California can collect more than enough solar energy to power its entire grid. The problem isn’t the amount of energy available; rather, it’s energy storage. When demand is high in off peak hours, we currently fire up non-renewable energy sources to offset demand. A solution exists: energy stored in supercapacitors.
Supercapictors can store high amounts of energy very quickly and also release the energy just as fast. Graphene supercapacitors have enough energy density to come close to lithium batteries and would be the perfect solution to handle the grid with their rapid release and storage properties. They also run cool, do not degrade for thousands of cycles, and are non-toxic and non-volatile.