Economic Dispatch of Non-Monotonically Increasing Generators

1. Economic Dispatch of Non-Monotonically Increasing Generators May06-07 Client: MidAmerican Energy Company Alan Oneal Faculty Advisors: Dr. John Lamont Students: Matthew Ellis, EE Robert Walter, EE Jeremy Hamilton, EE Noraima Fernandez, EE

2. Overview of Presentation • Introductory Material • Project Activity Description • Resources and Schedules • Closing Material May 06-07

3. Acknowledgements • Dr. John Lamont • Dedicated project team advisor • Alan Oneal • MidAmerican Energy client contact May 06-07

4. List of Definitions 1/3 Waste Heat Fuel Power CT (Airplane Engine) Waste Heat May 06-07

5. Power Fuel CT#1 Waste Heat Power Σ Power HRSG Waste Heat Fuel CT#2 Power List of Definitions 2/3 Average Cost per MWhr. $80 $30 Monotonic (MU)→ ←Non-Monotonic (NMU) May 06-07

6. List of Definitions 3/3 • Unit Commitment: Selection of which units to run(2 components) • Operating Costs (Economic Dispatch) • Start-up Costs • Economic Dispatch: Allocation of power to individual generating units on line to produce cheapest electricity demand solution (occurs when every unit has the same incremental cost) ________________________________________________________________ • Monotonic unit (MU): a generator that produces more power output as fuel input is increased (i.e. Combustion Turbine) • Non-monotonic unit (NMU): a generator that can have an increase in power output with no increase in fuel input • Heat recovery steam generator (HRSG): the second process of the combined cycle that recovers waste heat to drive a steam turbine May 06-07

7. Problem Statement • General Problem Statement • Conventional monotonically increasing algorithms will not dispatch non-monotonically increasing units without altering the data, thus currently an optimal solution can not be found. • General Problem Solution • Modification of a pre-existing algorithm incorporated into Microsoft Excel macros in order to give MidAmerican Energy the lowest cost solution to meet their power demand with the shortest solution time possible. • The project team will focus their concentration on improving the structure of the unit commitment page, reorganizing the way output is displayed, implementing a main menu, and finally restructuring the code to allow the user to dispatch a defined range of hours. May 06-07

8. Operating Environment • Windows based computer system • Adequate processing capabilities • Microsoft Excel workbook • Programming via Visual Basic macros May 06-07

9. Intended Users and Intended Uses • Users • MidAmerican Energy’s generation dispatchers • MidAmerican Energy’s short-term energy traders • Uses • Optimize the economic dispatch of monotonically increasing and non-monotonically increasing generators • Benchmark cost curves for future algorithm designs May 06-07

10. Assumptions and Limitations • Assumptions • Enumeration / iteration will be used as the optimization method for the algorithm • 12 monotonically increasing units and two sets of non-monotonically increasing units are being modeled • Limitations • Software must use Microsoft Excel as the interface • Input data for generating units will use piece-wise linear incremental cost curves • Results must be written into a single Excel workbook May 06-07

11. End Product and Other Deliverables • Microsoft Excel workbook with Visual Basic macros embedded • User instructional documentation • Easy to use interface • Programmer’s guide May 06-07

12. Previous Activities • The previous group accomplished • A working algorithm • Unverified complete solution • The problems with previous work • Errors in code • Code was hard to understand due to lack of comments • Main menu was hard to understand due to lack of instructions • Lack of features in the program May 06-07

13. May 06-07

14. Present Accomplishments • Added features to program • Unit commitment page • Output page(s) • Fixed errors from previous group • Increased usability • Main Menu • Embedded instructions • Restructured program • Secondary Menu • Range of hours • Verified solution May 06-07

15. New Main Menu May 06-07

16. New Secondary Menu May 06-07

17. Approaches Considered and One Used • Only one approach considered • Client requested not to change solution algorithm • Solution algorithm from previous group was used • Approach used • Modify existing program • Add features • Speed up run-time May 06-07

18. Project Definition Activities • Technology considered and selected • Client requirement was to use Excel with Visual Basic macros • Advantages • Previous program was already in this format • User friendly • Disadvantages • Slow • Lack of Visual Basic knowledge May 06-07

19. Research Activities • Meet with advisor • Background information on Economic Dispatch • How ED works for NMU • Reading previous group’s work • Understand how solution works • How to build and add to it • Research on Visual Basic • No prior knowledge May 06-07

20. Design Activities • Meeting with client • What needed to be changed • What needed to be added • Group meetings • How changes would be made • How features would be added • How it would be implemented • How it would work with existing program May 06-07

21. Implementation Activities • Individual work • Modifying existing code • Writing new code • Group work • Integrating new code modules • Integrating new features into menus May 06-07

22. Testing and Modification Activities • MATLAB • Linear programming used • Verified that solutions for program were correct • Client • Received feedback • Modifications made based on client feedback May 06-07

23. Resource Requirements 1/3 May 06-07

24. Resource Requirements 2/3 • Financial requirements: expenses May 06-07

25. Resource Requirements 3/3 May 06-07

26. Schedules May 06-07

27. Project Evaluation • Project divided up into 8 milestones • Priority status • Assigned to each milestone • Corresponds to percentage of time milestone required May 06-07

28. Project Evaluation May 06-07

29. Project Evaluation • Milestones evaluated as follows • Greatly Exceeded – Minimum expectations were met with the addition of several extra features. • Exceeded – Minimum expectations were met with the addition of one or more extra features. • Fully Met – Minimum expectations were met. • Partially Met – Some of the minimum expectations were met. • Not Met – None of the minimum expectations were met. • Not Attempted – The minimum expectations were not attempted. May 06-07

30. Project Evaluation May 06-07

31. Project Evaluation • Evaluations we given a per-unit score • Greatly Exceeded 1.1 • Exceeded 1.0 • Fully Met 0.9 • Partially Met 0.5 • Not Met 0 • Not Attempted 0 or Not Applicable • Evaluation Score = Priority Status x Per-Unit Evaluation Points May 06-07

32. Project Evaluation May 06-07

33. Project Evaluation • Passing Score = 90 • If any major tasks were only partially completed the project would be unsuccessful • Major tasks • Design • Implementation • Testing May 06-07

34. Project Evaluation • The project team’s final score: 95.7 May 06-07

35. Commercialization This product (as is) is meant to perform a client specific task. The final product is intended to be used only by MidAmerican Energy. Therefore, there are currently no plans for commercialization. May 06-07

36. Recommendations for Additional Work • Implementation of a faster solution algorithm • Additional user defined options for NMU configurations May 06-07

37. Lessons Learned • What went well? • Worked well as a team to produce a successful product • What did not go well? • Dividing up tasks • What technical knowledge was gained? • Economic Dispatch • Visual Basic Programming • What non-technical knowledge was gained? • How to interact with a client • Things to be done different next time? • More initial client interaction May 06-07

38. Risk and Risk Management • Anticipated Risks • Loss of a team member • Computer storage problems • A change to one part of the code unexpectedly affecting another section of the code • Planned Management • After any change to the program the newest version was sent to every team member • Software versions saved not only on ISU accounts, but also on every members personal account. • A separate log-book was made detailing who made the last version and what has changed about it. • Unanticipated Risks • *NONE* May 06-07

39. Closing Summary The electrical power industry is changing at an extremely rapid pace. This change is so rapid that there are many details that are being overlooked when it comes to economic dispatch. With the help of our product, MidAmerican Energy will not only be ahead of the times, but will also have the opportunity to make additional profit. May 06-07

40. Questions? Greater Des Moines Energy Combined Cycle Plant May 06-07