Solar panel grant 2026 in Luxembourg: how much do you really get?

Between €2,178 and €10,000, depending on the installed power. The Klimabonus 2026 scheme no longer works as a percentage of the quote but in euros per kilowatt-peak, with a sliding formula: the bigger the system, the less each kWp brings. Above 15 kWp, the grant is capped at €10,000.

Source: guichet.lu, official formula P × (1,155 − 1,155/35 × P) euros, P in kWp.

The battery has its own scale: usable capacity × (500 − 500/18 × capacity), for example €1,806 for 5 kWh and a maximum of €2,250 from 9 kWh. Minimum 2 kWh, and the battery must be connected to a self-consumption system.

One detail matters: the grant never exceeds the invoiced cost. And hybrid collectors producing both hot water and electricity count as photovoltaics.

Four main conditions: a new system of at least 2 kWp, mounted on the roof, the façade or integrated into the building, operated for self-consumption, and an invoice dated between 4 January 2026 and 31 December 2029.

The point that surprises most people: self-consumption is mandatory. You expressly waive the state-guaranteed feed-in tariff, for the whole lifetime of the system. You can still export your surplus to the grid and sell it to a supplier at market price, but without a guaranteed tariff.

The other rules to know:

• Who: owners, natural or legal persons, co-ownerships through the managing agent. Businesses fall under the de minimis rule.
• Energy community: sharing electricity with neighbours or within a building is accepted, provided everyone has waived the feed-in tariff.
• Apartment buildings: at least 1.5 kWp per dwelling for a battery to be funded.
• Extension: an additional system is funded only if its first grid injection takes place at least two years after that of the original system.
• Exclusions: second-hand equipment, plug-in balcony kits, systems already funded under the 2017 or 2022 schemes.

Co-ownerships file one application per building, with form COLL-2026 and a power of attorney or the minutes of the general meeting.

For a family home, the grant almost always wins. Luxembourg lets you choose between two schemes, and they cannot be combined: either the Klimabonus grant with self-consumption, or the state-guaranteed feed-in tariff for 15 years, with no grant.

The feed-in tariff remains attractive for a large roof whose electricity will mostly be sold: a farm, a shed, a building with little on-site consumption. For a household that consumes during the day, charges an electric car or heats with a heat pump, every self-consumed kWh avoids buying electricity at full price, and the grant arrives straight away.

Take 6 kWp: €5,742 of grant on one side, on the other a guaranteed payment of around ten cents per kWh exported, spread over the years. With a self-consumption rate of 30 to 40%, and more with a battery, the gap widens in favour of the grant.

Five steps, and no prior application is needed:

1. Compare quotes. Ask for at least two or three detailed offers with the power in kWp, the number of modules, the inverter, the estimated annual output and the price including VAT. Check that the installer works in Luxembourg and knows the Klimabonus 2026.
2. Order and have it installed. Keep the dated order form: it may be requested for the application. The installer notifies the grid operator that the work is complete.
3. Gather the documents. Form DEPA-2026, data sheet PHOT-2026 completed by the installer, certificate of conformity CCPHOT-2026, detailed and paid invoices with proof of payment, recent bank details, completion notice or POD number.
4. Submit on MyGuichet.lu. With LuxTrust or the eID card, in a few minutes. Posting the file to the Guichet unique des aides au logement remains possible.
5. Wait for payment. Files are processed in order of arrival. A complete file avoids back-and-forth.

The application must be submitted by 31 December 2031 at the latest. The invoice window runs from 4 January 2026 to 31 December 2029, extended to 31 December 2031 if the system was ordered before the end of 2029.

Since 4 January 2026, you can have the grant deducted directly from the installer's invoice. This is pre-financing, also called third-party payment: the State pays the aid to the company, which passes it on in full as a price reduction. The grant amount is identical, with or without pre-financing.

The conditions:

• The installer must appear on the official list of installers approved for pre-financing, kept by the Ministry of the Economy and available on guichet.lu.
• You sign the pre-financing form with them and a mandate stating the order date.
• The deposit paid before the work cannot exceed 30% of the price including VAT of the signed offer.
• No leasing, no battery added alone to an existing system, and a single route: pre-financing or a standard application, never both.

From 1 January 2027, this mechanism is integrated into the Klimabonus 2026 for all photovoltaic systems, with or without a battery. For invoices issued in 2026, the law of 19 December 2025 applies, with the same logic.

In practice, this changes everything for a household without €12,000 of available savings: the grant is no longer a cash advance lasting several months.

Often half the quote, sometimes less with a municipal grant. There is no single price: the roof, access, the number of modules and the inverter brand all move the invoice. On the Luxembourg market, turnkey residential quotes frequently sit between €1,800 and €2,300 per kWp including VAT, with 3% VAT when the home is over 20 years old and is your main residence.

An example with a 1990s house, 6 kWp on the roof, ordered in 2026:

The grant amount is that of the 2026 scheme; the price and the municipal grant are examples.

Add a 9 kWh battery and the grant rises by €2,250. Above all, add the annual saving: 6 kWp produce roughly 5,500 to 6,000 kWh a year in Luxembourg, and every kWh used on site is a kWh you do not buy. Our solar panel grants page details the orders of magnitude of profitability, and the subsidies guide lists the grants you can combine, including the reduced-rate Klimaprêt.

Three mistakes come up again and again:

• Signing a feed-in contract out of habit. If you opt for the guaranteed feed-in tariff at commissioning, the Klimabonus grant is lost, and the choice is final. Tell the installer clearly that you are aiming for self-consumption.
• Choosing an installer who is not on the list for pre-financing. Without registration, no deduction on the invoice. You can still file a standard application, but you advance the money.
• Paying too large a deposit or forgetting supporting documents. More than 30% deposit blocks pre-financing. An unpaid invoice, an incomplete PHOT-2026 sheet or a missing POD delay payment by several weeks.

The remedy is simple: a quote that states in black and white the Klimabonus 2026, self-consumption and the power in kWp, an installer on the register, and an application filed right after the invoice. Torn between several offers? Our solar page explains how to read a photovoltaic quote.