Solar panels and PV modulesMatched to your roof.

Are you looking for a single solar panel to take with you, for a balcony, garden shed or camper? Then we are the wrong contact. We do not sell individual panels or balcony power plants. We plan and install solar modules as part of a permanent solar system on your house or business.

On this page, you learn what matters with modules and how we select them for your roof. You can find the overall picture of the system under solar system and photovoltaics.

What is the difference between solar panel, solar module and PV module?

In everyday use, all three terms mean the same thing: the flat plate that turns sunlight into electricity. Specialists say solar module or PV module. A module consists of many solar cells set in glass and a frame. Several modules form a string, and several strings form the system.

The power the modules produce is direct current. The inverter turns it into the alternating current that your household needs.

What module types are there?

For roofs, almost only monocrystalline modules are used today. Their cells are made from a single silicon crystal and reach a high efficiency. Thin-film modules and polycrystalline modules hardly play a role on house roofs any more.

Within monocrystalline modules, there are differences that may matter to you:

Type	Feature	Useful for
Standard module (glass-film)	Glass on the front, plastic film on the back	normal pitched roofs, good value for money
Glass-glass module	Glass on front and back, particularly robust	in-roof, harsh locations, long service life
Bifacial module	also uses light from the back	light-coloured flat roofs, mounting on stands, facades
Black module (full black)	black cells, black frame and back	visible roofs, a calm appearance

The types can be combined. A bifacial glass-glass module in black is no longer an exception today.

How much output does a solar module have?

Modern modules for homes usually have 400 to 450 watts of peak output (Wp) on an area of about 2 m². Efficiency is typically 21 to 23 per cent. That means this share of the solar energy falling on the module is converted into electricity.

Efficiency matters most when roof area is limited. On a small roof, more efficient modules deliver more output on the same area. On a large roof, the price per watt counts more.

A worked example: 23 modules of 430 Wp each make just under 10 kWp. That is a typical size for a single-family home. How much power this produces depends on orientation, tilt and location. On the Swiss Plateau, you can expect about 900 to 1,100 kWh per kWp and year.

How long do solar modules last and what warranties are there?

Solar modules have no moving parts. They age slowly. After 25 to 30 years, good modules still deliver most of their original output.

Manufacturers usually give two kinds of warranty:

• Product warranty: It covers defects in materials and workmanship. The duration differs by manufacturer and model.
• Performance warranty: The manufacturer guarantees that after a certain time, the module still delivers a minimum share of its output.

The exact terms differ from model to model. We disclose the datasheets and warranty terms of the modules offered in the quote. Also check who pays for removal and reinstallation in a warranty case. That is often the more expensive part.

Which modules suit my roof?

There is no single best module. There is the one that suits your roof. We check this during the site visit:

• Little space: Modules with high efficiency get more output from the area.
• Visible roof: Black modules look calm and suit dark tiles.
• Partial shading from a chimney, dormer or tree: We plan the string layout or power optimisers so that one shadow does not slow down the whole system.
• Flat roof: Here we check mounting on stands, east-west orientation and ballast. Bifacial modules can be worthwhile.
• New build or roof renovation: Modules can replace the tiles. That is the in-roof solar system.
• Location at risk of hail: We pay attention to the hail resistance class of the modules.

The interplay is also important: modules, inverter and a later battery storage system must fit together. The same applies to an EV charger that you may only add in a few years. You can read how to enlarge an existing system under extending a solar system.

How are the modules installed?

Our own installers do the installation.

1. Mounting structure: Roof hooks or rails are fixed to the rafters. The roof skin stays watertight.
2. Modules: They are laid on the rails, clamped and wired into strings.
3. Inverter and connection: We install the inverter, connect the system to the house distribution and carry out the safety inspection.
4. Handover: We show you the system and the app where you see yield and consumption.

How long installation takes depends on the size of the system. For a single-family home, allow about a week. We also take care of the notification to the commune, the registration with the grid operator and the subsidy application. The subsidy can be pre-financed on request.

What belongs to the system besides the modules?

Modules alone do not yet produce usable power. A finished system includes:

• Inverter: It converts direct current into alternating current and controls the system. We size it according to the module output and the roof layout.
• Mounting structure: It holds the modules securely on the roof, even in wind and snow. We choose material and fixings to suit the roof covering.
• Cabling and protection: Direct-current lines, surge protection, isolating switches and the connection to the house distribution.
• Metering and monitoring: An app shows you how much power the system produces and how much of it you use yourself.

We plan these parts as one system. This way there are no interface problems between materials, installation and electrical work.

What do I need to know after installation?

Little. Modules do not need regular maintenance. Look at the app now and then: a sudden drop in yield is a sign that something is wrong. Then we are there for you, for example for hail damage or dirt (see cleaning).

What do the modules cost?

The modules are only one part of the total cost. Inverter, mounting structure, scaffolding, electrical installation and installation come on top. We therefore do not state a price per panel. The price depends on size, roof shape and effort. You receive your exact price after the site visit in the binding quote within 72 hours, with yield forecast and subsidies.

Solar modules in your region

Our locations are in Zumikon ZH and Lachen SZ. We install throughout German-speaking Switzerland. Enter your postcode in the appointment card, and we will arrange the free site visit on site.