Traditionally, biomass such as wood has been used for cooking and heating purposes. The oil crises of the 1970s, however, prompted interest in biomass to produce liquid biofuels and replace fossilbased transport fuels. Subsequent falls in oil prices evaporated much of the incentive and stalled the momentum to expand biofuel production in most countries, but recent years have seen a resurgence of interest, this time prompted by energy supply security, oil price volatility and the new driver: climate change mitigation. As a result, biofuel programmes have proliferated around the world, driven by mandates, targets and subsidies, whilst investment in the development of advanced biofuel technologies has racked up. And, as before, biofuels as an alternative to fossil-based transport fuel, gaseous or liquid, has been emphasized. The 2003 EU Biofuels Directive, for example, targets a 5.75% share of biofuels in transport energy by 2010 and 10% by 2020. However, biofuels can also be used to efficiently produce both heat and power in decentralized production systems based on combined heat and power (CHP) engines. Indeed, whereas transport accounted for nearly one-third of final energy consumption in the EU-27 countries in 2008, heat and electricity account for two-thirds of final consumption (Figure 1).

This content is only available as a PDF.