1. Load Forecast Adjustments for WECC Common Case Galen Barbose Lawrence Berkeley National Laboratory Data Work Group call December 8, 2015

2. Background, Context, Motivation Common Case is intended to be reflect current policies and utility plans (RPS, IRP, EERS, etc.) BA load forecasts vary in the manner/extent to which they account for planned energy efficiency and demand response policies and program plans –Some may not include any EE impacts, while others may only include a portion of the planned EE In prior study cycles, LBNL has assisted the DWG with making adjustments to the firm and non-firm load forecasts in order to: –Support the overarching intention of the Common Case (i.e., to reflect current policies) –Improve consistency across BAs in terms of EE & DR accounting 2

3. Energy Efficiency Adjustments Objective: Adjust firm load forecasts, as necessary, to fully capture energy efficiency impacts under current policy and program plans –Based on current Energy Efficiency Resource Standards or IRPs Last study cycle (2024 Common Case): –Focused only on utility ratepayer-funded programs; did not make adjustments for federal or state appliance standards, building codes, or other program/policy types –Focused only on those specific BAs (CISO, IPC, PNM, TEP) that, through prior study cycles, were known to systematically “under-count” energy efficiency impacts in the load forecasts submitted to WECC This year’s study cycle: –Replicate process from last time around, pending responses from BA staff –Reach out to regional EE experts to confirm appropriate basis for EE savings assumptions –Reach out to load forecasting staff with each BA to confirm how/whether EE is captured in their firm load forecasts 3

4. Demand Response Adjustments Objective: Adjust non-firm load forecasts, as necessary, to fully capture expected quantity of DR available under current policy and program plans Yields DR quantities then can then be dispatched in GridView; the MWG is leading a separate process to specify how DR resources will be modeled Last study cycle (2024 Common Case): –Compare each BA’s non-firm load forecast against other sources of utility DR planning data, including Utility IRPs and FERC DR survey results –Contact representatives from BAs to resolve discrepancies between LRS non-firm load forecast and plans identified in IRPs and/or FERC DR survey, making adjustments as necessary This year’s study cycle: –Replicate the process from last time, prioritizing effort on those BAs where significant adjustments were made (CISO, PACE, APS, PSE, TEP) 4

5. Next Steps Need green light from DWG and WECC on the approach Assemble initial set of BA load forecasts Assemble list of contacts (regional EE experts, BA load forecasting staff) Begin initial outreach efforts, enlisting help from DWG members as needed Develop draft adjustments to both firm and non-firm load forecasts, consulting with relevant DWG members Present draft adjustments to DWG on future calls Question on timing: By when do the Common Case load forecasts need to be approved by DWG? 5

6. Background Slides: 2024 Common Case Adjustments 6

7. 2024 Common Case EE Adjustments: Percent Adjustment to Monthly Energy 7 Balancing Authority Load ZoneJanFebMarAprMayJunJulAugSepOctNovDecAnnual CISOPGE_BAY-3.9% CISOPGE_VLY-3.9% CISOSCE-4.0% CISOSDGE-3.3% IPCOFAR_EAST-3.5%-3.9%-4.2%-4.5% -4.0%-3.5%-3.6%-4.0%-4.4%-4.0%-3.3%-3.9% IPCOMAGIC_VLY-3.5%-3.9%-4.2%-4.5% -4.0%-3.5%-3.6%-4.0%-4.4%-4.0%-3.3%-3.9% IPCOTREAS_VLY-3.5%-3.9%-4.2%-4.5% -4.0%-3.5%-3.6%-4.0%-4.4%-4.0%-3.3%-3.9% PNM -4.3%-4.9%-4.7%-4.9%-4.5%-4.2%-3.9%-4.0%-4.5%-4.6% -4.2%-4.4% TEPC -1.2% -1.0%-0.9% -1.1%-1.3%-1.4%-1.3%-1.1% Values represent the percentage of the total firm + non-firm LRS load forecast

8. 2024 Common Case DR Adjustments: Percent Adjustment to Max Annual Non-Firm Load After reviewing IRPs and contacting utilities, E3 made a number of substantial adjustments to the 2023 LRS forecast Most adjustments were confirmed with utility representatives The largest recommended change is in the California ISO Figure and table exclude BAs with no non-firm load submission to LRS and no recommended changes