PV modules can also be installed on sloping roofs. However, the roof may not have an optimal orientation or inclination for maximum electricity production.
The combined weight of modules, the mounting system, and any additional wind-loading needs to be considered to avoid damaging the roof. A space needs to be left between the roof and the PV modules to ensure ventilation because high temperatures will reduce the output of the modules. The installation will also need to comply with national building regulations.
PV modules being installed on a tiled roof. Mounting structures are available for different types of roofs.
PV modules being installed on a metal roof, which can get very hot on sunny days. Note the space under the modules for ventilation, and that the modules are not at the same angle as the roof.
Scaffolding will most likely be required for the installation, which adds to the cost. Working on roofs is one of the main cause of accidents in the solar industry, so special safety precautions need to be taken during installation work.