Cal. Pub. Util. Code § 399.15
(b) The commission shall implement renewables portfolio standard procurement requirements only as follows:
(1) Each retail seller shall procure a minimum quantity of eligible renewable energy resources for each of the following compliance periods:
(2)
(5) The commission shall waive enforcement of this section if it finds that the retail seller has demonstrated any of the following conditions are beyond the control of the retail seller and will prevent compliance:
(A) There is inadequate transmission capacity to allow for sufficient electricity to be delivered from proposed eligible renewable energy resource projects using the current operational protocols of the Independent System Operator. In making its findings relative to the existence of this condition with respect to a retail seller that owns transmission lines, the commission shall consider both of the following:
(B) Permitting, interconnection, or other circumstances that delay procured eligible renewable energy resource projects, or there is an insufficient supply of eligible renewable energy resources available to the retail seller. In making a finding that this condition prevents timely compliance, the commission shall consider whether the retail seller has done all of the following:
(D) Unanticipated increase in retail sales due to transportation electrification. In making a finding that this condition prevents timely compliance, the commission shall consider both of the following:
(e)
(2) If the commission determines that an electrical corporation may exceed its cost limitation prior to achieving the renewables portfolio standard procurement requirements, the commission shall do both of the following within 60 days of making that determination: