Except when it is not. The power company will need people to sign up to have their A/C turned off when there are clouds, or the power company will need spinning reserve to avoid blackouts.
Not even the most rabid pro renewable energy supporters have been suggesting that renewables can carry the whole load except in small scale, isolated cases like survivalists. Currently, however, it is now common for cities with electric companies required to have a renewable component to only be using 5 or 6 percent renewables including also hydro, biomass and geothermal (in volcano country), in addition to solar and wind. Surely, we can do better than that. Why waste money importing oil and/or burning up our carbon based resources that our posterity will need for important things like plastics and industrial chemicals? We could use so much more of our own wind and sun to save our resources and money.