Wind and solar power are 'bailing out' Texas amid record heat and energy demand

Wind turbines generate power on a farm near Throckmorton, Texas.

(CNN)Texans are cranking on the air conditioning this week amid an unusually early heat wave, setting new records for electricity demand in the state, which surpassed 75 gigawatts on Sunday and smashed the 2019 record. Texas grid operator ERCOT projects it could approach that peak again on Tuesday.

But unlike previous extreme weather events in Texas which led to deadly blackouts, the grid is holding up remarkably well this week. Several experts told CNN that it's owed in large part to strong performances from wind and solar, which generated 27 gigawatts of electricity during Sunday's peak demand -- close to 40% of the total needed.
"Texas is, by rhetoric, anti-renewables. But frankly, renewables are bailing us out," said Michael Webber, an energy expert and professor at the University of Texas at Austin. "They're rocking. That really spares us a lot of heartache and a lot of money."
      Despite the Texas Republican rhetoric that wind and solar are unreliable, Texas has a massive and growing fleet of renewables. Zero-carbon electricity sources (wind, solar, and nuclear) powered about 38% of the state's power in 2021, rivaling natural gas at 42%.
        This is a relatively recent phenomenon for the state.
          "Wind and solar would not have been available in years in the past, so the growing capacity helps to alleviate reliance on natural gas and coal," said Jonathan DeVilbiss, operations research analyst at the US Energy Information Administration.
          Not only have renewables helped keep the power on during a scorching and early heatwave, they have also helped keep costs low. Prices for natural gas and coal are high amid a worldwide energy crunch, but renewables -- powered by the wind and sun -- have no fuel cost.
          "Because the price of wind and sunlight hasn't doubled in the past year like other resources, they are acting as a hedge against high fuel prices," said Joshua Rhodes, an energy researcher at UT Austin.

          Peak demand during peak heat

          Texas and other states have been sweltering in triple-digit temperatures and dangerous heat indices. Texas state climatologist John Nielsen-Gammon told CNN that San Antonio has been a particular hot spot; it recently hit 102.5 degrees Fahrenheit, setting a new pre-July record.
          Texas is used to heat, but this year they're "getting August weather in May and June," Webber told CNN.
          Experts said the Texas grid was built to withstand extreme heat moreso than the extreme cold brought by the deadly 2021 winter storm. But with the state now experiencing August-like temperatures in early June many questioned whether the Texas grid could withstand the longer, hotter summers fueled by climate change.
          "As opposed to a winter storm, we were built for three months of 90-plus [degrees]," said Caitlin Smith, head of regulatory policy and communications at Texas-based battery storage company Jupiter Power. "Were we built for 4 months of 100-plus [degrees]? There's some uncertainty there."
          If the early spikes in temperature persist this year, it could stress out the grid and power plants, Smith and Rhodes warned. As well as the grid is working right now, that could change if this summer continues to bring unrelenting heat.
          "It's like the human body; heat stress is cumulative," Rhodes said. "The body has no time to recover. Power plants are like that as well, they need some time to recover."
          Rhodes added that renewables have been a big help during this early surge by taking strain off the traditional thermal power plants that use coal and natural gas to keep the lights on.
          Human-caused climate change is linked to rising global temperatures and extreme heat. And while it's too early to tell exactly how much climate change is to blame for the current heat wave, it's safe to assume it is a factor, said Andy Dessler who directs the Texas Center for Climate Studies at Texas A&M University.
          "It's 100% certain that climate change is contributing to this," Dessler told CNN. "Everything's getting hotter. August is getting hotter; June is getting hotter. It is hot and this is the future."

          Overcrowded transmission lines

          Even though Texas is an oil and gas giant, renewables -- and particularly, wind -- have long been thriving there. Texas generates the most wind energy in the country: In 2020, it produced more wind electricity than Iowa, Kansas, and Oklahoma — the next three highest states — combined, according to the US Energy Information Administration.
          Solar has been a smaller portion of the state's energy mix than wind, but it is growing as well. Solar generated about 4% of electricity in Texas last summer, and is expected to grow to 7.2% this summer, EIA projections show.
          Building out more solar will be important to deal with heat waves in the depths of summer, when wind speeds tend to drop, experts told CNN. That's because if it's really hot out, there's a good chance the sun is beating down.
          But Rhodes and Webber pointed to infrastructure issues limiting the potential of renewables; Texas needs more transmission lines to carry energy generated by renewables to customers. Rhodes pointed to ERCOT projects showing higher solar numbers than what was actually being used; a casualty of over-crowded power lines that can't let the power through to consumers.
          "About half of the solar that could be produced is not being produced right now because there's no more room on the lines," Rhodes said. "The numbers for renewables would probably be higher if we had the transmission capacity to move them around."
          Wind and solar have natural variability as well; solar can't generate energy during nighttime, and wind turbines don't turn when the wind isn't blowing. That is spurring a big focus on developing more massive batteries that can store and deploy renewable energy when the wind isn't blowing, and the sun isn't shining.
            "It does keep growth of renewables strong; it allows you to firm up that renewable capacity," Smith said.
            Correction: This story has been updated to correct Joshua Rhodes' name.