Wash. Rev. Code § 19.405.030
(1)
(3) The commission must allow in rates, directly or indirectly, amounts on an investor-owned utility's books of account that the commission finds represent prudently incurred undepreciated investment in a fossil fuel generating resource that has been retired from service when:
[ 2025 c 221 s 2; 2019 c 288 s 3.]