General information Location: Mont-Cenis Academy, Herne Sodingen, Germany Sunshine hours (annual average): 1 454 hours/ year; 3,98 hours/ day Type of project: Public/Commercial Type of application: BIPV Time for design process: 1991 - 1997 Time for construction: 1997 - 1999 Realization: 1999 [ Top ] Description At the end of the 1980s the Minister of the Interior of the state of North Rhine Westphalia took the decision to move the continuing training academy to Herne. In addition to the training academy the building includes today several other functions as well. It houses seminar facilities, meeting rooms, accommodation facilities, a restaurant, a gymnasium, a library, a civic hall and leisure facilities. It took just about ten years to complete an exciting architectural concept for the ecological and economic renewal of the region, which started with a two stage competition in 1991 for the International Building Exhibition Emscher Park (IBA), won by French architects Jourda & Perraudin. In the second stage of this competition the German architects Hegger, Hegger Schleif joined the design team. PV-modules and glass panes of the overhead-glazing rest on aluminium profiles and are hold in place with aluminium pressure plates. The vertical PV- and glass facade is carried out as a structural glazing facade. Their glass panes and PV-modules are glued onto aluminium profiles. All aluminium profiles are mounted on the load bearing wooden substructure and were designed specially for this project by Wicona Bausysteme GmbH, Ulm. The interconnecting plugs and the required cabling are integrated in the aluminium profiles which hold the PV-modules and glass panes into place. Like this they are invisible and protected against weather conditions and ultraviolet light. Thanks to a new developed PV-plug this mounting detail could be achieved. The plug is designed to use less space and easy to use and helps to cut down the installation time and costs. The plug is not thicker than the used glass panes (4mm) of the PV-modules and therefore it does fit as well in the rebate. [ Top ] System characteristics PV system power: 1 000 kWp Type of building integration: PV-Overhead-glazing: 925 kWp of semi-transparent PV-modules with different cell area ratio; orientation: south; inclination 5°. PV-Facade: 75kWp of semitransparent PV-modules; orientation: west; inclination 90° Type of cell technology: three types of cells are used, all multi-crystalline silicium, Manufacturers: Solarex and ASE Module dimensions: five types of modules are used, sizes 116 x 240 cm and 120 x 280 cm, Manufacturers: Flabec Solar International GmbH (Pilkington Solar International GmbH) Inverters: 569 inverters with nominal power of 1500 watt, Type: Sunny Boy 1500 [ Top ] Project cost breakdown The overall cost of the PV-system was DEM 15,7 Million (€ 8,0 million). A cost for a system that is roofing, facade, shading and solar generator in one. Solar-Modules: DEM 11,1 Million (€ 5,67 Million) Inverters: DEM 1,2 Million (€ 0,60 Million) Switches, cabling, etc: DEM 0,6 Million (€ 0.31 Million) Planning and engineering: DEM 1,1 Million (€ 0,56 Million) Mounting: DEM 1,7 Million (€ 0,86 Million) Maintenance (total estimated): DEM 30 000 € 15 300 Costs per kWp: DEM 15 700 (€ 8 000) [ Top ] Performance characteristics It turns out that building integrated PV-modules successfully allow to control the interior climate of this large micro-climatic glass house. The intake of solar heat and light is controlled perfectly for the different zones of the building by the choice of different cell densities of the PV-modules of the overhead glazing. Also for large projects like this one, the integration of PV in the glass envelope turned out to be a good choice to replace conventional shading systems as they not only provide shade but also act at the same time as weather skin and PV-Generator. It is also expected that they have a longer live time than conventional shading systems. It is the multifunction of these PV-Modules which make them attractive. The calculated energy output of approximately 700 000 kWh/Year was not reached yet. The measured energy output reached a maximum between 600 000 kWh/Year and 650 000 kWh/year. On the one hand it is assumed that the calculated figure was to optimistic and did not take special site conditions into account, such as a not optimized inclination and orientation. On the other hand it turned out, that the air temperatures below the PV-modules are much higher than expected. Responsible for this might be failures of the natural ventilation system of the micro-climate glass envelope. There are some problems with the opening mechanisms of the automatically driven ventilation openings of the roof. Although the PV-modules are mounted only with a slope of 5° the saw tooth roof cause some shading on the PV-modules in early morning and evening hours as well as in winter, when the sun is low at the horizon. The effect of this partial shading on the total energy output has been underestimated. [ Top ] Project team Client: Akademie Mont-Cenis, Entwicklungsgesellschaft Mont-Cenis, Herne (DE) Owner PV-System: Stadtwerke Herne AG, Herne (DE) Project architects: Jourda Architects, Paris and HHS Planer + Architekten BDA, Kassel (DE) Project management: dmp architekten gmbH, Stuttgart, (DE) Climatic Design: Universität Dortmund, Fakultät für Bauwesen, Dortmund (DE), Schmidt Reuter Partner, Köln (DE), Institut für Licht und Bautechnik, Köln (DE) PV-Engineers: Flabec Solar International GmbH, Köln (DE), abakus energiesysteme gmbH, Gelsenkrichen (DE) Contractor: Wicona Bausysteme GmbH, Ulm (DE) (aluminium profiles), Rheinelektra Technik GmbH, Essen (DE) (electrical connection team), ARGE Urban & Langwehr GmbH, Datteln (DE) (mounting of PV-modules and glass pains) PV manufacturers: Solarex Corp. Frederick, MD, (USA) (PV-Cells), Angewandte Solarenergie ASE GmbH, Heilbronn (DE) (PV-Cells), Flabec Solar International GmbH, Köln (DE) (PV-Modules), SMA Regelsysteme GmbH, Niestetal (DE) (Inverters), Leopold Kostal GmbH & Co. KG, Lüdenscheid (DE) (PV connectors) [ Top ]