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• Biomass Co-Firing

Biomass Cofiring

Description

With biomass cofiring, wood is substituted for a proportion of the coal used in coal-fired power stations. It is promoted as a way of reducing the greenhouse intensity of electricity.

Readings

Biomass Co-firing - Australia

Macquarie Generation Biomass Co-Firing. Australian Greenhouse Office

Biomass co-firing is the combustion of biomass combined with fossil fuels such as coal in power stations to produce electricity.

Biomass is organic matter available on a renewable basis from sources such as forest and mill residues, agricultural crops and wastes, wood and wood wastes and dedicated energy crops.

Australia produces about 50 million tonnes of biomass residue annually. Much of it is either burned in the field and factory sites, stockpiled or placed in landfill.

The natural breakdown of biomass releases previously stored carbon as part of the carbon cycle. When placed in a landfill the biomass can decay anaerobically and produce methane. Methane is a potent greenhouse gas estimated to be 21 times more damaging than carbon dioxide (CO2). By co-firing with fuel diverted from landfill the greenhouse benefits are even more significant.

Under accounting measures adopted by international agencies researching climate change, the use of sustainably harvested biomass for electricity generation is granted a 'zero' greenhouse gas status.

To determine the feasibility of biomass co-firing, Macquarie Generation conducted a trial at their Liddell Power Station, integrating untreated timber industry by-products such as sawdust and wood shavings into the coal fuel stream at a maximum blend of five per cent. The biomass contributed 4,760 megawatt hours of energy. If this power had been produced from coal it would have produced about 4,500 tonnes of CO2.

The trial enabled Macquarie Generation to sell almost 3,000 megawatt hours of greenhouse emission ‘credits’ to Great Southern Energy and Energy Australia. These two energy retailers are required to meet greenhouse reduction targets as part of their NSW retail licenses.

2003.4.13