Texas’s wind and sunlight complement each other exceptionally well. That’s huge for its grid.
But is the state ready to reimagine its power grid?
The astounding growth in wind and solar power coupled with their plummeting prices means that we are now radically rethinking how we produce, transmit, and sell power. Customers want 100 percent renewable energy, states want to cut their greenhouse gas emissions, and utilities are scrambling to come up with new business models and infrastructure to accommodate them.
The wind and the sun are some of the most abundant sources of energy in the world, and they’re free. But the big challenge of harnessing them is the simple fact of their intermittent availability: In general, the sun shines during the day, which means the amount of solar energy available is highest during the day. Wind, meanwhile, is usually strongest at night, so wind energy peaks after sunset.
Given this difference, one source could — in theory — compensate for the other’s lulls. But in practice, few places in America have enough sunlight and wind to balance each other out.
One place that happens to have plenty of both? Texas.
Researchers at Rice University recently mapped out the Lone Star State’s breezes and sunshine to assess what they called “complementarity,” how the energy available from one energy source rises and falls in relation to another. If a wind turbine farm’s highs occur as a solar array’s output bottoms out and vice versa, the generators are said to have high complementarity. By making power output more consistent, complementarity makes the grid more reliable, easier to schedule power, and cheaper.
What the Rice team found is that patterns of wind and sunshine in Texas complement each other exceedingly well, helping the grid provide enough power even at moments when electricity demand is highest, like during the searing summer heat when hundreds of thousands of air conditioners are switched on.
“The more complementarity you’ll have, the less you’ll need other expensive stuff,” said Daniel Cohan, an associate professor of environmental engineering at Rice and an author of the study published in November in the journal Renewables: Wind, Water, and Solar. That expensive stuff includes backup generators, energy storage, and power electronics.
To be clear, the findings don’t show that Texas could pull off a 100 percent renewable energy grid just yet. But they do show that renewables could replace a whole lot of dirty energy without breaking much of a sweat.
Though coal is increasingly being priced out of the market, it still provides about one-third of the state’s electricity. Wind provides roughly 17 percent, and solar barely registers. So renewables still have plenty of ground to gain, and the state is uniquely positioned to balance out its grid with the wind and solar resources it has.
Is Texas ready for this kind of drastic reimagining of the power grid? Probably not just yet. For now, the conventional wisdom that wind and solar are too unreliable continues to permeate planning discussions. Let’s break it down.
Texas has oil in its veins, but it’s a great testbed for renewables
Texas is a pretty unique case in the United States.
It’s the country’s largest oil producer. It’s the largest lignite coal producer. It’s the largest natural gas producer. At the same time, it’s the largest wind energy producer in the country and retired a record 4.2 gigawatts of coal capacity in 2018. And unlike other states, Texas has its own internal competitive power market, the Electric Reliability Council of Texas, or ERCOT, which provides about 90 percent of the state’s power.
That gives Texas a bit more room to experiment than other regions. In 2005, the state legislature passed a law signed by then-Gov. Rick Perry (now energy secretary), requiring that it increase its use of renewable energy. The problem was that some of the best sites for wind turbines — with the most consistent and highest speeds — are in the western part of the state. The massive, power-hungry cities like Houston and Dallas are in the east.
