Solar panels in Luxembourg: What you need to know

Solar panels in Luxembourg: find out if you need to declare your photovoltaic income. Installation ≤30 kWp? You're likely exempt! Complete 2025 tax guide for homeowners.

Have you installed solar panels on your roof, or are you thinking about doing so? Good news: the Luxembourg tax administration published a circular in 2023 that clarifies the tax rules for individuals.

Here's what you need to know.

Who is this for?

You're concerned if:

• You are an individual
• You have a solar installation at home (on your roof or your property)
• You consume the electricity produced for your home
• You potentially sell part of this electricity back to the grid

What if I sell electricity?

Don't worry! If your installation is 30 kilowatts (kWp) or less, which is the case for most residential installations, then you are considered an "amateur."

Good news: in this case,

• you don't need to declare the income generated by your solar installation
• you don't have to make complex calculations for the tax authorities
• you don't need to fill out specific forms

This applies even if you sell part of the electricity produced back to the grid operator.

What can you deduct?

Deductible:

• Loan interest (if the installation was financed through a bank loan), as Special Expenses in your tax return

Not deductible:

• The purchase cost of the panels
• Installation costs
• Maintenance or repair costs
• Depreciation (or amortization) of the installation

What if my installation exceeds 30 kWp?

If your installation exceeds this threshold, you will likely need to declare the income generated and file certain tax forms (forms 121 and 113). You'll need to report this income under the "Commercial Profit" category on your taxx.lu account.

What can you deduct in this case?

Deductible:

• All costs related to the installation: purchase, installation, maintenance, repairs
• Depreciation (equipment depreciation over several years)
• Loan interest related to financing

But be aware:

• Your income from electricity sales becomes taxable
• You must declare it
• Specific forms will need to be completed

Simplified Summary

Situation	Income to Declare?	Tax Deductions
Private use, ≤ 30 kWp	No	Loan interest only
Electricity sales, > 30 kWp or for profit	Yes	All costs (purchase, installation, maintenance, depreciation, interest)

Key takeaways

• Most private solar installations are considered amateur activities
• If your installation is 30 kWp or less, you are exempt from tax declarations for electricity produced or sold back to the grid. No tax is due in this case
• Otherwise, you must report income from electricity sales under the Commercial Profit category. This income will then be taxable and added to your other income on your tax return