Solar roof shingles work in the same way as standard solar panels, using photovoltaic cells to collect energy from the sun and convert it to electricity. It is the same technology first used in space by human-made satellites.
Solar roof shingles offer the advantage of protecting buildings against weather and producing solar energy in the same product, unlike solar panels installed over finished roofs. Before 2008, solar shingles were less efficient than solar panels, making them impractical for most buildings. After 2008, technological advances, such as copper indium gallium diselenide solar cells, allowed for thin flexible solar shingles with similar energy conversion rates to standard solar panels.
Installing solar shingles is tedious and time-consuming. Installers must individually attach each solar shingle to the roof and wire it into the building's electrical system. As of 2015, experts do not recommend self-installations. However, industry watchers also expect technological advancements to lead to easy-installation solar shingles in the near future.
Solar shingles convert sunlight into usable energy by bumping electrons with the photons in sunlight and using those moving electrons as electricity. Excess energy from solar panels generally goes back into the electrical grid, which continues to provide electricity for solar-shingle homes on cloudy days and during the night.