Comment by sambeau

The focus for these kind of alternatives should be on aviation—with the most difficult fuel to replace. Maybe we'd need this for classic cars, emergency generators and a few other smaller things, but even classic cars can get electric refits. Cars, motorbikes, trucks etc should be electric; shipping needs to embrace sail-electric hybrids; and bio-fuels/synthetic fuel should be aimed at aviation (and maybe as a stop-gap for shipping). My 10¢.