Topic of the Week: Commercial rooftop PV (Part 4): One of the largest rooftop systems in Germany
As part of this week's Topic of the week, we will present a number of (we think) impressive or interesting large-scale rooftop solar installations. Today, we look at a logistics centre in Germany that went really big when it came to their rooftop installation:
More than 20,600 modules with up to 6.44 MWp were installed on top of the Fiege Mega Center in Dieburg, Hesse, a 90,000 square metre logistics hall, to generate solar power. MaxSolar has thus realised the first roof-mounted solar power plant tendered by the German Federal Network Agency. The project developer installed the new Schletter FixGrid 18 system, which has been optimised to withstand strong winds and high loads.
“The MaxSolar GmbH project was not only special because of its size and complexity, but also structurally demanding,” said Björn Boehlkau, Sales Manager Solar Projects at the Schletter Group, who supervised the project together with his colleague Stephan Wild, Head of Technical Consulting Roof Systems. “Due to the low residual carrying capacity of the flat roof, the PV system had to be planned and installed with as little weight as possible, while still being able to withstand high wind loads.”
Only eight weeks of installation time
For this reason, the choice fell on the new Schletter FixGrid 18 system. Schletter has specifically optimized this system, which was released in 2018, with several design improvements – especially with regard to statics and load capacity. Windsafe plates and ballast tubs only have to be installed where they are actually needed for technical reasons. At the same time, the FixGrid 18 is now even more durable than the previous model. The optimised geometry of the profiles makes this system capable of withstanding very high snow loads.
A team of 25 people only needed eight weeks for the installation. This was facilitated by the high degree of prefabrication of the system. For example, the FixGrid 18 has a newly developed swivel connector that has been pre-assembled at the factory and can be put together without tools. As only a minimum of installation work is required on the construction site, the assembly time and thus the costs per kilowatt of installed PV power are significantly reduced. In addition, flame-retardant building protection mats were used in this project.
The Schletter Group and MaxSolar GmbH have a long-standing track record of successful collaborations. In 2018 alone, Schletter supplied the project developer with installations for ten open-area projects totalling 17.5 MW. Further projects are already in the planning phase. (mfo)