Darren’s Diatribe

We will be hearing a lot about bioethanol and biodiesel soon. They are being promoted as the “next big thing”, but I think that it is a huge con.

The general idea of bioethanol is that you grow a crop which is preferably high in starch or sugar content (corn, sugar cane, sugar beet etc.) and ferment it to get alcohol (Ethanol), distill the alcohol and mix it to give about 10% Ethanol in petrol. Biodiesel is produced by processing vegetable oils (soybean, canola, palm oil etc) to give a fuel which can be used directly in diesel vehicles.

The goal is to have a fuel which takes the CO₂ from the air while it grows, and then generates CO₂ when it burns again. This is supposed to have less impact on the levels of CO₂ in the atmosphere compared with using fossil fuels. It also reduces our reliance on oil.

The problem is that it takes an enormous amount of energy to cultivate the fields, sow and harvest the crop and then to process the crop. By the time you take into account the energy used to produce the fertilisers and other chemicals, there is almost no net benefit. The pessimists calculate that bioethanol actually creates more greenhouse gases than using fossil fuels. The optimists calculate a benefit of only 13%.

To me, a saving of 13% at the expense of dedicating vast amounts of land and effort to growing crops which could (and should) be used to feed people seems crazy. There are also other factors which can’t be overlooked. There will be vast tracts of forest chopped down to grow these crops. There will be land degradation. There will be lots of water used. There will be squillions of tons of fertilisers and pesticides used. The price of food will go up as crops get diverted into fuel production. All of these side effects are potentially quite serious.

It is true that it might get a bit better with volume manufacture and efficiencies of scale, but there is no escaping most of the side effects. If they stick to using waste products to generate biofuels, then it will be a great concept. I do hope that they think through this before they go charging ahead with yet another pointless scheme…