Right now we waste on order of 80% of the energy value of our oil between production and consumption inefficies. Energy density is really only required in aircraft at this point, and that can be phased into straight up algae biofuels reusing much of the same infrastructure to refine into JetA. The Navy is putting out huge contracts for it, so is Richard Branson to fuel Virgin.
Jay Leno is driving around in a H2 fuel cell vehicle, so are more in LA, pity they just throw away the water. The auto manufacturers still aren't thinking multi tiered efficiency, the water should be condensed and collected for either re-electrolisizing or home consumption.
We can no longer afford to look at this as a 'what is the cheapest way to get energy' problem any longer. We have to look at 'what is the best way to get energy and water for a population that nature cannot support under our current slash and burn market system.
Money will have no value when the water runs out, the food dies, and we don't have the energy left or the infrastructure to produce the volumes of fresh water required. Lets see you eat all the cash and gold you saved.