Biomass energy is derived from five distinct energy sources: garbage, wood, waste, landfill gases, and alcohol fuels. Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Rotting garbage, and agricultural and human waste, release methane gas - also called "landfill gas" or "biogas." Greengairs is Scotland's largest landfill site, handling around 750,000 tonnes/year of waste. The power plant at Greengairs uses landfill gas to generate almost 8MW of power. Biodiesel can be produced from left-over food products like vegetable oils and animal fats or from primary sources such as oilseed rape, which is the major biofuel feedstock grown in Scotland.
The most common use of biomass is the direct burning of wood. While burning fast-growing species certainly qualifies as renewable energy on one level, using biomass as a fuel produces air pollution in the form of carbon monoxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants, in some cases at levels above those from traditional fuel sources such as coal or natural gas.
E.on Renewables began generating power from the wood fired Stevens Croft power station near Lockerbie in March 2008. This 44MW capacity unit is the biggest biomass plant in Scotland and will generate enough electricity to power the equivalent of 70,000 homes every year. Peel Energy is proposing to develop a 20MW renewable energy plant fuelled by biomass. If planning permission is granted, it is proposed that construction starts in 2012 and that the plant could commence commercial operation in 2014. However, there are serious doubts as to whether enough indiginous wood is available to feed the plant, and environmental groups such as FOE Scotland are questioning the wisdom of large-scael biomass electricity generation with their 'Back Away from Big Biomass' campaign.
Smaller biomass CHP (combined heat and power) systems are operating in some areas, notably Argyll where CHP schemes operated by Fyne Homes in Lochgilphead and Campbeltown use woodchip boilers to power hosues and a respite care unit. However, the biggest use of biomass however is probably for domestic heating, with a resurgence of interest in woodburning. In particular, the development of automated wood pellet burning boilers has allowed wood fired central heating systems to achieve levels of convenience previously only associated with oil and gas fired systems.
|Biomass Action Plan for Scotland|
|2007 PDF document published by the Scottish Executive in March, 2007 dealing with Bbiomass heating, electricity from biomass, transport biofuels, biomass supply and environmental impacts.|
|A partnership between the Forestry Commission and others. Its role is to increase the awareness and understanding of the benefits of woodfuel technology and to promote cost effective heat generation in commerce and industry.|
|'Dash To Biomass' Could Damage Environment And Economy|
|ConFor news release dated April 2010 voicing fears that the UK's plans for large scale biomass electricity generation (including over 600MW in Scotland) will be bad for the environment and bad for the economy.|