33% of the California grid is currently being powered right now by renewables, mostly wind and solar. Renewable power is 7.4 GW, demand is 22.4 GW.TomT said:"Some of the world's top climate scientists say wind and solar energy won't be enough to head off extreme global warming, and they're asking environmentalists to support the development of safer nuclear power as one way to cut fossil fuel pollution."
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Add in big hydro and nuclear and it's a bit over 40%. That's quite a bit of carbon free electricity! (OK - it is sunny right now and the wind is blowing pretty good, too).
And there are quite a few large solar/wind plants currently under construction. Last year total renewables were 20% of total electricity generation, will be up to 33% by the end of the decade.
SolarCity/Tesla will soon be selling a 10 kWh home battery storage unit. This type of storage unit will go a long ways towards reducing the early evening peak in grid demand when everyone fires up their tvs and laptops. Maybe someone will take all the 4-bar loser battery packs and use them for grid storage - should be able to get 10 kWh out of them for a long, long time.