The Napa Valley Unified School District has been using a hybrid diesel-electric school bus for nearly a year and has seen significant benefits. With the diesel-electric bus, the school district has been able to reduce its green house gas emissions and double the gas mileage it gets with the hybrid bus as compared to its diesel-only buses. As a result, the school district saves about $5,000 in fuel costs for the hybrid bus.
While most "diesel-only" powered school buses achieve an average of six to seven miles per gallon, Ralph Knight, transportation director at Napa Valley School District, was surprised to learn just how much fuel the hybrid diesel electric school bus could save.
"Fuel costs are a major concern to me," said Knight. "Cutting annual fuel costs in half for this bus is a major advantage -- both for taxpayers' wallets and for the environment."
The fuel efficiency of the hybrid bus was close to 13 miles per gallon -- nearly double the fuel efficiency of a typical diesel school bus.
Based on 13,000 miles the hybrid bus traveled during the 2007-08 school year, annual fuel costs for a standard school bus would be just under $10,000 at $4.87 per gallon. Conversely, fuel for the hybrid bus costs approximately $5,000 at the same price per gallon.
Traveling about 65 miles per day, the hybrid bus typically transports roughly 60 children each morning and 60 each afternoon through a mixed route of highway and city driving.
Even the community has started to recognize the impact the bus could have on the environment and are excited about it. "The children are excited to be riding one of the first hybrid school buses in the nation," said Knight. "The parents have also commented on the positive environmental benefits of the bus."
Drivers also enjoy driving the bus. To the driver, it operates similar to a standard school bus. However, the diesel engine receives assistance from an electric motor at certain points during acceleration and deceleration. The hybrid drive system on Napa Valley's bus is recharged by plugging it into a standard outlet at night or between morning and afternoon routes.
The word in the industry has gotten out. Knight says he has fielded calls from school districts all over the country asking him about the performance of this new bus.
"I've told them the truth," said Knight. "I'm very pleased with the hybrid school bus."
One of the other advantages of the bus hasn't really been "seen." The exhaust of the hybrid school bus is smokeless with dramatically reduced emissions compared to older buses operating in California. In fact, emissions of particulate matter have been reduced by up to 90 percent.
"There's a host of new technologies incorporated into the hybrid school bus that provide the improvement in fuel economy and reduction in emissions," said David Hillman, marketing director at IC Bus. "With a year of customer experience in Napa, and the additional experience gained from hybrid buses at customers throughout the U.S. and Canada, we have shown that hybrid technology is a viable solution for bus operators in North America. The volume provided by our current customer base has allowed us to reduce our prices by $30,000 to $40,000. We encourage further efforts to provide federal and state funding, such as the California Proposition 1B funds, to help offset purchase prices and provide the opportunity for more school districts and bus operators to implement this environmentally vital technology."
In the case of Napa's hybrid unit, PG&E provided $30,000 to help with the purchase of the plug-in hybrid school bus. An additional $30,000 to fund the bus was provided by the U.S. EPA through the Clean School Bus USA program and the West Coast Collaborative, a public-private partnership to reduce diesel emissions.
Schools in California can use funds allocated by Proposition 1B to direct toward the purchase of a hybrid school bus. Funding to districts to support hybrid purchases from Proposition 1B and distributed through the California Air Resources Board can be up to $40,000 per bus.