Local environmental advocates say they are glad to see CPS Energy is continuing to move away from fossil fuel-powered generation as the utility officially moves to close down its Braunig natural gas units by the end of next spring.
CPS Energy filed a notice with the Electric Reliability Council of Texas, the state’s grid operator, this month indicating that, as of March 31, 2025, CPS Every “will indefinitely suspend operations” of Braunig’s three gas-fired units. Utility officials told the San Antonio Report this aligns with its growth plan and reflects the utility’s commitment to moving toward clean energy sources.
“CPS Energy is committed to our Vision 2027 Generation Plan which meets our community’s growing energy demand, replaces aging power plants, and discontinues the use of coal,” CPS Energy spokeswoman Milady Nazir said in an emailed statement. “It also helps to meet the Climate Action and Adaptation Plan target while maintaining reliable, affordable, and environmentally sustainable power.”
While expressing approval of the move, environmental advocates say they want to see CPS Energy continuing to move toward inexpensive renewables.
“If we can move away from older technologies that will produce more carbon dioxide, that’s always a good thing,” said Alamo Sierra Club Chairman Alan Montemayor. “We have to continue to move away from anything that releases carbon dioxide. That’s where batteries and renewables will play an increasing role.”
Dee Dee Belmares, a clean energy advocate with Public Citizen Texas office and a former member of the utility’s rate advisory committee, offered similar sentiments, adding that closing Braunig has been in talks since 2019, when Paula Gold-Williams was president and CEO of CPS Energy.
The move to close Braunig, which began operating in the late 1960s, is in line with CPS Energy’s generation portfolio plan approved by the municipal utility’s board early last year.
Since 2021, CPS Energy has secured over 500 megawatts of solar generation, 522 megawatts of “natural gas-powered firming generation” and 50 megawatts of two-hour battery storage to replace the Braunig units, Nazir noted. One megawatt is enough electricity to power 200 Texas homes on a hot summer day.
The utility is currently seeking additional battery and solar resources. This year, CPS Energy contracted with Dallas-based renewable energy architecture firm Genesis Consolidated Industries for a 150-megawatt solar project. The utility also is seeking bids for 500 megawatts of “energy storage systems” — such as batteries.
“I’m happy with the 500-megawatt battery [bid requests] and the contracts for more solar,” Belmares said. “Those are the things CPS [Energy] needs to keep pursuing.”
Monteymayor and Belmares said they understand cost could be a limiting factor, which is something they’re also paying close attention to.
Replacing lost capacity
The V.H. Braunig power plant opened in 1966, breaking ground in water conservation efforts by using treated wastewater instead of drinking water from the aquifer to cool its boilers. Its construction resulted in the creation of Braunig Lake, which has become a popular fishing spot just south of downtown.
Seeing success in Braunig, the Calaveras power station and lake were constructed soon after.
Braunig, whose three units generate about 860 megawatts of power, is a steam turbine power plant fueled by natural gas.
Discussions to start phasing out Braunig and O.W. Sommers units from CPS Energy’s generation portfolio began in the mid-2010s, with officials aware the plants were reaching the end of their useful lives.
Utility officials knew that in shuttering both plants, they’d need to create a plan to replace the roughly 1,700 megawatts of power being lost.
In 2019, CPS Energy launched an initiative called the FlexPower Bundle seeking to add up to 900 megawatts of solar energy, 500 megawatts of “reliable capacity from an open-ended source” (such as from natural gas) and up to 50 megawatts of battery storage.
Moving away from coal
As a part of the new generation portfolio its board of trustees approved last year, CPS Energy also committed to phasing out coal use completely by 2028.
Under the approved plan, CPS Energy will shut down its Spruce 1 coal plant by 2028 and convert Spruce 2 to a natural gas plant by 2027, which will run indefinitely. Spruce can produce roughly 1,300 megawatts of power.
CPS Energy’s approved generation portfolio looks to add roughly 4,928 megawatts of generation capacity to the utility’s portfolio by 2030, including 880 megawatts from combined cycle natural gas and about 800 from peaking internal combustion engines that run on natural gas or diesel.
Another 500 megawatts will come from wind, 1,180 from solar and 1,060 from lithium battery storage.
Environmental advocates such as Montemayor and Belmares have expressed mixed feelings about Spruce’s conversion. While moving away from coal is vital, they agree, replacing some of those lost megawatts with natural gas-produced energy isn’t ideal either, they’ve said.
The utility’s president and CEO, Rudy Garza, has said that for now natural gas is CPS Energy’s cheapest and most reliable method for producing “firming capacity” — power CPS Energy can reliably call upon at any time.
The cost of batteries and battery systems is still relatively high in comparison, he and other utility officials have noted.
A systemwide decision
While CPS Energy plans to close Braunig and Sommers and to convert Spruce, it will be up to grid operator ERCOT whether the utility will be allowed to do so.
Because CPS Energy is a part of the statewide grid system, the utility’s notice of shuttering a plant is more like a request, Benny Ethridge, CPS Energy’s executive vice president of energy supply explained to councilmembers in late 2022.
ERCOT has the right to weigh in on this notice and could require CPS Energy to extend operations, he said. According to CPS Energy’s notice to shutter Braunig’s units, ERCOT’s comments are due April 3.
Disclosure: CPS Energy is a financial supporter of the San Antonio Report. For a full list of our business members, click here.
