Incorporating Energy Efficiency into Western Interconnection Transmission Planning

The Western Electricity Coordinating Council (WECC) conducts transmission planning studies through its Transmission Expansion Planning and Policy Committee (TEPPC). In recent years, WECC’s transmission planning process has been substantially expanded and enhanced with funding from the U. S. Department of Energy provided under the American Recovery and Reinvestment Act (ARRA) of 2009. This expanded effort, designated the Regional Transmission Expansion Planning (RTEP) project, entails the development of biennial 10- and 20-year transmission plans that serve to identify future transmission expansion needs and options for meeting those needs. The analysis conducted for each plan evaluates numerous stakeholderdriven “study cases” (i.e., scenarios) using production cost modeling and capacity expansion modeling tools. These study cases are selected through WECC’s annual study request process, whereby stakeholder groups can recommend specific study cases for analysis during the annual study cycle. State regulators and energy agencies provide input to WECC’s transmission planning analyses via (among other channels) the State -Provincial Steering Committee (SPSC), an entity formed by the Western Governors’ Association (WGA), which participates in the annual study request process.

Lawrence Berkeley National Laboratory (LBNL) provides technical assistance to the SPSC and WECC with the development of demand-side management (DSM)-related assumptions and modeling inputs for WECC’s transmission planning analyses. In this capacity, LBNL’s work todate has largely revolved around the implementation of specific SPSC study requests for both the 10-year and 20-year plans. In particular, these study requests have included (a) “reference cases” that incorporate the expected impacts of current DSM-related policies and plans and (b) “High DSM” study cases that entail higher levels of DSM impacts than anticipated in the reference case. This activity has occurred under the auspices of the SPSC DSM Work Group. Participants in that group, including state regulatory and energy agency staff, utilities, and regional DSM experts, have vetted and provided input on key assumptions and methodologies. Critical review and input has also been provided by the TEPPC DSM Task Force, the TEPPC Data Work Group, and other key participant groups within the TEPPC process.

This report documents the energy efficiency-related analyses developed by LBNL and its contractors have conducted within the 2011 and 2012 TEPPC study cycles. This includes three distinct study cases: the 10-Year Reference Case (termed the WECC 10-Year Common Case), the 10-Year SPSC High DSM/DG Case, and the 20-Year SPSC High DSM/DG Case. Each of those study cases included assumptions and analyses for three types of DSM resources: energy efficiency, demand response (DR), and distributed generation (DG). This report focuses specifically on energy efficiency; the DR and DG components of the study cases are addressed in separate reports (Satchwell et al., 2013; Olson and Schlag, 2013).