Extend your solar systemMore power from the roof.

The family grows, a heat pump is added, or an electric car: electricity demand rises and the system is no longer enough. Then you can extend your existing solar system. This is often cheaper than a new system, because the inverter, the connection and parts of the mounting are already in place.

When is an extension worthwhile?

• An electric car or a heat pump needs more electricity than the system delivers.
• There is free area on the roof, for example on a second roof side, on the carport or on an extension.
• The feed-in tariff is low and you want to use more of the electricity yourself. Then a battery often helps more than extra modules.

We check with your consumption data whether more modules or a battery bring the greater benefit. Often it is the combination.

What we check at the site visit

1. Roof area and structural load: How many additional modules fit, and can the roof carry them?
2. Inverter: Output, age, free inputs. Is it enough for the additional modules?
3. House connection and distribution: Can the connection handle the higher output?
4. Condition of the existing system: We look at the modules, cabling and fixings.

Extension and inverter

Situation	Solution
Inverter has reserve and a free input	new modules on the existing unit
Inverter fully used	second inverter for the new modules
Inverter old or faulty	replacement with a larger unit, possibly with a battery connection

New and old modules should not run in the same string if they differ in output and orientation. We connect them separately so that no losses occur. You can read more about the modules under PV modules.

Where can additional modules be installed?

• Second roof side: East and west surfaces also deliver well and spread the electricity across the day.
• Extension, garage or carport: There is often unused area here.
• Facade: Steep modules deliver valuable electricity in winter.
• Gaps on the main roof: We check whether roof windows, chimney or shading still leave room. With partial shading, power optimisers help.

If the roof is full, swapping to more powerful modules can make sense. Modern modules deliver more output per square metre than those from ten years ago. We calculate this case by case.

An extension can also prolong the service life: during the inspection we see whether the fixings and cabling of the old system are still in good condition.

Extension with battery or EV charger

The extension is often the first step, followed by a battery or an EV charger. We plan the inverter and connection so that you can add to them later without redoing everything.

Notification and grid operator

An extension also has to be notified. The grid operator must know the new total output, and sometimes the conditions for feeding in change. Depending on the commune and location, a notification is enough, and for protected buildings a permit is needed. We clarify this for your address and submit everything, including updating the system data with Pronovo.

What does an extension cost?

The costs depend on the number of modules, the roof and the inverter. Scaffolding is often needed even if only a few modules are added. So the price per kWp falls as the extension gets larger. We do not give fixed prices, because every system is different. After the site visit you receive a binding quote within 72 hours, with yield and payback.

Subsidies for the extension

• Federal government: Under certain conditions, an extension can receive a one-off payment (Einmalvergütung, EIV) from Pronovo. The rules for this change, so we check the current status for your case.
• Canton and commune: Some bodies subsidise extensions, and the conditions differ by location.
• Taxes: In most cantons, the costs can be deducted from taxable income.

Subsidies that we handle for you can be pre-financed on request.

How the extension runs

1. Enquiry: Online or by phone.
2. Site visit: Roof, inverter, connection. Free of charge.
3. Quote within 72 hours: binding.
4. Notification: We take care of the grid operator, commune and Pronovo.
5. Installation: Our own installers.
6. Commissioning: We check the whole system and show you the display in the app.

Even if the system was not built by us, we are glad to check it. If you only want to add a battery, read retrofit a home battery. You will find the basics about the system under solar system.

Extensions in your region

We are based in Zumikon ZH and Lachen SZ and extend systems across German-speaking Switzerland.