Residential Rooftop Bad Mergentheim

Site Overview
LocationBad Mergentheim, Germany
Coordinates49.28° N, 9.50° E
Average global irradiance1,055 kWh/m2/yr
Average temperature10.8 °C, 51.4 °F
Average precipitation640 mm/yr, 25.4 in/yr
Technical Overview
Date onstreamOctober 2011
System capacity8.4 kWp
Panel typeSF150-L (150 W)
Number of installed panels56
Tilt angle, orientation4°, -165° N
Output7,795 kWh (01.10.2011 - 30.09.2012)
Total CO2 reduction4,389 kg, 9,676 lbs/yr (01.10.2011 - 30.09.2012)
InverterKostal Piko 8.3
Financing Bank
Volksbank Vorbach-Tauber

There are roofs that seem inappropriate to generate solar power using photovoltaic. This rooftop installations in the German town of Bad Mergentheim shows how to generate good yields by chosing the right modules.

This 8.4 kWp photovoltaic system was installed independently by the PV experienced homeowner and was connected to the grid in October 2011. All modules and other PV relevant components required for the installation, like mounting components, inverter and wiring were provided by the PV distributor Rusol.

The challenges for this atypical rooftop were both orientation and tilt angle. Since the garage rooftop faces almost directly to the north and the modules could not be mounted with a tilt angle greater than four degrees almost flat to the roof, the CIS modules of Solar Frontier were the first choice for the homeowner. The unique characteristics of good low-light behavior and high shadow tolerance were crucial because they compensate for nonoptimal conditions, worsened by shadows cast by nearby, higher-standing buildings. Two unique properties that lead to higher yields and convinced the homeowner completely. Initial analysis of the yield data already show that the calculated annual output of over 6,000 kWh could even be exceeded with more than 7.700 kWh during the first year of operation.