There is enough coal still in the ground to last an awful long time, same with oil and gas, also USA has enough of the atomic stuff in storage to generate all their electrical power needs for over 700 years, and they have enough left over to nuke north korea many times over.
USA and Canada are nett exporters of oil and gas due to fracking and shale. This has bought OPEC to heel and oil prices have plummeted, Saudi wants to undercut
North American cost of production by keeping oil flowing at low price.
Unfortunately it is too common a site in UK (one of the windiest and most suitable for wind power in Europe, if not the world) to drive past windfarms where the turbines are playing statues. The only way we can reliably have EV is to build another 20 nuclear power stations, anything else is just dreaming.
As for making biomethane from grass, it is calculated that over 60% of UK agricultural land would be required, this does not include the land needed to house the digesters and pipelines. The Co2 released converting gas to burnable quality is being ignored by ecotricity as are a lot of other things, no such thing as a free lunch.