Biofuels

Know what a biofuel is? What if I said that you've got some in your petrol tank at the moment? Still none the wiser?

Basically, biofuels are fuels that are, in some way, derived from a plant or animal source. For example, they can process corn, soya, or palm oil into a form that can run your car.

So what, you might ask.

Well, on the face of it, biofuels could be the answer to a lot of problems.

For the oil companies, it could be the future: a cheap and renewable replacement for crude oil which is getting increasingly more expensive to find and exploit.

For the rest of us, it's potentially a low (theoretically zero) carbon alternative to oil.

However, there are drawbacks:

• Firstly, at a time when we're trying to increase the food supply as our population grows, crops once grown for food are being diverted for fuel as the latter is more lucrative. If crops continue to be hijacked like this, it will force up food prices.

• Secondly, forests are being cleared at a frightening rate to provide land for biofuel crops, so increasing the carbon footprint of this supposedly low carbon fuel.

• Thirdly, the crops take a fair bit of processing before they can be used for fuel. As a result, some biofuels have a bigger footprint than fossil fuels!

As a result of all this, the EU is now looking to stop the use of these higher carbon versions.

This should encourage the use of so-called second generation biofuels, ones which do not use food crops, but use stuff like waste and the stalks of crops. This should reduce the footprint and the impact on food supplies.

Beyond these, there are third generation biofuels which are created from algae grown in vats.

These more advanced techniques are quite exciting for the future. But there's a problem for these and all biofuels. How do you manufacture enough of it to satisfy the massive wordwide demand? There are an estimated 600 million cars out there and up to a million planes for a start.

I can't see that happening myself.