If the grid goes down and you have a grid-tied system, you will lose power as well. This is a safety precaution for utility workers, since solar can send excess energy out on neighboring wires even if the local distribution system itself is not functioning. Some brands of inverter offer a backup power supply of 1,500 watts during a power failure and when the sun is shining. This would be enough to power small electronic devices or lighting via an electrical outlet connected to the inverter itself. You can also opt to pair your system with battery back up. Should the grid go down, you can power part or all of your home with the energy stored in your battery.