(1) A utility must report its greenhouse gas content calculation and metrics of energy and emissions intensity to the commission on or before June 1st of each year. The report must include annual values for each metric for the preceding ten calendar years. Each value reported must be based on the annual energy or emissions from all generating resources providing service to customers of that utility in Washington state, regardless of the location of the generating resources. When the metrics are calculated from generators that serve out-of-state and in-state customers, the annual energy and emissions outputs must be prorated to represent the proportion of the resource used by Washington customers.

(2) Each utility must perform its greenhouse gas content calculation in accordance with the rules enacted by the department of ecology, consistent with RCW 19.405.020(22).

(3) In addition to the greenhouse gas content calculation, the report shall include the following metrics:

(a) Average megawatt-hours per residential customer;

(b) Average megawatt-hours per commercial customer;

(c) Megawatt-hours per capita;

(d) Million metric tons of CO2e emissions; and

(e) Comparison of annual million metric tons of CO2e emissions to 1990 emissions.

(4) Unspecified electricity. For resources where the utility purchases energy from unknown generation sources, from which the emission rates are unknown, the utility must use an emissions rate determined by the department of ecology. If the department of ecology has not adopted an emissions rate for unspecified electricity, a utility must apply an emissions rate of 0.437 metric tons of CO2 per megawatt-hour of electricity. For the resources described in this subsection, a utility must show in the report required in subsection (1) of this section the following:

(a) Metric tons of CO2e from unknown generation sources;

(b) Megawatt-hours delivered to its retail customers from unknown generation sources; and

(c) Percentage of total load represented by unknown generation sources.

(5) The greenhouse gas content calculation and energy and emissions intensity report must include narrative text and graphics describing trends and an analysis of the likely causes of changes, or lack of changes, in the metrics.