(1) In support of its annual filings to the department under RCW 19.285.070, utilities must document the type, availability, and cost of the reasonably available substitute resource used to calculate the incremental cost of an eligible renewable resource.

(a) In documenting the incremental cost under RCW 19.285.050 (1)(b), a utility is encouraged to identify substitute resources using its integrated resource planning process, if one is available. If a utility elects to choose a substitute resource from a different source other than its most recently published integrated resource plan, it must document the basis for this decision. Documentation of the cost of a substitute resource may include, but is not limited to, formal offers for the sale of electricity, or published cost projections from reputable third-party sources.

(b) In its selection of a substitute resource, the utility shall develop documentation demonstrating that the substitute resource satisfies the requirements set forth in RCW 19.285.050. The requirements are:

(i) Equivalence between the eligible renewable resource and the substitute resource by demonstrating the equivalence in the amount of energy produced by each resource;

(ii) Equivalence between the eligible renewable resource and the substitute resource by demonstrating the same contract length or facility life of each resource;

(iii) The substitute resource is reasonably available to the utility; and

(iv) The substitute resource does not qualify as an eligible renewable resource.

(c) Only supply-side substitute resources shall be used by utilities in the calculation of the incremental cost of eligible renewable resources.

(d) When the renewable requirements under RCW 19.285.040(2) result in a utility having resources in excess of its load, the utility may use that excess resource as the substitute resource if the substitute resource requirements of (b) of this subsection are otherwise satisfied. The utility will document the resale revenues, net of transaction costs, received through the sale of excess resources or the purchase price for the sale of the excess facility sold as a result of the requirement to acquire eligible renewable resources. A utility that uses a value other than the documented resale revenue in the determination of the levelized delivered cost of the substitute resource, such as a forecast of projected market prices, must provide documentation to support this alternative approach.

(e) A utility may use foregone power purchases from BPA, plus any billing credit obtained for reducing its purchases from BPA, as the basis for the cost of the substitute resource if:

(i) The substitute resource requirements of (b) of this subsection are otherwise satisfied;

(ii) It is entitled under its BPA power sales contract to have the BPA meet its net power requirements for the expected life of an eligible renewable resource or eligible renewable resource purchase; and

(iii) As a result of meeting the renewable requirements under RCW 19.285.040(2), it foregoes part of its BPA entitlement in order to obtain that eligible renewable resource.

(2) For an eligible renewable resource acquired prior to the passage of chapter 19.285 RCW, November 7, 2006, a utility must support the selection of the related substitute resource used in the determination of the incremental cost under RCW 19.285.050 with documentation that was available at the time of the utility's decision to acquire the eligible renewable resource. If no such documentation is available, the incremental cost of an eligible renewable resource acquired prior to the passage of chapter 19.285 RCW will be assumed equal to zero.