Under the Power Source Disclosure Program, retail suppliers are required to annually disclose to their retail consumers the mix of sources used to provide electricity service during the previous calendar year. In those instances where a retail supplier offers consumers more than one electricity portfolio, the retail supplier is to provide information specific to each electricity portfolio offered. The Energy Commission uses this information, in part, to generate California’s total system power mix, known as “Total California System Electricity”. Additionally, retail suppliers are required to disclose the greenhouse gas (GHG) emissions intensity associated with each electricity portfolio. Retail suppliers then disclose to their consumers the power mixes and GHG emissions intensities associated with their electricity portfolios, as well as the Total California System Electricity on an annual Power Content Label. The Total California System Electricity represents the sum of all utility-scale, in-state generation and net electricity imports, and serves as a reference point on the Power Content Label.