Very interesting article. But there is an even more interesting quote at the end of the same article :
Journalist : Can you tell us about your long term view on Zero ?
Paschel : Well to be fair electricity is just a transition toward more efficient solutions.
Journalist : What do you mean ?
Paschel : In the really long term, hydrogen and compressed air offer the highest energy density, because with electricity you lose lots of energy turning coal or oil into electricity. This is why we are working on a new SR/G, based on compressed air technology. It will have a very low weight (300 lbs) because it will use an helium ballast, and the prototype already offers an impress 300 ftlb torque. We think that in the long term, governments will develop compressed air stations. in the short term, you can charge the SR/G at home in about 8 hours using a hand pump. Get out of the way, the new Zero is coming !