Originally Posted by Zathras
So from the wall, 22Kwh to go 20 miles. My EV which I will have in about a month will go about 110 miles on 33Kwh. Almost four times the efficiency (yes, they also claim further mileage as the air compressor will work as the engine runs, but I also get additional energy from regenerative braking).
For a commuter car, EVs using batteries is much more efficient.
I think the efficiency gained while it is burning fuel may be higher than you are estimating. If this is similar to their earlier concept, they claim that it will get 100 MPG when the car is burning fuel. Here's
where we discussed this before, complete with some calculations.
It's getting very hard to say one technology is "more efficient" or "more green" than another. First, "green" and "efficient" are only loosely correlated. Then, one person's "green" is another person's "environmental disaster." Then, there's "mission profile:" there's no true "in use" MPG number for a car (plug-in electric hybrid or compressed-air hybrid) that goes the first 30 miles before it starts burning fuel.
For most folks with access to natural gas, it appears to be the cheapest source of energy (calculations at above link, though gasoline was $4 at that time--and probably will be again). But the devil is in the details--how far you'll typically drive every day, efficiencies of all the conversions that will be needed to move the car, etc.