Capacity tariff in Flanders: calculate and cut your peak

The Flemish capacity tariff charges part of your network costs according to your peak: the highest average power you draw over a quarter of an hour, each month. In 2026, each kW of peak costs between 52 and 61 € a year depending on your Fluvius zone. Here is how to read that amount, check it and bring it down.

How is the capacity tariff calculated in Flanders?

On the peak, not on the volume. Since 1 January 2023, Fluvius, the distribution system operator (DSO) for all of Flanders, has measured every quarter of an hour the average power your home draws from the grid. Each month, the highest quarter hour becomes your monthly peak, expressed in kW. A monthly bill uses the peak of the month just ended; the annual bill uses the average of the twelve monthly peaks, as the Vlaamse Nutsregulator (VNR, formerly VREG), the Flemish energy regulator, explains.

Two safeguards complete the rule. Everyone pays at least 2.5 kW, even a studio that never goes above 1 kW, on the grounds that the grid exists for everybody. And a per kWh component survives alongside, lower than before the reform.

The word "average" changes everything, and it is the point the bills I go through most often get people wrong about. A 2 kW kettle boiling for three minutes weighs only 0.4 kW in its quarter hour, since 2 kW times 3 minutes out of 15 gives 0.4. A charging point set to 7.4 kW running the whole quarter hour, on the other hand, counts for its full 7.4 kW. So it is appliances that are powerful and long running that create a peak, rarely the powerful but brief ones. If the difference between kW and kWh is still hazy, our article on the difference between kW and kWh sets it out on one page.

On an analogue meter, nothing is measured per quarter hour. The household then pays the 2.5 kW flat amount, and a higher network rate per kWh makes up the difference: Test-Achats reported in 2025 a component of 9.64 c€/kWh on analogue against 6.40 c€/kWh on digital.

How much does one kW of peak cost in your Fluvius zone?

Between 51.99 € and 60.53 € a year, including 6 % VAT. We started from the Fluvius grid in force since 1 January 2026, published excluding VAT and reproduced in suppliers' tariff sheets, then calculated the annual cost for three profiles: the minimum billed, the average Flemish peak of 4.24 kW published by the regulator, and a 7 kW peak, typical of a household charging an electric car while it cooks.

Our VAT inclusive amounts match, within a one cent rounding, those CallMePower publishes for seven zones in its update of 29 July 2026. The Flemish average quoted by the regulator stands at 53.39 € per kW excluding VAT. On top comes a fixed data management fee of 17.85 € a year excluding VAT, the same in every zone.

At an equal peak, a household in West Flanders pays 36.21 € more a year than one in Limburg. There is nothing it can do: the zone depends on the address, not on a choice.

The minimum alone already costs 130 to 151 € a year.

Five steps to find and lower your peak

You will need: your latest electricity bill, access to Mijn Fluvius and a digital meter. Time for the check: 30 minutes. Cost: 0 €.

1. Find the line on the bill. It is labelled "capaciteitstarief" or "tarif capacitaire" and shows the kW billed. On an annual bill, that figure is a twelve month average; on a monthly bill, the peak of the past month only.
2. Open Mijn Fluvius. The Fluvius customer area shows the peak of each month measured by your meter. Note the three highest months: they explain most of the average.
3. Date those peaks and work out what was running. A Tuesday in January at 6.45 pm almost always tells the same story: the car plugged in on arriving home, the oven, the hob, sometimes the backup heater of a heat pump. Read the power on each suspect appliance's rating plate rather than guessing it.
4. Shift instead of cutting. Programme the dishwasher or the tumble dryer for late evening, set the charging point to a lower power spread over the night, or start the washing machine once the meal is over. You use as many kWh, but never all at once again.
5. Buy equipment only if the first four steps are not enough. A reader on the meter's P1 port shows power live, and we compare the options in our guide to tracking electricity consumption in real time. A charging point able to adjust its power to the load of the house, or a load shedder, goes into the fuse board: leave the job to a certified electrician and have the installation inspected as the regulations require.

Step 3 is the one people skip, and that is a mistake, because a peak can only be fixed once you know at what time it happened.

How much does a single badly timed quarter hour cost?

Less than you fear, if the peak stays isolated. Take a household whose peak sits around 4 kW every month. One January evening, the car starts charging at 7.4 kW while the oven and the hob heat up, and the meter records 10 kW over a quarter hour. The annual average rises from 4 to 4.5 kW, since eleven months at 4 kW and one month at 10 kW give 54 kW divided by twelve. Cost of the slip: 26.00 € a year in Limburg, 30.27 € in West Flanders.

The same scenario repeated every month changes scale. The average climbs to 10 kW, six more than before, and the bill grows by 311.94 to 363.18 € a year depending on the zone. The mechanism forgives the accident and punishes the habit, because an exceptional peak is diluted across twelve months while a routine peak sets the average on its own, so attention should go less to the spoiled Christmas evening than to the daily ritual that repeats itself while nobody looks at the monthly bill.

Five mistakes keep coming up in the Flemish bills I take apart:

• Plugging the car in on arriving home from work, at the exact moment cooking starts.
• Adding up the power ratings printed on appliances: an induction hob or an oven regulate in cycles and do not draw their maximum power continuously, so the real peak is almost always lower than the sum.
• Believing the time of the peak matters: only its height enters the capacity calculation, a peak at 3 am costs as much as one at 7 pm.
• Aiming below 2.5 kW: wasted effort, the minimum is billed anyway.
• Buying a home battery before reading your twelve monthly peaks, when a simple change of schedule is often enough.

Does the capacity tariff exist in Wallonia and Brussels?

No, not in the Flemish form. The three regions made three different choices for the current tariff period, and the question "what does one more kW cost me" only makes sense in Flanders.

In Brussels, Brugel, the Brussels energy regulator, kept a so called capacity term, but a flat one: it depends on the power of your connection, not on your behaviour. According to Infor GazElec, around 80 % of meters fall in the band up to 13 kVA, whose amount went from 27.38 € in 2024 to 47.24 € in 2026.

Wallonia took another route. The CWaPE, the Walloon energy regulator, widened off peak hours to 11 am to 5 pm and 10 pm to 7 am, every day, from 1 January 2026, and created an optional "Impact" tariff with three time bands, reserved for communicating meters, whose per kW component stays set at zero until 2029. Do not confuse this with the Walloon prosumer tariff, also calculated in kW but on the inverter's power, which we detail in our guide to the prosumer tariff.

Should you switch supplier to pay less capacity tariff?

No. The capacity tariff belongs to the grid: Fluvius sets it, the regulator approves it, and Engie, Luminus, Eneco, Bolt or Mega pass it on as is, to the cent. The supplier only acts on the energy part. One nuance all the same: a dynamic tariff contract pushes you to bunch consumption into cheap hours, which can create a peak if everything starts at the same minute. For the energy part, our ranking of the best electricity suppliers and the bill simulator put a figure on the gap by profile.