Understanding greenhouse gas balances of bioenergy systems

Thornley, P.; Adams, P.; Bows, A.; Gilbert, P.; Hammond, J.; Howard, D.; Lee, R.; McNamara, N.; Whittaker, C.; Whitaker, J.

There are many reasons why bioenergy appears attractive as a renewable fuel: it can replace overcommitted fossil fuel resources; aid biodiversity; help manage wetlands; diversify rural economies; support energy security and support industrial growth and exports. These are all acknowledged as important, but this report focuses on only one aspect: greenhouse gas balances, which is a key driver for the development and deployment of bioenergy. This report is published as an output from a SUPERGEN Bioenergy Hub workshop held in January 2013. The workshop aimed to provide an open forum for life cycle assessment specialists to discuss some of the issues surrounding greenhouse gas balances for bioenergy systems and to provide an overview of the extent to which bioenergy systems actually reduce greenhouse gas emissions. This report intends to inform stakeholders with wider energy and environmental policy or research interests on issues relating to bioenergy system greenhouse gas balances. Since there is already a substantial body of information focusing on first generation crop use for biofuels, most of the emerging issues discussed at the workshop focused on the use of solid biomass for heat and power from forestry, perennial crops, waste streams and therefore this is the main focus of the report. Whilst the report is attributed to the authors, they have endeavoured to reflect the diversity of opinions and ideas represented at the workshop. The report has been published by the SUPERGEN Bioenergy Hub, but readers are free to make copies or post the report for their own use, provided that they do not wilfully misrepresent its content and acknowledge its origin as the SUPERGEN Bioenergy Hub.