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.
Required by whom? People who know power? Or politicians. I go to every public meeting of my nonprofit electric power company and one of their number one goals is figuring out how to work poltically correct electrons into the grid without large price hikes or reduced reliability.
Surely, we can do better than that
Surely my power company's supplier, the nonprofit Old Dominion Electric Cooperative should be able to use its relatively new expensive coal plant for its engineered life. But the politicians have other plans.
We could use so much more of our own wind and sun to save our resources and money.
There is so much to learn about power. If you are in a cooperative like I am they will gladly explain it to anyone. They are not stupid people and their goal is very simple, get reliable power to their members at the lowest cost. The main use may be comfort which might be trimmed or optimized for cost. For example I signed up to have the power company turn off my A/C when they run out of power. They already shut off power to businesses during those times. They have no similar plan for winter, and I do not have electric heat anyway.
One more anecdote, back in January 1994 northern Virginia ran out of power and lots of my fellow apartment dwellers were forced out by cold and flooding. To propose unreliable power under those circumstances is criminal.