Texas-size Ambition: How ERCOT can Handle Renewables
The ground under Texans is full of natural gas and sky above them full of wind and sun. Those factors will both benefit and challenge the state’s power grid over the next 16 years, according to a new study.
The Texas Clean Energy Coalition (TCEC) released a new report that explored reliability issues for the Electric Reliability Council of Texas (ERCOT)—the region’s transmission system operator—under six different scenarios involving different potential gas prices and federal carbon rules. Projections in the 93-page report varied on the scenario, but all of them found natural gas and renewables providing all of the new generation going forward while coal-fired power would fall flat or even disappear from the mix under the most stringent federal pressure.
“In the absence of continued or enhanced policy supports, we did find that natural gas generation would be the primary addition of choice through 2032, even with significant declines in the price of wind and solar power,” the report reads.
“Exploring Natural Gas and Renewables in ERCOT Part II: Future Generation Scenarios for Texas” was done by the Brattle Group for TCEC. The partners have worked together on a series of research reports and papers focused on the impact of renewables upon the Texas grid dating back to 2013.
The Longhorn State ranks No. 1 nationally in wind power with close to 18,000 MW installed capacity, according to the American Wind Energy Association. Texas is also off the charts with natural gas potential, thanks to major shale plays such as the Eagle Ford and Permian.
The solar photovoltaic (PV) potential in west Texas—also a bastion of wind energy—is huge as long as PV prices keeping falling and maintain support via tax credits and other incentives. The TCED report, using the most likely scenarios, determined that the wind and solar portion of the generation mix would grow from its current 10 percent to somewhere between 25 and 43 percent by 2012.
Natural gas, meanwhile, currently costs between $2 and $3 per million British thermal units, a historically lower price. It also is an efficient fuel for power units which can ramp up quickly to smooth out the variable sources such as the wind and the sun. For that reason, the Brattle Group predicted that natural gas will add 12 to 25 GW of new combined-cycle capacity in the same period.
“Low natural gas prices have really been taking a toll on the margins of coal plants around the country,” Ira Shavel, principal with the Brattle Group, said in a webcast detailing the report. “ERCOT is no different.”
This shifts the generation fuel sources geographically, so the grid must have ways to move that new power efficiently while avoiding frequency and voltage drops. Analysts predict up to 10 GW of coal retired by 2020, Shavel noted. Another 1.7 GW in coal-fired generation may retire due to the federal government’s regional haze rule.
“Is there enough capacity on the ERCOT grid to make sure the lights stay on?” Shavel said. “Right now there’s an oversupply.”