Solar panels use photovoltaic cells to convert sunlight into direct-current electricity. An inverter changes this into alternating-current electricity for your home, where it can power appliances as they operate. If your panels produce more electricity than you need, the excess may be sent to the grid for a feed-in tariff or stored in a battery, depending on your system. When solar production is low, such as at night, your home can draw electricity from a battery or the grid. A licensed installer can recommend a system based on your roof, usage and local rules.