The sun is definitely a good source of energy if we can harness it. However I think our currency technology can't store and predict our energy usage at a cost-effective price. I think the only reason why we can use it is because the government subsidizes renewable energy.

I think eventually it should be cost-effective but I don't think pure renewable energy is the way to go at our current state. I do believe research into the renewable technology should continue and we should slowly turn it into renewable energies.