Solar panels in BelgiumBelgium solar calculator and 2026 figures
A 6 kWp system on a typical roof in Belgium generates 6,043 kWh a year, worth €830 in the first year against €8,100 spent up front. Everything below shows how that is worked out, on real climate data and this year's actual tariffs.
Where the money comes from
5,982 kWh in year oneEvery kilowatt-hour your roof makes is worth one of two very different amounts. Power you use as it is generated replaces power you would have bought, so it is worth the full retail price. Power you do not use goes to the grid at the export rate, which is far lower. The balance between those two is what actually decides whether solar pays here.
- Used in the house
- 1,795 kWh (30% of output) at 0.360 EUR/kWh, the retail price you avoid paying.
- Sold to the grid
- 4,187 kWh (70% of output) at 0.044 EUR/kWh, the export rate your supplier pays.
Averaged out, each kilowatt-hour is worth 0.139 EUR/kWh. That blended figure, not the headline retail price, is what drives every number on this page. Using more of your own power (an EV, a heat pump, a battery, or simply running appliances by day) shifts output from the lavender side to the mint side and raises it.
A year on the roof
1,007 kWh per kWp · PVGIS-SARAH3Output is not spread evenly. May is the strongest month at 738 kWh, 4.0× what December manages at 186 kWh. Annual totals hide that swing, which is why a system sized purely on your yearly bill tends to overshoot in summer and undershoot in winter.
The 25-year picture
- Everything the system saves and earns
- €21,044
- What you pay up front
- − €8,100
- Left over
- €12,944
25 years of avoided bills plus export payments, after maintenance and one inverter replacement.
Install cost, with no grant modelled.
Straight subtraction, ignoring the fact that money arriving 25 years from now is worth less than money today.
Same result, in today's money
€4,687€12,944 spread over 25 years is not worth €12,944 today, because you could have done something else with the money in the meantime. Discounting future savings at 4% a year gives €4,687, the net present value. It is the honest number to compare against another investment, and the equivalent annual return is 8.6%.
On the same discounted basis the system pays for itself after 14.3 years.
When you break even
Your position starts at minus €8,100 on install day and climbs as the system earns. The line crossing zero is the payback point.
Cumulative cash position
Break-even in year 11Net position after each year (−net capex up front, then cumulative savings). Crossing the dashed line is payback.
How that figure is built
No step here is a rule of thumb. Every one of them is the same code path the calculator runs on your own address.
Start with the weather, not a brochure
PVGIS-SARAH3 holds satellite-measured irradiance for this location. For a 6 kWp array at 35° facing south it works out to 1,007 kWh per kWp per year. That is the number a brochure would round up.
Scale it to the system
6 kWp × 1,007 kWh/kWp = 6,043 kWh a year. Panels lose about 1% in year one and 0.4% a year after, so year one is modelled at 5,982 kWh.
Price each kilowatt-hour twice
30% is used in the house at 0.360 EUR/kWh, the rest exported at 0.044 EUR/kWh. Together: €830 in year one.
Subtract what you actually hand over
A 6 kWp install in Belgium runs about €8,100, with no grant modelled, so €8,100 out of pocket.
Run it for 25 years, honestly
Electricity prices rise 2% a year, panels keep degrading, maintenance costs about 1% of the system price annually, and the inverter gets replaced once. Total savings come to €21,044, clearing the upfront cost after 10.2 years.
What we assumed for Belgium
Change any of these and the answer changes. They are published so you can check them against your own bill and your own quote.
| System size modelled | 6 kWp at 35° facing south |
| Install cost before any grant | €8,100 |
| Grant or incentive | No national/Flanders capital grant; net metering abolished 1 Apr 2026. (Brussels still has green certificates.) |
| Net cost to you | €8,100 |
| Electricity price you avoid paying | 0.360 EUR/kWh |
| Export rate paid to you | 0.044 EUR/kWh |
| Share used in the house | 30% of output |
| Electricity price inflation | 2% a year |
| Panel degradation | 1% in year one, then 0.4% a year |
| Maintenance | 1% of system cost a year, plus one inverter replacement |
| Discount rate for present value | 4% a year, real |
| CO₂ avoided | 786 kg a year · 18,537 kg over 25 years |
Estimate only, not a quote. Tariffs and grants change; figures use the rates on file for 2026 and an installer's survey will produce the exact number.
Questions people ask about solar in Belgium
- Is solar worth it in Belgium?
- A 6 kWp system in Belgium pays for itself in about 10.2 years and returns €21,044 of savings over 25 years against €8,100 spent up front. Your roof, orientation and shading move the result, which is what the calculator works out for your exact address.
- How much do solar panels cost in Belgium?
- About €8,100 for a 6 kWp install, with no national grant modelled. Installers quote against your specific roof, so treat this as the middle of the range.
- What do you get paid for exporting solar power in Belgium?
- Exports are modelled at 0.044 EUR/kWh against a retail import price of 0.360 EUR/kWh. Because exporting is worth much less than using the power yourself, how much you consume during daylight matters more than the size of the array.
Your roof is not the average roof
Orientation, pitch, shading and how much power you use by day move these numbers more than anything on this page. The calculator runs the same model on your actual address.
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Solar by city in Belgium
Same model, run on each city's own climate data.
For the incentives, tariffs and the 2026 rule changes in detail, read our Belgium solar guide.