Usually, the best location for a PV system is mounted on an existing roof. For the most part, if your modules are oriented at slopes 45° or less (typical roof pitches) and oriented within 30° of south, your system will provide at least 90% of the optimal energy output. If a rooftop can’t be used, your solar modules can also be placed on the ground, either on a fixed-mount or a “tracking” mount that follows the sun to orient the PV modules for maximum performance. They can also be mounted to provide shade on window awnings or over patios.
The amount of space needed by a PV system is based on the physical size of the system you purchase. A starter 1 kW residential system will need about 100 square feet. If your location limits the physical size of your system, you may want to install a system that uses more efficient PV modules which use less surface area to convert sunlight into a given amount of electric power. A PV system can be installed on any roof type, but some may be easier to work with than others.
If your roof is older and needs to be replaced in the very near future, you may want to replace it at the time the PV system is installed to avoid the cost of removing and reinstalling your PV system. There is an increasing number of building integrated photovoltaic products such as shingles or raised-seam metal roof sections. One benefit of these systems is their ability to offset the cost of roof materials.