1. ERCOT PUBLIC 6/17/2014 1 2014 LTSA Load Distribution Methodology June 17, 2014

2. ERCOT PUBLIC 6/17/2014 2 Outline  Purpose  Background  Current Trends  Other scenarios  Next steps

3. ERCOT PUBLIC 6/17/2014 3 Purpose  To reflect differences in how load is distributed from scenario to scenario  Need to project trends into future years  Presentation by the Texas State Demographer at LTSTF Scenario Workshop #1 stated that higher growth rates are expected along the I-35 corridor, especially in the “ring counties”

4. ERCOT PUBLIC 6/17/2014 4 Projected percent population change 2010-2030

5. ERCOT PUBLIC 6/17/2014 5 Background  Scenario-specific load forecasts are provided by weather zone  The load growth for counties within their respective weather zones are expected to vary between scenarios  This variation can be modeled by using scenario- specific county level growth rates to adjust distribution factors

6. ERCOT PUBLIC 6/17/2014 6 Current Trends  County load growth in the SSWG DSB cases was used as means to capture load growth in current trends  Compound annual growth rate (CAGR) values were calculated for each county using the 2015 and 2020 SSWG DSB cases posted on March 3, 2014  The loads from the final 2018 case from the 2013 RTP were grown to 2024 and 2029 levels using county CAGR values  Distribution factors were calculated for 2024 and 2029 by normalizing each load value relative to the total load for its weather zone  Self-served loads were not changed

7. ERCOT PUBLIC 6/17/2014 7 Other scenarios  High economic growth:  Accelerated growth rates  Increased activity in dry gas basins  Stringent environmental:  Growth rates stay close to current trends  Dampened growth in oil and gas activity  County specific load distribution can be modeled by adjusting CAGR values for specific counties  Oil and gas counties can be identified based on oil and gas well count growth rates

8. ERCOT PUBLIC 6/17/2014 8 Next steps  Update distribution factors to be used for Current Trends, Stringent Environmental, and High Economic Growth scenarios  Update distribution factors to be used in UPLAN for generation siting  Update distribution factors to be used in PowerWorld for reliability analysis

9. ERCOT PUBLIC 6/17/2014 9 Questions

10. ERCOT PUBLIC 6/17/2014 10 Appendix: Input load assumptions excerpt from scenarios Input Assumptions 1. Current Trends 3. High Economic Growth 6. Stringent Environmental System Load Growth (Peak and Total Energy) MedHighMed I-35 MedHighMed Houston MedHighMed Midland/Odessa MedHighLow Lower Rio Grand Valley MedHighMed Dry Gas Basins LowHighLow