Changes to HGV Operation
The charging infrastructure needed for all HGVs in Scotland will enable approximately 70% of routes to be completed without additional stops for charging.
This section explores some headline operational implications of a switch to BEVs. Under consideration is whether existing journeys can be completed with or without recharging, and any additional penalties in journey time and/or distance may be incurred.
Assumptions
The Agent-Based Model assumes a full transition (100%) of the HGV fleet to electric vehicles. Further research is required into how the transition will occur and the resulting mix (if any) of fuel/energy types.
The model also assumes a 44-tonne HGV with a 350 kWh usable battery capacity and a conservative 1.7 kWh/km energy consumption rate based on previous published research10. Actual performance could be better.
Three primary scenarios are analysed:
- Home Depot Charging Only: Vehicles start each day 100% charged and can only recharge at their own company depots. Forestry vehicles are an exception. They have no depot and only charge en-route, reflecting real-world individual operations.
- En-Route Charging Only: Vehicles recharge solely at designated en-route chargers, leaving their depot with their previous day's charge state.
- Mixed Charging: Vehicles can charge at both their home depot and en-route.
For proposed new locations, two analyses were run: one with 500 kW and another with 350 kW chargers.
No charging at delivery destinations is assumed due to current infrastructure limitations. En-route charging is capped at 80% battery capacity.
These assumptions are conservative in nature.
Key Findings
For 70% of trucks in the Agent-Based Model, charging at the depot where they are based is enough to cover their routes. They do not need to make any extra charging stops.
A mixed charging strategy allows over 90% of current journeys to be carried out, albeit 30% of the total experience some level of route or journey penalty.
Across all charging scenarios the percent of journeys which require one charging stop is between 4 and 6%.
The percent of journeys which require 2 to 3 stops is between 7 and 13%.
The percent of journeys which require more than 4 stops is between 1 and 4%.
Relying just on en-route charging results in 34% of current journeys not able to be completed.
The average route time increase with 350kW chargers is within the range of 37 to 46% across depot, en-route, and mixed charging strategies.
The use of 500kW chargers – on average – makes relatively little difference. The route time increase in this case being in the range 30 to 40%.