Solar and wind finally managed to get a few of the coins that fell behind the couch cushion in about 2008. They took it and ran. Now it's starting to look questionable as to whether just running a steam turbine is going to stay competitive even if the heat source were free.

What we need subsidies for now is electrolysers and batteries made of abundant materials as well as manufacturing in more than a couple of countries.

If you have a billion or three left over after the current run at fusion fails it'll probably be enough to get tidal off the ground too.