It is possible to fit photovoltaic modules to many different building types. There are various methods of affixing module arrays to buildings – both integrated and mounted.
Modules can be fitted to vertical facades, building roofs (pitched and flat) and ground mounted structures. On roof systems can be fitted to or between slate, tiled and glass roofing. Modules can also be glazed – giving a practical and functional method of adjusting a building temperature, whilst generating electricity. PV systems, as well as generating electricity, become an additional part of the buildings shell, offering it additional protection from weather, sun shading and noise insulation.
Flat roofs leave the Solar PV system designer a great deal of freedom, whereas pitched roofs dictate the orientation and elevation angle of the modules. Your Solar PV Installation company will therefore carry out a site survey before system planning commences, to check the roofs suitability.
In on-roof mounting, solar panels are fitted above the existing roof covering with the use of a retro fitted metal structure. This method holds the roofs water proofing capability, and is generally the most cost effective method of fitting a PV array to an existing roof. The only real disadvantage to this method is that the whole system is exposed, leaving it exposed to the elements.
The system layout will be decided and agreed before work commences – this is to ensure that customers are aware of the reasons for any non-grid like layouts. Shading should be considered also – as if any panel is partly shaded, the systems performance will suffer.
The metal framework which supports the PV array is comprised of three main components. Roof mounts, rails and module fixings are used to hold the panels to the roof structure on pitched roofs. Generally, on a domestic install, where the roof covering is tiles, the roof mounts will be fitted directly to the roof structure itself by removing a number of tiles. On a rood where the covering itself is strong enough, the mounts will be fitted directly to the covering. If on any roof the covering is structurally sound enough, the mounting brackets can be directly fixed to it as long as any forces applied to the mounting frame and panels would be directly transferred to the building’s structure.
PV arrays are seen as building structures, so must comply with building and planning codes. Loads and weather applied to the array should not make the system tilt, slip overturn or lift from the structure it is fixed to. To ensure this, consideration must be given to the amount of, and spacing between roof mounts.
Copyright (c) 2010 Aaron Dicks