Ground-mounted solar on a farm: permit, land and grid limit

For panels on the ground next to a farm, you need a planning permit in Flanders and in Wallonia. The panels must serve the farm and stand close to its buildings. Solar parks on productive land have little chance. Then comes the grid: your connection limits how much solar power you may connect. With a semi-off-grid system, the field array feeds your own battery and loads, and the grid only steps in as a back-up.

The roof of the barn is full, or it faces the wrong way, or it cannot carry the weight. Behind the yard lies a strip of grass that earns little. "Can I put the panels in my meadow?" is the question farmers ask on every forum. Then the answers contradict each other: 40 square metres, 80 square metres, never, always.

The hidden cost is not the permit, but the second refusal. A farmer gets the permit for a field array, orders the panels, and then learns that the connection only takes a fraction of their power. Or the grid voltage in the countryside is so high that the inverter switches off on sunny mornings. A farmer with a field array wrote exactly that: most of the sunny hours, the panels produced nothing. The obvious fix, a heavier connection or a cabin, costs far more than the panels.

Large farms with high consumption show where the power has to go. In Beveren-Melsele a site that uses 350,000 kWh a year runs 200 solar panels with a 154 kWh battery. It uses as much of the solar power as possible on the spot. A growing dairy farm in Lokeren avoided an expensive move to medium voltage with solar panels, a wind turbine and a battery system.

Do you need a permit for solar panels on the ground in Flanders?

Yes, in practice you do. The Flemish exemption decree lists which works need no permit. For solar panels it only names panels on a flat roof, on or in a pitched roof, on a facade or on a balcony railing.

The exact conditions: on a flat roof up to 1 metre above the roof edge, or in or on a pitched roof. On a facade, up to 4 square metres per facade, or on a balcony railing. That list applies at a home and at other buildings, such as farm buildings. Panels on the ground are not on it.

You will read online that 40 or 80 square metres on the ground is free of a permit. Those figures come from other rules in the same decree. 40 square metres and 3.5 metres of height apply to freestanding outbuildings. 80 square metres and 1.5 metres apply to open constructions in the side and back garden of a home. The decree does not say that solar panels fall under those rules. The general exemption for technical installations even excludes solar panels explicitly.

The farm articles of the decree, for constructions that protect crops, do not mention solar panels either. The Flemish government page on solar panels adds one piece of advice: always check with your municipality, because local rules can differ.

Is it allowed to put solar panels on agricultural land in Flanders?

Only under conditions, and not as a solar park. On the zoning plan, solar panels are in principle not compatible with agricultural zoning, according to the legal publisher Schulinck.

An exception is possible through the so-called clichering rule in the Flemish Codex Spatial Planning (article 4.4.9). You then describe and evaluate the possible effects of the installation in a location note, the lokalisatienota. The permit authority weighs that against the agricultural use of the land.

The Flemish government has made its line clear. In March 2025 two solar park projects on farmland received negative advice, because the layout allowed no combination with productive farming. "Solar panels belong on hard surfaces or where they add value to the crop," the government stated, as reported by agricultural news site VILT. The minister saw room for a farmer who uses agrivoltaics for his own farm operation. "That is something else than simply filling your field with solar panels."

Do you need a planning permit for ground-mounted panels in Wallonia?

Yes. The Walloon planning code, the CoDT, only exempts solar modules on a pitched roof, a flat roof or a facade, within set limits.

Solar modules that do not meet those conditions, such as panels on the ground, need a permit. The CoDT places them among the works of limited impact that do not require an architect. That makes the file lighter, but it remains a permit.

In the agricultural zone, the CoDT sets one more condition. A solar module is allowed either directly on an existing building, or anchored in the ground behind the buildings, seen from the access road. The permit must then explain the effect on farming, the landscape, the soil, runoff and nature.

What do Flanders and Wallonia ask for a ground mount on a farm?

Both regions ask for a permit, and both protect farmland. The route differs.

Where do you place a ground-mounted array on a farm?

Behind the buildings, on land that earns little, with a short cable to the switchboard. That place usually also fits the permit rules best.

The battery and inverters belong in a dry, accessible place, usually in or next to a farm building. What fire safety, distances and the insurer ask for a battery is explained in our article on how safe a business battery is.

Why is the grid connection often the real limit for a field array?

Because every inverter on your connection counts toward a maximum, whatever the permit says. A field of panels quickly goes beyond it.

In Flanders, Fluvius allows up to 5 kVA on single phase and up to 25 kVA on three phase. Above that, a grid study comes first. In Wallonia, a small production installation goes up to 10 kVA. On rural lines, a full grid can also cap what you may inject, or push the voltage so high that the inverter switches off. The rules and the ways around them are in our article on more solar panels than your connection allows.

Before any panel is used, the installation is inspected under the AREI. A grid-connected installation is then registered with Fluvius, with the inspection report and the single-line diagram. That applies to a ground mount just as to a roof.

How does semi-off-grid get a field array past the connection limit?

The panels feed your own island grid, not the public grid. A transfer switch keeps the two systems apart.

In a semi-off-grid system the power comes either from the public grid or from your own installation. The battery is never charged from the grid, and unused solar power never flows back. Because those panels are not connected to the grid, you can extend them without paying taxes on them. Consumption from the grid drops by 75% on average. The system works for powers up to 75.6 kVA, a connection of 3 x 400 V + N, 63 A.

There is a second gain. When the public grid fails, you keep working on your own installation, so the farm keeps running. A farm in Tielt runs semi-off-grid with smart control that sends surplus solar power to its boilers.

What do you check before you apply for a permit?

Five questions, in this order, save you a refused file or a useless array.

1. Step 1: Is there a roof or hard surface that can take the panels first? Both regions prefer it, and a roof needs no land.
2. Step 2: What is the zoning of the parcel, and is it in a protected or flood-prone area? The municipality and the online zoning maps tell you.
3. Step 3: Can the array stand close to the farm buildings, behind them seen from the road?
4. Step 4: How much power does your connection accept, and how much does the farm use when the sun shines?
5. Step 5: If the connection is too small, do you plan a battery and a semi-off-grid set-up from the start? Then the permit file describes the whole system at once.

Does the parcel also count for your area aid? Ask your paying agency before you build: the answer can depend on how much of the parcel the panels cover and whether farming continues underneath.

When is a ground-mounted array not the right answer?

When a roof is available, or when the goal is to sell power rather than use it.

Farm sheds, stables and machine halls often have large roofs. They need no land, and both regions prefer them. Do panels still pay off on a business roof, and when does a battery belong with them? Read our article on solar panels on a business roof.

A field full of panels to sell power to the grid is a solar park. On productive farmland it has little chance of a permit. And if the farm uses most of its power in the dark hours, a wind turbine can be a better partner for the panels. See our article on a small wind turbine for a farm.

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

We start from what the farm uses, and when.

1. Step 1: Analysis. We look at your consumption over the day and the year, your connection and where panels can go.
2. Step 2: Design. We choose the battery, the inverters and, if the connection is too small, a semi-off-grid set-up with a transfer switch.
3. Step 3: Installation and commissioning, followed by monitoring of consumption, yield and the battery.

When solar panels and a battery pay off on a farm is covered in our article on solar panels and a battery on a farm. For a larger site with a cabin question, read cabin or battery.