A net energy meter keeps track of the all the power your solar system produces. Any solar energy that you do not use simultaneous with production will go back into the electrical grid through the meter. At night or on cloudy days, when your system is not producing more than your property needs, you will consume electricity from the grid as normal. Your utility will bill you for the “net” consumption for any given billing period and provide you with a dollar credit for any excess production during a given period.