I hate to break it to folks, there is no such thing coming.
The industrial use and production of energy is a messy business, both environmentally and financially. This will not change.
Consider the recent advent of two major "clean" energy alternatives, solar and wind. They are FAR from "clean" environmentally no matter how you slice them. Photovoltaic solar is really a horrible thing for the environment. Manufacturing and scrapping of solar cells is a messy thing and creating and operating those "let's build a huge array of mirrors to focus the sunlight to make something really hot thing is even worse as it takes huge swaths of land, has a serious issue with local wildlife and is *really* expensive. Wind isn't all that much better. It takes large areas of land, puts substantial structures on it and has a detrimental affect on the local environment too (killing birds, bats, bugs and such).
About the only real hope here is fusion, but we are a LONG way from even being able to field an operating industrial level facility so there is no way we can judge the environmental impact of such a thing. I can tell you that right now, they are pretty messy, with superconducting magnets and emitting radiation.
"Clean" energy is like "Free" food. It doesn't really exist.