Are biofuels the silver bullet?

Err no. In order for biofuels to be worthwhile they need to emit fewer greenhouse gas emissions over their entire life cycle (from feedstock through production to use) than what we have now which is almost exclusively petrol or diesel. They must also have a negligible effect on food prices and food harvests and avoid indirect effects. A biofuel which achieves this is known as a sustainable biofuel.

Sustainably produced biofuels exist right now. One example is using waste cooking oil to make biodiesel, another is upgrading biogas to biomethane which can be used in vehicles that operate on natural gas. By using waste streams, neither of these fuels competes with food crops, they avoid indirect effects and they have really low greenhouse gas emissions. In fact biomethane can be CO2 negative in some instances.

Crop based biofuels can be good too. Jatropha is one example of a fast growing oil rich plant which grows on marginal land, is draught tolerant and is inedible. These characteristics mean that Jatropha doesn’t compete with food crops either as it can be grown on scrub land which is too heavily degraded to support food crops. Its draught tolerance allows it to be grown in equatorial regions without the need for irrigation systems which makes it a potential income source for some of the poorest countries in the World. Jatropha offers environmental benefits for the World and human benefits for local communities.

Far greater use of waste streams for fuels could be made and forestry waste can be turned into bioethanol or biobutanol (bio petrol). The processes necessary to do this have been proven and are being used to produce small volumes of fuel. When these processes become commercially viable on a large scale they could become a significant source of sustainably produced biofuels.

However despite all of this it isn’t possible to produce enough biofuels sustainably to replace all of the petrol and diesel currently used, at least in the short to medium term. So for this reason they are not the silver bullet. This doesn’t mean that we shouldn’t exploit the full capability of sustainable biofuels. Sustainable biofuels will play an important part in our future fuel mix and shouldn’t be viewed as any less important just because they can’t do the job on their own.

Looking longer term the fuels and vehicles that we will be using might be very different from today. It is widely predicted that electrification of cars and small vans is likely to increase. The first stages of this are already being seen with hybrid cars becoming increasingly common and major manufacturers moving into pure electric cars.

Hydrogen is seen as the end game by many, something we don’t fully hold with, but nonetheless a fuel cell vehicle is an electric vehicle with the electricity being produced on board by the fuel cell rather than stored in a battery, whilst vehicles using hydrogen in an internal combustion engine (ICE) will benefit from hybridisation just as much as any other ICE vehicle.

Assuming all things are equal an increase in the use of electricity would result in a decrease in the amount of liquid and gaseous biofuels required in the future which might make it more viable for them to completely fulfil our fuel needs. In particular they may be need in areas which will find it impractical to move to electrification which are likely to include aviation and haulage.