Pitched-Roof PV Installation on a Purpose-Built Roof Support System

This method is particularly suitable for pitched roofs on existing buildings, where the solar generator is installed on a purpose-built metal roof support system (see Figures 1.10, Figures 4.49 and 4.50). The requisite sealing against precipitation is provided by the existing tile roofing underneath the solar generator.

The fireproof and electrically isolating roof between the solar generator wiring and the mainly wooden roof substructure provides effective fire protection in the event of a serious problem with the solar generator.

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Figure 4.49 Pitched-roof installation of ~2.2 kWp solar generator mounted on a purpose-built roof support system. The spacing between the roof and modules allows for good underside ventilation (Photo: Siemens)

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Figure 4.50 Pitched-roof installation of ~30kWp solar generator mounted on the purpose-built substructure of a farm building in Schwarzwald, Switzerland. Solar power is an attractive source of income for farmers if the feed-in tariffs are high enough (Photo: Sunpower Corp./SunTechnics Fabrisolar AG)

The underside of the modules, as well as the tiles under the solar generator, are extremely difficult to access once such a system is installed. In order to achieve adequate rear module cooling (which reduces power loss), sufficient clearance of the order of 10 cm should be allowed between the roof and the solar generator. Moreover, the mounting system needs to be properly sized for snow load, wind pressure and wind suction. Such systems are available from various vendors.

Updated: August 6, 2015 — 10:22 am