A standoff between the San Francisco Municipal Railway (Muni) and the city Board of Supervisors may result in Muni’s adoption of a diesel-electric hybrid technology that does not meet California’s new, more stringent emissions standards.
At issue are over 80 heavily-polluting diesel buses, some 20 years old, currently belching three tons of soot and 100 tons of smog-creating nitrogen oxides into the city’s air each year.
On December 16, Muni unveiled plans to replace these and other aging buses with a new generation powered by either liquefied natural gas (LNG), battery electric, or diesel-electric hybrid engines.
“The problem,” said Ina Shlez, a member of the SF Department of the Environment and Muni’s Independent Oversight Committee, “is that none of [those] technologies is currently available.” Two of the buses that Muni is pursuing — the LNG and the battery electric — are still in development, while the diesel-electric hybrid is unavailable because it fails to meet the state’s emissions standards on nitrogen oxides.
The only buses that meet the California Air Resource Board’s (CARB) emissions guidelines are powered by natural gas (NG), a fuel that Muni has resisted for years, even in the face of a November Board of Supervisors resolution supporting it. Muni spokesman Joe Speaks says NG buses did not perform well in recent tests.
Representatives of CARB say they will let Muni skirt the emission law and buy diesel-electric hybrids if concerned environmental groups consent. Diane Bailey, a scientist with the Natural Resources Defense Council and a member of the Oversight Committee, says that if Muni shows “a good faith effort [to replace its old buses], we could consider looking the other way.”
