To generate most electricity, the location of solar panels should be such that the maximum amount of solar radiation reaches them. In the northern hemisphere, the optimum solar panel location is a south-facing roof. The following factors should also be taken into account:
Roof orientation, tilt and condition
For best performance, you need around 100 square ft of unshaded south-facing space for every kilowatt of electricity. Thin-film panels may need up to 175 square feet. The amount of solar radiation will be less if your roof faces SE or SW.
Photo Credit: NREL.gov
The condition of your roof is important, too. Ensure the roof can hold the weight of the system (about 3-5lb per square foot) and that the roofing material will last as long as the PV system (25-30 years).
Most PV modules are mounted flat on the roof, and so have the same tilt as the roof. The best angle for PV panels is that of your latitude, but a roof is rarely at that angle. A PV installer can calculate the right angle for the panels, or any performance decrease if the panels are flat on the roof.
Potential Shading
Try to avoid mounting PV panels in areas that receive shade from trees, electrical cables, buildings, chimneys, vents or any other source. Remember that shading in an area can change from summer to winter as the sun’s path changes. An installation professional can estimate the shading your system will receive.
Alternatives
If your roof is not south facing or has a lot of shade coverage, there are other options. Pole- or ground-mounted systems are suitable for homes with large yards. Tracking systems allow entire arrays to track the sun over the course of a day and through seasonal variables as well. They maximize the number of sun-hours received in a day.
Before you install solar hot water, consider the following factors: solar resource: the amount of sunlight reaching your solar collectors ...
Once you decide to install a home solar panel system, the first question is: how many solar panels do I ...
Monocrystalline solar cells are cut from a single crystal of silicon. This method makes them the most efficient but also ...
Polycrystalline solar cells are made by heating the silicon from multiple crystals of silicon and pouring the molten silicon into ...
Recognizing all the advantages of solar panels, often the most important question households ask before going solar is: how expensive ...
