2026 Budget Act
Tax Incentives for Solar Thermal Energy
Installing a solar thermal system in 2026 costs much less thanks to government incentives.
There are three programs available for solar thermal collectors: the Ecobonus, the Renovation Bonus, and the Conto Termico 3.0.
The first two are tax deductions; the third is a non-repayable grant. On this page, you’ll find detailed information about the deductions, including rates, caps, and eligibility requirements updated for 2026.
The Conto Termico 3.0 program, which deserves
its own discussion, is covered in detail on its dedicated page.
Pleion solar thermal systems meet the technical requirements set forth in the regulations governing incentives, making it straightforward to qualify for the Ecobonus and the Renovation Bonus:
- Solar Keymark-certified collectors;
- guarantees that comply with the minimum legal requirements;
- production capacity in line with the minimum required values;
- technical support for the documentation required for the incentive.
A Summary of the Three Tax Incentives for Solar Thermal Energy
In 2026, anyone installing solar thermal collectors can choose from three incentives, which cannot be combined for the same expense:
- Ecobonus: IRPEF/IRES tax deduction for energy-efficiency upgrades. The deduction rate is 50% for the primary residence and 36% for other properties. The maximum deduction is 60,000 euros.
- Renovation Bonus (Home Bonus): a tax deduction for construction projects that include the replacement of systems. The same rates as the Ecobonus apply, but with a higher spending cap of up to 96,000 euros.
- Conto Termico 3.0: a non-repayable grant provided by the GSE, covering up to 65% of expenses, credited directly to your bank account.
The choice among the three depends on your tax situation, the type of project, and the property. Our technicians will help you identify the most cost-effective option.
2026 Ecobonus for Solar Thermal Systems
The Ecobonus is the IRPEF/IRES tax deduction for energy-efficiency retrofits of existing buildings, as provided for in Article 14 of Decree-Law 63/2013.
The installation of solar thermal collectors for domestic hot water production, whether for residential or industrial use, qualifies for subsidies. It is the most suitable option for those seeking to improve energy efficiency directly, without undertaking a complex building renovation.
Tax Rates and Threshold for 2026
The 2026 Budget Law confirmed the tax rates already in effect in 2025, which vary based on the property’s
intended use:
■ 50% for the primary residence (owner or holder of a real right of use);
■ 36% for other properties (second homes, tenants, borrowers).
The maximum deduction is 60,000 euros per property. The deduction is divided into 10 equal annual installments. Starting in 2027, barring any extensions, the rates will drop to 36% and 30%, respectively: those planning such a project would be wise not to delay.
Who Can Access It
All taxpayers who incur the expenses and hold a real right to the property are eligible: owners, usufructuaries, tenants, and borrowers.
Unlike the Renovation Bonus, the Ecobonus is available regardless of the property’s cadastral category and may also be claimed by a corporation with business income.
How It Works
The amount is claimed on your tax return over a period of 10 years. Payment must be made via a specific bank or postal transfer (designated for building tax deductions), and you must notify ENEA within 90 days of the completion of the work. Failure to notify ENEA will result in the loss of the right to the tax deduction.
2026 Renovation Bonus for Solar Thermal Systems
The Renovation Bonus, also known as the Home Bonus, is a tax deduction for building renovation work governed by Article 16-bis of Presidential Decree 917/86. The installation of a solar thermal system is eligible for this bonus when it is part of a renovation project on a residential or predominantly residential property, for example, in conjunction with the replacement of utility systems.
Tax Rates and Threshold for 2026
Starting in 2025, the rates for the Renovation Bonus will be the same as those for the Ecobonus: 50% for the primary residence; 36% for other properties. The main difference is the higher spending cap: up to 96,000 euros per property, compared to the 60,000-euro deduction under the Ecobonus. This deduction is also claimed in 10 equal annual installments.
When Is It More Advantageous Than the Ecobonus?
The Renovation Bonus is the natural choice when solar thermal systems are part of a larger renovation project, because the higher spending limit makes it easier to finance a larger overall investment. The Ecobonus, on the other hand, remains the more straightforward and flexible option when the sole project involves energy efficiency improvements, and it is the only option for those working on non-residential properties or for companies. The two bonuses cannot be combined for the same expense; you must choose the one best suited to the specific project.
Conto Termico 3.0: Non-Reimbursable Grant
In addition to these two tax credits, the Conto Termico 3.0 is available for solar thermal systems—a non-repayable grant disbursed directly by the GSE that can cover up to 65% of the expenses incurred. Unlike the Ecobonus and the Renovation Bonus, this is not a tax deduction spread over 10 years, but a lump sum credited to your bank account quickly. It is particularly advantageous for those with a low IRPEF tax bracket. It cannot be combined with other tax deductions for the same expense. Learn more about the Conto Termico 3.0 on the dedicated page.
Technical Requirements for Solar Collectors
To qualify for the incentives, the system must meet specific technical requirements. The main ones are: Solar Keymark certification for solar thermal collectors; a minimum warranty of 5 years on collectors and water heaters, and 2 years on accessories and electrical/electronic components; a minimum specific energy yield of more than 300 kWht/m² per year for flat-plate collectors, and 400 kWht/m² per year for vacuum and evacuated-tube collectors, based on conditions in Würzburg; professional installation in accordance with manuals and applicable standards, with a declaration of conformity pursuant to Ministerial Decree 37/08; an existing building that is properly registered with the land registry. For systems with a collector area of less than 20 m², the technical certification may be replaced by a manufacturer’s declaration attesting to compliance with the technical requirements.
Frequently Asked Questions
Three: the Ecobonus (50%/36% tax credit, maximum of 60,000 euros), the Renovation Bonus (50%/36% tax deduction, maximum expenditure of up to 96,000 euros), and the Conto Termico 3.0 (non-repayable grant of up to 65%). These cannot be combined for the same expense.
The tax rates are the same (50% for primary residences, 36% for other properties), but the maximum deduction and scope differ. The Ecobonus has a deduction cap of 60,000 euros and applies to energy efficiency improvements on properties in any cadastral category, including those owned by companies. The Renovation Bonus has a spending cap of up to 96,000 euros and applies to solar thermal systems installed as part of a renovation project on a residential property.
No, not for the same expense. When installing solar collectors, you can choose only one incentive. However, in a larger construction project
, it is possible to use different incentives for separate work and expenses; for example,
the Ecobonus for exterior insulation and the Conto Termico for solar thermal systems.
Description form submitted to ENEA with the CPID code (for the Ecobonus), technical certification or manufacturer’s declaration for systems under 20 m², technical data sheets for the collectors, declaration of conformity pursuant to Ministerial Decree 37/08, and invoices and detailed bank transfer receipts.