RTO Winter Resource Adequacy Assessment Status Report

Transcription

1 RTO Winter Resource Adequacy Assessment Status Report RAAS 03/31/2017

2 Background Analysis performed in response to Winter Season Resource Adequacy and Capacity Requirements problem statement. Per CP rules, Reliability Requirement is Annual. In other words, summer requirement is equal to winter requirement. According to PJM s 2017 Load Forecast Report, the forecasted annual (summer) peak for 2021 is 153,384 MW while the forecasted winter peak for 2021 is 133,050 or 86.7% of the annual peak 2

3 Winter Versus Summer 3

4 Forecast Distributions Winter vs Summer Load in 2014DY was 11.1% higher than W/N, consistent with a 98 th -99 th percentile load. Weather was more consistent with around 90 th percentile. Weather would have had to be comparable to 1994 to reach ratio (11.1%) seen in 2014 DY. In 1994, winter peak weather was 8 degrees colder. 4

5 Background (contd.) If the IRM for 2021 is equal to 16.6%, then the installed reserves during the 2021 winter peak week are equal to / = or 34.5%. The most recent IRM study shows that such level of reserves during the winter peak week result in a winter peak week LOLE= days/year The LOLE in this week must be this low because the total LOLE in the remaining 51 weeks is days/year The question is: Are we accurately capturing the LOLE risk during the winter peak week (and other non-summer weeks)? 5

6 Factors impacting non-summer LOLE in PRISM Winter peak forecast accuracy (monthly peaks as well) Load uncertainty Generator forced outages Generator planned outages Transmission system maintenance outages (not currently modeled in PRISM) 6

7 Winter 10CP Model Error by Forecast Vintage 0 Year Out Forecast 7

8 Winter 10CP Model Error by Forecast Vintage 3 Year Out Forecast 8

9 Winter Weather: Wind-Adjusted Temperature Since 1998 Jan 7, 2014 and Feb 19,

10 Winter: Load versus Weather 10

11 Load uncertainty Comparison between Winter CP1 and Load uncertainty during Winter peak in PRISM 11

12 Data from DY 2007 through DY All Units Generator Forced Outages In PRISM: Current Probability Of Exceeding 10% Forced Outages: ~

13 Generator Forced Outages Data from DY 2007 through DY Gas Units only 13

14 Generator Forced Outages Grouping the Forced Outages Rates of the weekdays in the winter peak weeks of the last 9 DYs results in the following approximate density function Mean = 8.3% Standard Deviation = 4.0% In PRISM, Winter Peak Week Forced Outages: Current Mean = 7.3% Current Standard Deviation = 1.3% 14

15 Generator Forced Outages Replacing the Forced Outage Rates from Winter 2014 with those from Winter 2015: Mean = 7.3% Standard Deviation = 2.0% In PRISM, Winter Peak Week Forced Outages: Current Mean = 7.3% Current Standard Deviation = 1.3% 15

16 Forced Outage Rates in all Winter Weeks Generator Forced Outages 16

17 Generator Forced Outages Replacing the Forced Outage Rates from Winter 2014 with those from Winter 2015: 17

18 Data from DY 2007 through DY All Units Generator Planned Outages 18

19 Planned Outage Rates in all Winter Weeks Generator Planned Outages In PRISM, Current Planned Outage Rate Winter Peak Week = 1.3% 19

20 Generator Planned Outages Replacing the Forced Outage Rates from Winter 2014 with those from Winter 2015: In PRISM, Current Planned Outage Rate Winter Peak Week = 1.3% 20

21 Transmission System Maintenance Outages A maximum of 280 transmission elements (lines or transformers) were on planned maintenance at some point in January 2017 Could these transmission maintenance outages result in winter deliverability problems? 21

22 Transmission System Maintenance Outages 22

23 Next Steps Winter peak forecast accuracy Concern over accuracy on extreme winter events (the days that are most crucial for LOLE calculations). Investigate means to tighten accuracy on these type of days. Load uncertainty Current winter peak load uncertainty seems to be a good representation of winter CP1 uncertainty If winter CP1 uncertainty changes, this topic will be revisited 23

24 Next Steps Forced outages Develop new ways to represent distribution of forced outages during winter: At RTO level, using log-normal distribution or empirical distribution Planned outages Vary planned maintenance schedule in PRISM to make it more consistent with historical data 24

25 Next Steps Transmission system maintenance outages (not currently modeled in PRISM) Obtain data from previous summer and winter periods to assess difference in number of transmission system elements on outage by season How to translate these outages into MW of generation not being delivered? Still an open question 25