There are 2 different metering ways to connect our solar photovoltaic system to the grid, The first is net metering and the second is gross metering.
In net metering, our solar inverter will push the generated electricity into the energy metering panel, then into our house, so our electrical appliances/equipment and electronics can work normally. At that point of time, if our house equipment’s need whole solar generated electricity to work, then it’s okay, and we therefore consume such electricity free of charge, in other word, we will no electricity bills. But if there will be surplus electricity generated from the solar system at that point of time in which our house equipment does not need, then where will it go?
The answer is: It will be exported back to the power grid to be used by the electricity company to supply other neighborhood houses and that we called feed-in tariff.
The energy meter in that case will measure how much net kwh will be exported to the grid, so you can get paid form the electric utility based on the contracted feed in tariff. Usually, the price for each exported kwh ranges from 10 cents to 15 cents, and the price of consumed kwh ranges from 20 cents to 50 cents.
At night our house electrical equipment consumes electricity, and in some times during the day, we they also consume electricity, so the net energy meter will add both to each other. Also the net meter will measure the exported energy during the day as we sometimes export energy as clarified aforementioned and finally at the end of the month, you will get the readouts from the energy meter for how much exported and imported energy and the difference between them (net), so you can pay or get paid accordingly.
The feed in tariff rate differs from one state to another, and from electricity company to another, so you have to check carefully about the best for your benefits. We recommend to ask your solar company their advice, because they will be aware of the best solar retailer that provides high feed in tariff.
In gross metering, the whole solar system generated electricity will go to the grid, and you will get paid for it as a form of credit shown in the electricity bill. In other word, we can say that in gross metering, it measures the entire output energy separately from your energy consumption, and you pay for electricity bill (energy consumption), and get paid for exported energy, in where no relation in between them "no net".
Some states follow net metering scheme while others follow gross metering scheme, and at the end the solar system owner will be winner in both cases, he will not lose at all from his installed solar photovoltaic system.