When you take electricity from the electric grid for your needs, your meter runs "forward" as it counts up the kilowatt hours consumed. But if you generate electricity with a photovoltaic (solar panel) or wind generating system and you make more electricity than you need at the time it's produced, net metering allows this excess electricity to run the other way through the meter and back into the electric grid. Net metering measures the difference between the electricity you buy from your utility and the electricity you produce using your own generating equipment. At this point, Net Metering is applicable to solar and wind generators that are 1 MegaWatt (MW) or less in size. Net Metering allows you to effectively store excess electricity you generate in the transmission grid, therefore curtailing the need for expensive storage batteries for your on-site generation system. If you produce more power than you consume, your bill will be zero. At this point, you would not receive a credit from the utility for additional power you produced beyond your own demand. Please be aware that if there is a power outage and you are net metering without a battery storage mechanism, you will not be able to use the power produced by your system during the outage.
Learn about Net Energy Metering In California
Learn about How Solar Electricity Systems Work
Learn about the Interstate Renewable Energy Council's (IREC)
Download a copy of SDG&E's Interconnection Agreement to connect your solar or wind-powered system to SDG&E's power grid.