10 April 1999

yielding up FUEL OPTION

Better yields could push short rotation coppice towards being an economic alternative to fossil fuels, reports Debbie Beaton.

IN theory short rotation coppice has everything going for it: a natural and renewable fuel which can reduce atmospheric carbon dioxide, one of the main greenhouse gases contributing to global climate change.

Add in Britains commitment in Kyoto to cut UK greenhouse gas emissions by 12.5% by 2010 – and the DTIs promise of generating 10% of electricity from renewable sources by the same date – and growing wood fuel crops appears to be a ready solution.

But simple economics currently preclude short rotation coppice as a practical option. Energy from fossil fuels is cheap at 2.5p/kW/hour, but biomass at 5.5p/kW/hour is over twice that.

Although it is not a strictly accurate economic picture of the two types of energy because fossil fuels themselves are heavily subsidised, coppice enthusiasts recognise that the only way biomass can be seriously considered as an alternative fuel source is to reduce its production costs.

"Governments are not going to promote biomass with an open cheque book," said Silvan Robinson, chairman of British Biogen, speaking at a Forestry Commission symposium.

Thats why he endorsed a £3m research project currently being conducted by the Forestry Commission to find ways to reduce biomass production costs.

Better yields are one way of doing this so news of willows reaching 17t/ha of oven dried wood in year one of production has made researchers optimistic that they can put biomass on the fuel map. The Forestry Commissions Paul Tabbush puts it into perspective: "This yield is 70% greater than the yields assumed in planning the 8-megawatt, wood-fuelled ARBRE power station being built at Eggborough in North Yorks."

New Swedish bred willows promise even higher yields. These are preliminary results, but the research aims to:

&#8226 boost yields

&#8226 identify best sites of production

&#8226 reduce establishment costs

&#8226 identify best cultural techniques

&#8226 identify herbicides, fungicides and fertiliser strategies

Mr Tabbush believes the trials will enable new biomass industries to be planned with more confidence and less risk.

Last summer short rotation coppice growers received a grant boost; the ceiling for establishment grants – available from the Forestry Commissions Woodland Grant Scheme – was increased to £1,000/ha (£400/acre). Set-aside payments are also available for short rotation coppice grown on eligible arable area.

What is short rotation coppice?

Trees, mainly willow or poplar, grown as energy crops. They are harvested every two to five years and the wood is chipped to provide fuel for power stations.

About 125,000ha (312,500 acres) of short rotation coppice would be needed for the UK to meet its commitment to cut greenhouse gas emissions by 12.5% by the year 2010.