City buses are getting even cleaner as lithium ion batteries are enabling the drive for short distances using only electric power.

The city of Flint Michigan, along with Lithium Technology Corporation, Transportation Techniques, Kettering University, and UQM Technologies will soon test new diesel-hybrid electric buses using lithium ion batteries. The new buses can reduce fuel consumption by up to 40 percent by running part time in "zero emission" battery-only mode.

Lithium Technology of Plymouth Meeting, Pennsylvania will provide the batteries as part of a $4.7 million contract.

Daimler is also moving ahead with lithium batteries in the new line of Mercedes-Benz Citaro G BlueTec Hybrid buses. The buses, which store energy in the roof mounted batteries, are expected to increase fuel efficiency by 30 percent over diesel buses.

The Benz buses use a diesel generator to recharge the batteries, so the buses are always powered by electricity. This is what GM calls an "extended range" electric vehicle, although since petroleum is involved, they are really hybrids with better battery system.

The city of New York is testing other Daimler bus technology, the Orion VII Next Generation diesel hybrids that according to a government report are far superior to an earlier version. Perhaps New York will be one of the places where the new buses are tested.

Diesel hybrid technology in trains and buses have proven to be fuel efficient, so we should expect large utility and construction vehicles to incorporate lithium ion batteries.