Are biofuels sustainable? If biofuels are sustainable in theory, can they be used in fulfilling the renewables element of an average UK housing project in place of roof mounted renewables?
The prospect it holds out is to enable the use of a multi-fuelled CHP system capable of running a mixture of fuels, i.e. a biodiesel mix of 20% renewable fuel and 80% diesel. This in theory would satisfy the routine requirement for a 20% zero carbon contribution to the buildings emission reductions to fulfill the ‘Merton Rule’ renewables requirements.
The likelihood is that if such a system were sustainable, then it would offer a very cost-effective solution to local authorities renewable energy requirements and meet BREEAM and CfSH credit requirements.
The question is whether biofuels are sustainable enough to be offered as a realistic solution.
– biofuels are similar to biomass but have a generally higher calorific value so less fuel volume is needed to be stored on site
– burning liquid fuels means that a ‘normal’ CHP engine can be used instead of the exotic technologies required to burn biomass. A gas-fired engine modified to run on biofuels is a much less scary technology than a hot air turbine for a biomass CHP.
– liquid fuels do not suffer from the fuel quality problems associated with biomass, they can be delivered to guaranteed quality standards that will not cause maintenance problems.
Biofuels have had very bad press caused by the indiscriminate use of agricultural land to produce transport fuels, thus increasing emissions overall rather than decreasing them.
The use of primarily food crops to produce biofuels is diverting edible produce to fuels and endangering the ability of agricultural nations to produce sufficient food for export.
Where will biofuels go from here? Are there circumstances where biofuels will make sense?
The House of Commons Environmental Audit Committee suggested in 2008 that a moratorium be placed on the Renewable Transport Fuel Obligation until a way of assessing the sustainability of biofuels has been defined. Switzerland was held up as a model in this regard. The then Government refused. It will be interesting to see how ‘the greenest government yet’ will deal with this thorny subject.
The Zero Carbon Britain 2030 report suggests that second generation biofuels which produce fuel from wood or grasses and which do not supplant food production from agricultural land have a role to play in a zero carbon britain. They suggest that if agricultural and is used to produce biofuel then if the land was previously used to rear livestock, then the carbon balance would still be positive in favour of biofuels. They only see the fuel being used in agricultural machinery, aviation and shipping.
Given that we have to meet an 80% reduction in our CO2 emissions by 2050 it is likely that biofuels will play a role, how great a role remains to be seen, but we shouldn’t dismiss them out of hand provided that their sustainability in the widest sense can be demonstrated.