QMWG 10/7/13

Generation Resource Energy and Regulation Deployment Performance

2

GREDP –NON-WIND Summary

• Conventional Resources - September– 311/312 scored above 90%

• 1 failure SCGT90

• Scored ½ hour for the month of September with average error of 2 MW.

• Non-wind resources scoring >85% in previous summer months were resources with very low Capacity Factors

• August 2013 316/319• July 307/308• June 313/315• May 287/292

3

CONTROL PERFORMANCE (September)

• CPS1(167) trending favorably

– Consistently scoring 160+ this summer

– Slightly lower than July and August 2013

• CPS2 (98.84) has improved from 2012

– August performance particularly impressive (99+)

• ½ of the days perfect score

• 2012 CPS2 trended very positively

• Passed 2012 CPS2 (ERCOT Waiver)

• Other ISO CPS2 performance declined over the same period

– Other Improvements observed

– Ramping periods RMS1 decreased

• Startup/shutdown improved performance

– Overall RMS1 declining in 2013

• Up slightly in September from August

4

WIND AND RENEWABLES Summer 2013

• Scoring consistent/above previous years in the summer– Reduced congestion (Slide 7) with similar or increased Energy

from Wind (Slide 5) and GREDP scores• SEPT 2013

– 58 scored/21exceeded 95% GREDP Monthly– 2,250 intervals scored, 1,950 intervals passed (86.5%)– July & August intervals ↓ sharply (slide 6)– 3 resources 100+ intervals/>95%: 94%(112), 71% (115),

92%(142)– Recent analysis indicates a very positive trend from previous

summers. • Significant issues reduced/mitigated

• Recent months indicate resources line up with technology

5

Wind Energy Ratios and Totals

Total Energy (GWH)

% Wind Energy

INTERVALS SCORED

MAY2011 2,700 10.20% 39,7002012 2,600 9% 19,3002013 3,700 13.60% 7,600

June2011 3,200 9.30% 46,4002012 2,400 7.50% 9,6002013 3,100 9.40% 4,000

July2011 1,900 5.30% 2,2002012 1,950 5.80% 1,2002013 2,100 6.20% 283

6

Congestion Management

• Congestion in wind areas has dropped off in 2013 – CREZ lines energized earlier in summer– Reduction in intervals scored

• No reported or observed issues regarding Congestion Management.– No Inter-zonal Interface limit issues in West

• No issues in Q2 or Q3 2013• One instance in Q1

– Forced outage initiated a unit-step drop in the west-north flowgate

– Immediately resolved by Wind redispatch

7

Summer IRR GREDP Summary and Congestion Trends

May June July

Average GREDP 91% 83% 94%

Scored 70 58 36

Scored < 95% 43 34 5

DEVIATION Average

3.8 3.9 3.1

INTERVALS 7,600 4,000 283

PASSED 7,000 3,300 266

85-95 19 7 0

>100 intervals 29 45 35