Carbon budgets will be very difficult to achieve without the use of bioenergy, and the successful development of Carbon Capture and Storage (CCS) technology, according to a review of bioenergy by the UK's Committee on Climate Change (CCC). However, the Committee warns bioenergy use must be limited to ensure sustainability.
The review concludes that a 10% share of bioenergy in total energy could be required to meet the UK’s 2050 emissions target, compared to the current share of 2%. Bioenergy would ideally be used with CCS, which would allow for the removal of carbon from the atmosphere and for higher emissions reductions to be achieved. The review suggests that a 10% share in 2050 could be feasible within sustainability limits, but any higher than this could be unsafe given sustainability concerns – and even at the 10% level, there may be trade-offs with wider environmental and social objectives.
“The extent to which bioenergy should contribute to economy decarbonisation is highly controversial,” says David Kennedy, Chief Executive of the Committee on Climate Change. “Our analysis shows that there is a crucial role for bioenergy in meeting carbon budgets, but within strict sustainability limits – and trade-offs with wider environmental and social objectives may be needed.”
Stronger regulation and CCS needed
In the report the Committee makes five key recommendations to the Government:
Regulatory frameworks should be strengthened to ensure sustainability of bioenergy. Under current approaches, use of bioenergy could result in emissions increases rather than emission reductions; particularly due to indirect land use impacts (i.e. growth of bioenergy feedstocks can displace agriculture production to carbon rich land). Therefore EU and UK frameworks should be extended to cover these impacts. At the UK level, the emissions benchmark for use of biomass in power generation should be made more stretching (i.e. reduced from 285g CO2/kWh to 200g CO2/kWh). These changes should be complemented by agreement at the climate change conference in Durban on accounting for land use change emissions under the Kyoto Protocol and any successor agreement.
CCS should be demonstrated as a matter of urgency. This is not just because of its potential application with fossil fuels, but because of its use with biomass, which would effectively allow the removal of carbon from the atmosphere. Without CCS, carbon budgets would be significantly more difficult to achieve, and would require currently unforeseen technology breakthroughs or significant behaviour change. Therefore the Government should move forward with its four proposed demonstration projects without delay, setting clear milestones to provide confidence that these will be delivered on time.
Government should regard targets on biofuels and biomass as flexible and should delay setting any new targets until new regulatory arrangements have been put in place to ensure the sustainable supply of bioenergy. In particular, if it becomes clear that sustainable supply is below levels currently targeted, targets should be adjusted downwards, rather than delivered in an unsustainable fashion.
Subsidies should not be provided to new large scale biomass power generation under the Renewables Obligation. Such subsidies, recently proposed by the Government, would be costly and unsustainable. The focus in power generation should be on co-firing and conversion of existing coal plant, and new small-scale generation, using sustainable local bioenergy supplies.
Other low carbon options should be developed given limited sustainable supply of bioenergy. These include energy efficiency improvement, nuclear and wind power generation, electric vehicles (battery and hydrogen) and electric heating. Bioenergy refers to combusting solid, liquid or gas fuels made from biomass feedstocks, which may or may not have undergone some form of conversion process.
The Committee assessed the role of bioenergy both globally and in the UK and considered how it might best be applied to help meet climate targets. The role of bioenergy in climate change mitigation is controversial and the review illustrates significant uncertainties around its use, in relation to:
The emissions reductions that can be achieved through using it – It is hard to account fully for all emissions resulting from the use of bioenergy and often lifecycle emissions are excluded – so higher than anticipated emissions may be produced.
The sustainable supply of bioenergy - Population growth, coupled with increasing wealth, means that in the next decades there will be an increasing need for land to grow food. Growth of bioenergy feedstocks could risk displacing food production. In addition, there are wider environmental and social impacts associated with the use of bioenergy e.g. negative impacts on biodiversity, natural habitats and deforestation.
Taking these concerns into account, the Committee assessed where bioenergy might best be used to support the UK in building a prosperous low-carbon economy, recommending that the following approach be taken across sectors:
Power generation – biomass could be used alongside or instead of coal in existing coal-fired plants. However, any role for new dedicated biomass without CCS should be very limited given its high cost.
Industry – There is scope to significantly reduce emissions from buildings by using wood in construction as this would lock in carbon and replace high emission building materials e.g. concrete, steel and cement. Biomass can also be used in energy-intensive industries, alongside CCS, as an alternative to coal – this would result in negative emissions.
Aviation – Biofuels could play a role through the 2020s and beyond in supporting emission reductions from aviation, but this should not be seen as a ‘silver bullet’. Efficiency improvements and constrained demand growth will also be required.
Surface transport –there is likely to be only niche use of biofuels in surface transport, which will predominantly require use of electric technologies to decarbonise cars, vans and heavy goods vehicles (HGVs). This underscores the need for Government to support development of electric vehicle markets now.
A range of sensible smaller-scale local uses for bioenergy- this includes using old cooking oil to run buses, making use of food or farm waste in anaerobic digestion plants, or using woodchip from tree surgery waste in biomass boilers.
“Strengthening of regulatory arrangements is required both here and in Europe to provide confidence that bioenergy used over the next decade is sustainable. CCS should be demonstrated and demonstration projects commenced given the crucial role of this technology when used with bioenergy to meet carbon budgets,” Kennedy concludes. “The Government should change its approach to supporting new biomass power generation, which as proposed could raise costs with limited carbon benefits.”
The findings of the bioenergy review will feed in to the UK Government’s new bioenergy strategy and to the Committee’s advice on the inclusion of international aviation and shipping in carbon budgets which will be published in Spring 2012.
[Image: Render of Teeside Biomass Plant designed by Heatherwick Studio for the developers Bio Energy Investments Ltd]