Up to €10,000 in grants
How do you make a success of a solar panel project in Luxembourg in 2026?
In Luxembourg, a solar PV project comes down to four choices: the output (3 to 9 kWp for most houses), the scheme (a €5,742 Klimabonus for 6 kWp or the €0.1333/kWh feed-in tariff up to 10 kWp), the installer and the financing. A 6 kWp system costs €10,500 to €13,000 including VAT, without a battery (renov.lu price survey, September 2026), and pays for itself in 9 to 11 years.
Your result in 2 minutesFree simulator Installable outputkWpProductionkWh/yrTotal grants€ Instant result, no obligationStart the simulation →- Production: about 1,000 kWh per kWp per year (PVGIS: 1,067 kWh due south)
- Price: €10,500 to €13,000 incl. VAT for 6 kWp on a pitched roof, without a battery, i.e. €1,750 to €2,170 per kWp (renov.lu price survey, September 2026); €1,600 to €2,200 per kWp from 6 to 15 kWp
- 2026 grant: €5,742 for 6 kWp, €10,000 from 15 kWp, which the installer can deduct from the invoice
- Alternative: guaranteed feed-in tariff for 15 years of €0.1333/kWh up to 10 kWp and €0.1252/kWh from 10 to 30 kWp (first feed-in in 2026), without the Klimabonus
- VAT: 3% on supply with installation
- Formalities: municipal rules, registration with the grid operator from 800 W; no grant application before the works
- Lifespan: 25 to 30 years for the modules, one inverter to replace along the way
How a solar PV system works
The modules turn light into direct current, the inverter converts it into alternating current, and your home uses that electricity first; the surplus goes to the grid. In Luxembourg you become an « active customer »: the electricity you use yourself pays no network tariff, no compensation-mechanism contribution and no electricity tax.
- With the Klimabonus, the surplus is sold at market price under a buy-back contract; a single-meter solution (Smarty) is possible up to 30 kVA of inverter output.
- With the guaranteed feed-in tariff, the surplus is paid at a fixed price for 15 years; this requires a separate production meter.
- A battery stores the daytime surplus for the evening; an energy management system runs the heat pump, charger or water heater while the sun is producing.
A balcony kit under 800 W works on the same principle, with no registration and no grant: see our guide to the balcony solar panel.
The steps of a solar project, from idea to commissioning
A project runs in seven steps; the only formality before the works is to check your municipality’s rules, since the grant is claimed after installation.
- Estimate: note your annual consumption, spot the well-exposed roof slopes on the geoportal’s solar cadastre and run a first simulation.
- Check the rules: the municipal building regulation, protected areas, co-owners’ consent if needed.
- Compare three quotes after a site visit, on the same scope, and choose between the Klimabonus and the feed-in tariff.
- Sign: with pre-financing, the deposit does not exceed 30% and you co-sign the statement mandating the installer.
- Install: most of the work on a house takes a few days.
- Connect: the electrician registers the system with the grid operator (on myCreos for Creos, with an Energy ID), then notifies completion. With two meters, Creos acts within 30 days; with a single meter, notification must follow commissioning within 7 days.
- Receive the grant: deducted from the invoice with pre-financing, or claimed by you after installation, by 31 December 2031 at the latest.
Each quote should detail these steps: see our method to compare solar quotes.
What output should you install?
Aim for production equal to 80 to 100% of your annual consumption: a typical household using 3,900 kWh a year needs 3 to 4 kWp on a south roof, a house with a heat pump 7 to 9 kWp. Allow 5.5 to 6 m² of roof per kWp. Method, orientation coefficients and examples: how many kWp to install.
Self-consumption with the Klimabonus or the feed-in tariff?
You must choose before commissioning, with no going back. The Klimabonus pays €5,742 for 6 kWp and the surplus is sold at market price under a variable buy-back contract, often indexed to the « MW Solar » index; the feed-in tariff pays €0.1333 for each kWh fed in for 15 years up to 10 kWp, and €0.1252 from 10 to 30 kWp (first feed-in in 2026, Klima-Agence), with no investment grant. From 3 to 6 kWp, the Klimabonus pays at least as much; from 10 kWp with little self-consumption, the guaranteed tariff often wins. The full calculation is on our page on solar payback, and ways to increase your self-consumed share are in our guide to self-consumption.
Flat or pitched roof: what output and what extra cost?
A flat roof is no obstacle to solar PV: mounted due south on tilted frames, the modules produce almost as much as on a sloping roof, and about 15% less in an east-west layout, for an extra cost of €500 to €1,500 on a 5 to 6 kWp system. The Klimabonus is exactly the same.
| Layout | PVGIS production per kWp | Share of the optimum | Points to watch |
|---|---|---|---|
| Pitched roof due south, 35° | 1,067 kWh | 100% | Hooks under the tiles; condition of the roofing |
| Pitched roof south-east or south-west | 1,006 kWh | 94% | None |
| Flat roof, modules south at 10° | 983 kWh | 92% | Row spacing to avoid shading |
| Flat roof, east-west at 15° | 903 kWh | 85% | More modules per m², output spread over the day |
| Pitched roof east or west, 35° | 868 kWh | 81% | Use both slopes if possible |
- Load capacity: on a flat roof, a ballasted system weighs in the order of 40 to 120 kg/m², against 15 to 20 kg/m² for an on-roof system on a sloping roof. The slab must be checked.
- Waterproofing: redo it before installation if it is near the end of its life; redoing it afterwards means removing the modules.
- Height and appearance: the municipal building regulation may limit frame height or require black modules in a protected area.
- Sloping roof: on-roof mounting is the cheapest; in-roof integration costs more and makes most sense when re-roofing.
Coefficients for every orientation are on our kWp sizing page, extra costs on the solar panel cost page.
Permits: municipality, co-ownership, grid operator
In Luxembourg, it is the municipality that decides whether rooftop panels are exempt, subject to declaration or require the mayor’s authorisation, under its building regulation. The model regulation of circular no. 2023-119 recommends exempting solar PV up to 30 kWp outside protected areas, but each municipality is free to decide; the City of Luxembourg, for example, lists rooftop panels among works requiring authorisation.
- No « silence means consent »: bill 8480, which would introduce it for solar, has not been passed; without a reply from the municipality after 3 months, the application is deemed refused.
- Listed building or green zone: authorisation from the Minister of Culture or of the Environment in addition to the municipality.
- Co-ownership: an installation producing or storing renewable energy in the common parts is voted by a majority of the votes of all co-owners.
- Grid: any installation of 800 W or more is declared to the grid operator (Creos, Sudstroum or the towns of Diekirch and Ettelbruck) and entered in the national register. Feeding in without declaration is a criminal offence.
The general rules on works requiring authorisation are on our page on building permits and works declarations.
Budget, grants and financing
- Price: €10,500 to €13,000 incl. VAT for 6 kWp, i.e. €1,750 to €2,170 per kWp (€1,600 to €2,200 per kWp from 6 to 15 kWp), with 3% VAT (renov.lu price survey, September 2026): see solar panel costs.
- Grants: a Klimabonus of P × (1,155 − 33 × P) euros, €10,000 from 15 kWp, up to €2,250 for a battery, €500 for an energy management system: see 2026 solar grants.
- Financing: a registered installer can deduct the grant from the invoice, with a deposit of at most 30%; the Klimaprêt can cover 1.5% of interest (to be confirmed for solar PV with the Guichet unique des aides au logement): see pre-financing and financing. For a company roof, see our financing options for businesses.
- Payback: 9 to 11 years for 6 kWp without a battery, €550 to €700 of savings a year.
Maintenance, warranties and lifespan of solar panels
Today’s solar modules run for 25 to 30 years or more, losing in the order of 0.3 to 0.5% of output a year; the inverter is usually replaced once during that time, for €800 to €2,000. Maintenance mostly comes down to monitoring production.
| Warranty | Usual duration on the market | What it covers |
|---|---|---|
| Module product warranty | 12 to 25 years depending on the manufacturer | Manufacturing defects: delamination, junction box, frame |
| Performance warranty | 25 to 30 years | Minimum output guaranteed at the end, usually 80 to 90%; prefer a linear warranty |
| Inverter warranty | 5 to 12 years, often extendable | Replacement or repair of the unit |
| Workmanship warranty | According to the installer’s contract | Roof waterproofing, fixings, wiring |
- Monitor: the inverter app flags a drop in production; compare each year with the previous one.
- Clean: on a sloping roof, rain is usually enough; cleaning is worthwhile on a shallow flat roof or under trees, by a professional equipped for work at height, without abrasive products.
- Check: after a storm or hail, have fixings and cables inspected.
- Choose a lasting installer: the workmanship warranty is only worth something if the company still exists; favour a business established in Luxembourg for several years.
Solar, heat pump, charger and battery: useful combinations
Solar PV earns the most when you use its output during the day. A heat pump run during sunny hours, an EV charger that charges the car with the surplus or a home battery increase the self-consumed share. An energy management system controlling at least two of these appliances receives a €500 grant for invoices issued from 1 October 2026.
No roof available? A balcony kit under 800 W, collective self-consumption in the building or an energy community still let you use solar electricity.
Take action
Simulate your roof to find the output and grant, then ask installers established in Luxembourg for three quotes on the same scope. If the roof needs repairing first, find a verified roofer before the installation.
Simulate, then compare three quotes
Output, production, grant deducted and payback: everything you need to decide, free and without obligation.
Frequently asked questions about solar panels in Luxembourg
Where should I start with a solar panel project in Luxembourg?
Note your annual consumption from your bill, identify the well-exposed roof slopes and check with your municipality whether the installation is exempt from a permit. Then run a simulation and ask for three quotes after a site visit. No grant application is needed before the works.
Do I need municipal permission to put solar panels on my roof?
It depends on the municipality. Its building regulation can exempt solar PV, make it subject to declaration or require the mayor’s authorisation. The model regulation recommended to municipalities exempts systems up to 30 kWp outside protected areas, but the City of Luxembourg, for example, requires authorisation for rooftop panels.
Can solar panels be installed in a co-owned building?
Yes. Since 1 October 2022, an installation producing or storing renewable energy in the common parts is voted by a majority of the votes of all co-owners. The electricity can then be shared between the flats through collective self-consumption, and the grant remains available.
How long does it take from quote to commissioning?
Usually a few weeks to a few months, depending on the installer’s availability and the municipality’s reply if a permit is needed. Installing a residential system takes a few days; with the two-meter solution, Creos acts within 30 days of the electrician’s request.
Do solar panels produce electricity in winter in Luxembourg?
Yes, but little. According to PVGIS, 1 kWp facing due south produces about 32 kWh in December against 132 kWh in July, i.e. 3% of annual production in December. That is why systems are sized on annual consumption, never on winter.
Do solar panels need maintenance?
Little. Monitor production in the inverter app, have fixings and cables checked after a storm and plan to replace the inverter once, for €800 to €2,000. Cleaning is only useful on a shallow flat roof or one heavily exposed to dirt.
Solar PV or solar thermal panels: which should I choose?
Solar PV produces electricity usable throughout the house; solar thermal only heats water, and possibly the heating. In 2026, solar thermal for hot water receives a €2,500 Klimabonus, and €4,000 with heating support. Our solar water heater page compares the two.