Electrifying a fleet is less about buying vehicles and more about energy logistics. Every bus, van or truck has to leave the depot with enough charge for its next duty, every day, without a grid upgrade that wipes out the savings. Getting depot charging right at the start avoids the two most common outcomes we see: chargers that sit idle, and vehicles that leave with a half-full battery.
Start with the duty cycle, not the charger
The first question is how much energy each vehicle needs per day and how long it is parked. We gather this for every route or vehicle class:
- Daily distance and the worst-case route, including summer air-conditioning load and traffic.
- Energy use per kilometre for the actual vehicle model, measured where possible rather than taken from a brochure.
- Dwell windows: when vehicles return, how long they stay, and whether they can top up between shifts.
- Buffer: a reserve state of charge so a delayed return or a cold morning does not strand a vehicle.
Energy needed divided by available dwell time gives the minimum average charging power per vehicle. That single number usually rules out half the options straight away.
Matching power to the dwell window
| Power | Typical use | Where it fits |
|---|---|---|
| 30–60 kW | Overnight charging of vans and small trucks | Long dwell, many bays, lowest cost per bay |
| 120–240 kW | Shift-change top-ups, intercity buses | Short daytime windows, shared between vehicles |
| 360–600 kW | Opportunity charging at terminals | Buses on tight timetables |
| Up to 1,200 kW | Megawatt charging (MCS) for heavy trucks | Long-haul tractors during driver rest stops |
Most depots end up with a mix: many lower-power chargers for overnight work, plus one or two high-power units for vehicles that miss their window. Power cabinets with dispensers that share capacity let the same hardware serve both patterns.
The grid connection is the real constraint
Adding up every charger's rated power and requesting that from the DISCOM is the expensive way to do it. Vehicles rarely all need full power at the same moment, so we model the depot's load hour by hour and size the connection to the real peak. Smart charging then keeps the site inside that limit, prioritising the vehicles that leave first.
A realistic charging schedule often lets a depot run on a much smaller sanctioned load than the nameplate total suggests. That can change the project from a new substation to an upgraded transformer.
Layout, civil works and the future
Charger placement follows vehicle movement. We plan bays so vehicles park nose-in or drive through without reversing, keep cable runs short, and protect dispensers from impacts. We also lay ducts and space for the next phase now, because trenching an operating depot later costs far more than an extra conduit today.
Operating the depot
Once live, the charging management system becomes part of daily operations. Depot managers see which vehicles are ready, which are charging and which need attention. Remote monitoring and preventive maintenance keep chargers available, which matters more in a depot than anywhere else: one failed charger can mean one cancelled route.
How we can help
PxT Energies runs fleet electrification projects from duty-cycle analysis through design, DISCOM coordination, installation and ongoing operation. If you are planning your first electric vehicles or scaling up an existing depot, our team can model your routes and give you a charging plan you can budget against.