California Code, Public Utilities Code - PUC § 9500

(a) Each publicly owned electric and gas utility that provides the energy for space heating for low-income customers shall also provide home weatherization services for those customers if a significant need for those services exists in the utility's service territory, as determined by the utility, taking into consideration both the cost-effectiveness of the services and the public policy of reducing financial hardships facing low-income households. Publicly owned utilities shall not have to duplicate low-income home weatherization services provided by gas and electrical corporations serving the same service territory.

(c) “Weatherization” may also include other building conservation measures, energy-efficient appliances, and energy education programs determined by the utility to be feasible, taking into consideration both the cost-effectiveness of the measures and the public policy of reducing the financial hardships facing low-income households.