Zero Emission Bus Technologies

FACT SHEET

ZERO EMISSION BUS TECHNOLOGIES

There are several types of zero emission buses that are currently being manufactured. These types differ in fueling types and technologies utilized, A hydraulic system for hybrid which subsequently affect which routes and vehicles to capture braking energy usages these buses best service. to convert to electricity

Battery Electric Vehicle (BEV) Buses

Battery electric vehicles (BEV) have a battery pack and an Battery Electric electric motor instead of a fuel tank and an engine. This battery Vehicle (BEV) Buses is the vehicle’s sole source of power and must be recharged, often from the electric grid. Medium- and heavy-duty BEVs have been predominantly used Hybrid Electric on urban or suburban routes, characterized by frequent stops and starts, high idle times, lower average speeds, and a daily Vehicle Buses range of 100 miles or less. These BEVs have included, but are not limited to, urban transit buses and intracity delivery vehicles.

1 BEV maintenance costs can be as low as 20% that of Fuel Cell Electric conventional vehicles. Furthermore, the electricity used to Vehicle (FCEV) power the vehicle can cost less than diesel fuel, further lowering operational costs. Electric powertrains are more eﬃcient than Buses internal combustion powertrains2 and are able to perform the same amount of work as other vehicles while using less fuel. Contact Us As battery technology continues advancing with increased use of electric vehicles, overall costs of BEVs and their batteries are [email protected] projected to decrease over time.

www.transportation.gov/r2ze The American Fuel Cell bus. An all-electric bus in Shanghai, China during Expo 2010.

Hybrid Electric Vehicle Buses

Hybrid electric vehicles (HEV) have also known as extended range vehi- when it combines both its gasoline both an electric motor and an inter- cles, as the engine can be used to and electric mileage. Increased fuel nal combustion engine, utilizing both operate the vehicle in the event that economy reduces fuel costs and can electricity and gasoline. While the the battery is completely depleted. save ﬂeets money. vehicle can use gasoline for part of its mileage, it can also run emission-free There are several types of hybrid Plug-in Hybrids once switching to electric mode. vehicles. Like BEVs, Plug-in hybrid electric vehicles (PHEV) can be charged by There are two primary categories of Conventional Hybrids being plugged into an outlet. While HEVs: parallel hybrids use both the Conventional hybrid vehicles these hybrids have gasoline capabili- electric motor and the engine to recharge their electric batteries from ties, its ability to be charged reduces move the vehicle, while series the energy created from braking. the need for gasoline present in hybrids’ engines can generate Because it also has a battery, hybrids conventional hybrids. Users can opt electricity for the motor as well to have an increased fuel economy to operate entirely on electricity, move the vehicle. Series hybrids are compared to conventional vehicles with gasoline for emergencies.

Fuel Cell Electric Vehicle (FCEV) Buses

Fuel cell electric vehicles (FCEV) to conventional transit buses in and used will decrease individual bus contain a fuel cell system powered by terms of availability, performance, costs3 due to a better positioning for hydrogen that generates electricity and durability. Other forms of FCEV purchasing components and transi- to operate the vehicle. This electricity have included step vans, walk-in tion toward assembly line produc- used to power the vehicle, along with delivery vans, shuttle buses, and tion. Larger volumes makes on-site heat and water vapor, are the only semi-tractors for drayage services. hydrogen fueling feasible, which can byproducts of fuel cells. Electricity is make it equivalent or cheaper than stored in a battery system. While fuel cell vehicles have demon- diesel fuel. strated comparable performance FCEVs have performed a variety of with conventional vehicles, their tasks but have mostly been used as capital costs are still high due to low transit buses since 1991. Recent production volumes. However, man- demonstrations show the technolo- ufacturers are projecting that gy’s growth to become competitive increasing the amount of buses built

1 http://www.arb.ca.gov/msprog/tech/techreport/bev_tech_report.pdf 2 Ibid = http://www.arb.ca.gov/msprog/tech/techreport/bev_tech_report.pdf 3 http://www.afdc.energy.gov/uploads/publication/fc_buses_2014_status.pdf