(1) An electrical company may account for and defer for later consideration by the commission costs incurred in connection with a long-term financial commitment for:

(a) Baseload electric generation; or

(b) An eligible renewable resource as defined in RCW 19.285.030 that the electrical company owns or has entered a power purchase agreement for a term of five or more years.

(2) Deferred costs may include operating and maintenance costs, depreciation, taxes, and cost of invested capital.

(3) An electrical company deferring costs under subsection (1) of this section must:

(a) Notify the commission within ten business days of its intent to defer such costs; and

(b) File quarterly with the commission a report documenting the balances of costs deferred in a form specified by the commission.

(4) The deferral begins with the date on which the power plant begins commercial operation or the effective date of the power purchase agreement and continues for a period not to exceed twenty-four months; provided that if during such period the company files a general rate case or other proceeding for the recovery of such costs, deferral ends on the effective date of the final decision by the commission in such proceeding. Creation of such a deferral account does not by itself determine the actual costs of the long-term financial commitment, whether recovery of any or all of these costs is appropriate, or other issues to be decided by the commission in a general rate case or other proceeding authorized by the commission for recovery of these costs.