Is short rotation coppice
now a viable option?
Mike Williams reports
MOST of the £30 million of government funding announced last month to encourage production of crops for fuel is likely to go to farmers growing short rotation coppice, which should be good news for contractors who offer the specialist services growers need.
The idea of growing willow and poplar to be coppiced or harvested to provide fuel for small power stations has suffered from a credibility gap. There has been plenty of talk dominated mainly by enthusiastic environmentalists, but farmers who looked for signs of practical progress and financial backing were often disappointed.
Even the sceptics must be realising that the situation is changing. The £30 million of funding over three years is a significant commitment, and further evidence of real progress will come early next year when the first UK power station designed to burn wood chips from short rotation coppice (SRC) is due to start generating electricity at Eggborough, Yorkshire.
Another factor encouraging interest in growing wood for fuel is the fall in farming profits. When SRC was discussed in the early 1990s many farmers were earning healthy margins, and there was less incentive to venture into an unconventional crop that is virtually untried. Since then farming profit margins have fallen and there is plenty of interest in alternative crops such as SRC.
Project Arbre in Yorkshire, backed by First Renewables, is designed to supply electric power for about 33,500 people, and will need about 37,000 tonnes of wood fuel (on a dry weight basis) in a full year. About half of this will be from forestry waste and the balance will be in the form of chips supplied from 1550 ha or more than 3800 acres of willow grown within a 40-mile radius of the plant.
About 60% of the required acreage has been planted in a programme designed to ensure a phased supply of crop material, with the balance due to be planted next year.
Project Arbre experience suggests that contractors will have a major role to play in SRC crops. The grower will usually prepare the ground for planting and probably deal with weed control in the early stages of willow or poplar growth and provide the rabbit fencing which is essential on most sites, but planting and harvesting are the big jobs needing special equipment provided by contractors.
Some contractors have already added SRC work to their list of services. Phil Collins operates a general agricultural contracting business at Kington, Worcester, and he is closely involved with some of the trials and development work, including the Salix Project in mid Wales. He is designing his own planter for willow and poplar rods and he uses his self-propelled forage harvester with a special header to cut and chip the crop.
"I believe there is a good future for SRC, and it will provide an alternative enterprise a lot of farmers will welcome," he says. "The Government has shown its commitment to developing alternative energy sources, but this must extend to making the funding available to build more power stations. I hope this will happen as soon as the Arbre station is operating."
Tim Shuldham of Retford, Notts, is also concerned about the lack of funding for new power stations. He is a land agent and also a partner in Coppice Resources, formed to carry out research and development work in SRC production.
"Although finance is now available for planting energy crops, there is no news about the funding that will be needed to build the power stations, and one is not much good without the other," said Mr Shuldham.
At this stage the willow planted for Project Arbre is the only commercially grown SRC in the country, although there is also a substantial acreage for demonstrations and trials purposes. Further commercial plantings will not be possible until the power station plans are firmed up, and proposals for new SRC fuelled power stations face financial and planning uncertainties.
Another uncertainty for contractors hoping to benefit from growth in SRC cropping is the type of equipment they will need. Established ideas about planting rods vertically are being challenged by the lay-flat approach developed by Border Biofuels, and Tim Shuldhams company has developed a tractor mounted harvester which could be an alternative to using a self-propelled forage harvester.
The forage harvester approach is attractive because winter harvesting of willow and poplar provides additional work for an expensive machine which would otherwise be idle.
But doubts about the suitability of the forager have come from ETSU, which says the size and weight of a forager make it unsuitable for the difficult working conditions in some of the areas where SRC will be grown.
The alternative, developed by Coppice Resources under an ETSU contract, is a cutting attachment on the rear of a reverse-drive tractor, with the chipped material blown into a trailer towed from the front hitch of the tractor.
"We have done a lot of development on the cutting mechanism in order to achieve a clean cut and good height control, which are important factors in SRC harvesting, and the tractor mounted machine works well, but the overall length is a problem," said Mr Shuldham. "It could be suitable for small areas, but at this stage the forage harvester is probably more appropriate for large areas of SRC." *
In action with Coppice Resources prototype reverse drive unit.
Far left: Good cutting height control offers regrowth advantages.