Trinity Public Utility District’s Application for a Solar Photovoltaic and Battery Storage Cost-Effectiveness Determination for Nonresidential Buildings

The California Energy Commission’s (CEC) 2022 Building Energy Efficiency Standards (Energy Code) went into effect on January 1, 2023. The 2022 Energy Code requires the installation of solar photovoltaic systems and battery storage systems for newly constructed nonresidential buildings and for newly constructed high-rise multifamily buildings. In conjunction with those requirements, section 10-109(k) of the 2022 Energy Code states, “The Commission may … determine that the photovoltaic or battery storage requirements … shall not apply, if the Commission finds that implementation of public agency rules regarding utility system costs and revenue requirements, compensation for customer-owned generation, interconnection fees, or other factors, causes the Commission’s cost-effectiveness conclusions, made pursuant to Public Resources Code 25402(b)(3), to not hold for particular buildings.” 

The Trinity Public Utility District applied on November 21, 2022, for a CEC determination regarding whether the solar photovoltaic system and battery storage system requirements should apply to nonresidential and high-rise multifamily buildings in its service area. As a result of specific exceptions in the 2022 Energy Code, the solar photovoltaic and battery storage system requirements do not apply to high-rise multi-family buildings or multi-tenant nonresidential buildings in the Trinity Public Utility District, and to nonresidential buildings that have lower conditioned floor area as explained in this report. Staff has performed a cost-effectiveness analysis based on the public agency rules adopted by Trinity Public Utility District. Staff finds that the solar photovoltaic system requirements are cost effective, but that the battery storage system requirements are not cost effective for nonresidential buildings. Staff recommends that the CEC determine that the 2022 Energy Code solar photovoltaic system requirements are applicable to newly constructed nonresidential buildings in the Trinity Public Utility District, but that the battery storage system requirements are not applicable.