Photovoltaik Beschattungsanlage Würth Chur

• Research unit: SFOE
• Project number: 47134

Key words (German)

TP0038;Solarenergie (thermisch & PV)

Short description (German)

Geeignet ins Gebäude integrierte Photovoltaik (PV) Beschattungsanlagen können neben der aktiven Stromprod., durch die Beschattungsfunktion und der damit verbundenen reduzierten Kühllast, die Gesamtenergiebilanz eines Gebäudes zusätzlich positiv beeinflussen. Die Fa. Würth Solar hat auf der Grundlage ihres bestehenden PV-Moduls mit CIS Zellen ein teiltransparentes PV Dünnschicht-Beschattungselement entwickelt,k dass erstmals beim neuen Geschäftssitz der Würth Holding in Chur zum Einsatz kommt.

Final report (German)

Bei der Würth Holding in Chur wurde im Herbst 2002 eine PV-Anlage integriert. Diese dient zur Beschattung des Atriums und zur Energieproduktion. Um den Einfall von Sonnenlicht im Gebäude in den Sommermonaten zu begrenzen, mussten die Oberlichter abwechselnd mit einer motorischen Storenanlage und einer teiltransparenten PV-Anlage belegt werden. Diese reduziert zusätzliche Kühllasten und ermöglicht zudem eine innovative Technologie (CIS) einzusetzen und auszutesten. Andererseits ist es auch notwendig genügend Tageslicht in das Atrium hereinzulassen um auf das Kunstlicht während der Tageszeit verzichten zu können. Die Firma TransSolar-Deutschland erarbeitete ein Konzept, wie beide Gesichtspunkte vereint werden konnten.

Related documents

• Monitoring of the CIS BIPV plant Würth in Choire - final report [PDF] 1'364 kB

Final report (English)

In October 2002 an exciting BIPV installation was concluded at the Würth Holding in Chur. The outstanding aspect was the application of new CIS BIPV modules. These were custom made CIS modules, producing energy and reducing the heat gain in the building by shading the skylights of the atrium. The goal was to find a balance between sufficient natural light and low heat load, because of the incoming sunlight. A combined concept was applied. On half of the skylights fully automated roller blind were installed and on the other half CIS modules. To achieve the semi-transparency, the CIS-disposition of the modules were removed in 1 cm strips, getting a 50% light gain. As each skylight has different dimensions, individual BIPV modules had to be manufactured. In overall were three types of modules manufactruered, but all with identical operation voltage. The PV design resulted in PV peak power of 3.7 kW, which is connected to a TopClass 4000/6 inverter and to the building grid. The PV system was monitored over a period of 2 years. One of the main goals of the project was to get experience and results with the performance of the custom-made CIS modules. Further we attempted to analyse the influence of the BIPV shading device to the building energy performance. In an other activity we interviewed working staff concerning their impression towards aesthetics, impression of the semitransparency and the application (shading device) of the BIPV installation. Since commissioning of the installation the system operates reliable and no breakdowns were noticed. The monitoring equipment features a datalogger with several inputs and a modem connection for downloading the data. All sensors and datalogger were installed mid of November 2002. November/December 2002 were used to adjust the data and the sensors to secure a safe operation for the 2 years monitoring. The project was delayed due to the later installation. The monitoring started 1st of December and provided extensive data for this final report. Actual monthly energy yield was compared to estimated values based on solar irradiation. Results shows, that the PV system operates as expected and in summer time even better. The performance matrix of the system in dependency of temperature and irradiance was derived from the TISO analysis methods for outdoor measurements. Calculations show for the CIS Plant a power value of 3362 Watt under STC. The analysis of outdoor measured values at standard test conditions (STC) has shown an average module efficiency of 8.5 %, increasing 1% over two years compared to the specifications from the manufacturer. This can be related to a similar effect like a-Si modules, so-called annealing of the physical combinations. Module performance under lower irradiance shows a high energy yield. On several occasions we interviewed staff of Würth Holding. Reaction of respondent persons were positive, although few persons did actually really noticed the semitransparent PV modules overhead. In a final analysis we tried to determine the shading effect of the semi-transparency module to the building energy performance. Rule of thumb shows no large impact to the building energy performance. Thanks to a very engaged co-operation and good participation of all parties the project could be successfully finished.

Auftragnehmer/Contractant/Contraente/Contractor:
Enecolo AG

Autorschaft/Auteurs/Autori/Authors:
Rasmussen,Jochen
Hürlimann,Katharina