What

ZE Buses

Zero emission buses (ZE buses) are buses with no tailpipe emissions.
Types of ZE buses: Battery electric vehicle (BEV), fuel cell electric vehicle (FCEV), plug-in hybrid electric vehicle (PHEV).

BEV

Battery electric vehicle

Battery electric vehicle (BEV) uses electricity stored in rechargeable battery packs, with no secondary source of propulsion. BEVs use electric motors instead of internal combustion engines (ICEs) for propulsion.

PROS

no tailpipe emissions

more energy efficient (77%) than ICE vehicles (13%) and FCEVs (30%)

less noisy than ICE vehicles

fuel cost saving

CONS

higher cost of ownership compared to ICE vehicles

lower driving range than ICE vehicles (100-200 miles depending on the model)]

long charging time (3-4 hours for a single decker bus)

life of battery only lasts 3-10 years, cost of replacement and recycling is incurred

FCEV

Fuel cell electric vehicle

Fuel cell electric vehicle (FCEV) uses electricity from a fuel cell to power an electric motor, instead of drawing electricity from a battery. The fuel cell is usually powered by hydrogen to generate electricity.

PROS

no tailpipe emissions, the only by-product at point of use is water

higher driving range than BEVs, have a range similar to conventional diesel vehicles achieving 350-400 miles on a single tank of fuel

can be refuelled within 3-5 minutes (similar to ICE vehicles)

less noisy than ICE vehicles

fuel cell has a higher energy density and weighs less than battery

CONS

less energy efficient than BEVs

safety concern as hydrogen is flammable

higher cost of ownership compared to ICE vehicles

higher cost to refuel, average price for hydrogen fuel is about US$16/kg, price of gasoline-per-gallon equivalent between US$5 and $6

PHEV

Plug-in hybrid electric vehicle

Plug-in hybrid electric vehicle (PHEV) uses both electric motors and internal combustion engines.

PROS

CONS

Source: U.S. Department of Energy, Hydrogen London, European Federation for Transport and Environment