Carbon Intensity Adjustments Maintain Low Carbon Fuel Availability

This emergency rule change, which effectively increases the carbon intensity (CI) requirement to 46 gCO2e/MJ, is effective for 180 days. This adjustment simply maintains the fuel products that were approved by Portland City Council when they adopted PCC 16.60, while aligning with recent changes at the state level. It gives the City time to advance a long-term solution for adjustments to the carbon intensity requirement.

The renewable fuel standard requires diesel sales in Portland to meet two requirements: a minimum percentage blend of 50% renewable fuel such as biodiesel or renewable diesel, with an increase set for 2030, as well as the requirement that the carbon intensity (CI) value of biodiesel and renewable diesel products be equal to or less than 40g CO2e/MJ.

This emergency rule responds to concerns raised by the RFS Technical Advisory Committee about alignment between Portland's carbon intensity (CI) requirement and new Oregon DEQ Clean Fuels Program requirements for generating lifecycle carbon emissions with the OR-GREET model.

The Oregon DEQ Clean Fuels Program is moving from OR-GREET Model 3.0 to 4.0, which increased the CI value of all fuels in Oregon. BPS reviewed DEQ's data comparing the change in operational CI values and found that, for renewable diesel and biodiesel, there was an average increase in the operational CI of 5.5g CO2e/MJ for all products.

BPS reviewed each fuel product allowed in Portland before the modeling change and determined that adding 6g CO2e/MJ would ensure products previously approved by Portland City Council would still be allowed in Portland. This is why the rule change effectively increases the carbon intensity (CI) requirement from 40 to 46 gCO2e/MJ for fuel products with Oregon approved CI values generated by OR-GREET Model 4.0. This change maintains the CI value threshold adopted by City Council. The code continues to exclude biofuels using virgin agricultural feedstocks in diesel blends.

DEQ's modeling change impacts Portland's fuel supply as some products that had previously been allowed would have been disallowed. At the same time the Portland RFS blend requirement was scheduled to increase from 15% to 50% biofuels on May 15, 2026. Given the resulting risk of diesel fuel supply constraints, Portland approved an emergency rule to remedy the issue.

Portland supports the DEQ model change because it improves the accuracy of accounting for lifecycle carbon emissions. Portland will continue to work with impacted partners and businesses over the next six months, and staff welcome questions and feedback.