Save on taxes with a photovoltaic system? Cantonal differences must be taken into account.
Solar electricity is not only becoming increasingly popular as a sustainable energy source, but also offers tax benefits in Switzerland. However, these can vary from canton to canton. This article focuses on the tax aspects that private individuals should consider when operating a photovoltaic system (PV system) (Status: 2026, with outlook for 2027/2028).
Value appreciation and income deduction
The installation of a PV system on a building is classified for tax purposes as either a value-preserving or value-increasing measure depending on the situation. As a general rule: On existing buildings, private individuals can deduct the investment in a solar system as property maintenance in all cantons – similar to other energy-saving renovation measures.
Important for practice:
- “Existing” is defined at cantonal level: Depending on the canton, deadlines apply from completion/move-in (often 1–5 years). Check the guidelines of your canton for this.
- Distribution over several tax years: If the deductible investment costs exceed taxable income, the deduction can generally be spread over a maximum of three tax years.
- New builds: In some cantons, the practice has been eased (e.g. Bern: deductions may also be possible for new builds under certain circumstances). Clarify this at cantonal level.
Subsidies (one-off payment) and tax deduction
Receiving subsidies (e.g., the one-off payment) frequently reduces the deductible investment base in practice, as only the costs effectively borne by yourself are deductible. Depending on the canton and the timing of the payout, the subsidy may also be recorded as income in the year of payment. Since practice varies by canton, it is worth checking the cantonal information sheets or seeking a brief clarification.
Taxation of solar yield and principles
The revenue from feeding solar electricity back into the grid is generally taxed as income. However, what matters is which principle your canton uses to determine the taxable amount.
Gross principle vs. net principle
Under the gross principle, feed-in remuneration is treated as income without offsetting electricity consumption. Under the net principle, in simplified terms, often only the difference is taxed, to the extent that the remuneration exceeds grid consumption. In practice, many cantons have switched to the net principle or softened the gross principle in recent years (e.g., Zurich). Note also that individual cantons may have special forms (e.g., net-kWh rates).
Note: Because cantonal practice is constantly evolving, it makes sense to check current sources or the Swissolar leaflet for an up-to-date overview.
Thresholds and special models
Individual cantons have simplifications such as de minimis thresholds or treat part of the yield as near self-consumption (e.g., models where a certain amount is not taxed). Examples frequently cited in practice are cantonal regulations in Vaud and Valais (self-consumption up to a specific kWh amount) as well as special models that may require precise delineation.
Deduction from income tax
In addition to investment costs, private individuals can in principle also claim ongoing costs related to solar yield (e.g. maintenance/repairs, certain metering/billing costs). Depreciation in private assets is generally not deductible.
Please also note: if you choose the flat-rate deduction for property costs instead of the actual costs, you cannot additionally claim all actual maintenance items in the same tax period. Which option is more favourable depends on your overall situation in the tax year concerned.
Solar battery system and taxes
A battery storage system is treated differently for tax purposes depending on the canton. As a rule of thumb: If the storage is installed together with the PV system as part of an energy efficiency measure, it is more likely to be accepted in practice than when added as a standalone retrofit. Subsidies and cantonal practice also influence deductibility here.
New aspects from 2026 – and outlook for 2027/2028
Änderungen bei Vergütung und Abrechnung ab 1. Januar 2026
From 2026, new rules on the obligation to purchase and remunerate renewable energies will apply. Without an individual agreement, the remuneration will orient itself more strongly towards the quarterly reference market price; minimum remunerations have been discussed or introduced for smaller systems. This is tax-relevant because it can change the amount and volatility of the potentially taxable solar yield. Separate remunerations (e.g. for origin guarantees) can also become relevant as income.
Residential property taxation (imputed rental value) – possible implications from 2027/2028
With the adopted reform of home ownership taxation, the environment for deductions may change. According to the published guidelines, energy-saving and environmental protection deductions under the direct federal tax (DBG) are no longer planned, while cantons may continue to have some flexibility under the Tax Harmonisation Act (StHG). The specific entry into force will be determined by the Federal Council. For planning larger investments, it is therefore worth keeping an eye on the timing of implementation and the cantonal regulations.
Conclusion
Installing a photovoltaic system in Switzerland can offer tax advantages. These vary by canton and include, in particular, the deduction of investment and maintenance costs as well as the cantonal taxation of solar yield (gross/net principle, special models). From 2026 onwards, the framework conditions for remuneration and billing will also change, which may affect the taxable solar yield. For 2027/2028 – depending on the entry into force of the imputed rental value reform – further changes to deduction options are conceivable.
Please note that the information in this article represents general guidelines and cannot replace individual advice from a tax expert.
Tip: If you are planning a PV system, a quote comparison is worthwhile. On solar-guide.ch, you can compare providers and request suitable quotes for free.
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