What government aid is available for solar panels in Luxembourg?

The main forms of government aid for solar panels in Luxembourg are the photovoltaic Klimabonus, the domestic battery subsidy when the battery is connected to a solar installation, and prefinancing, which allows the aid to be deducted directly from the final invoice when the project meets the required conditions.

The amount depends in particular on the installed capacity in kWp, battery capacity in kWh, building type, applicable scheme, order date and final invoice date. The Klima-Agence calculator remains the official reference for an initial estimate, but a technical assessment is still essential before approving the project.

Aid or scheme	What it covers	Important point
Photovoltaic Klimabonus	Photovoltaic solar installation	Amount calculated according to installed capacity, capped at €10,000 from 15 kWp.
Domestic battery storage	Battery connected to a photovoltaic installation	Amount calculated according to usable capacity, capped at €2,250 from 9 kWh.
Photovoltaic prefinancing	Possible deduction of the aid from the final invoice	Available only when the conditions are met and the installer is approved for the procedure.
Municipal grants	Additional grants depending on the municipality	They vary according to where you live and must be checked on a case-by-case basis.
Klima-Agence calculator	Estimate of potential financial aid	Official tool providing an initial indication before the technical assessment.

For more technical information, also visit our dedicated page on solar panel installation in Luxembourg.

Photovoltaic Klimabonus 2026: what homeowners need to check

The photovoltaic Klimabonus supports solar projects that comply with the applicable technical and administrative conditions. Before signing a quote, you should check the proposed capacity, the applicable scheme, whether a battery is included, the order date, the final invoice and the documents required for the application.

• Minimum photovoltaic capacity of 2 kWp.
• Installation operated for self-consumption, with a waiver of the guaranteed feed-in tariff provided under the scheme.
• Panels installed on the roof, facade, building envelope or an eligible structure such as a carport.
• Any battery included must have a capacity of at least 2 kWh and be correctly connected to the photovoltaic installation.
• An installer listed in the approved register is required to use the prefinancing procedure.

The subsidy amount is not the only important factor. A solar installation must first be sized correctly. Excessive capacity compared with your consumption can reduce the project’s economic value, while a properly assessed system can make better use of self-consumption.

Photovoltaic prefinancing: how can it reduce your final invoice?

When a project is eligible, photovoltaic prefinancing allows the Klimabonus aid to be deducted directly from the final invoice. The homeowner therefore does not necessarily have to pay the full subsidy amount upfront and wait for reimbursement.

1. The project is assessed and sized with an installer approved for the prefinancing procedure.
2. The eligibility of the installation, any battery and the beneficiary is checked before the final commitment.
3. The beneficiary and installer co-sign the document confirming the choice of prefinancing, and the beneficiary authorises the installer to act on their behalf.
4. After installation, the final invoice states the capacity, any battery, the deposits paid and the amount of subsidy deducted.
5. The installer submits the application on behalf of the beneficiary after sending the completion declaration to the grid operator.

Important points: deposits paid before the final invoice cannot exceed 30% of the total amount of the final invoice. The minimum photovoltaic capacity is 2 kWp and, when a battery is included, its minimum capacity is 2 kWh. A standalone battery added to an existing photovoltaic installation must follow the standard post-financing procedure.

Solar battery subsidy in Luxembourg: when is battery storage worthwhile?

A domestic battery stores part of the electricity produced by your solar panels for later use, for example in the evening or when production is lower. It may be worthwhile when your electricity use is not concentrated during daylight hours.

The battery subsidy depends on the installed capacity and remains capped. A battery should therefore not be selected simply because it is subsidised. The right choice depends on your consumption, solar production, electricity price, feed-in tariff and desired level of energy independence.

Municipal grants for solar panels: what should you check?

Some Luxembourg municipalities offer a grant in addition to Klimabonus, but this is neither automatic nor identical across the country. The amount, eligible equipment, supporting documents and deadlines depend on the municipal rules in force at the time of the project.

• Check that the building is located within the municipality concerned.
• Check the order date, invoice date and application deadline.
• Prepare the required documents: invoice, proof of payment, technical data sheet or decision relating to national aid, depending on the local rules.
• Confirm the rules for combining the municipal grant with Klimabonus and any other aid.

Ecoclima can highlight the points to check and provide the available technical information. However, the municipal application must be submitted by the homeowner when required by the municipality.

Previous scheme or new scheme: why check before signing?

Different situations may apply to photovoltaic installations depending on the order date, final invoice date and project conditions. During certain transitional periods, the previous scheme and the new Klimabonus scheme may need to be compared. This matters because it can affect the amount of aid, access to prefinancing and the value of adding a battery.

Our recommendation is simple: do not choose a project based solely on the announced subsidy. You should also consider sizing, actual consumption, potential self-consumption, any battery, roof constraints, grid connection and the rules applicable to your file.

Why is a technical assessment still essential?

A subsidy does not automatically make a solar project profitable. A system that is too large, poorly oriented or unsuited to your consumption can reduce its economic value. Conversely, a correctly sized installation can make better use of the electricity generated, especially if you consume significant electricity during the day or combine photovoltaics with a battery, heat pump or EV charging.

• Roof orientation and pitch.
• Potential shading on the solar panels.
• Annual electricity use and daytime consumption.
• Condition of the electrical panel and grid connection.
• Actual value of domestic battery storage.
• Compatibility with a heat pump or EV charger.

Energy grants in Luxembourg: estimate your solar project

Financial aid for energy renovation can make a substantial difference to a project budget. However, rules change, cases vary according to the property, equipment and technical conditions, and it is easy to overlook an important requirement.

Ecoclima has created a simple calculator to provide an initial estimate of the cost, Klimabonus and remaining amount to pay. It also helps structure your request before the technical assessment by collecting the property type, proposed capacity, possible battery and project profile.

Complete the calculator below for an immediate result without providing contact details. You can then request an assessment to verify the assumptions, grants and procedures applicable to your home.