Air District Commissions Sustainable Aviation Fuel Report

Sustainable aviation fuel, or SAF, is a drop-in replacement for conventional jet fuel that can significantly reduce full-fuel-cycle greenhouse gas emissions from jet aircraft engines. It is currently required to be blended with conventional jet fuel, at up to 50 percent SAF by volume.

The world’s commercial aviation sector contributes roughly two-to-three percent of combustion-related greenhouse gas emissions. In California’s Bay Area (greater San Francisco-Oakland), aviation contributes about six percent of transportation-related GHG emissions.

Commercial aviation companies have made important strides in reducing carbon emissions through aircraft fleet-efficiency improvements, but sustainable aviation fuel has emerged as the leading approach to further reduce GHG emissions from jet aircraft.

In this report, a high-level estimate was performed to roughly calculate the full-fuel-cycle GHG reductions that could be realized by widely using SAF blends at the three largest Bay Area airports. It is estimated that GHG reductions from SAF blends would range from 0.47 million metric tons per year up to 4.7 million metric tons per year, depending on the specific blends, and based on 2019 emissions estimates.

A similar analysis was performed to estimate criteria pollutant emission reductions that could be realized within the Air District boundaries. For the best-case scenario, it is estimated that displacing all conventional jet fuel use at the three major airports with a 50 percent SAF blend could provide reductions in CO emissions of 2.27 tons per day, SOx emissions of 0.39 tons per day, and PM10 emissions of 0.28 tons per day.

This report was prepared by the clean transportation and energy consulting firm of Gladstein, Neandross & Associates (GNA), with input from Air District staff. It is the result of work sponsored and paid for, in whole or in part, by the Air District.