Michigan's Customer Choice and Electric Reliability Act of 2000 (P.A. 141) requires electric suppliers to disclose to customers details related to the fuel mix and emissions, in pounds per megawatt-hour (MWh) of electric generation. Electric suppliers must provide this information to customers twice annually in a standardized, uniform format. The Michigan Public Service Commission (MPSC) staff must calculate the regional electricity generation and environmental characteristics and make it available to be used by the state's generation providers. The web site above describes the methods for updating the regional generation characteristics and is updated annually by November 1st.