8:24am Wednesday 6th May 2009
By Keith Thomson
Over the centuries, the natural woodland cover world-wide has been substantially reduced. What’s left is now being plundered for biofuels and soya for cattle food.
Some suggest that this destruction does little to add to the CO2 in the atmosphere, as the burning only releases the carbon recently taken out of the air by the growing plants.
However, this is only true if the trees are replaced, and it also disregards the role they play in regulating water run- off into rivers and the stabilising of soils.
Moreover, burning a tree releases all the CO2 into the atmosphere at one go, and it would take a more than a century for a growing tree to remove it all again.
Despite this, there are situations when burning recently-grown vegetation may have merit – a very efficient power station near Cambridge burns 200,000 tonnes of straw to produce heat which can generate 38MW of electricity.
The downside is that the straw isn’t ploughed back into the soil to help replace artificial fertilisers, and transporting the straw produces a considerable amount of CO2. However, there are now plans to develop mainstream biomass production, and Drax, the UK’s largest coal-fired power station, will build carbon-neutral plants at Immingham, Hull and at Selby, close to the present power station. It will be 2020 before this £2bn project is complete, but the first step will be a straw-burning unit at Goole later this year.
While the port and waterway connections suggest that much of the timber fuel will be imported, there’s scope for local farmers to use marginal land to grow fast-growing willow and grasses such as miscanthus, a tall elephant grass. A bonus is that the waste heat can be used to grow vegetables, fruit and flowers under glass.
Yorkshire could show the way again.
© Copyright 2001-2012 Newsquest Media Group
http://www.thetelegraphandargus.co.uk/trade_directory/