Charging a 50-truck electric truck fleet from a single depot is a power problem long before it is a vehicle problem. Without load management, 50 trucks plugging in at once can demand 18 MW and blow the site transformer; with smart scheduling and peak shaving, the same fleet charges on a 2-3 MW supply and never pays a demand penalty. For operators in the Uzbekistan electric truck market, where grid tariffs reward off-peak use, the savings are large and the risk of getting it wrong is a six-figure utility bill.
Start with the worst case. A heavy tractor like the TE8L electric tractor supports 360 kW DC fast charging. Fifty trucks at 360 kW equals 18,000 kW or 18 MW if all charge together. Few depots have that supply, and even fewer can afford the demand charge. The table below compares charging strategies for a 50-truck fleet with 420 kWh packs needing one full charge per 24 hours.
| Strategy | Peak demand (kW) | Charge window (h) | Daily energy (MWh) | Demand cost index |
|---|---|---|---|---|
| All-at-once uncontrolled | 18,000 | 2 | 21.0 | 100 |
| Fixed 2 MW cap | 2,000 | 11 | 21.0 | 22 |
| Smart scheduled 2.5 MW | 2,500 | 9 | 21.0 | 19 |
| Solar + storage shave | 1,600 | 13 | 21.0 | 11 |
The fleet needs about 21 MWh per day (50 trucks x 420 kWh). The only variable is how fast you pull it. Stretching the window from 2 hours to 9-11 hours cuts peak demand by 7-9x and the demand-charge portion of the bill by a similar factor, which is the entire point of load management.
Uzbekistan and similar markets price the highest 15-minute demand window heavily. Peak shaving caps the depot draw so that window never spikes. A site controller polls each truck's state of charge and allocates the 2.5 MW budget to the trucks that need it most, throttling others. The TE8L electric tractor accepts a dynamic charge rate command, so the controller can drop it from 360 kW to 120 kW without driver action and without stranding the truck.
Scheduling turns the 21 MWh into a smooth overnight curve. The practical rules are:
With these rules the 50-truck fleet finishes a full charge by 06:00 on a 2.5 MW supply, leaving the daytime peak untouched and the demand meter calm throughout the billing period.
Transformer sizing must cover the managed peak, not the theoretical one. For a 2.5 MW managed load at 0.9 power factor, the apparent power is about 2.78 MVA. Add 25% headroom for future growth and the right unit is a 3.5 MVA transformer. Choosing 18 MVA would multiply capital cost tenfold for capacity the load manager never uses. The Uzbekistan electric truck market teams at Fenghan model this before the depot is built so the utility connection matches reality, not fear.
Where 5-6 minute battery swap is available, the depot can service a truck in a fixed power bay instead of a high-power charger, flattening the curve further. Swap bays draw a steady 200-300 kW each, predictable for the transformer. This hybrid of scheduled charging plus swap bays is the most grid-friendly design for a 50-truck site and removes the risk of a charger fault cascading into a missed departure.
The deepest saving comes from pairing the depot with a 1-2 MWh battery and a solar canopy. The storage absorbs the 2.5 MW evening peak from cheap midday solar, shrinking the grid draw to 1.6 MW and the demand-cost index to 11. For Uzbekistan's sunny climate, a canopy over the depot also shades the packs and extends battery life, a double win that the raw demand math alone understates.
The control stack is simple: a depot energy management system reads the utility meter, the charger states and each truck's state of charge, then runs the scheduling rules every minute. It must fail safe, defaulting to a conservative cap rather than full power if comms drop. A well-tuned system needs one operator glance per shift, not constant attention, which is what makes a 50-truck site practical for a normal fleet staff.
The value of peak shaving is clearest in money. The table below compares the monthly demand charge for the same 50-truck, 21 MWh depot under two control modes, using a representative demand tariff of USD 12 per kW of peak.
| Control mode | Peak (kW) | Monthly demand charge (USD) | Annual (USD) |
|---|---|---|---|
| Uncontrolled | 18,000 | 216,000 | 2,592,000 |
| Smart scheduled 2.5 MW | 2,500 | 30,000 | 360,000 |
| Solar plus storage shave | 1,600 | 19,200 | 230,400 |
The scheduled mode saves about USD 2.23 million per year in demand charges alone, against a load-management system that costs a fraction of that to install. Even ignoring the energy tariff arbitrage from off-peak charging, the payback on the controller is under two months. This is why depot design should start with the peak number, not the charger count, and why the TE8L electric tractor fleet in Uzbekistan is specified around a 2.5 MW managed cap rather than an 18 MW supply.
The charger mix should match the 2.5 MW budget, not exceed it. A sensible 50-truck depot uses a mix of power levels so the controller has granularity to shift load minute by minute without stranding a departure:
This mix peaks at about 2.5 MW only if all run flat out, which the scheduler prevents, and it gives the controller enough nodes to balance the 21 MWh demand across the off-peak window. The TE8L electric tractor accepts the full 360 kW on its reserved bay while the cargo units trickle on the 120 kW units, keeping the aggregate draw inside the transformer cap and protecting the demand-charge saving.
Load management is the difference between a fleet that fights its utility and one that exploits off-peak tariffs. Size the transformer to the managed peak, schedule by departure and state of charge, and a 50-truck electric truck depot runs cleanly on a fraction of its worst-case power while keeping every truck charged for the morning dispatch.
Ready to electrify your fleet? Contact Shaanxi Fenghan Trading — authorized Dongfeng EV truck exporter. WhatsApp: +86 153 1943 1311 | Email: sales@fenghan-trade.com | dongfengevtrucks.com
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