One of the components of the SunRoof roof is the system of photovoltaic cells that convert solar energy into electricity. Photons (i.e. particles of light) fall on the silicon plate from which a photovoltaic cell is built. Each photon is absorbed by the silicon and knocks an electron from its position, forcing it to move. This electron movement is the flow of electricity. By using a p-n type semiconductor connector, it is possible to combine this process of electron flow to create a power grid, where light is transformed into electricity.