Bitcoin uses a fuckton of energy for some stupid/clever reason. But a wise man once said to me that if you have an idea which relies on people being stupid or greedy, it will be a winner. This might be exactly what we need to get people building solar plants really fucking quickly.
Create an energy-intensive get-rich-quick currency so humanity’s inexhaustible greed drives it to build ENORMOUS renewable energy systems. Then upgrade its algorithm to be super efficient.