"Energy doesn't come free."
This is only true as long as you have your mind stuck into resources that come from the ground.
Don't get me wrong, but I think solar power has a cost too, even in the best of the worlds possible. And so do wind power, tidal power, hydroelectric.
For hydroelectric, we know that it ruins the rivers, the dams get clogged up with debris, there are almost every time minor or major problems with wildlife, plants, water distribution.
Or, to produce the solar panels you have to use a lot of resources, which are not free, nor unlimited, and can be polluting during production.
I push myself a little farer, but I am just freeing my imagination now: what will happen if you fill a sea strait with so many tidal plants as to actually stop the tide from passing? Debris? coastal pollution? sea currents circluation modyfications? Who know.
Yes, always better than other alternatives, but never free.
And this is theory. For what we know now about renewable energy, they are so expensive and so unefficient now that they struggle to compete even with oil or coal. We wouldn't research on them either, if it was not that the cost of pollution is gettin higher and higher, making fossil-fuel less and less desirable.
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That said:
I like the idea of solar, wind and tidal power, I hope they will become reality soon and if it was for me, research on these technologies will be funded heavily. I also don't like nuclear power very much (because of the waste and the potential ravages it could unleash upon all of us). But I can not avoid reality.