How to keep a business running in a planned power cut

List what must keep running and check the announced window. Then bridge it with a rented generator, your own generator or a battery system. A battery takes over without a gap and can also switch back cleanly. Our guide to the right emergency power supply for your business compares UPS, generator and battery in general. This article applies it to the cut you know is coming. A battery that only waits for that one day rarely pays. Business battery systems that also shave your peak and store solar power every day do.

You probably know one of these two moments. A letter or a text message from the grid operator: next Tuesday, from 8:00 to 16:00, no power in your street. Or the maintenance company asks when it can switch off your high-voltage cabin for the yearly inspection. Either way, somebody else picks the hours, and your site stops.

What is easy to underestimate is the restart, not the cut itself. Cold rooms need hours to come back to temperature. A production line that stopped mid-batch loses the batch. Servers that went down hard need someone to check them. And a generator rented at the last minute only helps if an electrician can connect it safely.

A site in Maasmechelen shows another way. The customer already had a generator for emergencies, but it stood idle. Our semi off-grid system made it useful: the customer chooses the grid or the generator to charge its own off-grid system. The system has 24 kVA of inverter power and 30.8 kWh of battery.

What is a planned power interruption, and how much notice does a business get?

A planned power interruption is a cut the grid operator announces in advance, usually for works on the grid in your area. Fluvius says it announces them beforehand. The Flemish technical regulation (TRDE) sets the minimum notice.

Source: Vlaamse Nutsregulator, Technical regulation for electricity distribution, version 2026, articles 2.3.4 and 2.3.5. Read the full text of the TRDE.

Three practical points follow from the Fluvius FAQ. A planned interruption can usually not be moved at your request, because the works are planned in detail. You are usually not without power for the whole announced window. And you can get a text message or e-mail about interruptions on your address.

In Wallonia, the Walloon technical regulation also requires advance notice, longer for high voltage than for low voltage. ORES adds a useful promise: it provides a generator when a planned cut would last more than 4 hours, unless that is technically impossible. In Brussels, Sibelga publishes its planned interruptions on its website.

Why does maintenance of your own high-voltage cabin mean a power cut?

Because the law asks a yearly check of your cabin, and the cabin must be able to go dead for it. The AREI (the Belgian electrical code), Book 2 on high-voltage installations, requires a yearly control visit by an approved inspection body after the first inspection.

The same text says the installation must be able to be switched off during that visit. The inspection body Atlas Contrôle gives an average duration of 2 to 4 hours for the yearly verification. It covers tests of the protections, insulation measurements, the earthing and the disconnectors.

When the cabin is switched off, everything behind it is off: offices, production, cooling, lighting and alarms. Cleaning, repairs and a transformer swap can take longer than the inspection. The difference with a grid interruption is that you choose the day, together with your maintenance company.

Are you still deciding whether you need a cabin at all? Then read our article on a high-voltage cabin versus a battery. Is your transformer too small for what you plan? Our article on a transformer that is too small weighs a new one against a battery behind it.

What stops at your site when the power goes, and what does it cost?

Start with a list of loads, not with a machine. Some loads can simply wait. Others lose money, stock or safety within minutes. That list decides how big your bridge must be.

For cold rooms, our article on how long a battery keeps a cold room cold gives the calculation. For livestock, read how to keep barn ventilation running in a power cut. For IT, a UPS often covers a clean shutdown: our article on which inverter or UPS a business needs explains the difference.

Rented generator, own generator or battery: what keeps your site running during a planned cut?

For a single cut once in a while, a rented generator is often enough. When cuts or shutdowns return, and the loads cannot miss a second, a battery system or a battery with a generator is the robust answer.

According to Victron, a MultiPlus-II takes over in less than 20 milliseconds, fast enough to keep computers running. A Victron GX controller can start a generator automatically, for example when the battery gets low. In Maasmechelen, the idle emergency generator became a charger for the battery. Our article on combining a generator with a battery explains how the two share the work.

The same idea works at a smaller scale. At a home in Maaseik, a generator was already there. The battery system got an off-grid mode, so the generator can be connected to it.

How do you switch over to back-up power safely, and back to the grid?

The golden rule: your back-up source must never feed power back into the grid or into a cabin where people are working. A proper changeover separates your installation from the grid before the back-up source takes over.

Switching back is the moment many sites forget. With a simple changeover switch, your site goes dark for a moment again when the grid returns. The Synergrid rule C10/11 allows an emergency supply system to run in parallel with the grid only briefly: at most 5 minutes per switchover. Every parallel connection must be recorded in a logbook.

How big must a battery be to bridge a planned power interruption?

Multiply the average power of your critical loads (kW) by the hours of the announced window, and add a margin. 15 kW of critical loads over 4 hours needs about 60 kWh of usable energy.

Two things set the size. Energy (kWh) sets how long the battery lasts. Power (kVA) sets whether everything can start at once. Motors and compressors draw several times their running current for a few seconds. So measure the loads, rather than adding up nameplates.

An 8-hour window at 15 kW needs 120 kWh. For that, a generator as second line is usually more logical than a battery twice as large. In a Victron system you keep a fixed reserve in the energy management (ESS). The battery only goes below it when the grid fails. Above that reserve, it shaves peaks and stores solar power.

What should you do before a planned power interruption?

Treat a planned cut like a small project with a checklist. Five working days is enough if you start on day one.

1. Step 1: Read the notice and confirm the window. Note the date, start, expected duration and the reference, and ask the grid operator if the window is unclear.
2. Step 2: List the critical loads and decide what may stop. Plan production, deliveries and cleaning around the window.
3. Step 3: Arrange the bridge. Rent the generator or check your own, test the battery reserve, and book the electrician who will switch over.
4. Step 4: Protect stock and data. Precool cold rooms, keep doors shut, save work and shut down servers you do not keep on.
5. Step 5: Open what needs power to open. Automatic gates, roller doors and barriers stay shut without power.
6. Step 6: Restart in order. Switch heavy loads on one by one, check the cold rooms and servers, and reset clocks and timers.

Fluvius gives similar tips: avoid lifts, keep fridges and freezers closed, save your work and open automatic gates beforehand.

Can your business claim compensation for a planned power interruption?

Usually not. The Flemish compensation for long cuts only applies to unplanned interruptions of more than 4 hours. The cut may not have been announced in advance. What a business can claim after an unplanned cut is explained in what your company can claim after a power cut.

For a business the Flemish compensation for such an unannounced cut is 20% of last month's distribution costs, with a minimum of 35 euro. ORES compensates cuts of more than 6 hours that were not announced beforehand and were not caused by force majeure.

The trade magazine Buurtsuper warns that compensation for a planned cut is uncertain. The grid operator is only liable when the cut was no emergency and the notice came late or was deficient. So check your own insurance for damage from planned and unplanned cuts. The load-shedding plan is a separate case: our article on what a company should do about a blackout in Belgium explains it.

When is a battery not worth it for planned power cuts?

When it would only wait for one announced cut a year.

Our article on what peak shaving is and when a battery pays off shows that daily work. The back-up is the bonus.

What happens when you ask us to bridge planned cuts at your site?

We start with what must keep running and what it really draws.

1. Step 1: Analysis and sizing. We list the critical loads and their starts. If data is missing, we can monitor your consumption for a short period first.
2. Step 2: Technical design. We choose the reserve, the inverter power, the changeover and, where useful, an automatic generator start or a connection for a rented one.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support. You follow the state of charge and consumption in the app and the VRM portal.

Our battery systems for businesses range from small SME installations to modular systems up to 1 MW. Our monitoring software shows what your site draws, also during a cut.