According to one new report from the Royal Academy of Engineering, the UK should focus on using waste products such as chip fat for biofuels over crops such as wheat.
The authors argue that biofuels will still be necessary for aviation and heavy goods, even with increased use of electric vehicles, saying that incentives should be given to farmers to grow fuel crops such as Miscanthus on their marginal land.
The EU has required that 10 percent of transport fuels should come from sustainable sources by 2020, but biofuels have caught on more slowly in the UK.
Fuel suppliers in the UK are already blending as much as 4.75 percent of diesel and petrol with cleaner fuels, but the authors of the study say it may take as much as ten years to double this figure. They say several changes are key to making this happen.
In places such as Brazil and the US, biofuels come primarily from corn or sugar cane, but in the UK, they are derived mainly from wheat and cooking oil. The authors say there should be restrictions on crops grown for fuel, in order to boost production.
According to the Department for the Environment, Food and Rural Affairs (Defra), nearly half the land in the UK used for biofuels is used to grow wheat. In reviewing scientific literature, they found that if the extra emissions needed to change land to grow wheat were considered, fuels derived from wheat were actually worse for the environment than petrol or diesel.
According to Professor Adisa Azapagic from the University of Manchester, who chaired the panel that authored the report:
“Generally, we know if land use change is involved, do not use wheat to make biofuels, it is higher than petrol in terms of carbon footprint…What we need to understand about agriculture, is that it is different from farm to farm. This is what we have found across the world, how people farm wheat in different ways and the emissions would be different depending on soil, previous carbon stocks and so on, it really is a very complex science.”
The authors suggest the government should set a cap for crop-based biofuels to cut down on indirect land use changes.
“We would be concerned if we went up to 10% and allowed all of that 10% to come from food based crops, then we would say no, that’s not what we’re recommending.”
The report recommends a renewed focus on developing fuel from waste, of which the UK produces 16 million tons annually, enough to double biofuel supplies. The authors say that many kinds of unavoidable waste, such as cooking oil, sawmill residues, and the dregs from whiskey manufacture, could all play a role in biofuels.