Plugging In: The Electrification of Bus Fleets
U.S. transportation is embracing an exciting shift: electric vehicles (EVs). And not just light-duty cars and trucks anymore. Medium- and heavy-duty electric vehicles, specifically buses, are becoming a focus for city transit agencies because of their lower noise and air pollution, reduced maintenance, and advancements in charging capabilities.
However, as many agencies have learned from EV bus pilot projects, smart infrastructure must be considered and addressed well in advance of deployment.
Obstacles to Consider and Overcome
Transit bus operators have two main efficiency concerns when it comes to their fleet, whether diesel, compressed natural gas (CNG) or EV: space and operations. Even with the profound benefits of EV buses, the switch to electric — electrification of the fleet — could be impeded if these two factors aren’t as efficient or more efficient than the current state.
For example, current diesel buses take minimal time to refuel and clean after a route. They can be parked overnight to maximize the space available, often within inches of other buses on all sides. This parking method also means that buses cannot always be specifically designated for specific routes, so all must be fueled and ready for either short- or long-haul routes.
This familiar process to maintain space and operational efficiencies could prove an unnerving adjustment for EV adoption. Transit bus operators would need to allow time to fully charge each bus — from 4 to 8 hours — and designate valuable parking space for charging stations. To accommodate these needs, four specific smart infrastructure solutions have risen to the top for EV buses.
Options for Powerful EV Infrastructure
Several models to establish EV charging systems exist, and they should be evaluated based on each transit agency’s unique space requirements and operational processes.
- Charging catwalks — If parking space is at a premium, catwalks can be constructed over the entire parking area with charging cables running down to buses. Though the catwalk itself would require support structures, it would still take up less real estate than free-standing charging stations.
- Multiple charging hookups — Another option to save space is to install charging stations with multiple plug-in connections. While most stations can only charge one or two buses at a time, these enhanced stations could fully charge a handful of EV buses at once, saving precious real estate on often cramped bus lots.
- Inductive charging — Offering a wireless alternative, this innovative charging technology places plates underground either at bus stops on-route or at the depot to administer charges to stopped or parked buses without the need to connect to charging stations. This offers another way to save real estate because aboveground chargers, and the bollards that protect them, would be unnecessary.
- Rapid on-route charging — Using flash chargers installed on bus stop or transit center rooftops, short-haul buses can automatically latch to the charger when stopped to load and unload passengers. This brief charge could continuously top off the bus’s battery throughout its route, eliminating the need for overnight charging stations at the depot.
Optimizing Public Transportation
Strategic and thoughtful EV charging infrastructure is key to the long-term success of EV bus fleets, and transit agencies that embrace the challenge could realize significant benefits. The charging options available today are continuing to improve and have the potential to surpass the efficiencies of diesel buses, whether in operations, space or funding, if implemented effectively.
Read more on how advancements in EV bus technology are filtering into the landscape of smart transportation.