Bio-fuels - Renewable but not Sustainable

With the oil peak upon us, governments around the world are spinning for the next solution, bio-fuels. Ethanol from corn, sugarcane and wood biomass. Bio-diesel from soya beans, sunflower, rapeseed and other oil seeds, or palm oil. Looking closer and using simple assessment tools like EMERGY (embodied energy) and EROEI (energy returned on energy invested) it just doesn’t stack up. First of all, there is not enough land to grow energy crops as well as food crops. Water shortages in agriculture, salination, erosion and soil collapse are on the increase. With erratic weather patterns and climate change, growing grains is becoming more and more difficult as we can see in Australia. World grain reserves are down to a few weeks. Virgin rainforest is razed to grow oil palms for bio-diesel. In Malaysia alone 87% of deforestation happened to create palm oil plantations. A further 6 million hectares are scheduled for clearance in Malaysia and 16.5 million hectares in Indonesia.

Corn, sugarcane or rapeseed grown with artificial fertilisers and pesticides, which are oil-based products with high emergy, are not net producers of energy. Ethanol conversion is even worse, it also generates mutagens and carcinogens and increases ozone levels in the atmosphere.

Anaerobic digestion to harvest biogas especially from green algae for carbon capture and sustainable bio-diesel looks promising. Biogas is a renewable and carbon-mitigating fuel. It is more than carbon neutral. Methane-driven vehicles are already used, thousands of them in Sweden. Anaerobic digestion also creates excellent organic fertiliser, high in nitrogen and phosphorous for soil productivity and prevents pollution of ground water, soil and air with nitrates, methane, nitrous oxides and other contaminants.

The huge amount of tallow in New Zealand is also a resource for bio-diesel and urgently needs more research.

But in the end we have to look at a drastic reduction in transportation of our goods and ourselves. Local production, local consumption and we might have to stay more at home.