Cal. Pub. Util. Code § 2789
Notwithstanding any provision of this part, the commission may permit or require any electrical or gas corporation subject to its jurisdiction to institute energy conservation programs for its customers, including related financial assistance at terms found reasonable by the commission. Such terms may include any provision of this chapter. This chapter shall not apply to solar water heating systems or active solar space conditioning systems. The commission shall initiate appropriate actions to secure exemptions or waivers which may be required under federal law. Nothing in this chapter shall expand, limit, or contract the general powers of the commission contained in this part or the authority of the commission regarding the terms and conditions of service by a utility. Any work requiring a license pursuant to Chapter 9 of Division 3 (commencing with Section 7000) of the Business and Professions Code which is performed pursuant to such an energy conservation program shall be performed by a licensed contractor.
Ca. Pub. Util. Code § 2789