This week, Metro introduces five new buses to its fleet. These buses employ a new technology named "mini-hybrid."
The buses aren't smaller, nor are they hybrid, but they do get almost the same MPG as hybrids, as well as cost $240,000 less than a hybrid bus. The technology was developed by Engineered Machined Products and uses an electrically powered cooling fan, which would normally be powered hydraulically and take horsepower from the engine. The mini-hybrid buses still run on diesel fuel, but get gas mileage closely comparable to that of a hybrid.
"It's basically like running the air-conditioner in your car without using the power it takes from the engine," says Daron Brown, quality assurance manager for Metro.
Metro is one of the first transit agencies in the country to obtain a Clean Fuels Grant, which is normally given for the purchase of hybrid buses, for the mini-hybrid technology. Brown put together a report suggesting that the new technology will give a six to seven percent increase on fuel economy compared to traditional diesel buses, while hybrid buses get about 10 percent better MPG.
The Federal Transit Authority requires that buses must have at least a 12-year life before being replaced and Metro now has 70 at the 12-year mark. With a total fleet of 345 buses, Metro looks to replace 30 buses per year and has 40 more mini-hybrid buses joining the fleet in coming months. The money saved by purchasing mini-hybrid buses will allow Metro to replace more old buses and create a greener fleet.
"From now on, all of the buses we purchase will have this technology," Brown says. "We try to get 30 to 35 new buses each year. If we get funding that says we must purchase a hybrid bus, obviously we will, but the mini-hybrid buses give us a cheaper option to replace buses with a more environmentally friendly option."