Nuclear with breeder reactors can run with known resources for 4 billion years. Renewable doesn't mean infinite (nothing is infinite). The sun will run out of its wholly finite fusion fuel in about 5-6 billion years, and will consume earth well before that. I think nuclear fission with breeders is therefore just as renewable as the solar-derived energy flows.

Renewable is a great base load power option. You supply your base load with your cheapest available supply, which is usually renewable.

You then supply all power needs above what can be provided by your cheapest power with dispatchable supply. If your base supply is intermittent, that means your dispatchable supply has to be able to supply 100% of peak.