Alternative 1: Photovoltaics — the most accessible option
Photovoltaic solar panels convert sunlight directly into electricity. Today, it is the most accessible, best subsidized and most profitable alternative for a Swiss household. An 8 kWp installation on a well-oriented roof produces around 7 000–8 500 kWh/year in French-speaking Switzerland — enough to cover 60–80% of the annual needs of a household of 4 people. Thanks to PRONOVO (OIE) subsidies and cantonal tax deductions, the net cost of an installation can be reduced by 30–40%. The guaranteed lifespan of the modules exceeds 25 years, with an efficiency even higher than 80% at 25 years according to the manufacturer's guarantees. For whom? Any owner with a roof facing south, east or west, without significant shade.
Alternative 2: Solar thermal – free hot water
Solar thermal collectors do not produce electricity: they directly heat a heat transfer fluid which then heats your domestic water or supports your heating system. In Switzerland, a solar thermal system with 4–6 m² of collectors can cover 50–70% of the annual domestic hot water needs of a household of 4 people. The investment (CHF 8 000–15 000) is lower than a PV installation, but the recovery is more limited: you cannot resell the excess heat produced, nor use it for anything else. For whom? Households with high hot water consumption — large families, presence of bathtub, frequent use. Ideal as a complement to a heat pump or boiler.
Alternative 3: Wind power and micro-hydraulics — reserved for suitable sites
These two solutions remain niche in Switzerland, very dependent on the geography of the site. Domestic wind power (small turbines of 1–5 kW) requires an average annual wind of at least 5 m/s to be profitable — a condition rarely met in Swiss residential areas. The Plateau and Jura offer better potential. Allow CHF 15 000–40 000 for an installed residential turbine, with a payback period of 15–20 years in the best cases. Micro-hydraulics is a gem for properties crossed by a watercourse: even a small stream with a regular flow of 10 liters/second and 3 meters of head can produce 250–300 kWh/month continuously, 24h/24. It is rare, but where possible, it is the most stable source of energy available. For whom? Rural, alpine or riverside properties, with a long holding period to amortize the investment.