The 7 criteria for choosing the right solar installer in Switzerland. Approvals, certifications, customer reviews, warranties — everything you need to check.
Choosing the right installer is as important as choosing the right panels. Poor wiring, orientation, or inverter configuration can cost 10-20% of production over 25 years.
Criterion 1: Electrical authorization. Non-negotiable. Electrical connections must be made by a company or subcontractor with the necessary authorizations. Ask who signs off on the OIBT work, who controls the installation and where those responsibilities are written in the quote.
Criterion 2: Clear Pronovo file. Pronovo does not certify installers like a commercial label. Instead, check who files the file, with what power of attorney, what documents are included and what follow-up is planned until payment.
Criterion 3: Swissolar certification. Not obligatory but a guarantee of specific skills in photovoltaics. Look for the Swissolar logo on the installer's website. Swissolar training covers technical, regulatory and safety aspects specific to PV.
Criterion 4: Verifiable local references. Ask for 3 customer references in your canton or region, established at least 2 years ago. Call these customers and ask: Is production as expected? Is the after-sales service responsive?
Criterion 5: PVsyst simulation provided. A serious installer gives you a PVsyst simulation (or equivalent) of your installation with the expected PR, annual production per month, and detailed losses. Without detailed simulation, production promises are only rough estimates.
Criterion 6: Clear guarantees. Check: ten-year guarantee on installation (legal in Switzerland), after-sales service guarantee on the inverter and battery, response time in the event of a breakdown. An installer who disappears after installation will leave you alone with the problems.
Criterion 7: Reasonable price. A quote 20% lower than the market should arouse suspicion: lower quality panels? Unlicensed labor? Undersizing of the installation? Compare 3 quotes and question significant discrepancies.