INSIGHT-California's push for cleaner buses could edge out natural gas
By Nichola Groom
LOS ANGELES, July 2 (Reuters) - Fifteen years ago, California led the way to cleaner transit buses with strict tailpipe emissions standards that effectively ushered out diesel as the primary fuel for buses in the state and replaced it with natural gas.
Now, California is poised once again to take the lead, this time by mandating a switch to so-called "zero-emission" buses by 2040.
The new push by California's powerful Air Resources Board (CARB) has the potential to marginalize natural gas as a bus fuel in the same way its adoption once marginalized diesel.
In response, the California Natural Gas Vehicle Coalition has proposed expanding the definition of "zero-emission vehicles" to include not just electric buses, but also those powered by so-called "renewable natural gas," which is produced from cow manure or decomposing organic matter in landfills.
Whereas regular natural gas offers a reduction in greenhouse gases of about 15 to 20 percent over diesel, renewable natural gas offers a reduction of about 90 percent over diesel, according to the coalition .
"That's going to be a tremendous step forward over where we are today," said Tim Carmichael, president of the coalition, which includes T. Boone Pickens-backed fuel provider Clean Energy Fuels Corp, utility Sempra Energy and engine maker Westport Innovations Inc, among others.
The stakes are high. About 60 percent of California buses now run on compressed natural gas, or CNG, compared with 17 percent nationwide. And with roughly one seventh of the nation's 67,000 transit buses operating on California's roads, the state is a crucial market for both bus manufacturers and fuel suppliers.