AC or DC at a van depot: which charging power makes economic sense?

AC charging suits a van depot when vehicles can reliably draw the energy they need during their available dwell times. DC can make economic sense when short charging windows would otherwise require extra vehicles, public charging stops or rescheduled routes. Do not decide on maximum kW or a charger's unit price alone. Compare complete alternatives that meet the same operational requirements.

First check whether both options work technically

List the AC and DC charging functions actually supported by the intended van models. The specific version, battery and equipment matter. Do not rely on a general statement about the model family. Maximum achievable power may also depend on the state of charge and operating conditions. The official NOW quick guide to depot charging places charging power in the context of energy requirements and dwell time; the option comparison below is a separate operational application for vans.

The existing guide to AC, DC and HPC explains the technical terms. Procurement then requires a vehicle-specific assessment: how many kWh can realistically be transferred within the relevant window?

A hypothetical vehicle still needs 33 kWh from the charge point. At a constant available 11 kW, that would take three hours mathematically. If seven hours are actually available, AC may offer sufficient headroom. With only 45 minutes, at least 44 kW on average would be required on paper. A 50 kW label alone does not prove that the specific vehicle can meet this target.

Compare three complete operating concepts

Compare an AC baseline, a predominantly DC solution and, where appropriate, a mixed concept. In the mixed model, many connectors handle long charging windows, while individual faster charge points cover specific short turnarounds. What matters is whether those points are accessible and free when needed.

A single DC point can be a useful addition or a new bottleneck. If several vans need the same short window, include waiting and connection times in the plan. High theoretical daily capacity does not answer simultaneous demand at midday.

Calculate all costs on the same basis

Request a complete project scope for each option: charging hardware, planning, electrical installation, grid connection, civil works, communication, load management, commissioning and training. Add ongoing costs for operation, maintenance, software, metering and any power-related charges. Consistently compare net or gross amounts according to the basis set by Finance.

State the period covered by the economic assessment. A five-year assessment may yield a different result from a ten-year one. Include financing and residual values only with transparent assumptions. Simply spreading the investment annually is not yet a full net present value calculation.

Energy losses must also be checked for each option. Do not assume a blanket efficiency advantage for AC or DC without data on the actual design and use. Measured electricity drawn from the grid already includes certain losses; they must not be counted again.

A hypothetical comparison makes the added value testable

Suppose a depot compares an AC baseline supplemented by public top-up charging with the same AC baseline plus an additional DC charger at the depot. Hypothetically, the addition requires €24,000 net in extra initial investment. A simple five-year preliminary assessment converts this to €4,800 per year. Other assumed additional costs for maintenance, software and power total €1,200 annually. In this simplified calculation, the addition must therefore justify €6,000 of annual benefit.

It is also assumed to prevent two unplanned external charging stops per working day. Each stop would cause 20 minutes of genuinely additional working time. Over 220 days and using an internal time valuation of €30 per hour, this produces an imputed time value of €4,400 per year. That value alone does not cover the assumed €6,000.

If a further €1,600 in other annual costs were demonstrably avoided, the simplified calculation would break even. These amounts are freely chosen calculation assumptions, not market prices or StromNow savings. Financing, taxes, residual value and possible differences in electricity drawn have not been included here.

Do not automatically treat time saved as cash received

Time savings can have operational value without immediately reducing staffing costs. Someone may remain on duty but be able to take on extra tasks. Finance should therefore distinguish actual expenditure avoided from an imputed improvement in capacity.

Count only additional charging time eliminated by the option under review. A break already scheduled should not be counted entirely as lost working time. Likewise, the same avoided route delay must not be counted once as a time saving and again as full additional revenue without deducting costs.

The existing article on reducing fleet charging costs explains the importance of detours and extra time. For the investment decision, this becomes a clearly bounded comparison between operating options that are genuinely feasible.

Test the assumptions with sensitivity analysis

Deliberately vary the factors that drive the decision: the number of short charging windows, annual operating days, necessary additional working time and grid upgrade costs. Calculate one scenario with fewer vehicles than planned and another with earlier growth.

A particularly important question is whether the operational benefit occurs regularly. A rare exception may justify a different fallback process from daily top-up charging needs. Conversely, a single regularly critical van may determine operations more strongly than several vehicles with long dwell times.

Also check commitment to the site. If a move is likely, non-relocatable infrastructure and new connection costs change the comparison. The desired charging power should therefore be fixed only after the technical and economic scenarios.

Test the relevant vehicles before making the final decision

Use a pilot with real arrival states of charge and comparable conditions. Record energy charged over the actually available window, connection times and necessary vehicle movements. A single charging session under ideal conditions is not sufficient evidence for the whole year.

Also assess operation by staff. If different vehicle types require different procedures, the shift supervisor must be able to manage them reliably. A technically suitable concept can fail organisationally if sequencing or responsibilities are unclear.

StromNow Logistics describes selecting AC, DC and HPC options based on real routes and dwell times. For an economic assessment of your depot concept, bring vehicle data, short charging windows, connection information and existing quotations. Ask for options that achieve the same departure target and decide based on their total costs and operational consequences.