Energy generated from plant biomass could deliver up to one fifth of global demand without causing a decline in food production, although there are challenges involved, according to a new report launched this week by the UK Energy Research Centre (UKERC).
Modern energy services, such as heat, power and transport fuels, can be provided from biomass; sources of which include waste timber, agricultural residues, and dedicated energy crops. Increased use of bioenergy has the potential to increase to energy security and stimulate rural development. It may also contribute to reducing carbon emissions; this is because plants absorb carbon dioxide from the atmosphere as grow, and provided minimal non-renewable energy is used when processing them into useful materials or energy products, the net emissions can be very small.
Yet the use of biomass for energy purposes has attracted criticism and controversy. Criticism has often focused on the potential for biomass to compete for land and water resources that might be needed for food production as the global population grows.
The report, Energy from biomass: The size of the global resource, examines the share that biomass might contribute to the future global energy system and is the first systematic review of the evidence base. Scientists working in Imperial’s Centre for Environmental Policy (CEP) carried out the research to understand why there are a large range of estimates and how this affects the wider debate about bioenergy.The authors found the root cause of contention is that many scientists disagree about how factors such as diet, population, future land use and the rate of agricultural innovation will change in the future. After reviewing the results of more than 90 separate studies, they concluded that supplying up to one fifth of global energy sustainably from biomass would be challenging but by no means implausible.
“The more bioenergy you want, the harder it becomes to reconcile demand for food, energy and environmental protection” said Dr Raphael Slade, who authored the report with colleagues Drs Robert Gross and Ausilio Bauen. “Land management will remain a critical issue; regulation will be needed to ensure biomass is produced sustainably.”
The researchers argue that technical advances are likely to provide the least contentious route to increased bioenergy production, but only if policy encourages innovation and investment. “A renewed focus on increasing food and energy crop yields could deliver a win-win opportunity as long as it is done without damaging soil fertility or depleting water resources. There’s plenty of scope for experimentation to make sure we get it right”, said Dr Slade.
“Bioenergy may need to play a part in a future low carbon energy mix,” said Dr Bauen. “Ensuring bioenergy, food and forests don’t compete for land won’t be straightforward. But, if we use land more productively, and make use of residues and wastes, we should be capable of producing bioenergy, feeding a growing population and conserving the environment at the same time.”