Background
#A photovoltaic system is a decision for 25 to 30 years – and most expensive mistakes happen before the first module is on the roof: in the order of the decisions.
Anyone who fixes the system size first and only then looks at their own electricity use plans past the actual need. Anyone chasing the highest feed-in tariff often overlooks the far bigger lever of self-consumption. And anyone who signs the first offer never sees what a second or third quote would have revealed. The points below put the important topics in the order in which they depend on each other – from roof suitability to comparing providers.
For your roof
What does a system on your roof cost?
With your address we calculate price range, incentives and payback for your roof from federal data. We email the report straight away.
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What matters in Switzerland
#The most common planning mistake is to size the system by the available roof area instead of by electricity use. The sensible order is the other way round: first clarify your annual consumption and daily profile, then derive the size. As a rough guide, in Switzerland 1 kWp of capacity yields around 900 to 1,000 kWh per year; a four-person household using roughly 4,500 to 5,000 kWh therefore lands at about 5 to 6 kWp for household electricity alone. Even so, it usually pays to cover as much of the roof as possible – the extra cost per additional module is small, and consumption rises with a heat pump and an electric car anyway.
Every kilowatt-hour you use yourself is worth considerably more than one you feed into the grid. Electricity from the grid costs roughly 30 centimes per kWh, while the feed-in payment for exported electricity is often only about a third of that, depending on the grid operator (as of 2026, varying widely – pvtarif.ch shows your local tariff). The biggest economic lever is therefore not the feed-in tariff but a high level of self-consumption: loads such as the water heater, heat pump, dishwasher or charging the electric car can be shifted deliberately into sunny hours. A battery can raise self-consumption further – but whether it pays off is a separate question.
Before any talk of modules, the roof decides. A south-facing orientation at around 30 degrees of tilt gives the highest annual yield, but east-west layouts work very well and spread production more evenly across morning and evening. The single biggest loss of yield rarely comes from a slightly unfavourable orientation, but from shading by trees, chimneys, roof structures or neighbouring buildings. Roof condition and structural load matter just as much: if a roof renovation is due in the next few years, it belongs before the installation. A first, free estimate of the potential is provided by the federal Sonnendach.ch tool – but it does not replace an on-site roof survey.
With components, it is not the brochure that counts but lifetime and warranty. Modules typically last 25 to 30 years; the inverter, the heart of the system, usually has to be replaced after 10 to 15 years – this replacement belongs in any honest calculation. Look for separate product and performance warranties on the modules, a warranty covering installation and roof watertightness, and an inverter with headroom for a later expansion. Where there is partial shading, power optimisers or micro-inverters are worthwhile. In Switzerland, the hail resistance of the modules is also relevant – including with a view to building insurance.
Incentives are not a side issue but part of the economics – and in Switzerland they come in several layers. Nationally there is the one-time remuneration handled by Pronovo, which covers part of the investment cost. On top of that come cantonal and municipal programmes whose level depends on where you live; energiefranken.ch offers an overview by postcode. Thirdly, on an existing building a system is tax-deductible as property maintenance in most cantons. All of these amounts and rules change regularly (as of 2026); concrete figures belong in the property-specific quote, not in a blanket rule of thumb. Because incentives influence the sequence and the deadlines, you should check them early and for your canton.
EnergieSchweiz, the federal programme, explicitly recommends obtaining and comparing several quotes before deciding – a good rule of thumb is three. That is exactly what we advise too. The lowest price is not automatically the best offer: quotes are often hard to compare because they contain different assumptions, components and services. Gather several impressions – and make our free orientation one of them. A quote that discloses its assumptions and calculates over the full lifetime will hold up to comparison. Do not jump at the first offer – and scrutinise ours too, rather than simply taking it.
Grid connection by canton
#Where the canton, municipality or grid operator sets its own rules, responsibilities or amounts, you will find the details for your canton here.
- AargauPV grid connection Aargau
- Appenzell AusserrhodenPV grid connection AR
- Appenzell InnerrhodenPV export limitation AI
- Basel-LandschaftPV grid connection Basel-Landschaft
- Basel-StadtPV grid connection Basel-Stadt
- BernGrid Operator Registration PV Bern
- LuzernPV grid connection Lucerne
- NidwaldenPV grid connection Nidwalden
- SchaffhausenPV grid connection Schaffhausen
- SolothurnPV grid connection Solothurn
- St. GallenPV grid connection in St. Gallen
- ThurgauPV grid connection Thurgau
- ZugPV export limit Zug
- ZugPV grid connection Zug
The process in seven steps
#Tick off for your project
Check the potential
the free federal tool Sonnendach.ch gives you a first estimate of how much electricity your roof could generate. That is the starting point – a binding assessment of orientation, shading, roof condition and structural load requires an on-site survey.
Assess consumption honestly
clarify annual use, daily profile and planned loads such as a heat pump or electric car before deciding on the system size. This profile shows how high your self-consumption realistically is and whether a battery is worthwhile at all.
Calculate the economics
over the full lifetime, not just the first year. Investment, incentives, self-consumption, the feed-in payment and the later inverter replacement all belong in the same calculation. The EnergieSchweiz solar calculator helps establish a first order of magnitude with transparent assumptions.
Compare quotes
gather several offers on the same basis – the same system size, comparable components, the same assumptions about self-consumption and yield. Make sure scaffolding, electrical work, grid registration and commissioning are fully included – this is exactly where the differences between seemingly cheap and serious offers hide.
Clarify permits and insurance
sufficiently integrated roof systems outside protected zones usually only require notification rather than a building permit – but the municipality regulates this, and special rules apply for heritage protection or in townscape-protection zones. Also register the system with the cantonal building insurer before construction begins.
Secure incentives
the one-time remuneration is applied for at Pronovo after commissioning; many specialist firms handle this by power of attorney. Also check cantonal and municipal programmes so that no deadline passes and no contribution is lost.
Commissioning and operation
after connection and acceptance, monitoring and a regular look at production, self-consumption and feed-in matter. Plan for periodic checks and the later inverter replacement – this keeps the system reliable and economical over its full lifetime.
Checked for your roof, not just read up on
What does a system on your roof cost?
With your address we calculate price range, incentives and payback for your roof from federal data. We email the report straight away.
Free and non-binding · no unsolicited calls
Rather talk directly? +41 78 615 90 58
Frequently asked questions
#Sources
#The responsible authorities are decisive. Always verify binding details – amounts, deadlines and conditions – for your specific property against the current status of the respective authority.