What is the return on investment of solar panels in Western Switzerland?

The return on investment of a photovoltaic installation depends on several factors: the amount of sunshine at the site, the orientation and pitch of the roof, the size of the system, the share of electricity consumed on site and the electricity tariff of the local supplier. The higher the self-consumption share, the faster the installation pays for itself, because electricity that is produced and used on site avoids a purchase at the grid tariff, whereas surplus fed into the grid is paid at a lower rate. Federal and cantonal subsidies reduce the upfront cost. An installer can prepare a costed simulation for your roof and your consumption profile. Panels have a long lifespan: once the investment has been recouped, the electricity they produce remains a gain for many years.

What PRONOVO subsidies can you get for solar panels in Switzerland?

Federal support for photovoltaics is handled by PRONOVO. The main scheme is the one-off payment (rétribution unique, RU), granted for grid-connected installations above a certain capacity. Its amount depends on the installed capacity and the type of installation (roof-mounted, building-integrated or ground-mounted). The application must be submitted before the installation is commissioned. The cantons of Western Switzerland often add top-ups: Vaud, Geneva, Valais, Fribourg. Conditions and budgets change from one year to the next: check the PRONOVO website and your canton's website before committing.

What is the best orientation for solar panels in Western Switzerland?

In Western Switzerland, the optimal orientation is due south with a tilt of 30 to 35 degrees. This configuration maximises annual output. A south-east or south-west roof loses little output compared with due south, whereas an east- or west-facing roof loses more, while producing earlier in the morning or later in the afternoon, which can suit some consumption profiles. Flat roofs make it possible to achieve the ideal orientation and tilt thanks to adjustable mounts. Shading is the factor that degrades performance most: even a small shadow on one cell affects a whole string of panels if micro-inverters or power optimisers are not used.

Do you need a permit to install solar panels in Switzerland?

Since federal harmonisation, installing solar panels on existing roofs (outside protected areas) is generally subject to a simple notification in most cantons, without a formal building permit. The panels must in principle be well integrated into the roof or protrude only very slightly above its surface. In heritage protection zones, listed sites or historic buildings, cantonal or municipal authorisation is required. Always check with your municipality before the installation.

Is a solar battery system worthwhile in Western Switzerland?

Storage batteries remain hard to pay back on their direct economic return alone. They significantly increase the share of the electricity produced that is consumed on site, which reduces what is fed into the grid, but their purchase and installation cost lengthens the payback period of the whole system. Their benefits are also indirect: the ability to keep supplying the home during a power cut (with a hybrid inverter), added property value, and protection against rising tariffs. Battery prices change quickly: compare several quotes before deciding and ask for a simulation with and without storage.

Solar Panels in Western Switzerland 2026: Practical Guide

Western Switzerland gets enough sunshine to make a photovoltaic installation profitable, especially with the existing federal and cantonal subsidies. This guide explains how to assess your solar potential, understand what makes the cost and the return on investment vary, choose the right equipment and identify the aid you may be entitled to.

Assessing your solar potential in Western Switzerland

Before investing, it is essential to assess the real potential of your roof. The free tool PVGIS (from the European Commission) and the SolarGIS portal let you estimate annual output based on your geographical coordinates and the orientation and pitch of your roof. The solar cadastre offered by the Confederation and by several cantons also gives a first indication for each building.

In Western Switzerland, sunshine varies from region to region:

Valais (Sion, Sierre): among the sunniest regions in Switzerland
Vaud (Lausanne, Nyon): very good potential
Geneva: excellent potential, helped by the proximity of the lake
Fribourg, Neuchâtel, Jura: good potential, with more fog on the Plateau in winter

A well-oriented installation (due south, 30 to 35 degrees of tilt) produces the maximum electricity per installed kWp. The capacity of an installation is expressed in kWp (kilowatt-peak): the higher it is, the more roof area is needed. A simulation on PVGIS or by an installer will give you the expected output for your specific site.

A few points to check before taking any steps:

the condition of the roof: if it needs to be redone soon, it is better to coordinate the two projects;
the strength of the roof frame, which must bear the additional weight;
shadows cast by trees, chimneys, dormers or neighbouring buildings, at different times of day and in different seasons;
the possible location of the inverter and the electrical panel, as well as the cable route.

What makes the cost of a solar installation vary

The price of modules has fallen sharply in recent years, but the final cost of an installation varies greatly from one project to another. Here are the main factors:

Installed capacity: the larger the system, the higher the total cost, but the cost per kWp tends to fall as size increases.
Type of mounting: an installation on a pitched roof, an installation integrated into the roof in place of tiles, or a flat-roof mounting with supports each have different requirements.
Quality of the equipment: brand and range of the panels, type of inverter (central, micro-inverters, optimisers).
Site accessibility: height of the building, need for scaffolding or a crane, complexity of the roof.
Electrical connection: distance to the panel, possible upgrade of the existing installation, meter.
Options: storage battery, charging station for an electric vehicle, energy management system.
Paperwork: notification or authorisation, subsidy application, connection to the grid operator.

Always compare several detailed quotes. A good quote specifies the brand and model of the panels and the inverter, the capacity in kWp, the estimated annual output, the manufacturer’s warranties, what is included in the installation and the paperwork, and the payment terms.

PRONOVO subsidies and cantonal aid

The federal one-off payment (PRONOVO)

The main federal support for photovoltaics is the one-off payment (rétribution unique, RU), managed by PRONOVO AG. It applies to grid-connected installations above a capacity threshold set by law. Its amount depends on the capacity of the installation and its category: installation added onto a building, installation integrated into the roof, or another type of mounting. The rates are revised regularly, which is why you should always check the current values on the PRONOVO website.

Important: the application for the one-off payment must be submitted on the PRONOVO website before the installation is commissioned. Payment is made after commissioning and once the requested documents have been submitted. A registered installer can handle these formalities for you.

Cantonal aid in Western Switzerland

Depending on the year, the cantons of Western Switzerland offer top-ups to the federal aid. Each programme has its own conditions, budget and deadlines:

Vaud: cantonal incentive programme managed by the Energy Directorate, which can be combined with federal aid. Ask the cantonal energy office.
Geneva: aid managed by the cantonal Office of Energy. As annual budgets are limited, it is advisable to submit your application early.
Valais: cantonal support for solar installations, including on certain agricultural and mountain buildings.
Fribourg: aid that complements federal support, via the cantonal energy office.
Neuchâtel, Jura: more limited complementary aid; most of the support comes through PRONOVO.

Some municipalities and electricity distributors also offer aid or special buy-back conditions: ask them directly before signing a quote.

Understanding the return on investment

The return on investment of a solar installation is calculated by comparing its net cost (after subsidies) with the savings and income it generates each year. Three factors weigh the most:

The net cost of the installation, that is, the price of the equipment and installation, minus the aid obtained;
Annual output, which depends on sunshine, orientation, tilt and shading;
The self-consumption share, that is, the electricity produced that you use yourself rather than feeding into the grid.

Self-consumed electricity spares you a purchase at the grid tariff, which is considerably higher than the buy-back rate for electricity fed into the grid. A household that is at home during the day, or that has an electric vehicle, an electric water heater or a heat pump, consumes a larger share of its output, and therefore recoups its installation faster.

The return on investment also improves if electricity tariffs rise, and it is slower if daytime consumption is low or if the roof is poorly oriented or shaded. Ask the installer for a simulation based on your actual electricity bill rather than on an average.

Grid feed-in and payment for surplus

In Switzerland, surplus electricity fed into the grid is paid for by the local grid operator. This buy-back rate, known as the feed-in remuneration (rétribution de l’injection), varies by supplier and may change from one year to the next. It is generally considerably lower than the price at which electricity is bought.

That is why maximising self-consumption is the most profitable strategy. The levers are:

shifting electricity use to the daytime (washing machine, dishwasher, electric vehicle charging);
installing a storage battery;
combining the installation with a heat pump or a thermodynamic water heater;
considering a grouping under the self-consumption scheme (RCP, regroupement dans le cadre de la consommation propre) or a local electricity community, particularly in apartment blocks or co-ownership buildings.

Storage battery: who is it for?

A battery stores the surplus produced during the day so it can be used in the evening and at night. It makes the most sense when daytime consumption is low and the buy-back rate is low. Before deciding, ask yourself these questions: how much do I consume in the evening? Do I need a backup supply? Is my inverter compatible with later storage? It is often possible to plan for a battery to be installed later by choosing a hybrid or upgradeable inverter from the outset.

Procedures and authorisations

Before the work, three steps need to be planned: notification or authorisation from the municipality according to cantonal rules, the connection notification to the grid operator, and the application for the one-off payment from PRONOVO. After the work, an inspection of the electrical installation by an independent inspection body is required. Your installer can guide you through each of these steps; make sure that everyone’s responsibilities are set out in the quote.

Choosing a solar installer in Switzerland

For photovoltaic installations in Switzerland, the electrical connection work must be carried out by a company holding the installation permit issued by ESTI (the Federal Inspectorate for Heavy Current Installations). Things to check:

CFC (federal vocational certificate) as an installation electrician or equivalent training, with additional training in photovoltaics;
Membership of the SWISSOLAR association or references for projects comparable to yours;
Registration with PRONOVO, useful if the installer submits the subsidy application on your behalf;
Insurance and warranties: ask for proof before signing, as well as the manufacturer’s warranties on the panels and the inverter.

For work on the roof (integrating panels, waterproofing), a roofer must work alongside the installation electrician. Have it stated in writing who is responsible for waterproofing at the fixing points, and ask for several quotes to compare the services.

Updated 29 October 2026

Installing solar panels in Western Switzerland: a practical guide