A couple of two edged swords and a nitpick. The argument about importing ethanol cheaper than home grown ignores the case for self reliance. Some importers of Russian gas know why that's a good idea. If the biofuels group said there were cheaper forms of carbon reduction I hope they weren't talking about offsets which I regard as largely fraudulent.

Is there good ethanol and bad ethanol? The price of grains like corn, wheat, barley and sorghum are going through the roof and could hardly be economic feedstocks without subsidies. Sugarcane ethanol allegedly has an EROEI of 8. It's bizarre that only a few years ago cane growers were being paid to leave the industry and now there's not enough acreage. Other pathways to ethanol include fermented syngas (Khosla's new approach?), cellulosic variants still in development and catalytic conversion of bio and petro methanol. It's still inferior to butanol and a host of non-alcohol fuels, both in terms of energy density and storage properties.

Cut the mandates and the subsidies (R&D grants are OK) and I think we will end up with very little ethanol, more like FT diesel from sawdust at $3/L before excise. I also think that means that most pure piston engined cars (say half a billion) will be off the road within 20 years.

If the biofuels group said there were cheaper forms of carbon reduction I hope they weren't talking about offsets which I regard as largely fraudulent.

Presumably they mean various forms of energy efficiency - even The Economist will happily point out this is the cheapest way of reducing emissions.