Agree with you there, Adrian. There seems to be a fair bit of research going on, as indeed there should be. It always pays off to have options. At the moment, rechargeable batteries is being adopted as the way forward. But what happens, say, if one of the materials/elements of the battery or charging structure becomes unobtainable? What if the price of generated electricity goes through the roof? Putting all our eggs exclusively in the battery-electric basket is not wise. Much better to have some alternatives available, just in case.