The commission shall award reasonable advocate’s fees, reasonable expert witness fees, and other reasonable costs of preparation for and participation in a hearing or proceeding to any customer who complies with Section 1804 and satisfies both of the following requirements:
(a) The customer’s presentation makes a substantial contribution to the adoption, in whole or in part, of the commission’s order or decision.
(b) Participation or intervention without an award of fees or costs imposes a significant financial hardship.