I saw you post, Mike.
Let's do some quick comparison. One economic scooter can do 45km/l on gas. As a rule of thumb, we can calculate that alcohol can deliver 70% of the mileage than the same volume of gas. I believe the weight of a scooter is a good measure to compare against. But still, the price is much higher than the car moved by compressed air, charged by electricity.
Off course it will also depend on the price of electricity. Mine is one of the more expensive in the world, so expensive that having a cheap lenovo notebook instead of a desktop makes me save the price of the new notebook in less and 18 months, just in energy savings.
But to me, the beauty of the thing is in its simplicity. It's just air, it produces no pollution, and you could power it from a waterfall or wind turbine! But I still may try to build a custom tricycle powered by alcohol some day.
The thing with sugar alcohol, is that it depletes the land on its production. It's renewable but it's not sustainable. I saw the cultivations, it's very ugly. Kilometers and kilometers of a single specie and not a single weed. The earth becomes a red dust, that seems the very picture of death. A red desert. Ugly thing.
But the true source of unsustainability is our lifestyle. The cars, the cultivations, the pollution, they are all consequences of the way people live.