CPS Energy, the largest municipally owned provider of electric and natural gas services in Texas, has informed the Electric Reliability Council of Texas (ERCOT), the manager of the state's electric grid, of its intention to decommission the three oldest natural gas-fired generating units at its Braunig Power Plant. The notification was issued on March 13.

Serving 930,114 electric and 381,379 natural gas customers in San Antonio and surrounding areas, CPS Energy aims to cease operation of these Braunig units by March next year. However, this plan requires approval from ERCOT. On Monday, ERCOT responded to CPS Energy's proposal with a completed reliability analysis assessing the potential impact of the planned shutdown on grid performance. According to ERCOT's findings, "the analysis identifies performance deficiencies for which these Generation Resources have a material impact" on the operation of the Texas grid.

This announcement from CPS Energy comes amid a period where renewable energy sources are increasingly displacing dispatchable generation such as natural gas. This shift is leading to reliability challenges as renewable energy's capacity to generate electricity is contingent upon weather conditions. Over a five-year span from 2018 to 2023, coal-fired plant generation has seen a decrease of 34%, nuclear generation has dropped by 1%, while natural gas generation has only increased by 17%. In contrast, wind power generation has surged by 55% and solar power generation has skyrocketed by 900%.

The San Antonio Express-News reports that ERCOT's reliability analysis could potentially impede CPS Energy's plans. According to Express-News reporter Sara DiNatale, "Eventually, ERCOT could come to an agreement that keeps CPS operating the Braunig units but paying the utility based on the added costs to keep them going." She further elaborated that if this scenario were to unfold, these "added costs, ultimately, would be spread across Texas ratepayers."