Clean energy technologies could over the next several years replace CPS Energy’s oldest natural gas and coal units, according to results from a worldwide request for information by San Antonio’s electric and gas utility.

CPS Energy received 197 responses to requests for information for new energy generation and storage technologies, as well as energy-efficiency measures, utility officials said ahead of CPS Energy’s September board meeting Monday. Requests for information are public solicitations that may later lead to a contract.

Utility officials say the package, called the FlexPower Bundle, will help replace the capacity CPS Energy will lose over the coming decade. CPS Energy leaders say their oldest natural gas steam plants – the 1970s-era O.W. Sommers and V.H. Braunig – will end their useful lives in the 2020s. The utility has also committed to closing its 28-year-old Spruce 1 coal unit by 2030.

The utility had in July put out a request for information from companies that could supply up to 900 megawatts of solar-generating capacity, 50 megawatts of battery storage, and 500 megawatts of reliable capacity from an open-ended source. One megawatt is enough electricity for 200 Texas homes on a hot summer day.

The utility had also solicited information regarding the next generation of its energy efficiency efforts and programs to reduce its customers’ demand for electricity, which it calls FlexSTEP. It’s original STEP – the Save For Tomorrow Energy Plan – reduced demand by enough to allow the utility to avoid building another new fossil fuel plant in the 2010s.

In an interview Friday, CPS Energy President and CEO Paula Gold-Williams told reporters that the utility has “a lot of plants in our portfolio that are getting older,” including “coal units that ultimately need to close.”

“Now, we have to be careful about how we do that for customer affordability,” Gold-Williams said. “We have to be careful that we protect reliability and that we’re operating efficiently.”

The FlexPower Bundle process will not lead to the closure of CPS Energy’s Spruce 2 plant, which has drawn the focus of climate activists. The utility’s coal plants are among the largest standalone sources of greenhouse gas emissions in Bexar County. Officials say Spruce 2, completed in 2010, is capable of running into the 2060s. San Antonio’s Climate Action and Adaptation Plan calls for the city to effectively abandon fossil fuels by 2050.

CPS Energy has steadily added energy to its mix from renewable sources over the past two decades. The utility’s electricity generation capacity is 45 percent natural gas, 18 percent coal, 15 percent wind, 14 percent nuclear, and 7 percent solar, with less than 1 percent landfill gas.

Officials have also moved to make the FlexPower Bundle more open to low-emitting technologies than originally planned.

In late 2019, utility officials were poised to begin negotiations with a handful of natural gas plant operators on the Texas grid. Instead, after pushing from Mayor Ron Nirenberg along with environmental and social justice groups, CPS Energy leaders broadened the bidding process to all forms of technology that would fill that need.

“We’re in a state where gas is common,” Gold-Williams said. “It’s inexpensive and it’s abundant. But we said, ‘Is there something out there that’s as reliable as gas and can match the performance and is low- to non-emitting?’ We’re open to that.”

CPS Energy officials did not release a comprehensive list of companies that responded to its request for information. Instead, in response to requests from the San Antonio Report, they released a partial summary of responses broken down by type of technology.

Of the nearly 200 responses, the majority focused on providing solar projects, battery storage, and projects to reduce electricity demand. That’s to be expected, given that the request was specifically looking for information on solar, storage, and the next generation of STEP.

At the utility’s Monday meeting, Nirenberg said he’s “in favor of us moving expeditiously, particularly on the solar side,” especially given the economic uncertainty tied to the coronavirus pandemic.

“There is a global downturn, and the opportunity for us just at CPS [Energy] to be a key player right now with regard to solar, globally, is something that I think has benefits in many different ways for us,” Nirenberg said.

The responses for the 500 megawatts of what CPS Energy staff call “firming capacity” are the most varied, though batteries still weighed in as the most frequently suggested energy solution.

Of the 56 responses regarding how to fill that 500-megawatt order, 27 offered a combination of solar and energy storage. Another nine suggested batteries connected to CPS Energy’s local distribution grid in San Antonio.

Six of the 56 responses centered on conventional natural gas generation. Other responses fell into what CPS Energy called “innovative technologies,” such as storing energy using compressed air or via pressurized water that can move underground hydropower turbines.

CPS Energy will likely release a more complete request for proposals, the next step in a competitive bidding process, later this year, officials said.

Brendan Gibbons is a former senior reporter at the San Antonio Report. He is an environmental journalist for Oil & Gas Watch.