What DC fast charging actually costs

Public fast charging is the most expensive way to put energy in a car short of buying petrol, and the pricing is deliberately hard to compare. Here is how it is structured.

The three pricing models

Per kilowatt-hour. The straightforward one, and now the most common. You pay for energy delivered. Rates vary widely by network, state and time of day.

Per minute. Used where state regulation historically prevented non-utilities from selling electricity by the kilowatt-hour. This model punishes cars that charge slowly and punishes charging above 80 per cent, where the rate tapers. Most states have now amended their rules and the industry has largely moved to per-kWh, but per-minute pricing persists in places.

Session or connection fee. A flat charge on top, sometimes waived for subscribers. Small in absolute terms, significant on a short top-up.

Layered over all three: subscriptions. Most large networks offer a monthly plan that reduces the per-kWh rate. Whether it pays depends entirely on how much you fast-charge, and the break-even is usually higher than people assume.

Idle fees

Once charging completes, most networks begin charging by the minute for continuing to occupy the stall. Rates are steep by design — the intent is to free the stall, not to make money.

This is the single most common unexpected charge on a public charging bill, and it is avoidable simply by moving the car.

Rough comparison

Exact figures move, so treat these as orders of magnitude rather than quotes:

Source	Typical cost per kWh
Home, overnight off-peak	lowest by a wide margin
Home, standard residential rate	low
Public Level 2	low to moderate, often free at hotels and shops
Public DC fast	highest — commonly two to four times a home rate

Even at the top of that range, fast charging generally works out cheaper per mile than petrol for an equivalent vehicle. But the gap narrows sharply if you rely on fast charging routinely, and that is the real financial argument for having somewhere to plug in at home.

Why fast charging costs so much more

Three genuine cost drivers, none of them margin:

Demand charges. Commercial electricity bills include a charge based on peak power draw, not just energy used. A 350 kW charger creates an enormous peak. At a low-utilisation site the demand charge alone can exceed the cost of the energy.

Capital cost. A DC fast installation involves the hardware, the grid connection, often a transformer upgrade, and civil works. Utility interconnection is frequently the largest line item and the longest lead time.

Utilisation. A charger earns only when a car is plugged in. Sites are built ahead of demand, so many run at low utilisation for years while still paying the fixed costs.

Some networks are deploying batteries at sites specifically to shave the demand-charge peak, which is a direct response to the first of these.

What the register tells you about price

Not much, honestly. The AFDC record has a free-text pricing field. Some entries say “Free”, some give a rate, many are blank or stale.

We show the field as recorded when it is present, and say nothing when it is not. We do not estimate prices, because a wrong price is worse than no price when someone is deciding where to stop.

For current rates, the network’s own app is the only reliable source, and rates can differ between two stations on the same network in the same city.

Where free charging still exists

The register does record free sites, and there are more than people expect — typically Level 2 at hotels, shopping centres, workplaces and municipal car parks, where the charger is an amenity rather than a business.

Free DC fast charging is rare and usually promotional: bundled with a new car purchase for a limited period, or offered by a network entering a market.

The practical advice

• Charge at home if you possibly can; it dominates everything else on cost
• Use Level 2 where you are parked anyway — often free, and free beats fast
• Fast-charge from low state of charge to about 80 per cent; the last 20 per cent is slow and, on per-minute pricing, expensive
• Move the car when it finishes
• Do the subscription arithmetic against your actual usage rather than your intended usage