How do you lower the electricity peak of a wellness centre?

Spread the warm-up first, and add a business battery only if the peak stays too high or the connection is too small. In a wellness centre, the electricity peak often does not come from a busy Saturday evening. It comes from the warm-up, when sauna heaters, the steam generator and pool heating start in the same quarter-hour.

Running a day spa, sauna complex or fitness club with a wellness area? Guests arrive at opening time, but your capacity tariff is already set before the doors open.

In a wellness centre, everything starts at once, every morning. A Belgian user wrote about his own water heater: "I fear that my peak can be even higher if everything happens to come together".

How much electricity does a commercial sauna use?

A commercial sauna heater draws between 6.6 and 20 kW, depending on the size of the room.

For comparison: Küng, a Swiss sauna builder, lists home saunas from 6.5 to 15.5 kW and home steam cabins from 8.5 to 12.5 kW. A wellness centre with three saunas and a steam room therefore has 40 to 60 kW of heaters alone. Pool pumps, ventilation, shower water, lighting and the bar come on top.

The yearly electricity consumption of a commercial sauna in kWh depends on opening hours and insulation. The capacity tariff charges the kW of the heaters running at once.

A sauna or pool at home? Read about a pool, sauna or pool house on a home battery.

Why does the warm-up cost more than a busy evening?

Because a heater runs at full power until the room reaches its temperature, and after that only switches on and off to hold it. If all rooms warm up together, all heaters run at full power together.

A busy evening feels like the peak: every cabin full, the showers running, the bar busy. On the meter it usually is not, because the heaters are already hot and only top up. The warm-up comes as one block, often in the same quarter-hour every morning, so it sets the monthly peak every month.

Pool heating can add to it. Raising 1 m³ of water by 1°C takes about 1.16 kWh of heat, so a 200 m³ pool needs about 233 kWh per degree. A heat pump needs less electricity for that heat, but a pool reheated in the morning still adds to the same block.

How does the electricity peak of a wellness centre end up on your invoice?

In Flanders, your highest quarter-hour of the month is your monthly peak. You pay the capacity tariff on the average of the last twelve monthly peaks, with a minimum of 2.5 kW.

According to the Vlaamse Nutsregulator, the capacity tariff costs about 53.39 euro per kW per year on average in 2026, excl. VAT. So every kW that your warm-up adds to every monthly peak costs about 53 euro a year. You pay it even in a month when your solar panels cover most of the kWh.

It does not matter whether that quarter-hour falls at 8:15 or at 20:00. Larger sites with peak metering pay on their monthly peak too, on their own tariff. The full formula is in our explanation of how the capacity tariff for a sauna or any business is calculated.

Here, staggering takes about 19 kW off the peak. If that happens every month, it is worth about 1,000 euro a year in capacity tariff alone (19 kW x 53.39 euro). No hardware, only a schedule.

Our guide on how to read and lower your business peak demand shows how any business finds the quarter-hour that sets it.

What can a wellness centre do before it buys a battery?

Change the order, use the heat you already store, and measure. These steps cost little and make any battery you still need smaller.

In Wingene, a semi off-grid site where every kW counts, a boiler heats through a resistor once the battery is full. At a large house with a swimming pool in Sint-Laureins, smart controls make sure that all energy is used usefully.

Our guide on what an energy management system does for a business explains without jargon how a control layer decides what runs when.

Public pools show that the big savings are in heat. The Piscine de Spa, in the Ardennes, writes that nearly 300 solar panels on its roof produce part of its electricity. Some fifty solar thermal collectors and heat recovery from shower water help heat its large outdoor pool.

When does a battery make sense in a wellness centre?

A battery makes sense in three cases, and often two of them apply at once.

For peak shaving, two numbers from your quarter-hour data set the size: how many kW the warm-up goes over your limit, and for how long. Read how a battery holds that limit in our article on peak shaving with a battery.

Our high-power battery systems for businesses come with monitoring, control and optimisation included. That control is what turns a battery into a lower peak: without it, a battery is only a storage tank.

Does a fitness club have the same peak problem?

Only partly. A gym without a sauna spreads its load over the day; a gym with a sauna has the same warm-up peak as a wellness centre.

Treadmills, bikes and lighting are small loads that come and go with the members. Ventilation and cooling run for hours, most in summer; shower water peaks after the evening classes. The sauna, if there is one, is often the largest single appliance in the building.

So check first whether your peak comes from the sauna warm-up, from cooling on hot days or from the evening showers. A hotel with a wellness area adds kitchens and rooms.

Waiting for a new or heavier hotel connection? Our article on opening a hotel when the grid connection is delayed covers that case.

A sports club with a sauna in the clubhouse has its own profile: see whether a battery makes sense for a sports club.

Is it different for a wellness centre in Wallonia or Brussels?

Yes. In Wallonia the time of day weighs more than the peak for most low-voltage sites. Since 2026 the bi-hourly low-voltage tariff has an extra off-peak period from 11:00 to 17:00, every day, according to the CWaPE.

Off-peak also runs from 22:00 to 07:00; the evening from 17:00 to 22:00 is billed at the full rate. For a wellness centre, midday is the moment to heat the pool and the hot water, and the evening the moment to use stored energy. Professional sites with peak metering do pay a capacity term in euro per kW, so a morning warm-up still counts there.

In Brussels, Sibelga applies its own tariff structure. Our overview of grid tariffs for businesses in Wallonia and Brussels explains what a peak costs with ORES, RESA and Sibelga.