Special construction for Appenzell bypass: Vertical PV on the retaining wall


Canton supports PV project with double funding

Generating at least 40 per cent of the canton’s electricity consumption from renewables by 2035 – that is the target for Appenzell Ausserrhoden.

In order to meet the requirements of the Energy Act, the canton is doubling the subsidies for solar power systems and thus enabling the PV project on the Teufen bypass. As there is no direct consumer connected to the photovoltaic system, the energy is fed into the grid of St. Gallisch-Appenzellische Kraftwerke AG and the canton receives an attractive feed-in tariff for this.

Project planning began in 2022 by Roland Schlegel from ZENNA AG. The tendering office supports property owners, municipalities, cities and energy supply companies in analysing their initial situation with regard to photovoltaics and developing sustainable strategies for dealing with photovoltaics.

The engineering office of the road inspectorate was also involved in the planning phase, checking all the structural calculations. In order to attach modules reliably and long-term to the 75° inclined retaining wall, the planning professionals opted for a substructure from K2 Systems..

The solution for this extraordinary PV project is a clever special design:

The combination of the tried-and-tested K2 BasicRailand the HUS Schraubanker from Hilti proved to be the perfect solution. Both elements were anchored to the masonry using HIT Klebetechnikand Wings BSM. A particular challenge was the requirement that an anchoring depth of max. 90 mm could not be exceeded, as otherwise the retaining wall would be weakened.

Within a very short time, the specialist partner  Solarmotion AG  installed the vertical K2 BasicRail in a cross-connection with the  Insertion System with Full Black-Komponenten. Due to the extreme proximity to the asphalt, the components are subject to exceptional corrosion requirements and are coated with anodising for protection. Indirect components are made of aluminium or A2 – only the screw anchors are made of A4.

The 756 high-quality glass-glass modules have an output of 325 kWp and an energy yield of around 230,000 kWh/year. This corresponds to the consumption of approx. 52 households with four people.

The highlight: Especially in the winter months (when consumption and dependence on foreign electricity imports are at their highest), the vertically aligned modules will achieve a very good electricity yield.

Vertical PV systems

News from the canton

Information on funding

Video contribution from TVO - A CH Media company


Esslingen, Germany

Connecting “the Länd”: D-Dome 6.10 on EnBW properties

03/10/2022 Ahmadi Governorate, Kuwait

Harvesting Kuwait’s sunlight: Triangle system for self-consumption

01/09/2022 Grafenhausen, Germany

1.5 MWp system for Badische Staatsbrauerei Rothaus AG

2022 Grafenhausen, Germany


Get tips and news on solar energy