General information Location: Göteborg Energi Facade, Sweden Sunshine hours (yearly average): - Type of project: PV modules mounted on existing facade Type of application: Retrofit Time for design process: 1465 man hours Time for construction: 757 man hour Realization: September 1998 [ Top ] Description Göteborg Energi AB wanted to gain in-house experience on PV technology. One sub-goal is that the produced energy shall, on an annual basis, be enough to charge the batteries of all the electrical vehicles used by Göteborg Energi. Another sub-goal is to raise people’s attention to the company’s interest in renewable energy. This was done by mounting the plant with a decorative pattern on the facade of the office building, which is located in the center of Gothenburg. The installation is on the south façade of the head office of Göteborg Energi AB and covers a little more than 180m˛ of the façade. The nominal power is 6,8 kW. The project is made in co-operation between Göteborg Energi AB and Naps Sweden AB. The 570 pieces of 12Wp modules are mounted on specially designed aluminum profiles bolted to the façade. The technique allows rapid installation and possibilities to remove individual modules for easy inspection and replacement. The modules are installed in two separated surfaces and divided into 7 sections, each feeding a string-inverter that converts the power produced by the modules to AC-electricity fed into the existing building grid. The project is partly funded by money from the governmental “Local Investment Program, LIP”. [ Top ] System characteristics PV system power: 6,8 kW Type of building integration: - Type of cell technology: amorphous silicon Module dimensions: 12,7 Wp thin film amorphous silicon, manufactured by Fortum Finland. Inverters: SWR700 (Sunny Boy 700 W), manufactured by SMA and SWR850 (Sunny Boy 850 W), manufactured by SMA [ Top ] Project cost breakdown Design: € 34 114 Solar modules: € 64 130 Inverters: € 8 370 (approx.) Electro installation: € 6 920 Mounting system: € 5 805 Construction (labor): € 21 629 White enameled sheets: € 3 251 Miscellaneous: € 4 194 Total: € 148 413 [ Top ] Performance characteristics The plant was estimated to produce 4 200 kWh per year. With one year of production experiences it is now concluded that the actual production is 3 570 kWh. The main reason for this is a higher than expected cell temperature and some shadowing from a tree in front of the building. This tree fell in a storm in autumn 1999, and the sky is now open in front of the modules. Electricity generated: 35440 kWh from January 1999 to January 2000 System availability: 100 % Incidents or Outages: 1 Component: Modules Cause: Component failure: 10 modules had cracks in the protective front glass. They were changed from a skylift. The procedure caused only a few minutes downtime for the system Repair: Installer and manufacturer [ Top ] Project team Client: Göteborg Energi AB (local utility owner) Contractors: Neste Advanced Power Systems (NAPS) PV manufacture: NAPS [ Top ]