Enough methane from decaying waste in a private San Antonio landfill can be harvested to offset the need for fossil fuel use by most of VIA Metropolitan Transit’s bus fleet, officials say.

CPS Energy, VIA, and energy company EDL are working on an initiative that will provide CPS Energy with natural gas from Republic Services’ Tessman Road landfill just south of Interstate 10 on San Antonio’s East Side. That gas will be part of a renewable fuel credit swap that will generate revenue for VIA while putting a former waste product to use.

The landfill methane will make up only 1 percent to 2 percent of the entire supply in CPS Energy’s distribution system, said Richard Lujan, CPS Energy’s senior director of gas solutions. Still, CPS Energy expects it will receive enough of the landfill methane to offset the fossil fuel-derived natural gas needed for an estimated 75 percent of VIA’s fleet of 502 buses, Lujan said.

“That’s natural gas displaced from traditional fossil fuel sources,” Lujan said in an interview last week. “We’re taking this from our community waste and making use out of it.”

Gas harvested from landfills has long been used as a fuel for electricity generation. CPS Energy officials say the municipally owned utility receives 0.2 percent of its annual electricity generating capacity from two landfill gas-fired power plants on San Antonio’s Southwest Side.

But renewable natural gas (RNG) is gaining interest as a vehicle fuel across the U.S. Dallas Area Rapid Transit began integrating RNG into its fleet in 2018. The Environmental Protection Agency counts 67 active landfill RNG projects across the U.S. in 2020.

In San Antonio, this gas won’t flow directly from the landfill into a VIA bus. Instead, the gas supplier, CPS Energy, and VIA will participate in a renewable fuel credit swap arrangement that will assign a different role to all three parties.

EDL, an international power supplier headquartered in Australia, will convert its existing landfill gas power plant at the Tessman Road landfill to a plant that can inject pipeline-quality gas into CPS Energy’s system. CPS Energy will get the gas at a “favorable” price, Lujan said, though he declined to cite a specific price.

The entire exchange relies on renewable energy credits generated by the EPA as a result of the 2005 Energy Policy Act. That law set a standard for fuel refiners and importers to introduce certain amounts of renewable fuels into the market. It’s the reason gas stations sell gasoline blended with ethanol derived from corn.

Refining companies and importers who don’t generate enough renewable fuels can buy credits for them via this system, which the EPA oversees. Lujan said it could generate up to approximately $530,000 per year for VIA.

This method means VIA can continue using its compressed natural gas fueling station at 1721 N. Flores St. The facility was billed at its opening in 2018 as the largest of its kind in North America.

“One of the beauties of RNG is that the region reaps environmental benefits while VIA as a customer does not need to make any changes to our infrastructure, equipment, or practices,” VIA CEO Jeff Arndt said at the transit authority’s October board meeting.

The new partnership should also yield significant climate benefits. Landfills are constantly generating methane through the decay of organic material. Methane that escapes to the atmosphere has a potent effect on global climate, with a warming potential 80 times that of carbon dioxide, the most common greenhouse gas.

Kristi Villanueva, who serves on VIA’s board, is president of the West San Antonio Chamber of Commerce. She was also an important figure in San Antonio’s Climate Action and Adaptation Plan, where she served on one of the volunteer committees that helped draft the vision for the city to effectively abandon fossil fuels by 2050.

“There are no negatives to this, for us being a part of it,” Villanueva said in a phone interview. “VIA as an agency really has no risk.”

VIA’s trustees approved the initiative at their October board meeting, with the RNG plant expected to begin operations in fall 2021.

CPS Energy is a financial supporter of the San Antonio Report. For a full list of business members, click here.

Brendan Gibbons

Brendan Gibbons

Brendan Gibbons is the San Antonio Report's environment and energy reporter.