A well-oriented roof in Geneva or Lausanne produces more electricity each year than a family consumes. Since 1 January 2026, however, the rules have changed: power fed into the grid is paid at the market price, with a floor, and the electricity you use yourself is now worth far more than what you sell. A photovoltaic system is therefore sized differently than it was five years ago. This guide covers the formalities, subsidies, prices and technical choices that decide whether it pays off.

Do you need a permit to install solar panels?

As a rule, no. Federal planning law exempts solar installations that are sufficiently adapted to the roof in building zones from a building permit. They must stay in the plane of the roof, project no more than 20 cm perpendicular to it, not extend beyond the roof when seen from the front, and form a compact surface. A simple notification is then enough.

  • In Geneva, the notification goes to the building permits office at least 14 days before work starts.
  • In the canton of Vaud and in Lausanne, it goes to the municipality, which can require a permit if it considers the project non-compliant. Allow about a month.
  • On a protected building, a cultural asset or in a site of cantonal or national importance, a building permit remains mandatory, with the opinion of the monuments and sites service.

Flat roofs with tilted panels, facade installations and solar pergolas or carports often need a fuller procedure. It is better to know this before ordering the equipment.

Subsidies: one-off remuneration, cantonal bonus and tax deductions

The main support is the federal small one-off remuneration, paid by Pronovo for systems under 100 kWp. It covers part of the investment, roughly one fifth for a typical residential system, and it is higher for roof-integrated panels than for panels mounted on top. A bonus is added for steeply inclined systems, on facades for example, which produce more in winter. The application is filed after commissioning, and the exact amount is calculated with Pronovo's simulator.

In Geneva, SIG has topped up the federal support since January 2026 with a bonus equal to 25 % of the one-off remuneration for systems under 30 kWp, and 15 % between 30 and 100 kWp. A bonus of CHF 130 per kWh of capacity is also paid for a storage battery, up to 15 kWh. In the canton of Vaud, some municipalities and Lausanne's Services industriels offer their own support, with conditions that change from year to year.

Finally, in an existing building, the photovoltaic investment is generally deductible from taxable income, minus the subsidies received, both in Geneva and in Vaud. On a CHF 25,000 system, the tax saving often exceeds the one-off remuneration. Have your accountant confirm the tax treatment before choosing the year of the works.

How much does a photovoltaic system cost?

For a detached house, expect between CHF 2,000 and 3,000 per installed kWp, turnkey and before subsidies. A 10 kWp system, about thirty modules on roughly 50 m² of roof, therefore costs CHF 20,000 to 30,000. The price per kWp falls with size, and small, complicated roofs cost more than large simple ones.

What moves the quote:

  • Roof access and scaffolding, often underestimated on two-storey houses.
  • The type of covering: tiles, slate, metal sheet or flat roof all use different fixings.
  • Roof integration, more expensive up front but better subsidised and sometimes required for aesthetic reasons.
  • The electrical panel, which sometimes has to be replaced to accommodate the inverter and protection devices.
  • A battery, a charging station and heat pump control, if added.

Around Lake Geneva, a well-oriented kWp produces about 1,000 to 1,100 kWh per year. The 10 kWp in our example thus deliver around 10,000 kWh, twice the consumption of a house without a heat pump.

Self-consumption: what makes the system pay

Since 2026, electricity fed into the grid is paid at the market reference price, calculated each quarter by the Swiss Federal Office of Energy, unless another price is agreed with the grid operator. For systems under 30 kW, a minimum remuneration of 6 centimes per kWh applies. In Geneva, SIG has announced a buy-back price of about 11 centimes for 2026. Each kWh you consume yourself saves you buying one at the grid tariff, network charges and levies included, which is two to three times as much.

Without any measures, a house directly consumes 25 to 35 % of its production. To go higher:

  1. Run the heat pump and the water heater during the day, when the sun is producing, with suitable control.
  2. Charge the electric car on a charging station that follows solar production.
  3. Schedule the washing machine, dishwasher and dryer for sunny hours.
  4. Add a battery only afterwards, once the free measures are in place.

With a controlled heat pump and an electric car, self-consumption often exceeds 50 %. The payback of a residential system is then generally between 10 and 15 years, for modules with a 25-year performance warranty.

Battery: useful, but rarely as a matter of principle

A 10 kWh home battery generally costs between CHF 7,000 and 10,000 installed. It shifts midday electricity to the evening and can add 15 to 25 points of self-consumption. With a gap of around fifteen centimes between a bought and a sold kWh, it struggles to pay for itself over its lifetime without support. The Geneva bonus, steadily falling battery prices and volatile buy-back tariffs change that calculation: it has to be done case by case, using your real consumption profile.

A cheaper solution is often to use the water heater or the heat pump's hot-water storage as a thermal battery.

Apartment buildings, condominiums and tenants: ZEV and local electricity communities

Solar is not only for detached houses. In an apartment building, a self-consumption grouping (RCP, known as ZEV in German-speaking Switzerland) lets the flats share the roof's electricity, with a single meter towards the grid. In a condominium (PPE), the roof is common property: the project goes through the owners' meeting and must settle how costs and revenues are shared.

Since 2026, local electricity communities also make it possible to sell solar power to neighbours in the same municipality over the public grid, with reduced network charges. For tenants, a small plug-in system of up to 600 W on the balcony is allowed in Switzerland, provided it is notified to the grid operator and the landlord agrees if it is fixed to the facade.

The roof and the electrical installation first

Modules installed today will produce for 25 to 30 years. If the roof covering is more than 30 years old, it is almost always cheaper to renew it before installation, or to choose an integrated solar roof that replaces the tiles. Removing and refitting a system for a roof renovation costs several thousand francs.

On the electrical side, a photovoltaic system is an electrical installation within the meaning of the OIBT ordinance. It must be built or connected by a company holding an installation licence, notified to the grid operator before the works, and then covered by a safety report and an acceptance inspection by an independent inspection body. The inverter, usually replaced after 12 to 15 years, must be placed in a ventilated and accessible room.

How SmartHaus Swiss runs the project

Our core trade is electrical work: the grid connection, the panel and the control system are at the heart of the project, not a last-minute subcontract.

  1. Site visit and analysis: orientation, shading, roof condition, electrical panel, annual consumption and future plans such as a heat pump or a charging station.
  2. Sizing and a detailed quote, including the subsidies and expected self-consumption.
  3. Notification to the municipality or cantonal office, and installation notice to the grid operator.
  4. Installation, connection, commissioning and acceptance inspection.
  5. Filing the one-off remuneration application and the cantonal or municipal bonuses.
  6. Setting up the control system so you use as much of your own power as possible.

Frequently asked questions

Do you need a building permit for solar panels in Geneva?

In most cases no: a notification at least 14 days before the works is enough for a system sufficiently adapted to the roof in a building zone. A protected building, or one in a site of cantonal or national importance, still requires a building permit.

How much does solar power fed into the grid earn in 2026?

Since 1 January 2026, it is paid at the quarterly market reference price, with a minimum of 6 centimes per kWh for systems under 30 kW. Some grid operators, including SIG in Geneva, pay more.

What capacity should a detached house install?

For a house with a heat pump, 8 to 15 kWp generally cover annual needs. It often makes sense to use the whole well-oriented roof, because the price per kWp falls with size and needs grow with an electric car.

Is a battery worth it?

Rarely on its own. It becomes more attractive with support such as the Geneva bonus, a low buy-back tariff or high evening consumption. Controlling the heat pump, the water heater and the charging station first costs much less.

Do solar panels produce in winter?

Yes, but much less: roughly a quarter of the annual output comes from October to March on the Swiss Plateau. Steeply inclined or facade-mounted modules perform better in winter, which the one-off remuneration rewards with a bonus.