Battery Electric Vehicles

Commitment to Saving Energy

Battery electric buses (BEB) come with a host of benefits to the environment, users and operators alike. If you are considering converting all or part of your bus fleet to battery electric buses, here are a few things you should know.

BEV Benefits

- Battery Electric Vehicles are considered zero emission vehicles since they have no exhaust emissions. The shift to electric vehicles and buses in particular will help to reduce green house gas emission in the United States.

- Battery electric vehicles are also more efficient. A 2016 study by the California Fuel Cell Partnership stated that battery electric vehicles convert 59% – 62% of grid energy to the wheels of the vehicle. Combustion vehicles convert 17% – 21% of gasoline energy to power at the wheels.

- Battery electric vehicles are also quieter due to the use of electric drive motors as opposed to combustion engines. Battery electric vehicles are so quiet that most states are requiring noise generators be added to the vehicle so that pedestrians can hear them coming.

- BEV’s have overall less maintenance costs per mile than their diesel equivalents. This is due to the limited number of moving parts on a BEV as compared to a diesel bus.

Things to Consider

On-route Charging, Depot Charging or Both?

- Each have their advantages and disadvantages – a review of your utility rates, transit routes and schedules will determine the best economic and operational charging option.
- Charging selection impacts bus battery configuration and size – on-route charging can utilize smaller batteries on the bus, providing lighter weight. Depot charging will require larger batteries with a heavier weight.
- Costs are a factor – depot charging is usually less expensive than on-route charging.

Types of Charging – plug-in, Pantograph or Induction?

- Each have their advantages and disadvantages in capital costs, operational costs and complexity – optimum selection will be based on on-route or depot charging selection as well as utility rate analysis and transit route analysis.

Electrical system considerations

- Impacts to depot electrical distribution system – addition of BEB’s will impact the depot electrical distribution system.
- Utility system feeds & transformers – discussions early on the process with the local utility are necessary as the addition of a large number of BEB’s will have an impact on the local utility distribution system.

Mechanical system considerations

- If a large number of chargers are located in the bus garage, a review of the HVAC systems may be necessary due to heat generated by chargers.
- BEB’s are typically heavier than their diesel counterparts. A review of bus lifts & hoists should be done to verify capacities are adequate.
- Fire suppression systems – Lithium Ion batteries are difficult fires to put out. Enhanced fire protection systems should be considered when charging & storing BEB’s indoors.

Resiliency

- When switching to BEB’s consideration should be given to upgrades to the depot for alternative energy sources such as solar, battery storage, fuel cells & other microgrid alternatives. This can augment power from the grid and potentially provide some resiliency to the BEB program.