The rap against renewable energy is that it doesn’t provide what energy wonks call “baseload” power around the clock. While a fossil fuel power plant will keep cranking out kilowatts 24/7 as long as you keep shoveling in coal or piping natural gas, solar and wind farms are at the mercy of the vagaries of the weather to generate electricity. No wind, no sun, no power. (The exception is carbon-free geothermal power plants, which operate continuously.)
Then there’s the fact that despite the explosive growth in wind and solar projects over the past five years and the billions of dollars poured into subsidies, green energy still only supplies a fraction of the United States’ electricity demand. Wind, for instance, provided 6 percent of demand at peak output.
But that’s the wrong way of looking at the balance of power. There is no national energy grid in the U.S. Rather, electricity is distributed through a series of regional grids that serve groups of states. (Except for Texas, as most of the Lone Star state operates its own self-contained grid.)
As the chart below from the American Wind Energy Association shows, wind energy is far from a bit player in states with significant installations of wind farms. The chart shows where and when wind energy production records were set. In Colorado, for instance, wind supplied 60.5 percent of the state’s electricity on May 24 of this year. In Texas, an epicenter of climate denialism, the payoff from its wind farm-building boom came on May 2, when greenhouse gas-free wind provided 28.1 percent of the state’s power.
On April 7, the nation’s most populous state, California, tapped wind farms for to meet 17.5 percent of its electricity demand. Even a group of nine coal-dependent Midwest states relied on wind for 25 percent of their power last Nov. 23. And last month, wind provided 32 percent of demand on October in Oklahoma and parts of three other states.
The next big leap in renewable energy will come when electricity generated by wind and solar can be stored for use when the wind isn’t blowing or the sun isn’t shining. It’s early days but already pilot projects have begun to store wind energy and California recently ordered its three big utilities to acquire 1,325 megawatts of energy storage by 2020. In other words, the grid is about to go green in a big way.