With a purchase, the system belongs to you – including incentives, the tax deduction and the entire yield after payback. With renting and contracting, a third party builds and operates on your roof; you pay nothing towards the investment, but pay on an ongoing basis instead – and usually more over the contract term. For the single-family home, buying is generally the stronger calculation; contracting plays its role above all with large roofs and limited capital. (As of: July 2026)
Key points in brief
- Three models, one difference: who owns the system – you (purchase) or a third party (renting/contracting)?
- «Investing zero francs» is real, but not a gift: the provider finances itself through your ongoing payments – its margin is your extra cost over the term.
- Incentive contributions and the tax deduction follow ownership – with a third-party model, the provider primarily benefits from these, not you.
- Contracting offers target larger properties – apartment buildings, commercial premises, large roofs; the typical single-family home usually falls below providers' suitability threshold.
- Long-term commitment is the underestimated point: a 15- to 25-year contract accompanies the house – right through to a possible sale.
The three models at a glance
Buying is the normal case: you invest, the system belongs to you, the one-off feed-in incentive and any municipal contributions flow to you, as does the tax deduction – and every kilowatt-hour produced works for your account. After payback, the system produces «for you» for the rest of its lifetime.
Renting reverses the relationship: a provider installs the system and remains the owner; you pay a fixed monthly instalment and use the electricity. Service and repairs typically lie with the landlord – that's the comfort core of the model.
Contracting is renting's professional sister, common for larger properties: the contractor builds, operates and maintains the system on your roof and sells you the electricity produced at a contractually defined price – usually below your grid tariff. In the City of Zurich, for instance, ewz offers this kind of PV contracting: ewz fully finances, implements and maintains the system, the contracts run for 25 years, and at the end of the term the system passes into the ownership of the property owners (as of: July 2026). The provider assesses the roof's suitability on a case-by-case basis – the model is clearly aimed at apartment buildings, commercial premises and large roofs, not the typical single-family home.
Economically, renting and contracting are the same principle with different labels: a third party bears the investment and recovers it – with financing costs, a risk premium and margin – through your ongoing payments.
The honest calculation: why «zero francs» has its price
The appeal of third-party models is real: no upfront investment, no installation effort, service included, a calculable electricity price from day one. For households without available capital, that can be exactly the difference between «solar power now» and «none at all» – and solar power from a contractor is always better than none.
But the counter-calculation belongs on the same table, and it's uncomfortably simple: the provider isn't a sponsor. It finances the system, operation and its business model from your payments – calculated over the full term, you therefore usually pay more than the purchase would have cost. On top of that come three structural disadvantages that rarely find room in the sales conversation:
1. Incentives and taxes follow ownership. The one-off feed-in incentive, municipal contributions and the tax deduction go to the owner – with a third-party model, that means the provider, priced into its calculation, not into yours. 2. The commitment. Contracts of 15 to 25 years accompany the house through life situations nobody knows today – at a house sale the contract becomes an agenda item: the buyer takes it over or you pay it off, and both need negotiating. 3. The roof is spoken for. Expansion, storage, changes – what happens on the roof is no longer yours alone to decide from then on.
Anyone who can manage the investment – including via the mortgage, which many banks support – therefore almost always does better with buying: the system pays off through self-consumption, and the entire benefit stays in the house.
Which model suits whom?
| Situation | Obvious model |
|---|---|
| Single-family home, capital or mortgage headroom available | Purchase – full incentives, full yield, no commitment |
| Single-family home, no capital, credit undesired | Check renting – but compare the full cost over the term with the purchase price |
| Apartment building / commercial, large roof, no investment budget | Contracting – this is where the model plays to its strengths |
| Institutional owners, many properties | Contracting or purchase with an operating contract – a portfolio question |
| Unclear horizon (sale/inheritance foreseeable) | Caution with long-term contracts – buy or wait |
Guidance, as of: July 2026 – the specific contract terms and your financial situation are authoritative; this guide doesn't replace financial advice.
If renting or contracting: what to watch for in the contract
If the choice falls on the third-party model, the contract decides the next two decades – the same care as with the works contract, just with different areas of focus:
- Price and adjustment clauses: how does the instalment or electricity price develop over the term – fixed, indexed, capped?
- Term and exit: what does early termination cost – for instance when selling the house? Are there purchase options during or at the end of the term, and at what residual value?
- Scope of services: who bears repairs, inverter replacement, insurance? What happens with reduced yield?
- End of term: takeover, extension or removal – and who pays for the latter?
- Roof and house: who's liable for roof damage, what applies if a roof renovation becomes necessary in the middle of the term?
A reputable provider answers all of this in writing and without dodging – the same bar as everywhere else.
The middle path that's often forgotten
Between «pay for everything yourself» and «leave everything to a third party» lies an unspectacular middle path: buying with external financing. Many banks help finance solar systems via a mortgage increase – the system then belongs to you, incentives and the tax deduction flow to you, and the interest costs over the term are usually significantly smaller than a renting or contracting provider's margin. Anyone considering the third-party model only because of the upfront investment should have calculated this variant first – the conversation with the bank costs nothing.
The renting question usually lands on our table with a brochure: zero francs, all-inclusive, sounds good – is something wrong there? Our answer is a calculation suggestion rather than a verdict: add up all the payments over the contract term and put it next to the purchase price after incentives; the question then usually answers itself. What's interesting is who actually ends up with the third-party model – almost never the single-family home, almost always the ownership of a larger property that can't or won't invest and for whom a professional contractor with operating responsibility simply fits. Both are legitimate; our point is a different one: the decision should be based on the full-cost calculation, not on the zero at the start of the brochure. The zero is true – it just doesn't stand for the price, but for the timing of the payment.
Frequently asked questions
Is a rented solar system more expensive over the term than buying?
As a rule, yes – the provider finances the system, operation and margin from your instalments, and incentives as well as the tax deduction stay with it. The exception would be an unusually cheap contract; that's exactly why the full-cost calculation over the term belongs before every signature.
Can I buy the rented system later?
Many contracts provide for purchase options – during the term or at the end, at defined residual values. Check these clauses before signing the contract: a fair purchase option makes the rental model more flexible; without it, you're tied to the term for better or worse.
What happens to the contract if I sell the house?
It doesn't disappear: the buyer takes it over, or you pay it off – both have to be clarified before notarisation and can complicate the sale. That's one of the silent costs of the long-term commitment; with ownership, the question doesn't arise.
Do I get the one-off feed-in incentive with renting or contracting?
No – incentive contributions follow ownership of the system and go to the provider, who factors them into its calculation. The same applies to the tax deduction for the investment. That's not fraud, but it's a calculation item that has to be visible in the comparison.
From what size is contracting worthwhile?
There's no fixed threshold – providers assess suitability on a case-by-case basis, and the model is clearly aimed at apartment buildings, commercial premises and large roofs. The offers generally aren't intended for the typical single-family home; there, buying or renting remain the options, and buying is usually the strongest calculation.
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Let's work through it – before you sign.
We put buying, financing and the third-party model side by side for your situation: full costs, incentives, commitment. Honestly – even if the answer is that you don't buy anything from us.
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Swissolar-certified specialist company · ESTI installation authorisation (Art. 14 NIV) · in Zurich since 2017 · over 150 systems completed · a personal answer from the specialist company, no call centre
Sources: ewz (PV contracting offer: financing/construction/maintenance by ewz, 25-year contract term, transfer of ownership at the end of the term — ewz.ch, as of: July 2026); experience from ecoEn GmbH's consulting practice, Zurich region.
Last updated: 9 July 2026 · Author: ecoEn editorial team
