1. VARIABLE GENERATION OPERATING RESERVE TASK FORCE VARIABLE GENERATION OPERATING RESERVE TASK FORCE Don Badley, Chair VGORTF Report to Operating Committee July 14, 2015 Salt Lake City, Utah

2. VGORTF MISSION To ascertain the different methods of estimating Regulating Reserve needed for next-day and within-day operating conditions related to variable generation.

3. VGORTF SURVEY 15 Question Survey Constructed – Distributed to all Balancing Authority Areas (BAA) on February 21, 2014 – Requested return by March 14, 2014 – Last completed survey received was on June 23, 2015. – Twenty two BAAs completed the survey. – Only four BAAs with variable generation did not complete and return the survey.

4. SURVEY FACTS Due to a lack of monitoring or record keeping, many survey questions could not be answered by every BAA. BAA survey responses, compiled survey results, and a summary of the results by survey question are posted on the WECC website.

5. SURVEY REVELATIONS Wind Generation – 19,215 MW wind generation installed within WECC. – Aggregated largest amount of wind generation within a single BAA is 5,900 MW. – 60% of BAAs with wind generation use 100% of it to serve load within their own BAA.

6. SURVEY REVELATIONS Solar Generation – 6,185 MW of utility-scale solar generation capacity installed within WECC – Aggregated largest amount of utility-scale solar generation within a single BAA is 5,499 MW. – 2,576 MW of distributed solar (PV) generation capacity installed within WECC – Largest amount of distributed solar generation within a single BAA is 2,000 MW.

7. SURVEY REVELATIONS 13 BAAs reported losing various quantities of wind generation over a 15-minute period due to high speed cutout. – The single largest amount lost by a single BAA was 958 MW. The largest amount of solar generation lost over a 15-minute period by a single BAA was 495 MW.

8. SURVEY QUESTIONS BAA Authority – Dispatch control Under what circumstances? Ability to disconnect? – Ability to deny schedules Under what circumstances?

9. SURVEY QUESTIONS Forecasting Variable Generation – How often? – Are commercial services used? Day-ahead Planning – Balancing – considerations for regulating – Unique components to consider

10. SURVEY QUESTIONS Would you support a common regional method for determining the amount of regulating reserve required due to variable generation?

11. WHERE TO FROM HERE Survey results were just compiled last week. Task Force must meet to see discuss the results and determine what more needs to be done.

12. Variable Generation Operating Reserve Task Force July 2015 Questions?