Renewable energy is, well renewable, self-sustaining

however nonrenewable energy isn't, so compared to your world, and mine. You would run out of energy eventually, and I doubt that you can advance fast enough to travel to another planet with sufficient energy that can be harvested by you
With Renewable, its sustainable and reliable
With Unrenewable, its expensive, unreliable, unsustaining, hard to gather, and hard to process.
Do the downsides REALLY outweigh the upsides? no