Nationalization and renewable energy engineering are two different animals.
The old Soviet Union had a nationalized energy grid. In retrospect, their safety program didn’t look particularly good after the Chernobyl disaster. Japan, on the other hand, hired private companies such as TEPCO to build their reactors and ensure safety. In retrospect, their safety program didn’t look particularly good after the Fukushima disaster.
Renewables R&D, the climate change project, doesn’t have short-term profitability as its goal. Nor does it benefit one nation with one nationalized electric grid. Nor does it benefit one small power co-op, so the co-op has no financial incentive to get the R&D done.
Humanity does this R&D because we can’t have the whole world’s grain belts turning into scrubland or desert. The world becomes food-insecure if we don’t get the climate R&D work done. This is an all-in problem for all of us, not some kind of economic zero sum game.