Net metering allows you to bank your electricity by spinning your meter backwards.
For many homes, solar power would not be a practical and cost effective energy alternative were it not for net metering. In essence, net metering turns the electric grid into a power bank, allowing you to both deposit and withdraw energy. During the day, when your solar electric system generates more power than you use, you actually send electricity back to the utility, spinning your meter backwards. Its like putting money – in the form of electricity - in the bank. At night, when you use more electricity than you produce, your meter spins forward again; a withdrawal of electricity from the utility. At the end of the month, you are only charged for the net difference. It’s a cleaver way for a home to ‘store’ electricity from the sun without needing bulky battery arrays.
The physical component of net metering is an actual electric meter installed by the utility. It spins forward or backward depending on your system’s output at any given moment. At the end of the month, if your home used more energy from the grid than your system produced, you'll owe the utility some money. If your home produced more electricity than you used, you won't.
Because you are using the utility to bank your electricity, it is important to size your solar system just right. An ideal net-metered solar electric system produces enough power on an annual basis to eliminate almost all of your electric bill. Paying a tiny electric bill is a good thing, it means your solar array is designed to economic perfection.