San Antonio municipal utility CPS Energy wants to replace aging fossil-fueled generation with more than a gigawatt of solar, energy storage and flexible capacity, and it’s asking for ideas on how to get there. 

A request for information (RFI) released this week is the opening step toward meeting CPS’ “Flexible Path” plan, which calls for an 80 percent non-carbon-emitting energy portfolio by 2040 and reaching net-zero carbon emissions by 2050. Responses will help inform options to meet its FlexPower Bundle plan, which envisions adding about 900 megawatts of solar, 50 megawatts of energy storage and 500 megawatts of “new technology solutions” to replace the need for buying natural-gas-fired power from outside power plants.   

CPS has set an August 31 deadline for would-be resource providers to respond to its RFI, and it expects to solicit formal bids through a request for proposals in early 2021. 

The new resources are needed over the next decade to help replace about 1,700 megawatts of fossil-fired generation set for retirement over that time. They’re also part of the utility’s goal to increase its renewable energy capacity to half of its generation mix by 2040.

CPS now gets about 22 percent of its electricity from about 1,000 megawatts of wind power and about 500 megawatts of solar, with natural gas making up 46 percent of its remaining portfolio and coal-fired power another 18 percent. 

CPS closed two of its coal-fired plants in 2018 and has not announced a retirement date for its two remaining ones. It’s also planning to retire the aging Braunig and O.W. Sommers natural-gas power plants. 

The utility’s call for 500 megawatts of “new technology solutions" seeks options to replace the natural-gas-fired power it had planned to purchase on the grid markets operated by Texas grid operator ERCOT. CPS backed away from its procurement plan in February under community pressure to reduce its carbon emissions but hasn’t defined just what technologies could meet its needs for power to serve customers when wind and solar aren’t available. 

“We are looking at this capacity...to ultimately replace a power plant, so it has to be available when our customers need it,” CPS Energy Chief Operating Officer Cris Eugster said at the Monday meeting where the utility’s board approved the RFI.  “It could be natural gas, it could be long-duration storage, it could be a technology we’re not even aware of right now.”

CPS will also be relying on getting about 16 percent of its 2040 energy needs from “flexible generation,” Paula Gold-Williams, CPS president and CEO, said in a February presentation at the DistribuTech conference in San Antonio. That’s essentially a placeholder for technologies ranging from demand response to flexible electric-vehicle charging and necessitates heavy reliance on the demand side of its portfolio to reach its goals. 

CPS serves more than 840,000 electric and 350,000 natural-gas customer accounts, amounting to approximately 1.9 million residents, and has already instituted a broad set of commercial and residential demand response programs that have successfully reduced peak load by 771 megawatts. It's also testing out integrated solar-storage-grid controls at its Fort Sam Houston microgrid project, funded by the National Renewable Energy Laboratory's Project Integrate, designed to investigate "plug-and-play" solutions for a smart power grid. 

CPS also approved a “green tariff” program this week that would allow large commercial customers to secure their own renewable energy resources through long-term utility contracts. The new tariff was supported by Microsoft, which operates a data center in San Antonio it wants to power with cleaner energy. Similar dynamics from data center operators such as Google and Facebook have driven clean energy tariff programs in other states. 

Texas municipal utilities CPS Energy and Austin Energy have both set goals of becoming zero-carbon by 2050, making them outliers in a state that has been getting an increasing amount of its energy from renewables but which still lacks a statewide carbon-reduction target. They are among a growing number of U.S. utilities making such commitments, including Southern Company, Duke Energy, Arizona Public Service, NRG, PSEG, Xcel Energy, Consumers Energy and Alliant Energy.