Solar Renewable Energy Certificates (SRECs) or Transition Renewable Energy Certificates (TRECs) are credits that solar users can earn for their solar production. They sort of work like the stock market.
If your state has an active SREC or TREC market, you can earn one credit for every 1,000 kWh your solar panel system produces. The average solar user will earn about one credit per year. Then you can sell those credits for money, with the values dependent on the current market value for that state.
Unfortunately, Arizona doesn’t have an active SREC or TREC market at this time.