The California Public Utilities Commission has defined the breadth of issues it expects to consider in its ongoing investigation of time-of-use rate windows. The CPUC’s investigation will inform the consideration of actual revisions to TOU rates in ratemaking proceedings. The CPUC anticipates it will issue a decision this summer that addresses:

• Minimum data, analysis and information requirements for supporting a TOU window change.
• The methodology for incorporating the data into the analysis of proposed TOU window changes.
• Other steps, if any, to be taken when evaluating proposed changes to appropriately address grid needs, cost-causation, customer acceptance and other legal requirements.

The CPUC also issued a long list of questions to parties that, among other things, address:

• The relevant data needed and data availability, covering different measures of load to be used in developing TOU periods, as well as distribution system, greenhouse-gas emissions, wholesale market and customer impacts.
• Principles to be used in setting TOU periods, and specifically factors that could or should cause a departure from the results of an approved methodology.
• Whether rate periods should remain fixed for a period of time, the process for updating them (e.g., outside of a rate case or rate window application), and grandfathering of existing customers into older structures.
• Whether rate periods could or should vary for different customers, between utilities or between different locations within a single utility territory.
• How rate periods could be tested for customer response.
• Whether TOU differentiation should be applied only to variable energy costs, or to a composite of costs that include variable and fixed components.