Solar in Luxembourg: 12 Questions to Ask Before Signing a Quote

Introduction

Photovoltaics have become an essential investment in Luxembourg, thanks to climate challenges and attractive financial aids like the Klimabonus Wunnen 2026. However, before signing a quote, it is crucial to ask the right questions to avoid unpleasant surprises. This article guides you through the 12 key questions to ask your installer, with Luxembourg-specific information: subsidies, VAT, administrative procedures, and technical aspects.

1. What is the exact capacity of the proposed installation?

The capacity of a photovoltaic installation is measured in kilowatt-peak (kWp). It determines annual production and the subsidy amount. In Luxembourg, the Klimabonus Wunnen offers up to EUR 10,000 for an installation, with a cap of EUR 8,300 for 10 kWp and a maximum reached from 15 kWp. Ask your installer for the exact capacity, number of panels, and required roof area. Ensure this capacity matches your actual needs and roof size.

2. What types of panels and inverters are included?

The quality of equipment influences performance and durability. Ask about the brand and model of the photovoltaic panels (monocrystalline, polycrystalline, etc.) and the inverter. A quality inverter has a warranty of 10 to 15 years, while panels typically have a product warranty of 10 to 25 years and a performance warranty of 25 to 30 years. Request technical datasheets and compare efficiencies.

3. How is the installation carried out?

The installation includes mounting panels, wiring, connecting to the inverter and electrical panel. Ask if the quote includes labor, scaffolding, removal of old installation (if applicable), and site cleanup. Specify the execution time and warranties on workmanship. Verify if the installer is certified, for example by myenergy.lu or a recognized professional qualification.

4. Does the quote include administrative procedures?

In Luxembourg, procedures for a photovoltaic installation go through guichet.public.lu and the grid operator (CREOS). The quote must specify who handles the grid connection request, the building declaration, and the Klimabonus subsidy application. Some installers include this service, others do not. Clarify any costs and responsibilities.

5. What are the connection and electricity costs?

Connecting to the grid may incur fees, sometimes included in the quote. Ask about the bi-directional meter and conditions for selling excess electricity. In Luxembourg, the feed-in tariff varies; ask your installer for the latest conditions. Also check if your electricity supplier offers a favorable offer for self-consumption.

6. What warranties are offered?

A photovoltaic installation must be covered by solid warranties. Ask for warranty on panels (often 25 years), inverter (10-15 years), and workmanship (usually 2 to 10 years). Ensure the installer offers a ten-year liability warranty, mandatory in Luxembourg for construction work. Also verify professional liability insurance.

7. What is the expected yield and annual production?

Yield depends on orientation, tilt, shading, and region. A serious installer should provide an estimate of annual production in kWh, based on real data. In Luxembourg, a 10 kWp installation can produce about 9,000 to 12,000 kWh per year. Ask for a simulation using professional software and compare with your past consumption.

8. What is the lifespan and maintenance required?

Photovoltaic panels have a lifespan of 25 to 30 years. Maintenance is minimal: occasional cleaning and annual inspection. Ask if the quote includes a maintenance contract or if it is optional. Also clarify availability of spare parts and potential replacement costs.

9. How are permits and compliance handled?

Before signing, check if the installation complies with your commune's urban planning rules. In Luxembourg, some communes impose aesthetic conditions. The installer must inform you of necessary permits. The quote must mention compliance with electrical and safety standards, as well as installation certification.

10. What financing options and aids are available?

The Klimabonus Wunnen 2026 is the main program for photovoltaic subsidies. It replaces PRIMe House since January 2026. Amounts are: up to EUR 10,000 for PV (about EUR 8,300 for 10 kWp, maximum from 15 kWp), and up to EUR 2,250 for a home battery. Check eligibility conditions: the home must be older than 2 years to benefit from the 3% VAT. Your installer can help you prepare the file, but you can also do it via klima-agence.lu. Also check green loans offered by some Luxembourg banks.

11. Is the quote detailed and transparent?

A professional quote must be clear and detailed: equipment prices, labor, connection fees, VAT, administrative procedures, warranties. Beware of quotes that are too vague or too low. Request a cost breakdown and compare several quotes (at least 3). Ensure the total price is in euros and there are no hidden fees.

12. What are the references and customer reviews?

Ask the installer for references from recent projects in Luxembourg. Check online reviews and certifications. A reliable installer should be a member of a professional organization like myenergy.lu or have partnerships with recognized manufacturers. Do not hesitate to contact previous clients to learn about their experience.

Summary Table of Key Points

Conclusion

Signing a photovoltaic quote in Luxembourg is an important decision. By asking these 12 questions, you will be better equipped to negotiate and choose a reliable installer. Remember to check Klimabonus Wunnen 2026 subsidies and follow procedures via guichet.public.lu. Take time to compare and ask for clarifications. A well-prepared investment will bring you energy savings and added value for your home.