Even though electric motors have reached the high 90% in efficiency, storing the energy you must carry with you is a very difficult problem. A gasoline engine would strain to make 40% conversion efficiency, yet it is very hard to beat a system where 15/16 of the weight (air) required to make power does not have to be lifted and carried, and the exhaust products (also having weight) are dumped overboard.
Here, once again, we see the results of a government trying to pick the winners by subsidizing technologies that are not yet viable. Legislators should be required to tattoo on their foreheads Thomas Sowell’s quote about prices: “It is hard to imagine a more stupid or more dangerous way of making decisions than by putting those decisions in the hands of people who pay no price for being wrong.”