Net metering is a billing structure with the utility that allows a solar homeowner to "store" energy in the electric grid. When your solar panels produce more electricity than what you need, excess energy is sent to the grid in exchange for a credit against future consumption. When sending electricity back to the grid, your electric meter will roll backward, and your credit will be applied accordingly to your utility account. Although net metering is widely available, net metering rules are set by the jurisdiction that you live in and can vary.
Ask your solar professional about the specific rules in your area.