Hydrogen is probably the most 'renewable', right? We already have hydrogen rockets to hydrogen cars... hydrogen will probably impact the environment way less than lithium-ion battery packs too. As these vehicles go, they'll only pollute the world with water... and when we create these hydrogen fuels from water..., we'll also end up creating more oxygen as well...
So ideally, I think we need a nuclear reactor in geo synchronous orbit so that it can suck up water from the ocean thru a very long straw and then send back hydrogen and oxygen back to earth for us to use and breath...
If something goes wrong with the reactor, we can just move it into deep space or toward the sun and replace it with another one. Likewise with its nuclear wastes.