February 25, 2019 | Diesel Technology Forum
A School Bus is Way More than Just a Way to Get Kids to School
School buses do so much more than delivering kids to and from school safely everyday. School buses are often a necessary element in state, county and municipal evacuation plans to make sure that residents without a private means of transportation can escape a natural disaster safely.
The nation’s fleet of over 500,000 school buses do more than just make sure kids get to and from school safely. Many states, counties and municipalities rely on their fleets of school buses to make sure residents without a means of transportation can be evacuated in the event of a natural disaster or other event. Diesel is a prime technology to make sure school buses get an A+ when delivering residents to safety. Other alternative fuel technologies don’t get such high marks. Ninety-five percent of those roughly 500,000 school buses across the nation are powered by diesel technology helping to assure that these buses can effectively complete this secondary function effectively.
While alternatives to diesel school buses exist, nothing compares to diesel’s energy density and near ubiquitous fuel supply. Diesel fuel is the most energy dense transportation fuel around, meaning diesel school buses can deliver evacuees farther on a tank of diesel fuel than any other fuel available.The extended range of these diesel school buses is critical to performing evacuation functions.
Access to diesel fuel is also another critical element in evacuation planning. Unlike other fuel and powertrain alternatives, access to diesel fuel is nearly ever-present across the country. Roughly one out of every two retail fuel providers across the country offer diesel fuel, with some regions reporting 70 percent of available pumps selling diesel fuel. Retail fuel providers in several storm prone states are required to install sources of backup power to help deliver fuel from storage tanks in the event of a power outage to help keep motorists on evacuation routes and allow first responders to refuel vehicles and equipment.
Relying on other fuels and powertrain technologies do not deliver these benefits. Legislation introduced in Maryland and in the New York City Council would require that new school buses sold in the next few years be all-electric. While all-electric buses deliver zero tailpipe emissions, their range is severely restricted. The State of Massachusetts, in a demonstration project, determined that all-electric school buses have a maximum range of 75 miles before a required recharge. An expensive DC fast charge system can take up to 30 minutes to replenish a battery system. Thomas Built Buses, one of the leading manufacturers of school buses, including alternative fuel options, determines that new diesel-powered buses have superior range at 510 miles per full tank of fuel. Without an ancillary series of expensive battery backup capabilities, a fast charge system is rendered nearly inoperable in the event of a power outage.
All-electric school bus mandates may also restrict the reliability of a school bus fleet than if school districts were allowed to choose cost effective technologies. The State of Arizona determined that new all-electric school buses come with a price tag three times higher than a comparable new diesel school buses. All electric options also require a network of expensive charging stations not covered by the purchase price of the bus.
Many school districts operate within strict budgets that include funds for the replacement of older buses. Requirements to purchase much more expensive technologies results in older buses remaining in the fleet. Older technology that is approaching or has exceeded its service life may result in rising maintenance costs and poor performance.
When a big storm or severe weather event threatens, the nation’s fleet of about school buses are often a vital component to mission critical evacuation plans. Efforts to mandate away procurement of new diesel buses in favor of alternatives, including all-electric options, may severely hinder the ability to successfully meet these critical functions.