Klimabonus 523
Photovoltaics (New Regime)
What is Klimabonus 523?
Klimabonus 523 is a public subsidy scheme in Luxembourg supporting the installation of photovoltaic (PV) systems under the new regulatory regime.
The programme is intended for building owners who want to:
produce their own electricity using solar energy,
operate their photovoltaic system primarily in self-consumption mode,
reduce dependence on the electricity grid,
contribute to climate protection.
Technical requirements for photovoltaic systems
To be eligible for Klimabonus 523, the photovoltaic installation must meet the following technical conditions:
The installed peak output must be at least 2 kWp, with no upper technical limit.
The maximum subsidy amount of €10,000 is reached with an installed capacity of 15 kWp.
Photovoltaic panels may be:
mounted on the roof,
installed on the façade, or
integrated into the building envelope.
Installations are allowed on:
residential buildings, and
non-residential buildings.
Hybrid solar collectors producing both electricity and hot water are also eligible.
Additional photovoltaic installations
An additional photovoltaic installation on the same roof, façade or building envelope is eligible if:
the injection of electricity into the grid takes place at least two years after the first injection of the previous installation.
For apartment buildings with fewer than three residential units, this rule applies individually to each unit, unless:
the applicant already owns an existing photovoltaic installation, or
the applicant belongs to a household that owns such an installation.
Subsidy calculation method
The subsidy amount is calculated using a formula based on the installed peak power (kWp) of the photovoltaic system.
The calculation follows the official formula defined in the regulation and results in a progressively adjusted subsidy amount, capped at €10,000.
📅 Validity:
applies to signed offers dated until 31 December 2029.
Key conditions for receiving the subsidy
To benefit from Klimabonus 523, the following conditions must be fulfilled:
The applicant must renounce the guaranteed feed-in tariff for the entire lifetime of the installation.
This decision is firm and irrevocable.A buy-back contract must be concluded with an electricity supplier for surplus electricity.
The installation must be operated in self-consumption mode.
Collective self-consumption or
participation in an energy community is also permitted.
Pre-financing option
For photovoltaic installations under Klimabonus 523, a pre-financing option is available.
Key points:
The pre-financing application must be submitted by the installer via a secure government platform.
Installers must first be listed in the register of eligible installers for the pre-financing procedure.
The beneficiary must be a natural or legal person who owns the building.
The building must include at least one residential unit.
The beneficiary cannot be a company engaged in an activity requiring an establishment authorisation.
In the case of co-ownership, either:
the building manager, or
a designated co-owner
may act as the beneficiary.
Non-eligible projects
The following projects are not eligible for Klimabonus 523:
projects where a deposit exceeding 30% of the final price (including VAT) has already been paid,
installations covered by a leasing contract.
Feed-in tariff without investment subsidy
The option of a guaranteed feed-in tariff remains available.
However, no financial support for installation costs is granted under this option.The level of the feed-in tariff depends on the grid connection date of the installation, in accordance with the applicable regulations.
Taxation of photovoltaic income
For the 2022 tax year, income from installations above 10 kWp is taxable.
From the 2023 tax year onwards, income from installations above 30 kWp is taxable.
How to apply for Klimabonus 523
Without pre-financing
The subsidy application can be submitted after the installation has been completed.
With pre-financing
The subsidy must be applied for by the installer before work begins.
Social Top-Up Klimabonus
Eligible households may apply for a social top-up subsidy after receiving the decision granting the Klimabonus subsidy.
Applications must be submitted to:
Guichet unique des aides au logement
11, rue de Hollerich
L-1741 Luxembourg
Grand Duchy of Luxembourg
📧 guichet@ml.etat.lu
📞 (+352) 8002 10 10
Required application forms
Klimabonus – basic subsidy
“Demande d’une aide dans le cadre du paquet banque climatique et logement durable – DEPA-2026 – Personne physique”
(or the form for Personnes morales)“Installation photovoltaïque – Fiche PHOT-2026”
Social Top-Up Klimabonus
“Demande en obtention d’une aide à l’assainissement énergétique (F3)”
“Déclaration relative à la composition de la communauté domestique (L/A21)”
“Déclaration sur l’honneur – Acquisition (A92)”
Validity of the Klimabonus 523 scheme
The Klimabonus 523 basic subsidy applies to:
installations ordered no later than 31 December 2029, and
applications submitted no later than 31 December 2031.