Photovoltaic (PV) solar panels are designed to absorb sunlight as an energy source and then generate it into current electricity. It is packaged and connected in different voltages and wattages and is perfectly suited for stand alone systems like rural electrification, lighting, telecommunications and water pumping. It can also be used as power back-up in both commercial and domestic settings. The most common use of solar energy beyond agriculture is solar water heating systems where the solar panel uses energy from the sun to generate electricity. Most PV modules use crystalline silicon cells to protect it from mechanical damage as well as moisture.