Workshop 7 – Hydropower_ Adding Power Plants and Generating Power

Last Modified: 2023-02-09 10:14:36.313

Software Version

HEC-ResSim pre-release Version 3.5 will be used during the 2023 PROSPECT #098 course.  Download here: https://drive.hecdev.net/share/YETr0az6

Workshop Instructions (PDF): Workshop 7 - Hydropower.pdf

Download Initial Zipped Workshop: WS7_Start.7z

Download Zipped Workshop Datafiles: WS7_data.7z

Download Solution Zipped Workshop: Workshop 7 - Hydropower_Solution.pdf and WS7_Solution.7z

Introduction

In this workshop, you will add the power plant to Crazy Mountain Dam with its existing regulating outlet and estimate the power generation available with reservoir simulation. The addition of a power plant will provide new simulation output, including power capability and generation. The workshop consists of three parts.

• In Part A, the objective will be to add the physical power plant with no operational power generation requirements and analyze the simulation results with power generation being incidental to operational release requirements.
• In Part B, the objective will be to add operational power requirements and analyze the results of the simulation operating to a meet a power schedule.
• In Part C, the objective will be to add operational outlet allocation to direct all flow through the power plant.

Part A - Add Physical Power Plant and Produce Incidental Power

Problem Description

Part A will focus on the power plant physical features, using the simpler options. Power generated by the power plant will be incidental to the releases derived from non-power releases. The Crazy Mountain Reservoir Regulation Manual (Hypothetical Reservoir Manual prepared for this class) contains power plant characteristics in its "PERTINENT DATA" section and penstock physical characteristics in Table A-6. You will add the power plant and penstock physical characteristics to the Crazy Mountain reservoir model.

Tasks

1. Open the hydropower workshop watershed: WS7_Start
2. Select the Network module
3. Open the Reservoir Network "Hydropower Workshop"
4. Edit the Crazy Mountain reservoir properties
5. Select the Physical tab in the Reservoir Editor

Section 1 - Adding a Power Plant at Crazy Mountain Dam

1. Add the Power Plant to the Dam level of the Crazy Mountain physical tree.

• Add the penstock rating in the Outlet tab of the new power plant using the data in Table A-6 of the Crazy Mountain Regulation Manual or by copy-paste from the "WS#7 Hydropower" sheet of the CrazyMountainData.xls Excel file
• Fill in the Power Plant parameters on the remaining tab panels with labels Capacity, Efficiency, Station Use, and Hyd. Losses using information from the reservoir regulation manual pertinent data or copy-paste from the Excel file

2. Add Tailwater Elevation to the Power Plant by right-clicking on it in the Physical tree

Enter a constant Tailwater Elevation from information provided in the reservoir regulation manual pertinent data.

3. Examine the existing Operation rules in Operation Set named "Hydropower". What minimum release will be made when:

• the pool elevation is within the drought contingency zone? 
• the pool elevation is within in the conservation zone?
• the pool elevation is at the top of the conservation zone? 

4. Save the Hydropower network.

5. Edit the Hydropower alternative.

• For the configuration named "Existing", select Hydropower alternative and then select the Lookback tab.
• The lookback period should have a starting elevation of 662.1 (one tenth foot above drought contingency zone), a constant flow of 1600 cfs through the regulated outlet, and a zero flow through the uncontrolled spillway.
• Add a constant zero flow through the new power plant.
• Save the Hydropower alternative.
• Close the alternative editor.

6. Save the Watershed.

Section 2 - Run the reservoir simulation

1. Select the Simulation module.
2. Open the 1997 Spring Freshet simulation.
3. For the Hydropower alternative, select "Replace From Base Directory …" to load the reservoir network data into the simulation alternative. Click to add a check in the Restore Data box and click OK to complete the replace from base.
4. Compute the Hydropower alternative.
5. When the simulation is complete, review the message output in the compute window to verify that the simulation computed successfully. (If the compute is not successful, ask for assistance before continuing.) Click the Close button to continue the workshop.

Section 3 - Become familiar with the power output options

1. Point at the Crazy Mountain reservoir in display area (within the simulation module) and right click to bring up the short cut menu. On the context menu select the Plot Power option.
2. Select the Tabulate from the plot File menu to see the tabulation.
3. From the simulation module Reports menu select the Power Summary.
4. Using the power output options and other outputs such as the Release Decision Report and the Reservoir Summary Report, view and analyze the results…

Question I

What were the minimum and maximum pool elevations in the simulation?

Question II

What was the average power generated?

Question III

When did the release from the reservoir increase over minimum?

Question IV

What rule determined the increase above minimum?

Question V

What is the maximum power that could have been generated when the pool was at the top of the conservation zone?

Question VI

What was the maximum power actually generated?

Question VII

Was the power plant flow the same as the total outflow from the reservoir? If not, why was it different?

Part B –Operating Rule: Hydropower - Schedule

Problem Description

In this part, you will add a hydropower energy requirement rule to the reservoir and evaluate the ability to meet this requirement with reservoir simulation. You will specify a scheduled energy rule and run the simulation. Power generated by the power plant in Part B will be based on a monthly energy requirement. The addition of power rules will provide new output for required power generation, which you will observe and analyze in the simulation.
Table 3-1 from the Crazy Mountain Reservoir Regulation Manual lists the monthly energy required from the Crazy Mountain power plant to be generated on a schedule of 4 hours per day Monday through Friday, 0600-1000 hours. Your job is to identify the power operation requirements in the regulation manual and add them as a rule to the Crazy Mountain reservoir.

Tasks (continued from Part A)

5. Close all plots, tables, and reports you may have opened in the Simulation Module, then go the Network module and open the Reservoir Network "Hydropower Workshop"

6. Bring up the Reservoir Editor for Crazy Mountain reservoir

7. Select the Operations tab in Reservoir Editor

8. Select the Hydropower Operation Set.

Section 1 - Adding a Scheduled Energy Operation Rule at Crazy Mountain Dam

9. Add the Firm Energy rule to the reservoir's Conservation Zone.

• On the New Operating Rule dialog select the Crazy Mountain-Power Plant from the dropdown list in the Operates Release from: field.
• Select the Hydropower - Schedule rule from the dropdown list in the Rule Type: field.
• Type Scheduled Power (or any label meaningful to you) in the Rule Name field to name the rule and click OK.

10. Add the scheduled energy information shown in the Table 3-1 in Section III (Water Control Plan) of the Crazy Mountain Reservoir Regulation Manual. Optionally, you may copy the same data from the Excel file, CrazyMountainData.xls under the worksheet labeled "WS#7 Hydropower" and paste them into the ResSim rule tables.

• Edit the Scheduled Power rule in the Conservation Zone.
• Select the "Options..." button to bring up the Power Generation Requirement dialog.
• As noted in Table 3-1, the energy Requirement Varies Monthly and is specified as Monthly Total MWH. For this workshop, allow the period over which the generation requirement is satisfied to be Each Time-Step.
• Close the Power Generation Requirement dialog by clicking OK.
• Fill in the Monthly Requirement (MWh) from Table 3-1 or by a copy-paste from the table in the Excel file.
• Click the "Power Generation Pattern …" button to bring up the Power Generation Pattern dialog.
• At top of the Power Generation Pattern dialog, the Seasonal Variation check box should remain unchecked and the label below it should read "Pattern Applies all Year" to allow the same pattern to apply throughout the simulation period.
• Since the regulation manual specifies a Monday through Friday schedule, select the Weekdays and Weekend pattern in the "Specify Pattern for" field.
• Enter "1.0" as the proportional pattern weighting factor for each of the four hours indicated for Weekdays in the regulation manual and excel worksheet. The weighting factor could be any number, but must be of equal magnitude for the four hours to indicate an equally weighted pattern. The remainder of weekday hours and the weekend should be zeros to indicate no generation required in those periods. Alternately, the pattern may be entered more conveniently with a copy-paste from the table in the Excel file.
• Close the Power Generation Pattern dialog with an OK.
• Add the new Scheduled Power rule to the Drought Contingency zone by selecting Use Existing from the Rule menu.

Question VIII

11. How much energy will your new scheduled power rule attempt to generate during the month of June?

12. Close the reservoir editor and Save the Network.

13. Save the Watershed from the File menu.

Section 2 - Run the reservoir simulation

13. Select the Simulation module.

14. Open the 1997 Spring Freshet simulation.

15. For the Hydropower alternative, select "Replace From Base Directory …" to load the reservoir network data into the simulation alternative. Click to add a check in the Restore Data box and click OK to complete the replace from base.

16. Compute the Hydropower alternative.

17. Click Close on the Compute dialog when the simulation is complete.

Section 3 - Analyze the scheduled power simulation by examining the power output options

18. Examine the plot produced by the reservoir context menu item, Plot Power. Note that there is a new variable, Power-Required, which indicates how power was scheduled to meet energy requirements.

19. Select the Tabulate from the plot File menu to see the tabulation.

20. Select the Release Decision report to see when the power rule or other rules determined the powerhouse releases.

21. From the simulation module Reports menu select the Power Summary.

22. View and analyze the results using the power output options and other outputs such as the Release Decision Report.

Question IX

What dates comprised the weekend in this simulation?

Question X

Did the power plant generate power only on the required schedule? If not, what other rules cause power generation?

Question XI

What was the average power generated during the simulation?

Question XII

What effect did the lower pool elevation at the beginning of the simulation period have on power generation?

Question XIII

Did the simulation make all releases through the power plant? If not, did these non-power releases occur during scheduled hydropower periods?

Part C – Outlet Allocation

Problem Description

In this part, you will add an outlet allocation to the reservoir to ensure all releases generate power. You will specify the appropriate allocation method and determine the effect on power generation during the simulation.

Tasks (continued from Part B)

23. In the Simulation module create a trial of the Hydropower alternative and name it Outlet Allocation.

24. Bring up the Reservoir Editor for Crazy Mountain reservoir

25. Select the Operations tab in Reservoir Editor

26. Select Hydropower Operation Set.

Section 1 - Adding outlet allocation to operation rule set

27. Select the Rel. Alloc. Tab.

• At the dam level in the Rel. Alloc. dialog, select the Sequential allocation type.
• Using the up-down arrow button move the Power Plant to the top of the list.

• In this specification, all flow will pass through the power plant up to its capacity. If release beyond the power plant capacity is required, the Regulated Outlet will make the additional release.

  

  Note

  You will need to create a new "allocation set" to be able to select the sequential allocation type

28. Close the reservoir editor and Save the Simulation.

29. Save the Watershed.

Section 2 - Run the reservoir simulation trial

30. Compute the Outlet Allocation trial.

31. Click Close on the Compute dialog when the simulation is complete.

Section 3 - Analyze the scheduled power simulation by examining the power output options

32. Using the power output options and others as necessary, view and analyze the results…

Question XIV

Did the simulation make all releases through the power plant? Other than the specified flows in the lookback period, did the reservoir make any releases through other outlets?

Question XV

Did the power plant generate additional incidental power?

Question XVI

If the average plant factor from the Part C simulation applied to the whole month, how much energy would be generated? Is this the same as the monthly energy requirement? If not, why is it different?

Question XVII

Check both the alternative and the trial to compare generation. What was the increase in average power generated during the simulation when comparing the results of Part B and Part C?