Solar photovoltaic cells, typically made from silicon alloys, convert the sun's energy in to direct current (DC) electricity. Strings of photovoltaic cells are encased in a rigid frame and connected together to make up a solar panel. Panels are typically installed on a rooftop to maximize their exposure to the sun. Multiple panels are required to meet the electricity requirements of an average household.
Racking for home solar power installation is placed just above the existing roof. Racking connects through small penetrations into footings, which are mounted directly into the roofing truss, which is the strongest part of the roof structure.