"But 2030 is in the future, and alternative power is lucrative enough to drive development, so who know what the problems with batteries or whatever fuel cells appear will be in the future? "
Zinc-air fuel cells utilising a liquid fuel solution which can be pumped out and refilled at a service station when the zinc has been depleted:
i) Already developed as a demonstration model by the University of Singapore
ii) Zinc is a common and relatively non-toxic material
iii) The depleted fuel solution can be regenerated and re-used
iv) The energy density of zinc-air technology is higher than any of the lithium technologies as one of the electrodes is freely available from the atmosphere and doesn't have to be built into the cell
v) An old and proven portable energy source, in use in a non-rechargable form in millions of hearing aids.
vi) The rechargeable version is easily scaled up to house/community/national grid level storage of wind or solar generated electricity for later use, as the fuel solution can be regenerated, either externally or in place, by the application of electricity, just like recharging any other sort of battery.