1. Northwest Power and Conservation Council
Sixth Northwest Conservation & Electric Power Plan Update: Modeled Operation of Combined-Cycle Combustion Turbines in the Pacific Northwest
Maury Galbraith
Northwest Power and Conservation Council
Portland, OR
September 25, 2008

2. Using EPA CEMS Data to Improve Modeled Dispatch of Northwest CCCTs
EPA CEMS Data: 2006 – Q1 2008
Hourly Operating Data: 19,704 hours
Generating Unit Data:
Aggregate to plant level
Gross Generation (in MW)
For gas turbines only (not for HRSGs)
Fuel Input (in MMBtu)
Fuel Factor (i.e., Hourly Fuel Input / Max(Fuel Input)) as proxy for CCCT capacity factor
July 17, 2008

3. Coyote Springs 1: Actual Operation in 2007
July 17, 2008

4. Coyote Springs 1: Modeled Operation in 2007
July 17, 2008

5. Hermiston Power: Actual Operation in 2007
July 17, 2008

6. Hermiston Power: Modeled Operation in 2007
July 17, 2008

7. Klamath Cogen: Actual Operation in 2007
July 17, 2008

8. Klamath Cogen: Modeled Operation in 2007
July 17, 2008

9. More modeled starts per year…
July 17, 2008

10. Much shorter modeled runtimes…
July 17, 2008

11. Q: Why is excessive shutdown an important problem?
A: Because it impacts:
wholesale power market price forecasts; and
power system carbon dioxide forecasts
July 17, 2008

12. AURORA CCCT Commitment and Dispatch Parameters
5th Plan
Proposed
Source/Comment
Minimum Up Time
24 hours
16 hours
EPA CEMS
Minimum Down Time
6 hours
3 hours
Minimum Capacity
.40 2 x 1
.80 1 x 1
Unit Specific
Ramp Rate
100%
(1 hour)
Startup Cost -- ??
Warm-up fuel, wear & tear?
Shutdown Cost
Cool-down fuel, wear & tear?
July 17, 2008

13. Minimum Capacity Estimation
July 17, 2008

14. Minimum Capacity In CCCT Mode: Estimation Using EPA CEMS Data
In AURORA Minimum Capacity is specified as a percentage of Nameplate Capacity
Used only for commitment (or non-cycling) operation
Separate Cycle-Only mode for simple cycle operation
Use EPA CEMS data to create cumulative frequency of operating level curves
Use judgment to select Minimum Capacity
Criterion: beyond all zones of infrequent operation (i.e., “forbidden zones”)
July 17, 2008

15. Coyote Springs 1: Cumulative Frequency of Operating Level (N = 14,180 hours)
July 17, 2008

16. PNW CCCTs: Cumulative Frequency of Operating Level Curves
July 17, 2008

17. Coyote Springs 1: Min. Cap = 185 MW in CCCT Mode Nameplate = 226 MW
July 17, 2008

18. Big Hanaford: Min. Cap = 198 MW in CCCT Mode Nameplate = 248 MW
July 17, 2008

19. Chehalis: Min. Cap = 416 MW in CCCT Mode Nameplate = 520 MW
July 17, 2008

20. Coyote Springs 2: Min. Cap = 201 MW in CCCT Mode Nameplate = 264 MW
July 17, 2008

21. Frederickson: Min. Cap = 242 MW in CCCT Mode Nameplate = 310 MW
July 17, 2008

22. Klamath Cogen: Min. Cap = 288 MW in CCCT Mode Nameplate = 480 MW
July 17, 2008

23. Port Westward: Min. Cap = 341 MW in CCCT Mode Nameplate = 426 MW
July 17, 2008

24. Minimum Capacity in CCCT Mode % of Nameplate
July 17, 2008

25. Minimum Capacity in CCCT Mode % of Nameplate
July 17, 2008

26. Ramp Rate Estimation
July 17, 2008

27. Ramp Rates: Estimation Using EPA CEMS Data
In AURORA Ramp Rate is specified as a percentage of Nameplate Capacity
Used for all modes of operation
Used at all levels of operation (e.g. zero to min cap. or min cap. to nameplate)
Use EPA CEMS data to find minimum time (i.e., fastest ramp) to full level of operation
Use judgment to select “full” operation level
July 17, 2008

28. Coyote Springs 1: Ramp Rate Illustration
July 17, 2008

29. Minimum Number of Hours to Heat Input Factor > = .95
July 17, 2008

30. Minimum Number of Hours to Heat Input Factor > = .90
July 17, 2008

31. Minimum Number of Hours to Heat Input Factor > = .85
July 17, 2008

32. Ramp Rates of PNW CCCTs % of Nameplate
July 17, 2008

33. Ramp Rates of PNW CCCTs % of Nameplate
July 17, 2008

34. Next Steps: Estimate Start-up and Shut-down costs
Use AURORA’s new “shutdown penalty” to adjust modeled CCCT operation
July 17, 2008