Solar optimists. Solar is extremely inefficient. Name 1 nation that uses it successfully.
There was a study done on Spain and solar power by Charles A. S. Hall and Pedro A. Prieto. Spain generates a lot of electricity from solar power (about 2.3% of total electricity at the time of study - highest in the world then). Their conclusion was that the final EROEI (energy return on energy invested - basically a measure of the energy yield of energy sources) of Spain's solar tech was 2.45:1. This is not enough to run an industrial society (which requires more like 14:1 EROEIs).
Basically, at the moment, solar is not the way for a society to be run. Small villages and households may find it useful.