California is already using Hydrogen power for road cars, as soon as someone finds a cheap enough way of getting Hydrogen to the consumer that will be the main source of power and the electric car will be second, we may even end up with hydrogen hybrids at some point. either way our government should be investing more in these technologies rather than subsidising wind/ solar farms if we want to be truly green. As with batteries being so expensive we are currently funding research into using mushrooms as a cheap replacement of lithium-ion battery cells as at least they realised there the costs need to come down for future use. Diesel and petrol will both be gone when this all happens, dare i say nearly all hydrocarbon use as we know it will be irrelevant. Won't be for a while though.