How is the ROI of a solar system calculated?
A project ROI estimate compares annual savings and feed-in income with project costs after the subsidies actually confirmed and any tax effects. The EIV and other programmes are not flat amounts: check the current EIV with the Pronovo calculator and verify local programmes separately. Payback is therefore a scenario, not a guarantee.
Swiss Plateau guide value
9 to 13 years
Ticino and Valais guide value
7 to 11 years
Key factors: what determines ROI most
The three most important factors are: (1) production at the site, (2) self-consumption rate and (3) local electricity price. A household in Lugano with a heat pump has a completely different ROI than one in St. Gallen without storage.
- Production at the site
- Self-consumption without storage: 25 to 35%
- Self-consumption with storage: 60 to 80%
- Median electricity price: 27.7 ct/kWh
- EIV according to the current Pronovo calculation and other support according to applicable programmes
ROI comparison by canton in 2026
Payback depends on the site, production, self-consumption, electricity price and confirmed project costs. The Swiss Plateau value (9 to 13 years) and the Ticino and Valais value (7 to 11 years) are guide values only and are not a promise.
- Swiss Plateau: guide value 9 to 13 years
- Ticino and Valais: guide value 7 to 11 years
Site, self-consumption, costs and confirmed support determine the actual payback period.
What happens after payback?
Solar modules have a lifetime of 25 to 30 years.
Frequently Asked Questions
How long does a solar system take to pay off in Switzerland?+
As guide values, payback is 9 to 13 years on the Swiss Plateau and 7 to 11 years in Ticino and Valais. The actual period depends on system size, site, usage, confirmed support and costs; these values are not a guarantee.
How much does electricity price affect ROI?+
Significantly. The Swiss median electricity price is 27.7 ct/kWh. Cantonal tariffs differ; the source is ElCom 2026.
Does ROI improve with a battery?+
Often yes, if you have high evening and night consumption.
Does a solar system increase property value?+
Yes. The effect is particularly measurable in energy-conscious cantons like Zurich or Geneva.
Elia Alacam
Founder of PvPro.ch
Elia Alacam founded PvPro.ch in Lugano. Since then, he has connected more than 1,000 quote requests with Swiss solar companies and writes here about costs, incentives and quotes.
About Elia Alacam →Indicative values, updated September 2026. Sources: Pronovo, ElCom, Swissolar.
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