El Paso Times. El Paso, NM is bringing in natural gas buses to replace its 159-bus diesel metro fleet. In October, the first of 25 new compressed natural gas-powered buses will begin arriving at a rate of three to five a week, joining another 25 diesel buses being converted to natural gas through a state grant. Another 25 new natural gas buses are expected to be added to the Sun Metro fleet next year.

Maintenance is a major issue for Sun Metro.

On an average summer weekday, [Sun Metro Director Terry] Scott said, six to eight of the about 100 buses on the road will need service. On days when the temperature reaches 100 degrees, as many as 15 buses can break down.

Sun Metro expects buses to make 3,000 miles between service calls, but that has dropped to 2,200 miles this summer. Scott hopes the new buses will extend the time between service calls to 4,500 miles.

The new buses will not expand the fleet, Scott said. Federal and state funding provide only for environmental replacement: trading diesel for natural gas. “The bottom line is the fleet is old. It’s time to change.”

So the replacement is not based on which technology is cleaner, or offers more trouble free operation; it is based on availability of funding. The difference a policy can make.