If your system generates more power than your home uses during one billing cycle, you’ll get credit for that excess juice during another billing cycle. For example, if you generate more power than you use in July, you can use the credit toward your December bill. But, at the end of the year, if you’ve generated more than you’ve used, some utilities will not compensate you. Beginning in 2011, all California utilities except LADWP are required to pay you for all of your surplus electricity. Please check with your utility to find out how the Net Metering or Solar Bank program in your area works.