Coverage of the Environment Agency's report into biomass has misled the public on a real carbon-neutral fuel alternative
http://www.guardian.co.uk/environment/cif-green/2009/apr/16/biomass-environment-agency"It is unfortunate that recent media coverage of the Environment Agency's report into using biomass crops to produce energy has focused on the circumstances under which energy crops may not provide carbon benefits over fossil fuels. If grown, transported and burned in the right way, crops such as willow and miscanthus do offer low-carbon energy — something the report, titled Biomass: Carbon sink or carbon sinner, makes very clear.
The BBC News article: Biomass energy "could be harmful", highlighted the negative aspects of growing energy crops on ancient grassland and the marginal superiority of waste wood over purpose-grown biomass crops. But in both cases, these are a red herring.
Energy crops are attractive because they are potentially carbon neutral. The carbon dioxide released when burning them to produce power and/or heat was extracted by the plant from the atmosphere during its lifetime. So unlike with fossil fuels such as coal and oil, burning them does not add new carbon to the atmosphere. But the carbon balance for biomass crops depends on the whole lifecycle. It looks less favourable if you need to transport the fuel for large distances using fossil-fuel powered vehicles, for example.
The EA report suggests that if permanent grassland were replaced with energy crops the carbon benefit of using the crop as fuel would be more than wiped out. That's because ploughing ancient grassland would release substantial amounts of carbon from the soil. But this is not where energy crops would be grown. As the EA report says, "there is no evidence that energy crops are currently being planted directly on permanent grassland in the UK". In any case, these habitats have high biodiversity value and so would be far from ideal sites.
In Wales, where most of our studies have been done, energy crops would most likely replace sheep grazed leys which are classed as "permanent" pasture. However, current management of these medium-term leys on many farms would create far more disturbance to their soil carbon store than the 20-year lifecycle of willow coppice or miscanthus. Additionally, the reduction of GHGs with removal of livestock from permanent "ley" grassland should be included in the calculations, since sheep and cattle produce vast amounts of methane and carbon dioxide accounting for over 5% of Wales' total greenhouse gas emissions.
Biomass crops can also benefit biodiversity. Our recent studies in Wales have demonstrated that replacing ecologically barren, re-sown and fertilised sheep grazed pasture with willow, miscanthus and reed canary grass, boosts the numbers of wild species. These include significant increases in the number of threatened farmland birds such as yellowhammer, willow warbler, reed bunting and redpoll in willow coppice, skylarks and lapwings in newly planted miscanthus and the declining harvest mouse in reed canary grass.
The comparison with waste wood is also not quite what it seems. While it makes good sense to utilise any organic waste products rather than put them into landfill, the long-term continuity and economics of supply will dictate the need for a mixture of feedstock including waste material and purpose grown crops. An excellent case example is the recently commissioned combined heat and power (CHP) system at the Bluestone Holiday Village in Pembrokeshire. This was installed and managed by Pembrokeshire Bio-energy and supplied by a cooperative of local growers and timber suppliers to provide 6,000 tonnes a year of woodchip and energy crops.
The need for sustainable feedstocks, mandatory standards, cohesive planning and auditing in the emerging biomass industry are rightly highlighted in the report. None of this is new to those working in biomass — good practice is already well established, for example in recent reports by Land Use Consultants and the Department for Environment, Food and Rural Affairs.
The report correctly identifies CHP — that is using the heat produced from burning as well as the electricity — with locally grown energy crops as the best way to reduce greenhouse gas emissions. CHP also reduces economic costs and provides direct economic benefits to local communities. In 2005, Sir Ben Gill's Biomass Task Force reported to the government that 49% of UK energy consumption is used for heating and that "biomass is unique as the only widespread source of high grade renewable heat". Many CHP projects have been hindered by a fragmented approach to energy planning and past market conditions. It is this that must change if the full potential of biomass crops is to be realised. Government should take the lead to provide better support for CHP and heat-only plants by revising the Renewables Obligation and through the new Renewable Heat Incentive"
Dr Simone Lowthe-Thomas Wales Biomass Centre, Cardiff university
