Environment Agency casts doubt over benefits of biomass power
Tuesday 14 April 2009
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| The Agency's report suggested biomass fuels "generally" save carbon emissions, but its warnings about certain cases of imported crops are being highlighted by national headlines |
The Environment Agency has attacked certain forms of biomass power generation for emitting "more greenhouse gas emissions overall than using gas".
A report published by the Agency today identified straw-fired power stations as among the worst performers in achieving carbon emission cuts compared to fossil fuel use.
The government's pollution watchdog was calling for new rules requiring biomass schemes to report publicly on their emissions, including the production and transport of fuel to their plants.
But in a report already inspiring national headlines suggesting "Biomass Worse Than Fossil Fuels" and "Biomass Power Could Be Harmful", the Agency highlighted concerns about biomass projects shipping fuels in over long distances, and the use of nitrogen fertilisers in growing energy crops.
The report, entitled Biomass: Carbon sink or carbon sinner? was assembled by consultants at AEA Technology on behalf of the Agency, and is now being carefully digested by the renewable energy industry.
It said energy crops and waste materials "could play an important role" in meeting UK renewable energy and climate change targets, and concluded overall that: "Greenhouse gas emissions from energy generated using biomass are generally, but not always, lower than those from fossil fuels," the report states.
But, while it suggested using short rotation coppice chips to generate electricity could save between 35-85% fewer emissions than fossil fuel power stations, it added that straw-fired power stations could "in some cases" produce 35% more emissions than a combined cycle gas power station.
The best projects would save 98% of the equivalent emissions of a coal power station, it said, but projects shipping in energy crops grown thousands of miles away can reduce emissions savings by up to half.
Excessive use of artificial fertilisers in growing energy crops also has a "major impact" on biomass plants' carbon footprint, warns the report, as does using previously fallow land for energy crop cultivation.
Reporting systems
The Agency wants the government to require biomass generators to publicly report greenhouse gas emissions from producing, transporting and using biomass fuels.
But while its report recommends mandatory standards be developed for both large-scale and small generators, the Agency said standards should only be brought in if a sustainability reporting scheme fails to encourage good practice.
Such reporting systems are already being introduced in the biofuels sector under the supervision of the Renewable Fuels Agency, and are now being considered for biomass fuels by lawmakers in Europe.
The biomass sector already has a tool to help them calculate and minimise their emissions, called the Biomass Environmental Assessment Tool, available from the Biomass Energy Centre website.
We want to ensure that the sector's growth is environmentally sustainable and that mistakes made with biofuels are avoided.
More than three million tonnes of carbon dioxide emissions could be saved by encouraging good practice among the biomass sector in fuel production, processing and transport, the Agency's report concluded.
Tony Grayling, head of climate change and sustainable development at the Agency, said: "We want to ensure that the sector's growth is environmentally sustainable and that mistakes made with biofuels are avoided, where unsustainable growth has had to be curbed.
"Biomass operators have a responsibility to ensure that biomass comes from sustainable sources, and is used efficiently to deliver the greatest greenhouse gas savings and the most renewable energy."
Mr Grayling added: "The government should ensure that good practice is rewarded and that biomass production and use that does more harm than good to the environment does not benefit from public support."
CHP
As well as sustainability reporting, the Environment Agency also wants the government to bring in greater incentives for plants to make use of waste heat through combined heat and power (CHP) systems, perhaps through the forthcoming Renewable Heat Incentive or the existing Renewables Obligation.
The report suggests that if biomass power plants are not designed with the capability of at least retrofitting CHP systems in future, they risk becoming "stranded assets within 20 years".
Co-firing - the use of biomass fuels within coal power units - was seen by the report as a "good short-term measure" to reduce emissions, but that unless carbon capture and storage technology is deployed, "it does not have a long-term role".
By 2030, the report predicted that the carbon intensity of the national grid would mean that "even with co-firing of biomass, coal-fired power stations will have to have carbon capture and storage operational".
The report predicts that 80 TWh (80 million MWh) of renewable electricity generation will be required from biomass power stations by 2020, just under a third of the UK's efforts in meeting its European renewable energy target for that year.
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