Solar cells in the modules mounted on your roof convert sunlight directly into DC power. A component called an inverter converts this DC power into AC power that can be used in your home. The system is interconnected with your utility. During the day, if your solar system produces more electricity than your home is using, your utility may allow net metering or the crediting of your utility account for the excess power generated being returned to the grid. Your utility would provide power as usual at night and during the day when your electricity demand exceeds that produced by your solar system. Systems are also available with a battery backup. Part of the power produced by your solar system during the day is used to charge the batteries, which provide power for your critical loads in the event of a power outage.