Net metering or reverse metering is an electricity policy where consumers who own small renewable energy systems such as photovoltaic (PV) or wind systems can sell back the electricity that they produce to the utility.  Smart meters are used to subtract the energy you produce from the energy you consume from your electricity bill each month.  A system operator receives a retail credit for the electricity they produce.  Most electric meters record in both directions.  It is a rewarding feeling to watch your electricity meter actually roll backwards for the first time. 

Net metering is a low cost and easy to operate incentive for people to invest in renewable energy.  It actually increases the value of the electricity you produce because you can bank it for use at a later time or date.  Providers also benefit from net-metering because consumers are actually producing energy during the peak time of usage. 

The rules for net metering vary across the country.  Currently net metering is allowed in 43 states and Washington DC.  Some states such as California offer a market rate for the electricity you produce while other states offer a reduced rate. Consult with a local solar installer for the details in your area.