(1) Each utility that is required to prepare an integrated resource plan under RCW 19.280.030(1) must establish by January 1, 2022, a standard for resource adequacy to be used in resource planning, including assessing the need for and contributions of generating resources, storage resources, demand response resources, and conservation resources. The resource adequacy standard must be consistent with prudent utility practices and relevant regulatory requirements and must include reasonable and nondiscriminatory:

(a) Measures of adequacy, such as peak load standards and loss of load probability or loss of load expectation;

(b) Methods of measurement, such as probabilistic assessments of resource adequacy; and

(c) Measures of resource contribution to resource adequacy, such as effective load carrying capability applicable to all resources available to the utility including, but not limited to, renewable, storage, hybrid, and demand response resources.

(2) Each utility not subject to subsection (1) of this section must identify by January 1, 2022, the resource adequacy standard relied on by the utility in preparing its resource plan and CEIP.

(3) In each CEIP submitted after 2022, each utility must identify and explain any changes to its resource adequacy standard.