ERCOT chief: Solar, wind key to grid
If it weren’t for wind and solar, this summer’s recordbreaking power use could be causing problems for Texans relying on the state grid to keep power flowing to their air conditioners.
Renewable energy has been a lifeline for Texas and its growing population, the state’s power grid boss said Tuesday, providing enough cushion to meet the soaring demand. No rolling blackouts. No mandatory conservation notices.
At least not yet.
But despite this summer’s success so far, concerns about the grid’s long-term reliability are what keep Electric Reliability Council of Texas CEO Pablo Vegas up at night. He’s increasingly worried the state’s mix of generation sources are falling out of balance as more renewables are added, he told a group of public power companies meeting Tuesday in San Antonio.
“Balance has to exist 24 hours a day, 365 days a year,” Vegas said in an interview after his speech to the Texas Public Power Association. “The sun shines during the day, the wind blows intermittently. When it’s not blowing, when the sun is not shining, everybody still expects power. So we have to have a balance of supply to meet the needs during all of those periods of time.”
It happened last summer: Traditional power plants — largely those relying on natural gas and coal — weren’t producing enough power to keep Texas running without the help of wind, solar and battery power. It was a new frontier for the Texas power grid. And when the wind didn’t blow enough to keep wind turbines spinning, the grid struggled to meet demand.
“Peak demand kept growing,” Vegas said during his presentation. “We’re in a place now where we are dependent upon renewables to meet demand.”
Utilities are investing to meet the needs. Since last summer, power companies across Texas collectively added more than 3,000 megawatts of solar and another 1,000 megawatts in wind, said Vegas.
So far this summer, ERCOT has reported five unofficial
power use records. Only once has it asked Texans to voluntarily conserve power. That’s largely because of the cushion provided by renewables. With Texas’ growing population, demand is predicted to keep climbing. The current peak demand record was 82,592 megawatts consumed on July 18. ERCOT, which manages the flow of power to 90 percent of Texans, expects more record-breaking use in days to come. It takes about 1 megawatt to power 200 Texas homes on a hot summer day.
The reliance on renewables has changed those peak demand patterns, Vegas said. Traditionally, the grid’s riskiest period on a hot day comes at 3 p.m. because that’s when power use was the highest. Now those riskier periods have shifted closer to 8 p.m. to 9 p.m., when the sun is down but it’s still hot outside.
“When we have an abundance of solar and wind, sure, we take advantage of that,” Vegas told reporters. “We leverage that for all the benefits that it offers. But when we don’t, we still need something to fill in. And that’s the balance I’m talking about, making sure we always have enough regardless of what’s happening with the wind and sun.”
But the fleet of thermal power equipment Texans rely on to create the most reliable and predictable energy inside traditional power plants on the hottest and coldest days are also the oldest, Vegas said. ERCOT reports 40 percent of the equipment responsible for that power is more than 30 years old. Fleet creations have remained static for more than a decade.
In his remarks, Vegas encouraged power providers to be as aggressive with replacing aging equipment as they have been with bringing on more solar, wind and battery options.
He said CPS Energy, the city-owned utility that powers San Antonio, is a good example for other power companies across the state.
“They’re building in a balanced way of doing exactly what we’d love to see the grid at large transforming in terms of replacing the older, less efficient, dispatchable generation new with new, cleaner, efficient dispatchable generation,” Vegas said. “That’s the kind of transformation we need to see happening across the board.”
At CPS, existing gaspowered generation equipment is over 30 years old, CEO Rudy Garza said.
“You have got to plan for the future and then make thoughtful investments,” he said after the meeting. “It’s all based on a diversified portfolio, which is exactly the kind of message that we heard (today).” Renewable energy sources are the quickest types of generation companies can build now while still planning for improvements to natural gas plants, Garza said.“You need it all,” he said.