Pitched-Roof Installation Integrated into the Roof

Direct integration of laminates or solar tiles into a roof is a more aesthetically pleasing solution. To do this, however, the solar generator needs to carry out all of a normal roof’s weather protection functions, which for new buildings obviates the cost of conventional roofing. In the interest of avoiding accidents on pitched roofs, it is advisable to use wiring connector systems that make it impossible to confuse one connector with another so that a roofer can mount and wire in series the various strings, and an electrician is only needed to hook up the string wiring and power line.

Wind suction needs to be taken into account for roof-integrated installations as well. In some cases, solar roof tiles whose area specific weight is less than that of standard roof tiles need special pressure bars or clips. It is also essential to provide sufficient rear ventilation for such systems. Figure 4.51 displays a small tile roof-integrated solar generator. Figure 4.52 displays a large laminate solar generator integrated into a pitched roof using large Megaslate solar roof tiles. This generator covers nearly half the roof.

Figure 4.53 displays a house with Solrif solar roof tiles, which are laminates with a special aluminium frame that frames the left, right and upper side of the laminate on both sides of the laminate, but at the lower edge is only arranged below the laminate so as to obviate the frequently observed problem of grit accumulating on the underside of the module frame. This solution allows the optimized lightning protection characteristics of a framed module to be combined with the lesser tendency to accumulate grit offered by laminates (see Section 6.7.7). The fact that each side of the Solrif profile exhibits a different form allows for the manufacture of laminate solar roof tiles and thus the realization of a hermetically sealed roof.

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Figure 4.51 A small laminate solar generator integrated into a pitched roof (Photo: SunTechnics Fabrisolar AG) 4.5.1.5 Fagade Mounting and Integration

Solar generators can also be integrated into building fagades, although the projected energy yield of such installations in flat areas is around 20 to 40% lower than for optimally sized roof installations (see Sections

2.4 and 2.5). However, in mountainous areas the fagade installation energy yield is on a par with that of optimally oriented roof installations. Moreover, the effects of snow loads can be almost completely obviated by mounting the solar generator vertically. Many fagade installations are mounted vertically (tilt angle 90°; see Figures 4.54-4.56), although installations that serve additional purposes such as window shading and that exhibit somewhat shallower tilt angles are also realizable (see Figure 4.57). Good underside ventilation is also essential for fagade-integrated installations.

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Figure 4.52 Pitched-roof installation of a roof-integrated 9.3 kWp solar generator consisting of Megaslate laminate roof tiles (Photo: 3S Swiss Solar Systems AG)

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Figure 4.53 A12 kWp Solrif solar generator integrated into a pitched roof. This installation combines the advantages of framed and laminate modules (Photo: Ernst Schweizer AG)

 

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Figure 4.54 Polycrystalline module solar generator integrated into two facades of a building in Riehen, Switzerland (Photo: SunTechnics Fabrisolar AG)

 

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Figure 4.55 A 9.35 kWp solar generator mounted on the facade of SLF (Eidgenossischen Instituts fur Schnee – und Lawinenforschung) on Weissfluhjoch Mountain (elevation 2690 m) in Davos, Switzerland (Photo: WSL Institute for Snow and Avalanche Research SLF, www. slf. ch)

 

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Figure 4.56 Solar generator mounted 2486 m above sea level at the valley station of the Piz Nair ski lift above St Moritz (Photo: SunTechnics Fabrisolar AG)

Efficient sealing is more readily obtainable for fagade installations than on roofs. Laminates (often custom made) or large modules (of which up to 300 W versions are commercially available) are mainly used for fagade installations. Customized modules can cost up to 100% more than standard products. As many laminate or module configurations entail extensive exposure to the elements, it is advisable to use connector systems for the wiring that make it impossible to confuse one connector with another so that a roofer can mount and wire in series the various strings and an electrician is only needed to hook up the strings and power line.

The cost of a fagade solar generator can be reduced by using it as an integral fagade element, instead of merely installing the generator on the fagade, particularly in cases where doing so would replace an expensive decorative material such as marble.

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Figure 4.57 A polycrystalline module solar generator mounted on the fagade of the US Embassy in Geneva. The modules are mounted at a 90° angle on the left side, whereas on the right side they are mounted at a smaller tilt angle so as to provide summer shading for the windows below (Photo: SunTechnics Fabrisolar AG)

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Figure 4.58 As the first solar generators to be installed on a highway sound barrier, this 110 kWp installation went into operation in late 1989. An unusual but bothersome problem with it has been repeated thefts of modules, which have had to be replaced time and time again (Photo: © TNC Consulting AG, Switzerland)

Updated: August 6, 2015 — 10:43 am