Impact of IDR Meter Threshold on Load Forecasting Models

1. IDR Meter Threshold Impact on Load Forecasting Models RMS/COPS Workshop III - IDR Meter Protocol Requirement Threshold January 30, 2015

2. Forecasting Categories • Forecasting process utilizes aggregated output from ERCOT settlement process • ERCOTs data aggregation process uses PROFILECODE to produce aggregated energy for the categories below: • Residential • Lighting • Business (excluding BUSIDRRQ) • BUSIDRRQ • Forecasting reduces the four categories above to three by combining Residential & Lighting • Forecasting then uses the load volume and ESI ID counts per each category by weather zone to produce forecast models

3. Load Summation Formulas

4. IDR Meter Threshold Impacts Load Forecasting Process • Eliminating/Modifying the IDR Meter protocol required threshold would shift loads between ERCOT forecasting categories • Process utilizes historical load volumes • Shifting of load would impact the accuracy of the load forecasting process • Impact is minimized if ERCOT has the ability to identify large customers with AMS meters no longer aggregated into the BUSIDRRQ category

5. An option that maintains integrity of forecasting process • If AMS meter reaches some defined threshold, switch the weather sensitivity code from “WS” to “NWS” • All AMS meters are currently defined by protocol section 11.4.3(2) as “WS” so a protocol change would be required • Allows for identification of all large customers as BUSIDRRQ or AMS meters with NWS • Does not require a new PROFILECODE • Allows load forecasting to continue to use settlement aggregated output • ERCOT will make appropriate internal changes to support • Allows the market to eliminate or modify the IDR requirement threshold where AMS meters are deployed

6. Questions