FAQ – frequently asked questions


What is the minimum size of a solar folding roof project?

The project should have a minimum area of 1’000m2 or approx. 120kWp installed power (ideally approx. 50m x 20m). It can already be taken into account that distances of approx. 5m from buildings and public roads which do not belong to this area have to be considered.


How big can a solar folding roof project be?

The size of a solar folding roof is not limited, as it is modular and can be scaled as desired.


What is an ideal layout for a solar folding roof project?

Ideally, a rectangular area is considered. But it can also be built in an L-layout. Curves, angles and arches cannot be realized.


What do I need to consider for the permit?

The solar folding roof usually has to go through a normal building permit.


What investment costs must be expected for a solar folding roof project?

EUR 2’400.-/kWp for the entire system including installation can be considered. In addition, there are site-specific costs for foundations and grid connection, which can vary greatly depending on the project location.


What electricity production costs can be expected for a solar folding roof project?

In the Swiss midlands and in the pre-alpine region, production costs of 12-16 cents/kWh can be expected. This already includes the basic service contract and the amortization over 25 years, but no interest on capital (calculated with IRR 0%).


What yield reductions / yield increases are taken into account for the solar folding roof due to the retraction in bad weather?

On average, the yield loss from retraction of the roof due to high wind volume (>50km/h) is 3%. This value is precisely calculated in the planning with local weather data. In winter, a slight increase in yield can be expected in the pre-alpine and alpine regions, because the modules are retracted even when snow falls and therefore have no winter losses, as is the case with modules on roofs. In Chur in Switzerland (approx. 600müM) an additional yield of approx. 3% was measured compared to comparable flat roof systems.


How do I start a solar folding roof project?

Get in contact with us and tell us the location, e.g. with a Google Maps link. We will get back to you with an initial assessment and offer you a preliminary study that costs between CHF 20,000 and CHF 30,000, depending on the size of the project and the number of variants. This very comprehensive document clarifies the technical feasibility (incl. external structural analysis report), the ability to obtain a permit, as well as the economic efficiency and serves as a reliable basis for the client’s decision. With the preliminary study dhp technology offers the solar folding roof at a fixed price, which makes budgeting reliable.

Do you have further questions? Then we look forward to hearing from you!


Did we spark your interest?

Carmen Scheuber is at your disposal for further information.

Or visit us at a trade fair!