How Solar Works
When sunlight strikes a photovoltaic (PV) cell, it turns the sun’s energy into direct current electricity. The PV module sends the current to another piece of equipment, called an inverter, where the electricity is transformed from direct current (DC) into alternating current (AC) electricity. AC is the type of power you can use in your home or office. The solar power system is connected to the utility grid through either a bi-directional electrical meter that measures both the usage load from the building and the energy generated by the system, or a separate net generation meter that measures only the energy generated by the solar power system.
You will always be connected to the utility grid and maintain a relationship with your local utility company. Your solar power system will be set up to either allow you to directly use the solar power generated by the system or, more commonly, to send the power to the grid while giving you credit for that power. In most utility service areas, when your solar power system generates more power than you use, for example during peak daylight hours, you get credit for the energy you send back to the grid. This concept of crediting your account for the energy you produce but don’t immediately use is called net metering. The specific net metering rules (such as the rate at which solar power gets credited or the number of months you can “rollover” credits) vary by utility.