In parts 3 and 4 we have seen how wood can be used to provide us with shelter and clothing. In this instalment, we consider how wood can be used to supply us with energy.
We have been using wood as a source of energy for the last 800,000 years, but 1/3rd of the world population still rely it on as their primary source of fuel and consumption is increasing fast in the developed world.
According to the FAO, globally around half of all wood is used for energy production.
The three main uses discussed here are for heat, electricity and the production of liquid biofuels.
The use of wood for energy is increasing rapidly. For example, in Europe between 2009 and 2020, per capita consumption of biomass use is expected to triple.
Wood is also used to generate electricity, such as in Combined Heat and Power plants and dedicated electricity power stations. A wide range of facilities are used, demonstrating the versatility of wood as a fuel.
The largest, Drax power station is expected to use 7.5 million tonnes of pellets, equivalent to 15 million green tonnes of wood per annum by 2018. This makes it the world’s largest single point user of wood in the world, consuming more than the entire UK timber harvest. Because of this, Drax imports pellets, mainly from North America.
Drax is the largest power-station in Western Europe, generating 7% of the UK’s electricity. Half of its generating units have been converted to burn wood.
On a more regional level, a number of industrial energy users now use locally sourced woody biomass to provide combined heat and power. As the ‘surplus’ heat is used, as well as locally available fuel, this can be particularly efficient.
UPM Caledonian used to be the largest point user of electricity in Scotland until it commissioned its CHP biomass plant using locally available woody biomass. The heat is used in the manufacture of magazine grade paper.
At the Diageo distillery at Cameronbridge, the largest in Scotland, 95% of the energy is provided from biomass, with the heat used for distillation.
Even more radically, wood is now being used to manufacture liquid bio-fuels, such as diesel. This can be manufactured using a range of technologies, such as the utilisation of pulp by-products, pyrolysis or biochemical fermentation.
The UPM bio-refinery at Lappenranta is the world’s first commercial scale process producing wood-based bio-diesel. It can produce 120 million litres annually.
So why, in the 21st century is global wood-fuel use increasingly so rapidly?
Firstly, wood is a great store of energy. Indeed, dry wood has a similar energy content to coal. However, unlike fossil fuels, timber does not release ‘fossil carbon’. The real carbon benefits however are through the ‘smart’ use of timber- for example using ‘waste’ wood (e.g. recycled wood) which otherwise would not be used, but would eventually decay.
Wood is also available locally, and the best solutions are specifically designed to use what is available- normally low value sources of woody biomass. By contrast, fossil fuel production is highly concentrated. For example, Drax Power station now sources its coal from Australia, Colombia, Poland, Russia and South Africa.
The flexibility of wood means that it can be used by an astonishing range of technologies. For example, the cost of a BioLite stove is around £35, whilst the Lapeenranta wood bio-refinery cost £140 million.
The best energy solutions use appropriate technology and locally abundant fuel sources. This BioLite stove has been developed to improve fuel efficiency and burn cleanly and is being supplied to a number of developing countries
“Around 3 billion people rely on open fires or traditional stoves as their primary form of cooking and heating”
The views and comments are those of the author and do not necessarily reflect those of any particular organisation.
Jason Sinden is a professional member of the Institute of Chartered Foresters and a Director of Tilhill Forestry Ltd.
Further information is available from:
Jason Sinden Linkedin profile
Institute of Chartered Foresters Website
Tilhill Forestry Website