Netmetering?

Net metering is a billing arrangement that allows solar system owners to receive credits for the excess electricity they generate and send back to the grid. When your solar panels produce more electricity than you need, the surplus is automatically fed back into the grid. The utility company then credits you for the excess energy, which can offset or reduce your future electricity bills.

Credited to customer's next bill at retail rate with no annual true-up (perpetual rollover)