[beat]

Synthetic fuels have it even worse, I think, in terms of cost. Unless we can get a really cheap form of electricity that is clean (solar) and connect it to a process that it more efficient than simply growing corn (or other biomass), then synthetic fuels will have the same problem. They can't be cost-competitive with fossil fuels without massive subsidy.

[epistasis]

Yeah, I agree. Making hydrogen, the first step for pretty much any synthetic fuel, is exceedingly inefficient. That means that transmitting electricity long distances is usually going to be much more cost-effective than making liquid fuels.

But I think that as electricity gets cheaper and cheaper, and as fossil fuels have a pigovian tax levied on them, that eventually synthetic or biofuels will be more cost effective than fossil fuels. Electricity is going to get super cheap, and there's going to be times when supply outpaces demand. If the electricity would go to waste otherwise, something that's 40% efficient may be a good use of it.