Q: What is "net metering"?
A: A homeowner's supplemental power system, such as a wind turbine or — more commonly — photovoltaic system, may generate more electricity than that needed by the home. A special electric meter (supplied by the local power company) measures the unused excess, which flows back onto the power grid and appears as a credit in the homeowner's account.
When the home needs more power than is generated by its supplemental system, electricity is drawn from the grid but is paid for by the accumulated credits before new charges are made. Thus, the homeowner pays only for the net amount of the utility's power.