The U.S. EPA finalized its update to the Renewable Fuel Standard on Friday after a monthslong review process. The rule includes higher renewable volume obligation requirements for cellulosic biofuels than the agency had proposed in a draft last summer — a key ask from the biogas industry.
The Set 2 rule, as the update is called, sets the level of credits that refiners and importers of petroleum fuels must purchase to offset the carbon intensity of their fuels. The credits are generated by producers of alternative fuels, including those derived from corn, soybeans, organic waste and landfill gas, among other sources.
As part of the final rule, the EPA removed a framework that would have set up a credit system for electricity used as fuel. The proposal was first introduced during the Biden administration but was never finalized, and EPA made its intentions to remove the language clear in a draft last year.
The final rule also keeps a proposal to cut in half the amount of credits that foreign fuels and feedstocks can generate beginning in 2028, per a release from the agency on Friday.
“For 20 years, this program has diversified our nation’s energy supply and advanced American energy independence,” EPA Administrator Lee Zeldin said in a statement. “EPA is proud to deliver on this mission and to do so at historic levels.”
Agriculture Secretary Brooke Rollins also praised the final rule in a statement, noting the final volume requirements “represent the highest levels of biofuels ever required to be blended into our fuel supply.”
The final version of the rule includes higher overall RVOs for the years 2025, 2026 and 2027 than the proposal and projects a higher growth rate than initially envisioned.
The proposed version of the Set 2 rule released in June cut back the total volume of Renewable Identification Number, or RIN, credits that petroleum fuel producers needed to purchase in 2025, drawing condemnation from the biogas industry. The growth rate in RVOs the EPA projected in its proposal was also smaller than the industry had hoped to see. A higher growth rate would demonstrate a vote of confidence in the industry's ability to produce more fuels like renewable natural gas over time as projects come online, biogas proponents argue.
In a statement, RNG Coalition founder and CEO Johannes Escudero said the final rule was an improvement over last summer's proposal. He highlighted the “hundreds” of facilities under construction today and noted the RFS has supported a decade of strong growth for the industry.
“The program is critical to supporting significant investment across American communities and growing volumes of clean fuel. The current instability in global energy markets means the RFS has a key role to play in buttressing U.S. fuel supply and energy security," Escudero said.
While development of new RNG facilities remains elevated across the United States, growth slowed in 2025, according to the American Biogas Council’s most recent annual data report. That's likely in part due to slowing demand for RNG as a transportation fuel, as fleets capable of using the fuel have largely already signed up to receive it. The EPA has acknowledged this potential shortfall in demand, and proposed new pathways for biogas to earn credits through the RFS program.
The American Biogas Council expressed its disappointment with the final rule in a release on Friday. Executive Director Patrick Serfass said in a statement that delays in issuing the final rule had already dampened development, and said the EPA’s method of forecasting RNG production understimates growth.
“This approach looks to constrain domestic, renewable fuel production, a foundation of RFS goals, instead of supporting U.S. fuel industries which recycle organic residues, and more fully utilize American crops,” Serfass said.
The agency has not released a complete copy of the final language yet, but the RNG Coalition noted it expected to see more details on Friday.
