Review of Upstate Load Forecast Uncertainty Model

Transcription

1 Review of Upstate Load Forecast Uncertainty Model Arthur Maniaci Supervisor, Load Forecasting & Energy Efficiency New York Independent System Operator Load Forecasting Task Force June 17, 2011 Draft for discussion only

2 Overview 1. Review 2010 LFU Models 2. Review 2010 ICAP Models 3. Review 2012 LFU Model 4. Compare & Assess LFU model appears to have too much saturation. 2. Recommend retaining 2010 LFU model 2

3 NYCA Peak-Producing CTHI And Design Criteria CTHI Stats to 2010 CE CH LI NGrid NYPA NYSEG OR RGE NYCA Max Mean Median Min Std Deviation Actual CTHI Percentile Design Criterion 67th 50th 50th 50th 50th 50th 67th 50th 50th Design CTHI Note: CTHI is the Cumulative Temperature-Humidity Index 3

4 (1) 2010 IRM Weather Response Models Two Models: Zones A to E and Zones F&G. Used NYCA-wide weather data to fit models. Each region showed saturation. Pooled data from 2006, 2007 & 2008 Developed in

5 Zones A to E Per-Unit MW Data y = E-06x E-05x E-04x E-03x E Vertical yellow lines show Design CTHI, +1 and +2 sigma CTHI - 57 PU_MW Check P.U. Model 5

6 1.20 Zones F & G Per- Unit MW Data 1.10 y = E-05x E-03x E-03x E Vertical yellow lines show Design CTHI, +1 and +2 sigma CTHI - 65 PU_MW Check P.U. Model 6

7 Weather Response Function for Zones A to E MW per CTHI 220 MW/F at 82 F 135 MW/F at 89 F Vertical yellow lines show Design CTHI, +1 and +2 sigma

8 Weather Response Function for Zones F & G MW per CTHI 120 MW/F at 82 F, 70 MW/F at 89 F Vertical yellow lines show Design CTHI, +1 and +2 sigma

9 (2) 2010 ICAP Weather Response Models One model per Transmission District. Used weather data specific to each district. Each district showed saturation. Used only 2010 data. 9

10 Modeled Weather Response - MW per CTHI, vs CTHI National Grid 145 MW/F at 82 F 94 MW/F at 89 F Poly_3 CTHI_75 PWL_2 10

11 80 70 Modeled Weather Response - MW per CTHI, vs CTHI NYSEG 56 MW/F at 82 F 12 MW/F at 89 F Poly_3 CTHI_75 PWL_2 11

12 40 Modeled Weather Response - MW per CTHI, vs CTHI Central Hudson MW/F at 82 F 17 MW/F at 89 F Poly_4 CTHI_75 PWL_2 12

13 40 Modeled Weather Response - MW per CTHI, vs CTHI O&R MW/F at 82 F 31 MW/F at 89 F Poly_3 CTHI_75 PWL_2 13

14 Modeled Weather Response - MW per CTHI, vs CTHI RG&E 35 MW/F at 82 F 19 MW/F at 89 F Poly_3 CTHI_75 PWL_2 14

15 (3) 2012 IRM Weather Response Model Single model for Zones A to G. Used Buffalo/Syracuse/Albany weather data. Region shows much more saturation than prior analyses. Used data from

16 2012 LFU Upstate Load Model 3 rd Order Polynomial Variable Coefficient StdErr T-Stat P-Value CONST % Wthr.CTHI % Wthr.CTHI_ % Wthr.CTHI_ % 15,000 14,000 13,000 12,000 11,000 10,000 Upstate MW vs CTHI Vertical blue lines show Design CTHI, +1 and +2 sigma Regression Statistics Iterations 1 Adjusted Observations 58 Deg. of Freedom for Error 54 R-Squared Adjusted R-Squared Durbin-Watson Statistic Durbin-H Statistic #NA AIC BIC F-Statistic Prob (F-Statistic) Log-Likelihood Model Sum of Squares Sum of Squared Errors Mean Squared Error Std. Error of Regression Mean Abs. Dev. (MAD) Mean Abs. % Err. (MAPE) 1.29% Ljung-Box Statistic Prob (Ljung-Box) , Actual Predicted Upstate Weather Response IRM Study Vertical yellow lines show Design CTHI, +1 and +2 sigma

17 2012 Upstate Load Forecast Uncertainty Model CTHI NGrid Load Model Derivative Max A E+02 Mean A E+01 Median A E+00 Min A Stdev 2.41 Ref CTHI 58 MW Ref at 50th 2012 MW at 50th Z' Cum Per Unit MW/tv MW/tv CTHI 2012 MW dmw dtv Prob Model from Bins from eqn 50th

18 (4) Comparison of Models All three analyses indicate upstate saturation is present. Estimates vary as may be expected given different years of analyses & weather data. Each region showed saturation in 2010 ICAP. Need to assess 2012 LFU Model, since it shows more saturation than either of the other two models. 18

19 Comparison of Upstate Weather Response Models (MW per CTHI) vs CTHI Design CTHI 83.5 Red vertical lines show design to +2 sigma Design CTHI 82.3 Blue vertical lines show design to +2 sigma LFU Model 2012 Model Estimate of 2010 ICAP 19

20 , 2010 & 2012 LFU Models for Zones A-G Model 2010 Model 2012 Model 20

21 Final Recommendation Retain 2010 LFU model LFU model is consistent in behavior with 2010 ICAP models LFU model is not consistent with the other two models. 21

22 The New York Independent System Operator (NYISO) is a not-for-profit corporation responsible for operating the state s bulk electricity grid, administering New York s competitive wholesale electricity markets, conducting comprehensive long-term planning for the state s electric power system, and advancing the technological infrastructure of the electric system serving the Empire State. 22