To spain anytime soon in a Hydrogen Plane . History shows that you need to start small and grow big. And that growth would take a while. But if this could be scaled to the largest of planes, then the difference to emissions would bejumbo. You know, it sounds like, if they can get it right, Hydrogen Planes could be a massive deal. Yeah. Its as much about the infrastructure, though. Theyve got a lot to do. Right, ok, noted. Ok, were going from the air to the sea now. You might not think of the worlds oceans as a great source of green energy, but when you think about it, the tides move an enormous amount of water around the globe every single day, and we are discovering new ways to harness this tidal power. And Adrienne Murray has been to the remote faroe islands, which are between scotland and norway, to see what theyre doing to help harness renewable energy