Solar calculator Canton of Solothurn: What can your roof do?

Yes. The visit and the quote cost you nothing and commit you to nothing. You only decide once you hold the binding quote in your hands.

For a single-family house of 4 persons the calculator proposes about 6.8 kWp. That costs CHF 17,700–23,200 including installation and VAT. After the one-off payment and the tax deduction, CHF 11,400–15,500 remain. For your roof, the solar calculator above works it out with your address.

With the median electricity price in the Canton of Solothurn (32.9 ct./kWh incl. VAT) this system saves CHF 800–830 in the first year and has paid for itself after 14–20 years. With a heat pump and an electric car it is CHF 2,330–2,380 and 9–13 years, because you use more of the solar power yourself.

Where grid power is most expensive: Kestenholz (47.1 ct.), Biezwil (40.1 ct.), Fulenbach (37.5 ct.). It is cheapest in Egerkingen (25.4 ct.). The more expensive grid power is, the more every kilowatt hour you use yourself saves.

The cantonal subsidy programme does not list photovoltaics as a measure of its own. It supports the building envelope, heat pumps and solar thermal systems, among other things. For photovoltaics, the federal one-off payment applies.

On existing buildings more than five years old, the costs are deductible. On new builds they add to the acquisition costs. Self-consumption does not raise the imputed rental value (Eigenmietwert).

It gives guide values, not a quote. It uses the federal roof data (sonnendach.ch), the electricity price of your municipality (ElCom 2026) and the one-off payment from Pronovo. What it cannot see: roof condition, shade from trees, electrical system, access. That is why we check these during a free site visit and send you a binding quote within 72 hours.

From the Swiss Federal Office of Energy (sonnendach.ch). It records area, pitch, orientation and solar irradiation of every roof face of every building in Switzerland. The aerial image is from swisstopo. We count about 70 % of the area as panel area; the rest is needed for edges, gaps and roof windows.

The federal one-off payment (Pronovo): CHF 360 per kWp for systems below 30 kWp, proportionally less above. Plus the tax deduction for existing private buildings, calculated with a marginal tax rate of 25 %. Cantonal and municipal grants are not included; we check them during the site visit.

A battery raises self-consumption but costs more. Whether it pays depends on the feed-in tariff and your consumption. That is why the calculator shows both options side by side.

We send you the results by e-mail, and a project manager looks at the figures. We do not pass on your details. We are not a referral portal; we plan and build the systems ourselves.

All of German-speaking Switzerland. We build most often in the cantons of Zurich, St. Gallen, Schwyz and Aargau. Our locations are in Zumikon ZH and Lachen SZ.