Atze Schroeder Stiftung Warentest Hubertus Albers

Stiftung Warentest: solar power for homes: Cheaper and more environmentally friendly

Sustainable energy: own solar system from around EUR 7000

In the test of Stiftung Warentest, photovoltaics came out on top as a cost-effective way to generate electricity yourself: According to the consumer organization, the investment in a home system costs around 7000 euros and pays off within 10 to 16 years. This means that the electricity is then almost free and the system contributes to climate protection.

The Stiftung Warentest experts assumed an electricity price of 30 cents per kilowatt hour as a basis for their calculations. The price has risen since then and will continue to rise. Accordingly, the investment in your own solar system is even more worthwhile.

Test result: higher electricity yield than expected

The testers also examined the performance of photovoltaic systems during their test: 13 systems were installed in various locations in Germany and have been monitored since 2018. The result: On average, the systems produced 946 kilowatt hours of electricity per kilowatt peak (kWp) of installed capacity. This is more than expected. According to Stiftung Warentest, the reason for this is that heat and humidity had less of an impact than expected on the solar cells.

With an electricity price of 30 cents per kilowatt hour, the additional electricity generated corresponds to an income of around 284 euros per kWp of installed capacity. However, additional costs for the inverter and storage must be taken into account. The payback period in sunny regions like Baden-Württemberg or Bavaria is around ten years, in northern Germany the payback period is around 16 years.

Stiftung Warentest: solar power only suitable to a limited extent for rented accommodation

The experts at Stiftung Warentest also pointed out that solar power is only suitable to a limited extent for rented accommodation:

• A photovoltaic system is a permanent fixture. Therefore, tenants must obtain the landlord's consent before installing it.
• As a rule, the tenant is not allowed to make any changes to the roof or facade. This means that solar modules can usually only be installed on a balcony or terrace.
• If the tenant moves out, the system will remain in the landlord's possession. The tenant can only take it with him if this was agreed in advance in the rental agreement.