Asbestos farm roof: add solar and a battery in one go?

Yes, in most cases it pays to plan them together, even if the battery comes a year later. The roof has to come off anyway, and the new roof is the ideal surface for panels. The support for removal is also tied to those panels. The limit is usually your grid connection, not your roof. A semi off-grid system lets you use the power of that large roof on your own farm. Nothing goes into a grid that cannot take it. On farms with a heavy daytime load, a business battery system also shaves your peaks.

"The roof has to be done one day anyway." That is how many farmers talk about the old corrugated sheets on the barn or shed. On a Belgian forum, someone wrote that farmers once laid solar panels on asbestos roofs, even though it was not allowed. Others say they wait with solar until the roof is renovated.

The trouble is the order. Replace the roof first and think about energy later, and you pay twice for the same disruption. The stable has to be emptied again, the crane comes back, and cables are pulled through a finished roof. Worse, you may find out that your connection cannot take the power of the new roof. Then half the surface stays empty, or the panels are throttled on the sunniest days.

Two dairy farms show what the grid can mean. In Londerzeel, the aim was to avoid an expensive medium-voltage cabin and connection. Solar panels, a wind turbine and an LFP battery now run a semi off-grid system for the fans, manure scrapers, pumps and milking robots. Avoiding the cabin saved at least 60,000 euro from the start. In Lokeren, a fast-growing dairy farm could not get enough power from Fluvius without medium voltage. It invested in solar, wind and a battery instead.

Can you put solar panels on an asbestos roof?

No. In Belgium you may not place solar panels, a second roof or any other construction on an asbestos roof. OVAM states this for all external asbestos roof and facade coverings, whatever the fastening method.

The rule comes from the federal protection of workers. According to Buildwise, the royal decree of 16 March 2006 and the Code on well-being at work forbid drilling or grinding asbestos materials. Mounting panels on a pitched roof always means working on the roof elements, so it is not allowed. The ban applies in every region.

OVAM adds a practical point. Before panels go on, the owner must be able to show that the roof or facade is free of asbestos. Otherwise an inspector can stop the works until a lab analysis gives the answer.

Does your farm have to replace its asbestos roof, and by when?

In Flanders, the goal is that all asbestos-cement roofs and facades are replaced by 2034, and that Flanders is asbestos-safe by 2040. For now, OVAM says these removal deadlines are only legally binding for public buildings.

Even without a legal deadline for your farm, age works against you. OVAM advises replacing an asbestos roof after about 30 years, because removal gets harder and more expensive as the sheets weather. According to its farm-roof brochure, brittle, crumbling or mossy sheets are in poor condition.

Only in Wallonia: the Walloon Region announced in November 2025 that it is strengthening its asbestos approach. It plans an asbestos inventory before a sale, a rental or building works. It did not announce a removal deadline for roofs.

Who may remove the asbestos roof of a stable or shed?

If the sheets must be broken, drilled or ground, you must hire a specialised, recognised contractor. If they can be removed whole, a roofing contractor with trained workers may do it. That is what the OVAM step-by-step brochure for farm roofs says.

If you do the work yourself with employees, federal labour law applies. Your workers then need the training certificate for "simple procedures with asbestos". OVAM advises a specialised contractor in any case, because removing sheets in poor condition releases a lot of fibres.

The space under the roof must be empty and clean before work starts. No animals, no feed, no straw or sawdust, no manure on the slats. Hay, feed and animal coats cannot be cleaned of asbestos fibres. OVAM also has a separate brochure on removing asbestos cement in a stable with animals.

That empty stable is your window for the electrical work. Cable routes, the inverter position and the space for a battery are easiest to prepare when nothing is under the roof. If the animals must stay on site, check first how you keep barn ventilation running during the works or a power cut.

What support is there for the asbestos roof, the solar panels and the battery?

In Flanders, three schemes help, and each pays for a different part. Check the conditions before you sign, because some depend on the order of the works.

For the OVAM collection, you register and choose a collection month. You get a processing certificate and weighing slips afterwards, which you can use for other support such as VLIF.

The Fluvius premium has dates you must respect. Apply by 31 December 2029 at the latest. The panels must be in service and inspected by 30 September 2031, and registered with Fluvius within 3 months of commissioning. The building must have been connected to the Fluvius grid, or have had its permit application filed, before 1 January 2006. Off-grid buildings are excluded.

Our article on aid for batteries and solar panels for businesses explains VLIF for a farm battery and what can and cannot be combined.

Your new roof holds more panels than your connection allows: what then?

Then you either throttle the panels, reinforce the connection, or use the power on your own farm. A large barn or shed roof can hold more panels than a farm connection can inject.

Fluvius asks for a grid study before any solar installation above 25 kVA. On a rural line, that study can limit how much you may send back. Our articles on more solar panels than your connection allows and on injection limits for business solar explain the options.

In our semi off-grid system, the power comes either from the grid or from your own system. The battery is never charged from the grid, and unused solar power is never sent back. It works up to 75.6 kVA (3 x 400 V + N, 63 A). That is why it suits a farm where the grid is the limit. Are you facing a medium-voltage cabin? Read a high-voltage cabin or a battery first.

Dairy farms often add a small wind turbine, because wind blows more in winter when the sun is weak. See our article on a small wind turbine for a farm.

In what order do you plan the roof, the panels and the battery?

Start with your consumption and your connection, not with the roof quote. They decide how many panels make sense and whether you need a battery or a semi off-grid system.

The battery does not have to come on the same day as the panels. What matters is that the design is done before the roof goes on. Conduits, cable trays and a place for the battery and inverters cost little while the stable is empty. Our article on the steps of a business battery project shows the timeline from measurement to commissioning.

Where does the battery go on a farm?

In a dry, clean technical room or a separate container, not in the stable air. Keep batteries and inverters away from dust, moisture and animals.

Choose the place during the roof project, when you can still route cables freely. Keep the distance to the inverters and the main board short, and leave room to expand. On a farm that grows, the panels and batteries simply grow with it, as in Londerzeel. Fire safety, permits and insurance are covered in our article on the fire safety of a business battery.

Want to see how a complete farm energy system fits together? Read our article on solar and a battery for a livestock farm.

When is it better not to add a battery now?

When your new roof is small, your use is low and your connection takes all the solar power without trouble.

What happens when you ask us to look at your roof project?

We start with what your farm uses and what your connection allows.

1. Step 1: Analysis. We look at your consumption over the day and the year, your connection and your plans to grow. If data is missing, we can measure first.
2. Step 2: Technical design. We choose the panels, the inverter power and the battery, or a semi off-grid system with an automatic transfer switch.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support, so you can follow production, storage and use.

Our semi off-grid system is built for SMEs and farms with a standard 3 x 400 V + N connection.