Two types of biofuel, biodiesel and bioethanol, dominate the market in the UK. There are a number of other biofuel types available but these currently only occupy a small niche of the total market. The most common of these is biogas, produced from biodegrading material, typically sold for fleet use. Other biofuels include pure plant oil (PPO) and hydrogenated vegetable oil (HVO) as diesel substitutes and biobutanol as a petrol substitute. Industry expects these to be more widely used in the future, as more advanced biofuel technologies become commercially viable.

Biodiesel

Biodiesel is produced using oil-rich crops including soy, oilseed rape and palm oil. Some biodiesel comes from other sources such as used cooking oil or tallow. As these oils are generally more viscous than fossil diesel, they require some processing (known as esterification) prior to blending. Generally used as a diesel additive.

• Generally more expensive to produce than fossil diesel but the differential fluctuates widely. High oil prices can narrow the gap but as fossil energy is often used in the production of biodiesel, this effect is more limited than might otherwise be expected. Biodiesel from recovered cooking oil tends to be much cheaper to produce than that from agricultural feedstocks, but there is a limited supply and the fuel is often of low quality prior to processing.
• Minimal additional infrastructure is required to supply biodiesel. Infrastructure used in the supply of fossil diesel is generally suitable for the delivery of biodiesel.Generally more expensive to produce than fossil diesel but the differential fluctuates widely. High oil prices can narrow the gap but as fossil energy is often used in the production of biodiesel, this effect is more limited than might otherwise be expected. Biodiesel from recovered cooking oil tends to be much cheaper to produce than that from agricultural feedstocks, but there is a limited supply and the fuel is often of low quality prior to processing.
• British biodiesel production has historically been a ‘cottage industry’ with individual manufacturers each responsible for low volumes. Most of these companies rely largely on used cooking oil (UCO) and tallow for feedstocks. There are now a number of large plants that buck this trend, such as a plant producing 50 million litres a year from tallow run by Argent in Motherwell.

Bioethanol

Generally produced from starchy crops like sugar cane, sugar beet, corn and wheat. As with potable alcohol, it can be made from virtually any organic substance (grass, wood, biodegradable element of municipal solid waste), but the technologies for doing so are not yet commercially viable. Generally used as a petrol additive.

• Generally used as an additive in petrol, usually in blended at no more than five percent of the fuel.
• Tends to be more expensive to produce than petrol, especially from crops like wheat, but some countries, notably Brazil, produce it at a relatively low cost from sugar cane. Tends to be cheaper than biodiesel to produce once specialised infrastructure is in place.
• Produced in huge volumes by Brazil and the US. Production in the UK is at a limited number of plants, including British Sugar’s refinery in Wissington which uses sugar beet as a feedstock and a plant operated by Ensus in Wilton, producing wheat-based ethanol.
• In 2009/10 ethanol accounted for 29% of the total biofuel used on the UK’s roads, but that proportion is increasing and is expected to continue to do so as more infrastructure comes online.

Biogas

The principal feedstocks are currently municipal solid waste (MSW) and sewage though methane could potentially be harvested from any biodegrading matter.

• Just like compressed natural gas (CNG), except that it is generally produced by collecting the methane which is naturally emitted from landfill sites or other forms of rotting organic matter.
• Only suitable for use in CNG-powered vehicles, which currently exist only in very low numbers in the UK.
• As it is generally produced from wastes, biogas is likely to qualify for double counting following RED implementation.