What Fleet Electrification Costs You
Fleet charging is becoming a much bigger part of how a depot uses energy. Grid capacity, peak demand, charging schedules and energy prices all start to influence what further electrification will cost.
As your fleet expands, more vehicles are drawing power from the same site, often within the same charging windows and alongside the depot’s existing electricity use.
That brings a new set of questions into the business case:
- How much capacity does the site have available?
- What happens when 20 vehicles return and plug in at the same time?
- Which vehicles need to charge immediately, and which can wait?
- When is electricity cheapest?
- How many more vehicles can the depot support with its current grid connection?
These factors determine how efficiently the site can support a growing electric fleet.
The Costs That Start to Matter as the Fleet Grows
What changes | What it can mean for the depot |
|---|---|
More vehicles charge simultaneously | Higher peak demand |
Available grid capacity gets tighter | Less room to expand |
Charging happens at expensive times | Higher energy costs |
Trucks require more power | Greater pressure on charging windows |
Charging becomes more complex | More operational management |
Site capacity is reached | A grid upgrade may be needed sooner |
Managing when and how vehicles charge can have a significant impact on the long-term cost of electrification and how far the fleet can grow within the capacity already available.
Why Grid Capacity Becomes so Important
Every charger shares the depot’s available capacity with buildings, lighting, machinery, heating, cooling and other electrical loads.
As more vehicles plug in, simultaneous charging can quickly create a new peak.
The important distinction here is between energy and power.
Energy, measured in kWh, is the total amount the fleet needs. Power, measured in kW, is how much can be delivered at a given moment.
A fleet might have 12 hours to receive all the energy it needs overnight. That gives the depot room to spread charging across those hours instead of delivering as much power as possible when every vehicle first plugs in.
What Coordinated Charging Changes
Available power can be distributed according to the fleet schedule and what is happening elsewhere on site.
A van parked from 18:00 until 07:00 has plenty of time to charge. A vehicle returning at midday and leaving again two hours later needs energy sooner.
When several vehicles are connected:
- Earlier departures can receive priority
- Longer dwell times can be used to spread charging
- Charging power can decrease when site consumption rises
- More charging can take place when capacity becomes available
- Flexible charging windows can make use of favourable energy prices
The result is a charging schedule built around the capacity already available and the vehicles that need to leave.
What can that mean for peak demand?
A parcel depot running 40 electric vans was reaching its grid limit every evening because the vehicles started charging at the same time.
After introducing coordinated charging, peak demand dropped by roughly 35%, with the same grid connection and fleet size.
For a growing fleet, reducing those simultaneous peaks can create more room for additional vehicles within the existing connection.
Smappee’s ROI calculator can help estimate what coordinated charging could mean for your fleet and energy costs.
Trucks Bring a Different Charging Profile
Electric trucks require considerably more energy than vans and often have tighter charging windows.
A truck arriving at 22:00 and leaving again at 05:00 gives the depot seven hours to deliver enough energy for its next route. Several trucks following a similar schedule can create a significant new load.
Planning truck charging therefore depends on a few practical questions:
- When does each truck leave?
- How much energy does it need for its next route?
- How much site capacity is available during that window?
- Which other vehicles will be charging at the same time?
Where DC charging fits
Higher charging power becomes valuable when vehicles need a lot of energy within a short period.
DC charging can support:
- Trucks with tight turnaround times
- Midday top-ups
- Vehicles returning briefly between shifts
- High energy requirements within short charging windows
Its higher power demand also needs to fit within the capacity of the depot.
A mixed charging strategy can use longer parking periods for lower-power charging and reserve higher power for vehicles with tighter schedules. Coordinating AC and DC charging allows both to share the same site capacity.
What Should you Consider When Planning Depot Charging?
The operational requirement is straightforward: vehicles have to be ready when they are scheduled to leave.
Planning how they get there means looking beyond charger numbers.
Site capacity
Know your current peak demand and how much capacity is available for charging at different times of day.
Fleet schedule
Departure times and dwell times show where charging can be flexible and which vehicles need priority.
Energy costs
Longer charging windows can provide opportunities to use off-peak tariffs, dynamic electricity prices or other favourable periods.
Vehicle mix
Vans and trucks have different battery sizes, charging requirements and schedules. The charging setup needs to support both as the fleet develops.
Other energy assets
On-site solar and battery storage can provide additional flexibility when they are coordinated with charging and the rest of the site.
Looking at these factors together gives you a more realistic picture of how many electric vehicles the depot can support and what the next stage of electrification will require.
How Much Room Does Your Depot Have Left?
Fleet electrification often happens gradually. A few electric vehicles arrive first, more follow as leases are renewed and trucks may be added later.
Knowing the limits of the site before the next phase makes it easier to plan that growth.
Ask yourself:
- Do you know your current peak demand?
- When do those peaks occur?
- How much capacity is typically available overnight?
- Could you add 20 electric vehicles today?
- Can charging respond to vehicle departure times?
- What would adding electric trucks mean for your site?
These questions give you a first indication of how prepared the depot is for further electrification.
Our full guide includes a nine-question depot readiness scan, with a scoring guide to help you assess your site.
Frequently Asked Questions
What does fleet electrification actually cost beyond the chargers?
Chargers and installation are the most visible costs. As the fleet grows, grid capacity, peak demand, energy tariffs and operational requirements have a greater impact on the total cost. Growing electricity demand can also bring forward the need for a grid connection upgrade.
Why does EV charging strain a depot’s grid connection?
Every depot has a fixed amount of power available. When several vehicles charge simultaneously, that demand is added to the electricity already being used elsewhere on site. The resulting peaks can push the depot towards its connection limit.
How much can coordinated charging reduce peak demand?
The result depends on the fleet and site. In one depot running 40 electric vans, coordinated charging reduced peak demand by roughly 35%, with the same grid connection and fleet size.
Do electric trucks need DC fast charging at a depot?
DC charging can be valuable for trucks with high energy requirements or short turnaround times. The right charging mix depends on routes, dwell times, battery requirements and available site capacity.
How do I know if my depot needs energy management?
Look at your current peak demand, available capacity and planned fleet growth. Vehicle schedules and charging requirements can then show how much flexibility you have within the existing grid connection.
Plan Your Next Stage of Fleet Electrification
Understanding your site capacity and future charging requirements gives you a clearer view of how far your depot can scale.
Download the full guide
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