Biomass Crops Fill-in for Wood Waste

Energy provider RWE owns a power station in Didcot, and ESD Biomass will generate electricity at the station from purposely-grown, or "coppiced" energy crops - in this case the willow. Coppicing is the art of cutting of trees and shrubs to ground level allowing vigorous regrowth and a sustainable supply of timber for future generations.

The partnership will help RWE meet the environmental requirements under the UK Government's Renewables Obligation plan. The companies plan to offer contracts for growers and landowners to supply at least 30,000 tons per year of short rotation willow for renewable electricity generation. This would involve the cultivation of around 3,000 hectares (7,350 acres) of land and the energy crops will come straight from the field and be co-fired at the existing Didcot power stations.

"By March 2009, generators will have to make sure that an increasing proportion of the biomass they use comes from purposely grown energy crops, including willow," said Kevin McCullough, who is the director of renewables at RWE. "This is the first time producers and a large energy generator have agreed a long-term relationship to co-fire specifically-grown energy crops within existing power stations rather than just making use of biofuels that happen to be around."

Previously biomass has been used opportunistically, with generators making use of existing fuels. This agreement aims to create a long-term supply chain to help establish a UK energy crop market.

The use of biomass fuels has an important role to play in helping to meet Government targets to reduce greenhouse gas emissions, according to the RWE. The utility has been investigating the potential of used vegetable oil, olive residues, palm kernels, tallow, recycled 'clean' wood, and coal or wood briquettes.

This will be the second biomass project for RWE, as the utility has operated a co-firing plant for the past year at Aberthaw power station in Wales. Up to 20 tons of wood chips, sawmill by-products and woodland residues are burned per hour. Eventually, the plant will extend its co-firing operations so up to 4 percent of the coal currently used at Aberthaw is substituted with biomass.

RWE's Didcot and Tilbury coal-fired stations are also beginning to co-fire biomass. Power produced at these stations is expected to produce enough green electricity to supply up to 20,000 homes, and plans are in place to significantly increase this contribution.

"The move towards a low-carbon future is challenging and complex," said McCullough. "The Government's target of producing 10 percent of the UK's electricity requirements from renewable sources by 2010 will require an important contribution from biomass projects. We see co-firing along with on-shore wind as crucial in the short term, while medium to longer-term technologies such as large scale offshore wind and marine energy projects are being developed."