Biomass has potential but we must assess its full environmental impact before it gets the green light
Government needs to develop an industry that meets strict standards and doesn't do more harm than good
Despite all the media attention on wind, solar and even wave power as key sources of renewable energy, the UK's largest green energy provider is biomass – using wood, annual crops or waste materials as fuel for heat and electricity. It now generates over 2% of our total electricity, enough to power more than 2m homes. In addition, it produces about 1% of heat for our homes and industry.
And it has the potential to deliver even more in the future, helping the UK to meet its target of 15% of energy from renewable sources by 2020 and reduce dramatically greenhouse gas emissions from heat and power generation, which contribute to climate change.
Heat and power can be generated from a large range of biomass fuels, such as wood, grasses and organic wastes. It is considered renewable because it is either based on wastes which would otherwise go to landfill or on energy crops and forestry that, after being harvested, can be grown again.
But like all "green" products, it's important that we assess its entire environmental impact before giving it the green light.
A new report launched by the Environment Agency this week shows that biomass energy has the potential to be a clean, sustainable energy source – but only if we do it properly.
The best forms of biomass energy have the potential to produce up to 98% less emissions than coal power. The worst would have higher greenhouse gas emissions overall than gas power.
Our report sets out how we can achieve our goal of clean, sustainable biomass. And it makes clear that we should avoid the same problems that have afflicted biofuels – which saw a headlong rush, followed by an abrupt slow down after the total environmental impact of growing crops for fuel had been recognised.
So what should we be doing to ensure that the emerging biomass sector blossoms into a green and low-carbon industry for the future?
The Environment Agency's report: Biomass: carbon sink or carbon sinner analysed the carbon footprint of a range of methods of biomass energy production and comes out with some clear recommendations. The carbon footprint is the overall greenhouse gas emissions from producing, processing, transporting and using the biomass to generate heat and power.
First, the biomass needs to come from sustainable sources, using wastes and local sources as much as possible, while avoiding major land use changes and minimising use of nitrogen fertilisers where crops are used. Second, the processing of the biomass into fuel needs to be efficient, consuming as little energy as possible. Finally, the generators used to turn biomass into useful energy need to be as efficient as possible. This means where possible using the heat generated to heat homes or in local industries.
Bearing in mind the difference between "good" biomass and "poor" biomass, it's important that we have a consistent approach to this emerging industry. Worryingly, there are currently no plans to ensure that best practice is followed, and there is little to suggest that the emerging biomass industry will adopt these standards without encouragement from the government.
We are therefore calling for immediate action to ensure that the biomass industry is encouraged to meet the recommendations outlined above and delivers the lowest carbon energy possible.
This means providing greater incentives for the most efficient plants that produce heat and power rather than electricity only. It also means requiring all plants that receive any public support to accurately report on their greenhouse gas emissions. Eventually, it is likely that we will need minimum standards for all generators.
Government needs to take the lead to develop an industry that meets strict standards and delivers clean heat and power. The prize of a major contribution to the UK's renewable energy and greenhouse gas targets is great. The alternative – an industry using inefficient generators to burn anonymous fuels – could ultimately do more harm than good.
Tony Grayling is head of climate change and sustainable development at the Environment Agency.
[This man evidently doesn't care that if you displace cattle and sheep out of Wales this mostly displaces the demand elsewhere, so exporting a lot of their emissions as well as causing new deforestation. Also writes "sheep and cattle produce vast amounts of... carbon dioxide" whereas "Energy crops... are potentially carbon neutral" - hmm.]
Biomass crops offer low-carbon energy — the media got it wrong
Coverage of the Environment Agency's report into biomass has misled the public on a real carbon-neutral fuel alternative
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