Solar panel obligation for companies in Belgium (2026)

Does your connection point in Flanders take more than 1 GWh a year from the grid? Then the owner of the buildings must install solar panels. A battery never replaces those panels. But it decides how much of their power you use yourself, and that is where a business battery earns its place. Whether solar pays on your roof at all is a separate question, answered in our article on the payback of business solar panels.

It usually starts with a letter, an accountant or a sales call. "Are we a large consumer? Do we really have to cover the roof now? And the installer says we need a battery too." Nobody on the site knows the exact threshold. Nobody knows whether the old asbestos roof counts.

The real risk is not the panels. It is the fine that keeps coming back, and a rushed installation that pays badly. Panels installed only to comply often send much of their power to the grid at a low price. Or they run into a limit on how much you may inject.

The word "large" also misleads. A site in Beveren used 350,000 kWh a year, a very high consumption by normal standards. That is still about a third of the Flemish threshold. There we installed 200 solar panels with a 154 kWh battery, so the site uses the solar power on the spot wherever possible.

Which companies must install solar panels in Flanders?

Every building in Flanders on a connection point (EAN) that took more than 1 GWh from the grid in a calendar year since 2021. That is 1,000 MWh. The figure known to your grid operator decides, not your own meter or your invoice.

• The duty lies with the owner, the leaseholder (erfpacht) or the holder of building rights (opstal). If there are several, they are jointly liable.
• It is counted per connection point, not per company. Two sites with 700 MWh each are both below the threshold.
• Only grid offtake counts. Power you produce and use yourself does not.
• Public organisations have a lower threshold: 250 MWh a year, and 100 MWh for offtake from 2026 with a deadline from 2030.
• You must check yourself, every year. A site that grows can fall under the duty later.

Two rules protect a site with one unusual year. If your average offtake in the three years before the first crossing was below 900 MWh, the duty does not start. And if offtake drops below 90% of the threshold in one of the three years before your deadline, the duty lapses. After the deadline, a lower offtake no longer changes anything.

How many solar panels, and by when?

The minimum is set per m2 of horizontal roof area of all buildings on the connection point, and it grows in three steps.

VEKA gives a simple example. Three buildings on one connection point have 1,000 m2 of horizontal roof together. The owner needs at least 12.5 kWp by the first deadline, 18.75 kWp by 2030 and 25 kWp by 2035. For a site with 10,000 m2 of roof, that becomes 125, 187.5 and 250 kWp.

The whole horizontal roof area counts. That includes roofs that are shaded, curved, too weak, full of technical installations or made of asbestos cement. The rules offer other routes for those roofs, so they are not deducted.

Two caps can lower the minimum:

• The consumption cap. The minimum never has to exceed 35% of the offtake in the year that triggered the duty, converted at 900 full-load hours. A site with 1.1 GWh and 20,000 m2 of roof needs 428 kWp by 2035, not 500.
• The grid cap. If a recent grid study (netstudie) shows how much injection capacity is left, the minimum is capped at that capacity divided by 0.7. You must submit the study to VEKA, and check it again when the grid situation changes.

VEKA publishes a spreadsheet that calculates your minimum, the deadlines and both caps.

Where may the panels go, and what counts instead of panels?

Panels count on the roofs or facades of the buildings, but also elsewhere on your site, on another own site or via a direct line. Carports, bicycle sheds, ground-mounted and floating panels and agrivoltaics over farmland all qualify.

Panels commissioned before 1 January 2023 count only on the buildings themselves, on the same site, or through a direct line. Panels at an affiliated company's site also count, if commissioned after that date.

Where panels do not fit, the rules accept other routes, alone or combined, and you may choose again at each step:

Alternative installations must be commissioned after 1 January 2023, and a heat pump needs an inspection report. The heat pump route is interesting if you are moving off gas anyway: read what a heat pump does to your connection and peak. A turbine is covered in our article on a small wind turbine for a farm or business.

Does a battery count for the solar obligation?

No. A battery produces nothing, so it cannot replace a single kWp. It is not in the Flemish list of alternatives. The EU directive also asks for solar installations, not storage.

That does not make storage irrelevant. It changes three things about the panels you must install:

• It decides how much of their power you use yourself. VEKA notes that solar is very profitable at about 10% of the roof, because most power is used on site. At 25 Wp per m2 the installation is twice as large, so weekends and slow days produce more surplus. A battery moves that surplus to the evening or the Monday start-up.
• It helps where the grid cannot take the power. The grid cap lowers the duty if injection capacity is short. If you still want to use the roof, a battery with an injection limit lets you install more panels than you may inject. See more solar panels than your connection allows and what to do about an injection limit.
• It lowers your grid offtake and your peak. The duty is measured on grid offtake, and so is your capacity tariff. Own production and storage reduce both. Read how the capacity tariff for businesses is calculated.

On a farm in Tielt, smart control lets the boilers heat extra when there is surplus power. The public grid only serves as a charger.

What happens if you miss the deadline?

VEKA imposes an administrative fine of 400 euro per missing kWp. Paying it does not release you from the duty.

• You pay and you still have to comply within two years. If you are still short after two years, a new fine of 400 euro per missing kWp follows, and so on.
• An example: 100 kWp missing means 40,000 euro, and the 100 kWp must still be installed.
• Not answering VEKA also costs money. You have 60 days to send the data VEKA asks for. After a reminder, a penalty of 100 euro per calendar day applies.
• A reminder step is coming. According to VEKA, the Flemish Parliament voted on 1 April 2026 that an owner first receives a formal notice to comply.

Some situations give a deferral or an exception, but only if you report them in time through the VEKA forms:

What does the EU buildings directive add from 2027?

Directive (EU) 2024/1275 requires solar installations on new buildings and on certain renovated ones, where technically suitable and economically and functionally feasible. Member states had to transpose it by 29 May 2026. In Belgium the regions do this.

• By 31 December 2026: all new public and non-residential buildings above 250 m2 of useful floor area.
• By 31 December 2027: existing non-residential buildings above 500 m2 with a major renovation. Works that need a permit for the roof or a technical building system also count.
• From 2027 to 2030: existing public buildings, in steps from 2,000 m2 down to 250 m2.
• By 31 December 2029: new homes and new roofed car parks adjacent to buildings.

In Flanders, new buildings are already covered by the EPB rules. For permits applied for since 2025, a new non-residential unit needs at least 20 kWh per m2 from solar systems. Participation is the only alternative. Otherwise a stricter energy level (E-peil) applies. In July 2026 the Flemish government approved a draft decree in principle to transpose the rest. Existing non-residential buildings will be handled through the energy certificate (EPC NR). Buildings or roofs already under the solar obligation stay out of that new duty.

Planning a new building? Read what architects and engineering firms must plan for a building with a battery.

Is it different in Wallonia and Brussels?

Yes. The obligation based on consumption is Flemish only. Wallonia and Brussels apply the EU duty for new and renovated buildings.

In 2023, the Walloon energy minister pointed companies to energy audits, sector agreements and third-party financing rather than an obligation. The Walloon energy portal now announces the EU duty for new non-residential buildings, with new regulatory texts. In Brussels, Bruxelles Environnement lists the dates above. Public buildings follow in steps: 2,000 m2 from 2028, 750 m2 from 2029 and 250 m2 from 2031. Check the final texts with your PEB adviser before you design.

How do you meet the obligation in a way that also pays?

Treat the obligation as the minimum, and design the installation around your consumption.

1. Step 1: Ask your grid operator for the yearly offtake of each connection point since 2021. Note the first year above 1 GWh.
2. Step 2: Measure the horizontal roof area of every building on that connection point. Run the VEKA spreadsheet for your minimum, deadlines and caps.
3. Step 3: Check the roofs. Weak or asbestos roofs point to a lighter structure, another location, an alternative route or a deferral for roof replacement.
4. Step 4: If injection capacity is doubtful, ask for a grid study early. It can lower the minimum, and it tells you whether storage or an injection limit is needed.
5. Step 5: Lay the solar profile over your quarter-hour data. Where the surplus is large, add control of flexible loads and, if it does a second job, a battery.
6. Step 6: Plan the commissioning date with the grid operator, with margin. Check which support applies: our overview of investment deduction and subsidies for solar and batteries helps. For financing, see how a company can finance a battery.

What happens when you ask us to look at your solar obligation?

We start from your consumption, not from the roof.

1. Step 1: Analysis. We read your quarter-hour data and look at what the mandatory solar power would do on your site.
2. Step 2: Design. We combine panels, control and, where it pays, a battery, so the power goes where it is worth most.
3. Step 3: Installation and commissioning, with the protections and the grid notification the rules require.
4. Step 4: Monitoring. Our energy management software shows production, use and storage, so you can prove what runs on your site.

Our battery systems for businesses range from SME installations to modular systems up to 1 MW, for solar self-consumption, peak shaving and back-up.