop that can provide you with a reliable source of sawdust, wood chips or even wood pallets.
* Space consideration - unlike modern gas and oil boilers, a biomass boiler is larger in size and requires a large area nearby to store the wood. It is wise to plan for this space in advance.
* Chimney consideration - a biomass boiler requires a chimney, and more specifically a lined chimney that is designed for wood fuel. However, in most cases such lining can be retro-fitted to carry the smoke.
* Smoke implications - some areas are designated 'Smoke Free'. If you live in such are, you need to find a unit that is exempted under the Clean Air Act.
* General considerations - check with your council on other implications in reference to your boiler installation. If you live in a conservation area or your property is a listed building, you may have to clear this with the planning department at your council.
