A primary goal of the hybrid-electric school bus project was to provide real world data for a transportation sector that has seen little improvement in engine efficiency since the adoption of the diesel engine in the late 1970s. The hybrid-electric school buses use the Eaton hybrid system, and were expected to achieve 30-40% greater fuel efficiency. Kentucky was selected as an ideal location for large scale deployment of hybrid-electric school buses because of the wide variation in terrain, including hilly, flat, urban, and rural bus routes. The Kentucky Clean Fuels Coalition (KCFC) and the Kentucky Department of Education tracked monthly mileage and fuel data from 2011-2013, and made the data publicly available on KCFC’s website.
The 156 hybrid-electric school buses in thirty five districts across the Commonwealth of Kentucky achieved an average of 8.5 mpg and 35% greater fuel efficiency than the standard diesel school bus. The highest cumulative miles per gallon achieved over the length of the project was 11.7 mpg. The lowest cumulative miles per gallon was 6.8.
The project has collectively saved almost 200,000 gallons of fuel and saved school districts over $700,000. These fuel savings are expected to continue over the fourteen year life span of the vehicles. The Hybrid Horsepower for Kentucky Schools project has logged over 4 million hybrid miles and provides a wealth of information for future hybrid-school bus deployment efforts across the nation.
Raw performance data — Monthly mileage and fuel data from 2011-2013
Summary graphs – 2011 & 2012 summary graphs
Compare bus performance — Use data filters to compare buses