Supermarket peak: refrigeration, chargers and a battery

In a supermarket the cooling runs all day and weighs most on hot afternoons. Add car park chargers, ovens and defrost cycles in the same quarter-hour, and that moment sets your peak for the month. First make the cooling itself use less power. Then business battery systems can cover what is left above a limit you choose. They also store solar power from your roof and feed the chargers without a heavier connection.

Maybe you recognise this. You run a supermarket or a franchise store, and the network part of the bill keeps going up. Head office wants charging points in the car park. The grid operator says the connection is at its limit. In the Netherlands, a new supermarket could not even open because the operator refused a connection.

What is easy to miss: the peak is not caused by one device. It is the moment when everything in the store runs together. On a hot July afternoon the cabinets work hardest, the air conditioning runs, and two customers plug in their cars. That one quarter-hour sets what you pay for the grid. A heavier connection only to cover it is an expensive fix.

How much of a supermarket's electricity goes to refrigeration?

About half or more, and it rises in summer. The Walloon energy administration (SPW Energie) published a guide on food refrigeration. In an average supermarket of 1,200 m², it puts cooling at 50% of the electricity in winter and 60% in summer. Lighting comes second.

In small shops the share is even higher. The same guide names butchers, fishmongers, frozen-food shops, superettes and delicatessens: there cooling can reach 70% of all electricity. An older Dutch study for the city of Amsterdam found 62% for an average supermarket.

Cooling in a store is not one machine. Think of open and closed display cabinets for dairy, meat and vegetables, freezer islands, cold rooms behind the shop, and plug-in freezers for ice cream. Some run on a central refrigeration plant, others have their own compressor built in.

Which devices set the peak in a supermarket?

The peak is the quarter-hour when the most devices run at the same time. In a food store the usual suspects are these:

• Refrigeration on a hot afternoon. The compressors run longer when the shop and the outside air are warm.
• Defrost cycles. Many cabinets and cold rooms defrost with an electric heater. The SPW guide calls this method very costly at peak times and warns about quarter-hour peaks.
• The bake-off oven and the kitchen. A shop that bakes bread or prepares meals adds a heavy load in the morning or at lunch.
• Air conditioning and heating. In summer the shop cooling adds to the cabinets.
• Chargers in the car park. Two 22 kW chargers can draw 44 kW together.
• Start-up after a pause. After a power cut or maintenance, compressors that restart together add up too.

What does that peak cost you?

In Flanders the capacity tariff charges your network costs on your quarter-hour peaks. The meter keeps the highest quarter-hour of each month. With a digital meter, Fluvius bills the average of the last 12 monthly peaks, with a minimum of 2.5 kW.

The 2026 Flemish average is about 53.39 euro per kW per year, excluding VAT. The exact rate depends on your network area. Take the two chargers from the list. If their 44 kW lands in your peak every month, that costs about 2,349 euro a year, only for the network.

The time of day does not matter for this tariff, only the height of the peak. So a store with a steady load pays less than a store with the same kWh and a few sharp peaks. Larger stores with peak metering or their own cabin are billed on other terms, but the peak counts there too. Our guide on how to calculate the capacity tariff for your business explains every case.

What should a supermarket fix before it thinks about a battery?

First make the cooling need less power. That is often the cheapest kW you will find.

The Dutch research centre ECN studied doors on supermarket cabinets for the city of Amsterdam. On an extension or a new store, it concluded, the doors can avoid the investment in a heavier connection or a bigger transformer. The customers kept buying: turnover did not suffer.

Night covers are a cheap and common measure, and ECN puts their payback at 1.8 to 4.1 years. But they save energy at night, when your peak is not. Do them for the kWh, not for the capacity tariff.

The SPW guide also suggests producing extra cold when power is cheap, at night, at the weekend or when the solar panels produce most. The cold is then used during the day. Agree the temperature band with your refrigeration technician first. The legal limits of your products always come first.

Chargers in the car park: how do you add them without a new peak?

Set a limit for the whole store and let the chargers use only what is left under it. Dynamic load management shares the remaining power between the cars. When the cooling works hard, the cars charge a little slower.

That works as long as the store leaves enough room under the limit. On a hot afternoon, or with fast chargers, there may be nothing left. Then a battery can deliver the extra power for the cars, and recharge when the store needs less. Our business battery systems include chargers up to 180 kVA.

Which chargers must your car park have, and by when? That depends on the region and the number of spaces. Our article on the charging points your business building must have explains the rules. For company cars and vans, see charging stations without a heavier connection. For public fast charging on a roadside site, see a fast charger with a battery buffer.

Where does a battery fit in a food store?

Behind the meter, as the buffer between the grid, the roof and the store. It works for you in four ways.

A farm in Tielt shows the principle, outside retail. Its connection was too small to grow, and the next step was medium voltage. A battery system of 45 kVA and 123.2 kWh now gives the site more power, so a heavier connection was not needed.

In a Victron system, peak shaving keeps grid offtake under the limit you set, and the battery recharges when demand is low. The energy management (ESS) also has a minimum state of charge that the battery only goes below when the grid fails. Our article on what peak shaving is and when a battery pays off explains the logic.

Solar panels alone do not keep the shop running in a power cut. The Synergrid rule C10/11 requires grid-connected installations to disconnect automatically when the grid fails. They only keep producing when a battery system forms a local grid for them. How long a battery keeps a cold room cold is covered in our article on a cold room in a power cut.

A software layer ties it all together. Read what an energy management system does for a business, or see our monitoring software, which shows consumption per phase.

When is a battery not the right answer for a supermarket?

When the cheaper fixes are not done yet, or when the battery would only do one small job.

Surplus solar power can also go into heat, for example hot water for a kitchen or a butcher's department. Our article on whether a boiler or a battery comes first compares the two. On a dynamic contract, a battery can also charge in cheap hours: see a dynamic energy contract with a business battery. And if your solar output is capped by the grid, read injection limits for business solar panels.

What happens when you ask us to look at your store?

We start with your peaks and your cooling, not with a device.

1. Step 1: Analysis and sizing. We look at your quarter-hour data, your cabinets, ovens and chargers, and the peaks you want to cut. If data is missing, we can monitor your consumption for a short period first.
2. Step 2: Technical design. We choose the peak limit, the battery power for the busiest quarter-hour and the reserve for a power cut. We also plan the link with your solar panels and chargers.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support. You follow the system in the app and the VRM portal.

Our business battery systems range from small SME installations to modular systems up to 1 MW. For the general logic of business peaks, see what drives peak demand in a business. If you still doubt the solar roof, read whether business solar panels still pay off.