What happens to the power I don't use?
A solar system can be connected to the grid using a Gross Meter or Net Meter.
Under Gross Meter scheme all the electricity generated by your solar system is exported back to the grid and you are paid for it usually by way of a credit on your electricity bill. The payment you receive for this exported electricity is called the feed-in tariff. Not all electricity retailers pay a feed in tariff. You may need to shop around. The Gross Meter measures the entire output of the system separately to your electricity consumption.
Today most of the solar power electric systems are installed under the Net Meter scheme. A net metering system means your inverter sends the electricity your system generates to the meter box.
If you consume electricity in your house at that point in time the solar system will supply it, therefore this electricity is "free". If the amount of electricity generated by your solar power system is more than you consume at that point in time, the additional electricity is exported back to the grid. Your net electricity meter then measures how much you exported. The payment you receive for this exported electricity is called the feed-in-tariff. At night you import electricity and the net meter measures how much you consumed and adds it to the electricity you consumed during the day from the grid.
The rate of feed-in-tariff you get paid varies from State to State and from energy company to energy company. We suggest you shop around. Your solar power system installer may be able to guide you as to which energy retailer offers the best feed-in-tariff rate. (LG Dealer Search)