Joint Agency Staff Paper on Time-of-Use Load Impacts - Staff Paper

nder the auspices of the Joint Agency Steering Committee, the California Public Utilities, California Energy Commission, and the California Independent System Operator jointly conducted supplemental analysis for the 2015 Integrated Energy Policy Report to examine potential forecast load impacts of possible changes to time-varying rates and other rate design elements. Dimensions of the analysis include residential fixed charges, time-of-use adoption rates, time-of-use periods for residential and nonresidential rate classes, and the transition to mandatory time-of-use and default critical peak pricing for small nonresidential customers. A critical policy question for the analysis is whether time-of-use rates might be able to smooth and flatten the net load curve (total electrical load less production of wind and solar generating facilities) by season to better match changing operational needs as renewable generation increases.

This staff paper, prepared by staff from the three agencies, summarizes two independent consultant studies undertaken at the request of the agencies. Work undertaken by Christensen Associates for the investor-owned utilities analyzed scenarios for both residential and nonresidential customers. The Energy Commission engaged MRW & Associates to analyze six scenarios for residential customers only. The time-of-use periods featured four seasons and at least three pricing periods for each season. Conceptual rates provided by the California Public Utilities Commission staff assumed a fixed customer charge and are designed for 2021 as a test year.