Personal income tax deduction for solar panels [Guide]

When it comes to recovering the cost of a photovoltaic installation, the most relevant tax incentive is the national deduction under Spain’s Personal Income Tax (IRPF). If you are wondering what personal income tax deduction is available for installing solar panels, current regulations provide for tax deductions ranging from 20% to 60% of the total cost of the work carried out, depending on the level of certified energy savings achieved in the property.

To answer how much tax relief you can claim for installing solar panels, the final recoverable amount depends on the applicable percentage and the maximum annual deduction bases established by law, which range from €5,000 to €7,500 per year. This tax benefit aims to accelerate the energy transition in primary residences and residential buildings, applying the 2026 personal income tax deduction for solar panels to work completed and certified within the legally established deadlines.

Who can claim a tax deduction for solar panels and what requirements does the Spanish Tax Agency impose?

To determine who can claim a tax deduction for solar panels, the law specifies that owners of primary residences or rented properties, or properties intended for rental provided they are let within the regulatory deadline, can benefit from this tax relief. Properties linked to economic activities are excluded from this deduction, as are independent parking spaces or storage rooms that do not form part of the residential property.

To apply the personal income tax deduction for solar panels with full protection against a possible inspection by the Spanish Tax Agency, the following technical and administrative requirements must be met:

• Energy Performance Certificates (EPCs): It is essential to have an energy performance certificate issued before the work begins and another certificate issued after the installation has been completed. The subsequent certificate must be issued within the authorised tax period.
• Bank payment method: Cash payments are not permitted. All invoices from the installation company, fees and equipment must be paid by card, bank transfer, named cheque or bank deposit.
• Treatment of public grants: The base to which the deduction percentage is applied is the actual total cost of the installation minus the amount of public grants awarded or received, such as Next Generation funds or regional subsidies.
• Completion deadline: Installation work must be carried out strictly within the tax years authorised by the regulatory extension.

Personal income tax deduction rates for solar panels

The Spanish Tax Agency classifies the deductions into three rates according to the type of property and the percentage reduction achieved in energy consumption or demand.

20% deduction for a primary residence

This option applies to installations in primary residences or rented properties that achieve a reduction of at least 7% in the combined heating and cooling demand indicators of the property.

• Maximum annual deduction base: €5,000.
• Maximum tax saving: €1,000 (20% of €5,000).
• Installation profile: Photovoltaic projects for direct self consumption in homes where no additional improvements are made to the building’s thermal envelope.

40% deduction for reducing non renewable energy consumption

This applies when the photovoltaic installation achieves a reduction of at least 30% in the property’s non renewable primary energy consumption, or when the improvements allow the home’s energy rating to reach class A or B.

Maximum annual deduction base: €7,500.

Maximum tax saving: €3,000 (40% of €7,500).

Installation profile: Detached houses or flats where the installed photovoltaic capacity covers a substantial proportion of electricity consumption, replacing the use of fossil fuel energy sources.

60% deduction for improvements to entire residential buildings

This deduction is intended for energy renovation work carried out in predominantly residential buildings, such as blocks of flats managed by homeowners’ associations. It requires a minimum reduction of 30% in non renewable primary energy consumption or an improvement to energy rating class A or B for the building as a whole.

• Maximum annual deduction base per owner: €5,000 per year. Amounts that cannot be deducted because they exceed the annual limit can be carried forward to the following four tax years, with a total cumulative limit of €15,000.
• Maximum cumulative tax saving: Up to €9,000 per owner (60% of €15,000).
• Installation profile: Communal photovoltaic installations intended for collective self consumption in blocks of flats.

Example of a personal income tax deduction for solar panels

To understand the real financial impact on an income tax return, we will look at a practical example of a personal income tax deduction for solar panels in a detached house.

Imagine a homeowner who installs a photovoltaic system with a total budget of €8,500, including VAT and installation, paid entirely by bank transfer.

Energy assessment: The initial Energy Performance Certificate recorded high non renewable energy consumption. After the installation is commissioned, the subsequent certificate confirms a 38% reduction in non renewable primary energy consumption. This exceeds the required 30%, meaning the homeowner qualifies for the 40% deduction.

Deduction of grants: The homeowner has received confirmation of a regional grant worth €2,000. Therefore, this grant must be deducted from the amount paid:

Actual deductible base = €8,500 – €2,000 = €6,500

Calculation of the deduction: As the actual deductible base (€6,500) is lower than the maximum annual base for this category (€7,500), the deduction applies to 100% of the net investment made:

Direct personal income tax deduction = €6,500 x 40% = €2,600

When submitting the income tax return for the tax year corresponding to the date of the second certificate, this taxpayer will reduce their gross personal income tax liability by €2,600, directly recovering more than 30% of the money spent.

Summary of solar panel deduction rates and limits

The following table summarises the energy efficiency requirements and limits of the personal income tax deduction for solar panels, allowing you to compare the three options quickly:

Type of deduction	Energy efficiency requirement	Maximum annual deduction base	Maximum tax saving
20% deduction	Minimum 7% reduction in heating/cooling demand	€5,000	€1,000
40% deduction	Minimum 30% reduction in non renewable energy consumption or energy rating class A / B	€7,500	€3,000
60% deduction (Buildings)	Minimum 30% reduction in non renewable energy consumption or energy rating class A / B for the entire building	€5,000 / year (maximum €15,000)	Up to €9,000 accumulated

As the table shows, the applicable deduction rate is not optional and does not depend on the taxpayer’s personal judgement, but on the technical improvement in energy efficiency reflected in the Energy Performance Certificates (EPCs) issued before and after the work. While installations with a moderate impact on energy demand usually qualify for the 20% rate, projects that achieve a significant reduction in the use of non renewable energy qualify for the 40% rate, where the personal income tax deduction triples to €3,000 per year for the same tax year.

On the other hand, the table highlights a key difference in the maximum deductible amounts between individual homes and entire residential blocks. For improvements carried out by homeowners’ associations under the 60% rate, regulations allow amounts paid above the annual €5,000 limit to be carried forward to the following four tax years, up to a cumulative maximum of €15,000 per property. This mechanism is particularly important for recovering the cost of large collective self consumption projects, where the initial investment per resident is higher but the medium term tax benefit is maximised.

How can I claim the tax deduction for a photovoltaic installation step by step?

To correctly include the personal income tax deduction for solar panels in the Renta Web platform without making processing errors, the procedure can be summarised in four steps:

1. Gathering technical and administrative documentation: Invoices issued by the installation company and proof of bank payments.

• Initial Energy Performance Certificate, issued no more than two years before the start of the work.
• Energy Performance Certificate issued after the installation.
• Proof of the award or receipt of associated public grants.

2. Accessing the relevant section in Renta Web: Within the draft tax return, go to the General Tax Deductions section and select the subsection relating to the Deduction for Energy Efficiency Improvement Work in Homes.

Entering the Energy Performance Certificate details: The Spanish Tax Agency requires the date of the initial EPC and the subsequent EPC, the regional registration number of both documents and the numerical values for energy demand or non renewable energy consumption recorded in them.

Validation of the deductible base: Enter the amount paid during the tax year. When the grants received are indicated, the system automatically deducts that amount and applies the corresponding percentage (20%, 40% or 60%) to the resulting net base.

Key points to ensure you can claim the deduction for your installation

Taking advantage of the personal income tax deduction for solar panels will significantly shorten the payback period of any photovoltaic project. However, in the event of a limited tax review by the Spanish Tax Agency, the burden of proof falls entirely on the taxpayer. To avoid requests for additional documentation or supplementary tax assessments with surcharges, it is essential to ensure that every stage of the project can be traced from the very beginning.

The most common mistake that invalidates the deduction is not the type of panel or the installed capacity, but inconsistencies in the dates of the documents. The date of the initial Energy Performance Certificate (EPC) must be strictly before the signing of the quotation or the start of the work, payments must always be made through banking channels without exception, and the final EPC must be processed as soon as the installation is completed so that it is registered within the corresponding tax year.