Since 2003 the European Union has made it an obligation for each of its member states that a minimum of 2% of the fuels consumed by road traffic are biofuels. This percentage should rise to 5.75% in 2010, and to 10% by 2020. Beyond the controversial debates sparked off by the use of this type of fuel, it is necessary to compare the two principal forms of product: bioethanol or biodiesel?

At the rate we are going, in less than two centuries we will have burnt the entirety of the reserves of fossil energy accumulated over the course of hundreds of millions of years: we are burning fossil energy a million times faster than nature produces it. We must therefore not wait until we have completely exhausted the supplies before thinking about replacement solutions: global warming is also fed by this frenzied consumption of fossil fuels.

Road traffic represents both a generous source of greenhouse gases and a large consumer of fossil energy. That is why since 2003 the European Union has made it an obligation for each of its member states that a minimum of 2% of the fuels consumed by road traffic are biofuels. This percentage should rise to 5.75% in 2010 and to 10% by 2020. In effect, in terms of renewable energies biofuels have for a long time been presented as an interesting substitute for petrol and diesel. It is a question of producing in the soil the products that will feed our cars, a little like the case was previously when agriculture provided the ‘fuels’ of horses and other working animals.

Far from being a recent discovery biofuels were in fact born together with the car. Already in the nineteenth century, ‘experimental’ cars were fuelled by beetroot alcohol. Rapidly supplanted by petrol products, biofuels are now on the way to making a comeback (even if so called first generation biofuels have been heavily criticised): less polluting, more effective, inexhaustible – such are the qualities that are progressively bringing them centre stage within the context of the contemporary ecological crisis.

Today, two particular pathways stand out from the rest of the pack. A first consists of producing a substitute for automobile petrol (bioethanol) from alcohol and thus the fermentation of sugar extracted from the beetroot grown on our territories or from the sugarcane grown in regions with a warmer climate. The second pathway is that of biodiesel, produced from fatty substances, such as rapeseed oil or sunflower oil. The name used here is ‘diester’. In the two cases, part of the lands normally used to provide humans and animals with foodstuffs are diverted towards fuel production.