Most household rooftop solar installations are grid-tied units, which means they remain linked to the utility grid. This relationship allows homeowners to: This photovoltaic effect was initial identified in 1839 but has become refined and commercialized over the past many a long time. This tool uses pictures from Google Earth https://bluetechsolarcell.com/solar-cell-%e0%b8%81%e0%b8%b1%e0%b8%9a-solar-rooftop-%e0%b9%81%e0%b8%95%e0%b8%81%e0%b8%95%e0%b9%88%e0%b8%b2%e0%b8%87%e0%b8%81%e0%b8%b1%e0%b8%99%e0%b8%ad%e0%b8%a2%e0%b9%88%e0%b8%b2%e0%b8%87%e0%b9%84%e0%b8%a3/