Fleet EV Charging Cost 2026: Depot vs Public — Where the Business Case Is Won

Charge an electric van fleet overnight at your own depot, on a commercial energy contract, and the electricity costs roughly 8 to 15 pence per kilowatt-hour in the UK — about $0.10 to $0.16 in the US [1][9]. Send those same vans to a public rapid charger and you pay around 79 pence per kilowatt-hour (the Zap-Map rapid/ultra-rapid average, mid-2026), or $0.40 to $0.60 in the US [5][8]. That is not a rounding difference; it is the same energy at three to six times the price. For almost every fleet, the depot is where the business case for going electric is won or lost, and the single most expensive mistake is treating the public network as a charging strategy rather than an emergency backstop.

This piece is about money, not virtue. It takes the four ways a commercial fleet can put electrons into its vehicles — slow AC charging at the depot, fast DC charging at the depot, public rapid charging on the road, and reimbursing drivers who plug in at home — and prices each one per kilowatt-hour, per bay of capex, and ultimately per mile. It also covers the traps that quietly wreck the numbers: the grid-connection upgrade nobody budgeted for, the standing charges on a commercial tariff, and the awkward question of how to pay a driver fairly for the electricity their company van drew from their own home supply.

The four charging modes, and why the gap between them is so wide

The reason depot charging is cheap and public charging is dear comes down to who is in the supply chain. At your depot you buy electricity close to wholesale, through a commercial energy contract, and you own the hardware that delivers it. At a public rapid charger you are buying that same electricity after a charge-point operator has added the cost of expensive high-power hardware, a premium grid connection, payment processing, maintenance, real-estate rent and a margin — all recovered in pence per kilowatt-hour from drivers who need power now. Convenience has a price, and on the public rapid network it is most of the price.

For a fleet, that means the strategic question is brutally simple: how much of your annual energy can you move from the expensive end of that spectrum to the cheap end? Everything else — charger choice, load management, reimbursement policy — is in service of that one goal.

Charging mode	Typical cost per kWh	Capex per bay/charger	Best for	Key caveat
Depot AC (7–22 kW)	~8–15p / $0.10–$0.16	~£1,000–£3,000 / $1,500–$4,000	Overnight back-to-base fleets	Needs depot dwell time + grid capacity
Depot DC (rapid, 50–150 kW)	~10–18p / $0.12–$0.20	~£25,000–£60,000+ / $35,000–$80,000+	Quick turnaround, multi-shift	High capex + heavy grid connection
Public rapid (50–350 kW)	~79p (mid-2026) / $0.40–$0.60	£0 (pay per use)	On-route top-ups, no home base	3–6× depot cost; the budget killer
Home reimbursement	~7–10p paid as ~7–8p/mile	£0 (driver's charger)	Field staff, company cars	Needs split billing or HMRC AER tracking

The table makes the hierarchy plain. Depot AC is the cheapest energy and the cheapest hardware, but it needs vehicles to sit still for hours and it needs grid capacity. Depot DC buys you speed at roughly ten to twenty times the capex per bay and a much heavier grid demand. Public rapid needs no capex at all because someone else owns the charger — but you pay for that convenience every single mile. Home reimbursement is nearly as cheap as depot AC, but it pushes the complexity into payroll and metering rather than the yard.

Depot AC versus depot DC: the trade-off that sets your capex

For most back-to-base fleets — vans that return to a yard each evening, last-mile delivery vehicles, pool cars — the default answer is alternating-current charging at 7 to 22 kilowatts. A 7 kW unit adds roughly 25 to 30 miles of range an hour; a 22 kW three-phase unit, where the supply allows, several times that. The appeal is twofold. The hardware is cheap, typically £1,000 to £3,000 per socket installed (around $1,500 to $4,000), and because each vehicle draws modestly, you can hang many chargers off a given grid connection and let them all sip overnight while the yard sleeps [4][6]. A van that sits for ten or twelve hours does not need to charge fast; it needs to charge cheaply and be full by the morning shift.

Direct-current rapid charging at the depot — 50 to 150 kilowatts or more — is a different financial animal. The hardware starts around £25,000 per bay and climbs past £60,000 for the higher-power units (roughly $35,000 to $80,000+), and because each bay can pull as much power as a small factory, the grid-connection demand multiplies fast [6][11]. DC at the depot earns its keep only in specific cases: multi-shift operations where a vehicle comes back mid-day and has to be turned around in 30 minutes, high-utilisation taxi and PHV fleets, or sites where vehicles simply cannot dwell long enough for AC to keep up. The common pattern for a mixed fleet is AC-first — a wall of cheap slow chargers for the overnight majority — with one or two DC bays reserved for the exceptions that genuinely need speed.

The mistake fleets make here is over-specifying. DC rapid feels like the "proper" solution, but every kilowatt of installed rapid capacity you do not actually need is capex and grid cost spent buying speed that your vehicles will use for a handful of minutes a week. Size the charging to the duty cycle, not to the spec sheet.

Smart load management: how to avoid the grid-connection bill

Here is the trap that derails more depot projects than any other. You add up the chargers — say twenty 7 kW units — and the headline demand is 140 kilowatts. Your existing connection cannot supply it, so you ask the Distribution Network Operator for an upgrade, and the quote comes back at anything from a few thousand pounds to six figures, with a lead time measured in months or even years [7]. That single line can turn a tidy business case into a stalled one.

The escape route is dynamic load management, sometimes called load balancing. Instead of running every charger at full power simultaneously, a smart system measures the total power available and shares it intelligently across the connected vehicles, throttling each one so the site never exceeds its connection limit [4][12]. The insight that makes it work is dwell time: vehicles parked overnight do not all need to charge at once, and most do not need full power to be ready by morning. A 140 kW nameplate demand might be satisfied comfortably by an 80 kW connection if the software spreads the load across the night and prioritises the vehicles leaving earliest. For many depots, intelligent load management is the difference between needing an expensive DNO upgrade and not needing one at all — which is exactly why it is now standard on serious fleet installations rather than an optional extra.

The energy contract: commercial tariffs, standing charges and time-of-use

The per-kilowatt-hour rate that makes depot charging cheap is not automatic — it comes from a commercial energy contract, and the details matter. A business electricity tariff is structured differently from a domestic one: the unit rate can be lower, but there is typically a higher daily standing charge, and large sites may face capacity charges and other non-commodity costs that domestic customers never see [1]. For a fleet drawing a lot of overnight power, the prize is a time-of-use commercial rate that captures the cheapest night-time hours, when wholesale prices and grid demand are lowest — precisely the window when a back-to-base fleet is charging anyway. Aligning the duty cycle with the cheap hours is most of the art of cheap depot charging.

This is also where a fleet should resist the temptation to treat depot energy as a fixed cost. Wholesale electricity prices move, standing charges vary by supplier and region, and the right contract structure for a 5-van yard is not the right one for a 200-vehicle distribution hub. Getting the commercial tariff right is worth more, per year, than almost any hardware decision.

Reimbursing drivers who charge at home

Not every fleet vehicle comes back to a depot. Field engineers, sales staff and company-car drivers often charge overnight on their own home supply, and the company has to pay them fairly for the business electricity they used — without overpaying or creating a tax headache. There are two clean ways to do it.

The first is HMRC's Advisory Electricity Rate (AER) in the UK: a pence-per-mile figure HMRC publishes quarterly that an employer can pay tax-free for business mileage in a company-provided electric car. It sits around 7 to 8 pence per mile in 2026, though the exact figure is reset every quarter and should be checked against the current gov.uk table before each payroll run [3]. The AER is simple — multiply business miles by the rate — but because it is an average, it can over- or under-pay a specific driver depending on whether they charge on a cheap overnight tariff or a standard rate.

The second, fairer for drivers on cheap tariffs, is to reimburse the actual metered cost. A smart home charger logged to the company can record exactly how many kilowatt-hours the vehicle drew and at what tariff, and bill that back to the employer — a "split billing" arrangement that separates the company's vehicle charging from the household's own consumption on the same meter. This is the most accurate method and the one that scales best across a field-based fleet, because it pays the real cost rather than an average. In the US, where there is no national equivalent of the AER, fleets reimburse either the actual metered cost or a per-mile rate set internally, drawing on DOE fleet guidance for the methodology [8][14].

The public-charging fallback: budget it, don't build on it

No fleet escapes the public network entirely. A van that overruns its range, a long inter-city job, a vehicle that could not get a full charge overnight — all end up at a public rapid charger sometimes, and that is fine, as long as it stays the exception. UK public rapid and ultra-rapid charging averages around 79 pence per kilowatt-hour on the Zap-Map price index (mid-2026), with some networks higher and the figure moving with the wholesale market [5]. In the US, public DC fast charging commonly runs $0.40 to $0.60 per kilowatt-hour [8]. The point is not that public charging is bad; it is that it is three to six times the depot rate, so every mile you can move off it is money kept.

The arithmetic of that gap is stark at fleet scale. Take fifty vans averaging 15,000 miles a year at about 35 kilowatt-hours per 100 miles — roughly 262,500 kilowatt-hours of energy across the fleet. Charge it all at a 12 pence depot rate and the annual energy bill is about £31,500. Charge it mostly on the public rapid network at a round 80 pence (just above the ~79p mid-2026 average) and the same energy costs around £210,000 (our calculation, consumption assumed, rates per [1][5]). That £178,500 gap is, for many operators, larger than the entire cost of building the depot charging in the first place — which is why the infrastructure pays for itself fast.

Even a hybrid strategy transforms the numbers. Push 70% of charging to the depot and leave 30% on the public network for genuine on-route top-ups, and the blended annual cost for those fifty vans lands near £94,500 — still less than half the public-heavy figure (our calculation). The lesson is consistent across fleet sizes: the depot share of charging is the single biggest lever on the energy bill, and the goal of every operational decision is to push that share up.

Per mile: the number that actually runs the fleet

Cost per kilowatt-hour is the input; cost per mile is the output that finance cares about. Convert the four modes for a typical electric van using around 35 kilowatt-hours per 100 miles and the picture sharpens. Depot AC at roughly 12 pence per kilowatt-hour works out near 4 pence per mile. Home reimbursement via the HMRC AER lands around 7 to 8 pence per mile, and depot DC, slightly dearer per kilowatt-hour than AC, sits near 5 to 6 pence. Public rapid at 80 pence per kilowatt-hour is about 28 pence per mile (our calculation, per [1][3][5]).

Set those against a diesel van returning 35 miles per gallon at UK pump prices, which lands well into the high-teens pence per mile on fuel alone, and the depot-charged electric van is dramatically cheaper to run — while the public-charged one can actually cost more per mile than the diesel it replaced. That single inversion is why a fleet that electrifies without sorting out depot charging can end up worse off, and why the order of operations matters: secure the cheap charging first, then put vehicles on it.

How to actually slash the per-mile cost

The moves that bring a fleet's charging bill down are not exotic; they are a sequence of decisions made in the right order. Start by maximising depot dwell-time charging: every vehicle that can return to base and charge overnight on a commercial tariff should, because that is the cheapest electron you will ever buy [1][4]. Default to AC over DC unless the duty cycle genuinely demands fast turnaround, since AC is cheaper to install and lighter on the grid [6]. Deploy dynamic load management from day one, both to avoid or shrink the DNO upgrade and to keep charging inside the cheapest night-time hours [4][12]. Get a time-of-use commercial energy tariff and treat it as a live cost to be re-tendered, not a fixed one [1]. For home-charging drivers, use split billing or the HMRC AER rather than guessing, so you pay the real cost and stay tax-clean [3]. And budget public charging as a small, controlled fallback — track it, cap it where you can, and design routes and charging windows to minimise it [5].

Do those six things and a fleet's energy cost per mile drops toward the 4-to-6-pence depot band and stays there. Skip them, lean on the public network, and the same vehicles cost three to six times as much to feed. The vehicles are increasingly the easy part of fleet electrification. The charging strategy is where the money is, and the depot is where it is decided.

Common questions

How much does it cost a fleet to charge an EV at a depot versus public charging in 2026? At a depot on a commercial energy contract, roughly 8–15p/kWh in the UK or about $0.10–$0.16/kWh in the US, against around 79p/kWh (mid-2026, varies by region) (or $0.40–$0.60) at public rapid chargers [1][5][9]. For a typical electric van that is roughly 4p per mile at the depot versus around 28p per mile on public rapid — a three-to-six-fold difference that decides most fleet business cases (our calculation).

Should a fleet install AC or DC chargers at the depot? AC (7–22 kW) for any fleet that returns to base and sits overnight: it is cheap to install and lets you charge many vehicles slowly off one grid connection. DC rapid only where vehicles need a fast turnaround between shifts, because the capex per bay is an order of magnitude higher and the grid-connection load is far heavier [4][6]. Most back-to-base van fleets are an AC-first story with a couple of DC bays for exceptions.

How do I reimburse drivers who charge a company EV at home? In the UK the simplest route is HMRC's Advisory Electricity Rate, a pence-per-mile figure updated quarterly that you pay tax-free for business miles [3]. Alternatively, reimburse the actual cost using a smart charger that meters exactly what the car drew and bills it back to the company — split billing — which is fairer when the driver is on a cheap overnight tariff. In the US there is no national equivalent, so fleets reimburse actual metered cost or use a per-mile rate [8].

Will charging a fleet need a grid connection upgrade? Often, yes — and it is the cost that derails depot projects. A yard full of chargers can ask for more power than the existing connection provides, and a Distribution Network Operator upgrade can run from a few thousand pounds to six figures with long lead times [7]. Smart load management, which spreads available power across vehicles overnight instead of running every charger flat out, is the standard way to avoid or shrink that upgrade [4].

What is the cheapest way to charge a commercial fleet? Depot AC charging overnight on a commercial energy tariff, ideally with a time-of-use rate that captures the cheapest night-time hours, is the lowest cost per kWh for most fleets [1][4]. The savings come from buying energy wholesale-adjacent at the depot rather than paying retail-plus-convenience prices at public rapid chargers. The public network is a fallback for on-route top-ups, not a primary strategy.

How much can a 50-van fleet save by charging at the depot? On the order of £178,500 a year against a public-heavy baseline. Fifty vans at 15,000 miles each consume roughly 262,500 kWh; at a ~12p depot rate that is about £31,500, versus roughly £210,000 if charged mostly on ~80p public rapid (our calculation) [1][5]. Even a mixed strategy that pushes 70% of charging to the depot lands near £94,500 — still less than half the public-heavy cost.