The market has spoken and it is battery electric technology.
The market has spoken to
not want electric technology as of today. This is why electric cars get massively subsidised. I agree with Heston that hydrogen is much more promising given the slow progress in battery performance combined with their very high weight. Possibly we might end at some combination of liquid or gaseous fuel that get converted to electric energy used by electrical engines.
Whatever we use to store the energy the energy itself must be generated "green". This is why the battery mantra is leading nowhere.