This PRR would amend current Protocols to include the measure of forecast error (i.e., ERCOT™s Mean Absolute Percent Error, or MAPE). Current protocols require ERCOT to provide a load forecast and the actual load. This PRR would isolate the forecast for the Day Ahead market at 1600 hours and at midnight. Additionally, the PRR would require ERCOT to post and maintain an up-to-date historical series for the monthly average MAPE data. Lastly, this PRR would require ERCOT to segregate the weather forecast error from the overall load forecast error
Load forecast error is a standard tool used to measure supply/demand forecasts and to enhance market efficiency. Publishing these statistics and maintaining an historical times series of the monthly average MAPE data would provide greater transparency to all market participants.