Conclusions

• With current technology, the production of liquid biofuels is at best thermodynamically questionable and at worst nonsense.
• The present increase in world food prices, significantly due to subsidised biofuel programmes, makes it ecomomically questionable too.
• We have not considered other factors such as net greenhouse gas emissions; N₂O from fertilizers could make these significant.
• Attempts to develop efficient conversion of cellulose to liquids may never succeed.

On the other hand:

• Solid biomass from agricultural byproducts, cofired in coal power stations, could indirectly meet the EU transport renewables target without diverting agricultural land.
• Algae and other simple organisms can have growth rates 100s of time greater than plants, addressing the fundamental problem of inefficiency of agriculture.