The city’s sustainability office pitched a plan Wednesday to turn municipal buildings into power generators as a way to meet one of San Antonio’s main climate plan goals.

Chief Sustainability Officer Douglas Melnick briefed the City Council on his staff’s plan to achieve the city’s aim, per its Climate Action & Adaptation Plan, to make municipal facilities carbon neutral by 2040 by adding solar to city building rooftops. The power generated by the panels would be used to power the buildings rather than sending the power back to the grid, Melnick said.

“To really achieve that zero net energy, it’s a combination of not just improving energy efficiency — we’ll need to offset with renewable generation,” Melnick said. “That’s really the driving point of this proposal.”

If the plan is approved by council, the city would issue a request for proposals looking for companies that could “basically do it all — design, engineer, build, operate and maintain and then decommission solar panels” on municipal rooftops and in city parking lots, Melnick said.

Council spent about 30 minutes deliberating what that request for proposals might look like. Several council members, plus City Manager Erik Walsh, said the request should remain open-ended to invite a wide array of proposals. Others wanted to see the request more narrowly tailored.

Powering buildings directly makes more sense than sending that power back into the grid due to metering restrictions, Melnick said. And while CPS Energy would not be directly part of this project, city staff would include its input throughout the process, he added.

In addition to helping the city meet its climate goals, the project has several other potential benefits, Melnick said, including improved air quality and the potential to create local jobs. Surveying the city’s full range of real estate that could support solar will be “a really exciting process.”

The city currently owns a tiny amount of solar infrastructure: panels on eight rooftops and two carports, totaling 677 kilowatts. One kilowatt could power a ceiling fan for about 20 hours.

In 2017, the council also approved an agreement with a third-party company, PowerFin, which had a contract with CPS Energy called the Solar Host Program. Under the program, the city provided its rooftops to PowerFin, and the power generated was sold to CPS Energy. The city receives 3 cents a kilowatt-hour credit from CPS Energy under the agreement. That revenue offsets the city’s utility budget.

The draft for the request for proposals focuses on proposals that are either cost-neutral or that can generate revenue, Melnick said. Typical solar projects can be financed up to 25 years, he added.

Councilman Mario Bravo (D1) said he would expect the city to see cost savings from the project.

“I know a lot of people are ready to be critical of our climate plan and say it’s going to cost us money,” Bravo said. “I would like for us to take those cost savings that we can achieve through this and invest them into the implementation of our climate plan in other programs.”

Councilman Clayton Perry (D10) said he’d like the request for proposals to specifically indicate where the revenue to pay for any of these projects was coming from before it’s issued.

Mayor Ron Nirenberg and Walsh expressed approval for the plan and said they hope to bring a final draft to council for final approval soon. It’s unclear when that will be; Melnick said staff will adjust the language based on Wednesday’s feedback.

Lindsey Carnett

Lindsey Carnett is the Science & Utilities reporter for the San Antonio Report.