What does off-grid mean, and is it allowed in Belgium?

Off-grid literally means "disconnected from the grid": your home or business has no electrical connection to the distribution grid of Fluvius, ORES, RESA or Sibelga. You generate power yourself (usually with solar panels), store it in a battery and cover shortfalls with your own back-up, such as a generator. The Belgian electrical safety code, building rules and your permit still apply, and Flanders has its own notification procedure for installations in island mode. So off-grid is not a product you buy, but an energy system you design around your measured consumption, including the darkest winter weeks. Read how we design such an off-grid system to measure on our product page.

Maybe you are building far from the street, the quote for a grid connection came back high, or you simply want to stop depending on the grid. A stable and cottage in Kasterlee, far from the public grid, is a good example: its owner did not want to start a generator every time he stayed there, and now runs on solar panels and a 16 kWh battery all year round.

What does off-grid mean exactly, and what does it not mean?

An off-grid building is completely separate from the electricity grid. When people talk about living off the grid, they sometimes also mean a home without a water, sewer or gas connection. This guide is about electricity.

The difference with "having a battery" is big. A classic grid-connected installation works in parallel with the grid. The Synergrid rule C10/11, which applies across Belgium, requires such installations to disconnect automatically when the grid fails. An off-grid system forms the grid inside your building itself: the inverter sets voltage and frequency, and the battery and the generator carry the full load.

What is the difference between off-grid, semi off-grid and on-grid with a battery?

With semi off-grid, the public grid acts as the "generator": a transfer switch chooses between the grid and your own installation. C10/11 then requires the switch between on-grid and off-grid to follow the break-before-make principle, so your island never runs in parallel with the grid by accident. Do you have a home battery and wonder why it still goes off during a power cut? Then read the answer in our article on a home battery with backup power.

Is it legal to live off-grid in Belgium?

Off-grid operation is provided for in Flanders: the Vlaamse Nutsregulator has a separate notification procedure for installations in island mode. Whether a specific building project without a grid connection gets a permit depends on your planning permit and the local rules, in Flanders as in Wallonia and Brussels. Check that with your municipality in advance. These rules also apply:

• Notification (Flanders): does your installation work in island mode, with an inverter of 800 VA or more in total? Then you report it to the Vlaamse Nutsregulator. In Wallonia and Brussels, ask the regional regulator (CWaPE or Brugel) which notification applies before you start.
• Electrical safety code and inspection (all of Belgium): an off-grid installation is an ordinary electrical installation under the AREI/RGIE. According to the FPS Economy, you have a new installation inspected before it is put into use, and then periodically every 25 years for household installations. An inspection is also required when a home is sold.
• Housing quality (Flanders): in a conformity check, the housing inspector assesses the electrical installation for electrocution and fire risk, under the Flemish housing quality standards.
• Energy performance and gas (Flanders): the EPB requirements apply to heated or cooled buildings that need an architect, also without a grid connection. Since 2025, a natural gas connection in new builds is in principle banned in Flanders.

Do you want to give up your existing connection? According to Fluvius, a removed meter can never be reopened, while a sealed meter can. In Wallonia and Brussels, ask ORES, RESA or Sibelga how they handle it. Only decide after a full winter.

Who is off-grid a good choice for?

Off-grid is a calculation about security of supply. It suits mainly:

• Remote buildings where a new connection is expensive or slow, such as sheds, farms or homes far from the street.
• Businesses that have to wait for the grid operator. If a heavier connection does not come soon, a battery system that can run on its own is often the faster answer.
• Owners who want to control the whole chain and match their consumption to the seasons.

A school in Incourt, in Walloon Brabant, shows the third group: it chose a fully off-grid system with new solar panels, a battery and a generator. Off-grid suits buildings less well when winter consumption is high and there is little room for solar panels, especially when heating is fully electric. Then semi off-grid is usually the smarter first step. In our worked off-grid case, you see how we build such a study for a home with 10 kWp, 16,000 kWh of yearly consumption and an electric car.

What do you need to arrange before you go off-grid?

• Measure your consumption. Size on quarter-hour values over a representative period, not on a rule of thumb or a yearly total. Peak power sets the inverters; winter consumption sets the rest.
• Calculate the winter. In December, solar panels in Belgium deliver only a fraction of their summer yield. Read how you match panels, battery and generator to that in our guide to off-grid solar panels with a battery.
• Plan the back-up. A generator with automatic start, or the grid as a back-up with semi off-grid.
• Check permit, inspection and notification. Permit in advance, inspection before use, and the notification that applies in your region (in Flanders, to the Vlaamse Nutsregulator).
• Provide monitoring. Without a grid, nobody covers a shortfall for you, so you follow your system remotely.