Corporate

Hybrid Electric School Bus

The Plug-in Hybrid Electric School Bus Project is a collaborative effort led by Advanced Energy to transform the nation’s school bus market by introducing plug-in hybrid technology. Already, the project has led to the delivery of buses across the nation, two of which were delivered in North Carolina in May 2007.

Background
Hybrid bus technology offers benefits ranging from cutting the costs of operation and maintenance of bus operators, to improving air quality, especially in urban / suburban areas that are experiencing non-attainment of EPA air quality standards, to improving the health of school children who presently ride diesel powered school buses.

Feasibility studies suggest that hybrid buses can be less costly to operate. Actual operation of a fleet of such buses, however, is needed to verify this. Operating costs for hybrid vehicles have been shown to be lower, both in fuel savings and in maintenance costs, particularly with plug-in hybrids. This feasibility study will help in fully understanding the life cycle costs of hybrid buses.

Mobile source air pollution continues to frustrate efforts to improve air quality. Estimates show that in North Carolina alone 25-30 counties will likely go into non-attainment for ozone levels once the 8-hour standard went into effect in 2004. Non-attainment particulate matter levels will likely follow suit for many of the same counties shortly after.

Recent medical studies highlight the dangers of particulate pollution of the sort produced by diesel bus engines. Particulate matter has recently been highlighted in several reports as a serious concern on school buses, causing problems ranging from increased cases of illness to lung cancer. Removing this type of exposure is the number one benefit of hybrid bus technology.

Hybrid School Bus as Pilot Program

Advanced Energy advocates using hybrid school buses as the pilot program for these four reasons:

1. The duty cycle of school buses makes them an ideal candidate for hybrid technology, particularly plug-in hybrid technology, in which most of the energy used by the bus comes from a "pre-charged" battery pack.
2. Hybrid bus technology, especially the plug-in design, dramatically reduces the environmental impacts of school buses by:
   • Improving the efficiency of energy use, resulting in fewer emissions per mile
   • Replacing mobile sources with stationary central power plant sources that already are much cleaner and easier to control
   • Moving emissions from daylight hours to nighttime hours, reducing the creation of ozone and smog
3. Hybrid school buses are not available on the market. The technology, however, has been demonstrated on transit buses. In addition to researchers and public interest entities, moving this technology into the market for school buses will require the involvement of bus operators, bus manufacturers, and vendors to the bus manufacturers who can provide the necessary technology.
4. Of all miles driven by buses in North Carolina, roughly 78% of those miles are school bus miles.

More Information

Ewan Pritchard, hybrid program manager
919 857-9028
epritchard@advancedenergy.org