UK Boosts biomass energy

Already the home of the world's largest and most efficient straw-fired power station, and Europe's biggest plant powered by poultry litter, the UK is to build a biomass-fired power station with an electrical capacity of 44 megawatts.

The power station, which will use a mixture of renewable wood-based fuels, will be built at Stevens Croft, near Lockerbie in Scotland. Work there has already started and commissioning is expected by the end of 2007.

Plant-based biomass fuel releases precisely as much carbon dioxide as was removed from the atmosphere during plant growth when it is combusted.

Following commissioning, the Lockerbie plant will provide approximately 70,000 households with a CO2-neutral supply of electricity. By contrast, if 44 megawatts of electricity was generated in a coal-fired power plant, over 150,000 tons of carbon dioxide would be released to the atmosphere.

The development is being carried out by the UK arm of the German utility company E.ON ¨C a major UK energy supplier that already operates hydro, wind and biomass power stations in Europe. It is being managed by the UK's Mott MacDonald engineering, management and development consultancy.

The project is a truly international one: planned by E.ON UK Renewables, masterminded by UK consultants and using technology developed by Siemens of Germany and Norway's Kvaerner company. Siemens PG has constructed a number of biomass-fired power plants throughout Europe ¨C some of which use even more unusual sources of fuel, such as lemon peel and olive pits!

The Lockerbie station will initially use burned forest residue of sawdust, branches and offcuts from a nearby sawmill. Ultimately, it will consume some 475,000 tonnes of sustainable wood a year, including 95,000 tonnes of short-rotation coppice. Some 220,000 tonnes of oven-dried fuel will be sourced from nearby areas, with 45,000 tonnes being made up of willow trees harvested by farmers. An E.ON UK spokesman said: "We are hoping local farmers will switch to producing fast-growing willows which will be used in preparing the plant's fuel."

The station will create 40 jobs, with another 300 people directly employed in related forestry and farming operations. The project is also expected to lead to further investment in sawmills in the region to provide feedstock for the biomass generator.

Currently, the UK's largest biomass power producer is a poultry litter station, producing 38.5MW of electricity in Norfolk, eastern England. As well as producing enough power for a town of 93,000 homes, the plant provides a welcome disposal solution for the 400,000 tonnes of litter produced each year as a by-product of the local poultry industry.

When used as a fuel, poultry litter has nearly half the calorific value of coal. An added bonus is that ash, produced as a combustion by-product, can be recovered from the furnace and exhaust flue and processed as a high quality fertiliser.

Eastern England is also the home of the largest straw-fired power station in the world. The 38MW Ely power station in Cambridgeshire consumes 400,000 bales of straw, collected from farms within an 80km radius and burned to make power for 80,000 local homes.

The range of fuels used has recently been widened to include miscanthus and oilseed rape, which could reduce costs and increase security of supply.

An increase in biomass will definitely have a knock-on effect on agriculture. A biomass industry spokesman said: "If biomass takes off, then farmers could plant thousands of acres of land with energy crops such as willows and miscanthus, or elephant grass, a bamboo-type grass which would be harvested to fuel small power stations."

Britain's energy policy target is 10 per cent renewables-based power generation by the year 2010. Biomass and wind power are expected to be the main sources chosen by energy companies to meet this target. If so, the UK will need to build many more biomass power stations to increase the number of megawatts generated ¨C from today's total of 100MW to something nearer 1,000MW.

The news source is from the British Embassy to China and edited by the People's Daily Online