The cities’ new green buses actually are “greener.”

Metro Transit, the organization that manages most Twin Cities busing, recently introduced 19 new hybrid-electric buses.

The bright green buses are quieter than regular buses and emit less pollution.

By August of next year, 45 more hybrid buses should be delivered and about one in five of the 680-plus buses in the Twin Cities fleet will be hybrid by 2012, according to Metro Transit.

The buses are part of Metro Transit’s “Go Greener” initiative.

David Kittelson, director of the University’s Center for Diesel Research, said the buses release almost no polluting particles.

“These buses are extraordinarily clean,” Kittelson said.

Parking and Transportation Services spokeswoman Mary Sienko said the University is interested in leasing some of Metro Transit’s hybrid buses, which are managed separately from University shuttles.

All buses are cheaper when purchased in large quantities, but doing a complete overhaul of the bus fleet is challenging.

“You kind of have to weigh what’s fiscally responsible with what’s environmentally responsible,” she said.

Bob Gibbons, director of customer services for Metro Transit, said the hybrid buses cost about $200,000 more than regular buses. The federal government pays for 80 percent of the new buses’ costs, and the remaining 20 percent comes from regional property taxes, he said.

Savings on fuel should pay for some – but not all – of the extra money spent on the hybrid buses. Gibbons said each hybrid bus uses about 1,965 fewer gallons of fuel per year than a regular bus.

Most of the 19 new hybrid buses are assigned to routes 17 and 18, which service Nicollet Mall.

However, one is rotating across different city routes. Service on that bus will be free through the end of the year.

Another part of Metro Transit’s “Go Greener” initiative is the use of biodiesel fuel.

Currently, 10 percent of the diesel used by Metro Transit is biodiesel, five times more of the soy-based additive than the state requires.

“The value of using biodiesel is that it displaces the use of nonrenewable fossil fuels,” Gibbons said.

Next summer, the organization’s buses will start running on a 20 percent biodiesel blend.

Gibbons said the biodiesel content will have to stay at 10 percent during winter months, because very cold weather caused the blended fuel to gel during Metro Transit fuel tests.

“We opted for the reliability factor,” he said

Now, the University and Metro Transit are beginning to work together to develop other environmentally friendly transit technologies.

Dick Hemmingsen, director of the University’s Initiative for Renewable Energy and the Environment, said researchers are interested in finding a way to run other electric services on buses, such as air conditioning, separately from the engine.

Less pollution would be emitted if the engine could turn off while the buses are idling at stops.

“It would be a more efficient system,” Hemmingsen said.