Net Metering is a utility billing mechanism, which means that if you’re making excess electricity with your solar panel systems and sending it back to the grid, you’ll be credited for it and can use free electricity.

How Does Net Metering Work?

With a solar system, you can often generate more electricity as compared to your daily consumption during daylight hours.
With net metering, the homeowner is only billed for the "net" energy used each month, that is, the difference between the energy produced by the solar power system and the energy consumed by the house over the monthly billing period.
When your house or business is net-metered, you'll see the meter run backward, and that means, depending upon local policies, you may get a credit to hedge against the electricity you use from the grid when it's not sunny or at night time. You are then billed only for your "net" energy use. The excess energy generated gets put back into the grid for your neighbors to use.