The main benefit of this design is effective and ample public transportation that produces no unhealthy internal combustion engine exhaust and no loud engine noise. It also doesn’t need its oil changed and requires less overall maintenance. To achieve this, most zero emissions buses use a highly efficient electric drive system that incorporates multiple high voltage storage batteries, a high speed charging system, and one or more forms of onboard electric power generation. Zero Emissions Electric Bus configurations in service currently include:

  • Full Battery Electric Buses that create zero emissions 100 percent of the time, using electricity from lithium-ion storage batteries to power a motor that propels the bus wheels, usually augmented with electricity produced by a regenerative braking system and, in some cases, outer shell solar panels. Most charging of the batteries takes place overnight, although some cities also add street charging capabilities under the bus at key locations where the bus is scheduled to wait for passengers.
  • Hydrogen Fuel Cell Electric Buses, also known as fuel cell electric vehicles (FCEVs), whose silent, non-polluting propulsion mixes hydrogen with oxygen through a “stack” of proton exchange membrane electrodes, creating only electricity, heat, and water. The electricity generated powers the bus wheels, air conditioning and other accessories, and some is sent to storage batteries. As with full battery electric buses, hydrogen fuel cell electric buses also use regenerative braking to produce more electricity, as well as outer shell solar panels.
  • Overhead Wire Electric Buses work more cleanly and quietly than internal combustion engine buses, but are considered out of date technology due to their absolute reliance on a city-wide grid of trolley-style overhead electrical wires for power. The limited operational usefulness of these buses, as well as the high costs, high maintenance, and potential dangers of such an infrastructure, have resulted in diminishing adoption of these systems over the years in most markets, so much so that most of those still in service today look and feel out of date.

In addition to zero emissions buses, most large municipal transit operations worldwide also use low emissions buses – Electric Hybrid Buses, Electric-Range Hybrid Buses, and Hybrid Motor Coaches – to help them move toward their zero emissions goals. They are not completely zero emissions vehicles, because they do use an internal combustion engine to charge their storage batteries, but they are significantly more efficient, clean, and quiet than traditional internal combustion engine buses.

Global Demand

These advances in electric bus power and propulsion systems – reinforced by strong growth in new battery technologies, sensor-optimized electric motor designs, and the global need to cut greenhouse gases – has resulted in a significant increase in worldwide demand for clean zero emissions bus power options that can only be satisfied by more advanced battery electric and hydrogen fuel cell electric systems. Most electric bus power and propulsion systems are developed in the United States, Europe, China, Japan, India, and South Korea today, but there is demand for them worldwide, and increasing climate change events are only heightening that demand.

Related Topics to Explore

All-Electric Buses • American Public Transportation Association • Battery Electric Buses • Combined Charging Systems (CCS) • Conductive Charging • Electric Drive Systems • Electric Bus Association of America • Electric Bus Manufacturers USA • Fuel Cell Electric Vehicles (FCEVs) • Global Electric Bus Integration • Inductive Charging Systems • Hydrogen Fuel Cell Electric Power • Hydrogen Fueling Stations • Plug-In Electric Buses • Smart Charging • Solar Powered Automotive Charging • Zero Emission Bus Manufacturers • Zero Emissions Day (ZED) • Zero Emissions Trucks • Zero Emissions Vehicles (ZEV)


This information page is provided as a service to our readers by BAE Systems, Inc., a U.S.-based world leader in aerospace, defense, power, and intelligence solutions. Learn more about us here.

Space Products

Electronic Systems

Learn more about our products and services.
Read more