Depot charging vs. opportunity charging - Careful assessment of relevant factors
Published on 17 August 2021
Germany
Hamburg
This is the good practice's implementation level. It can be national, regional or local.
About this good practice
In preparation of e-bus-deployment a decision on the type of charging by the VHH was required. A careful assessment of individual decisive factors was necessary.
There are basically two different charging strategies:
Depot charging means charging overnight and perhaps re-charging at the depot during the day. Most often it is done by plug-in charging (typically 30-50 kW).
Opportunity charging uses so-called superchargers located en route,e.g. at terminal stops (>150 kW); however, it includes overnight charging at the depot.
This good practice lists the main aspects to consider for choosing a future charging strategy.
Operational flexibility
Price for infrastructure
Impact on bus drivers
Distances driven
Availability of public space (for building opportunity chargers)
Limitations in the built environment (e.g. low clearance bridges, weight restrictions on old bridges
Acceptance by public
The VHH needed to answer a number of questions in order to find their individual best solution. Some of these questions can only be answered by integrating public authorities or other public or private stakeholders. As a result of in-depth analyses, opportunity charging was not feasible due to a lack of space for chargers in the city of Hamburg and higher investment costs, while on the other side the route topology and operational aspects allowed for a centralized charging at the depot due to short routes.
There are basically two different charging strategies:
Depot charging means charging overnight and perhaps re-charging at the depot during the day. Most often it is done by plug-in charging (typically 30-50 kW).
Opportunity charging uses so-called superchargers located en route,e.g. at terminal stops (>150 kW); however, it includes overnight charging at the depot.
This good practice lists the main aspects to consider for choosing a future charging strategy.
Operational flexibility
Price for infrastructure
Impact on bus drivers
Distances driven
Availability of public space (for building opportunity chargers)
Limitations in the built environment (e.g. low clearance bridges, weight restrictions on old bridges
Acceptance by public
The VHH needed to answer a number of questions in order to find their individual best solution. Some of these questions can only be answered by integrating public authorities or other public or private stakeholders. As a result of in-depth analyses, opportunity charging was not feasible due to a lack of space for chargers in the city of Hamburg and higher investment costs, while on the other side the route topology and operational aspects allowed for a centralized charging at the depot due to short routes.
Resources needed
Required resources are difficult to quantify. Human resources, i.e. management, technical staff, operational staff, are a big part of the resources. Depending on the existing expertise in the PTO, external experts might be necessary to perform technical and economic feasibility analyses.
Evidence of success
Evidence of success is given by the fact that VHH has successfully scaled up e-bus operations from pilot to regular operation. Smooth operation, sticking to one charging strategy and not changing or adapting it means that you have made the right choice.
Potential for learning or transfer
For regions wanting to implement e-buses in public transport it is of added value to know what parameters to take into account for the decision for or against a certain charging strategy. They can benefit from experiences gained by VHH and Hochbahn. In regions where concessions are granted to private operators, the public authority should have a clear position about what kind of charging strategy they want to have. If opportunity charging is considered additional decisions must be taken regarding the ownership of charging equipment in public spaces. This practice helps to gain confidence in making a decision towards one or the other charging strategy and helps to save money by choosing wisely.
Good practice owner
You can contact the good practice owner below for more detailed information.
Organisation
Verkehrsbetriebe Hamburg-Holstein GmbH
Germany
Hamburg
Contact
Agence Web