Transport fuels made from waste such as used cooking oil or dregs from whisky manufacture will be needed to help meet targets to cut UK carbon emissions, a report says.
The Government should also encourage dedicated “energy crops” such as willow and miscanthus or elephant grass, which are grown specifically to make fuels, particularly on land that is unsuitable for food production or housing, it said.
Renewable fuels from plants, known as “biofuels”, provide an alternative to conventional petrol and diesel which create carbon emissions that drive climate change.
But biofuel use became controversial amid concerns they drive demand for more land for agriculture, directly or indirectly leading to deforestation and draining of peatland which can cause more carbon emissions than conventional fuels.
A new assessment for the Government by the Royal Academy of Engineering has said some biofuels can reduce carbon emissions to well below the levels of conventional fuels.
But action is needed to make sure the sector is properly regulated, improve the traceability of products and avoid fraud, it said.
Professor Roger Kemp, one of the report’s authors, said: “If the UK is to hit its goal of 80% carbon reduction by 2050 we’ve got to use all possible low carbon technologies and fuels.
“Widespread adoption of electric vehicles … will reduce emissions from cars and light vans, assuming you can get charging from renewable energy.
“But there are no real easy alternatives for either aviation, HGVs or maritime transport, and it’s those areas where we anticipate seeing biofuels play a much bigger part.”
An assessment of many different studies for the report showed “second generation” biofuels from waste products or dedicated energy crops were on average significantly cleaner than fossil fuels.
But “first generation” food crops used for fuels, such as sugar beet or maize, did not deliver the same level of carbon savings and wheat was worse than fossil fuels if it caused land use change.
The newest biofuels, being developed from algae, were significantly more polluting than conventional diesel.
The report called on the Government to incentivise biofuels from waste, with some 16 million tonnes available in the UK, largely green waste such as garden prunings, straw, and waste paper.
This waste could produce around three billion litres of biofuels, or roughly twice the current UK supply, researchers said.
There is also “significant potential” for energy crops such as willow and miscanthus.
The report calls for an increase in the cap of how much biofuels are in the UK transport fuel mix from current levels of 4.75% to 10%.
This level could be reached within five to 10 years, the experts said, well after the original EU target for biofuel use to reach 10% by 2020, and there are enough resources in the UK to meet the goal.
Professor Adisa Azapagic, chairwoman of the academy’s biofuels working group, said: “Our report shows that with the right safeguards and monitoring, biofuels from waste in particular are well worth pursuing from a sustainability point of view and also provide business opportunities for development.”