Short rotation coppice chips were cited as offering significant emission reductions over fossil fuels. Image: Wikipedia
A new report from the UK's Environment Agency shows that using biomass to generate heat and electricity can offer major carbon emission reductions compared to burning fossil fuels, if best practices are followed and efforts are made to ensure that it is genuinely low carbon:Good News, Bad News on Biomass
The good news is that if the biomass is produced in environmentally sustainable ways and used efficiently then it can result in up to 98% reduction of greenhouse gas emissions as compared to coal. The bad news is that, if not used efficiently and when derived from environmentally unsustainable sources, the overall emissions are worse than using natural gas. (Which is still much better than coal, for what it's worth...)
If best practices are followed, the use of biomass could result in over 3 million tonnes of CO2 emissions per year being saved.
What is Best Practice for Biomass?
The report sites several key factors as influencing the level of greenhouse gas emission reductions possible from using biomass:
Type of Crop: Short rotation coppice chips can produce electricity at 35-85% less emissions than using natural gas. While using straw can produce up to 35% more emissions per unit of energy produced.
Transportation & Fertilizer: Shipping biomass over long distances and excessive use of nitrogen fertilizer can reduce the emission savings of a given biomass source by 15-50%.
Land Use Changes: Using formerly fallow land or, even worse, permanent grassland to grow biomass crops reduce emission savings of biomass by 10% in the former case, and actually negate entirely emission savings in the latter.
Efficiency of Energy Conversion: The report says that a wide range of emission reductions can result based on the efficiency of the conversion process. Improving existing efficiency standards will be necessary to make the most of biomass.
Co-Firing Biomass: Though increasingly being used at coal-fired power plants, co-firing biomass may reduce emissions somewhat in the short term, but without carbon capture and storage is not enough to offset the carbon emissions from burning the coal in the long term.
More: Environment Agency
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