1. Recommended Hydro Improvement April 11, 2017
A Continuation of 3/14 & 4/4 Meetings
Kevin Harris, ColumbiaGrid
TEPPC\Model Work Group - Chair

2. Overview Review How to Calc K and p Coefficients
Modeling of the Columbia River
Modeling Changes for the Columbia River
Propose Lowering HTC on the Columbia River
Hydro Dispatch Against Load – Wind - Solar
Convert Select Daily Dispatchable Hydro from Fixed Hourly Shape to PLF

3. Approved Items

4. HTC p Factor Review of the 2026CC results show an input error
GridView support two methods for evaluating HTC: Rectangle and Triangle method
Rectangle Method divides by 4
Triangle Method divides by 2
Issue: P factor in the 2026CC are divided by 4. This reduces the HTC dispatch range by 50%
Propose WECC: Correction all “p” factors to correspond to ‘Triangle Method’ by multiplying by 2

5. Castaic PS Current PS efficiency 85%, 75% and 65%
Notes from CEC the average operational PS efficiency is 70%
Proposed WECC lowering PS efficiency of Castaic to 71%, 66% and 61% (and adj the benefit cost ratio to 1.0)

6. Is Oroville and Thermalito PS
No use at Edward Hyatt (Oroville)
All 6 units modeled as PLF/HTC
Duplicate units exist for Thermalito 2-4. It is modeled as a hourly shape and PLF
Propose WECC consolidate modeling as Thermalito as PLF only

7. Aggregate Hydro Units by Plant
I have a scenario that aggregates the Core Columbia river plus Lower Snake River units by plant
This eliminates 197 units from the dataset
ABB is no issues with this aggregation in the PCM or the round-trip process
Propose WECC apply scenario that aggregate Hydro by plant when they become available or when WECC staff has time to create them
ColumbiaGrid will provide a scenario to aggregate the Core Columbia and Lower Snake River

8. Review How to Calc K & p

9. How does PLF Work
Proportional Load Following (PLF) assume the relative change in Hydro generation is proportional to a relative change in load
The reference frame for load and Hydro generation is average monthly value

10. Calc Hydro K Avg daily operating range by month (MW)
The difference between typical daily max minus min generation
Max used the average of the 3 highest values/day
Min used the average of the 3 lowest values/day
Avg monthly generation (aMW)
𝑯𝒚𝒅𝒓𝒐 𝑲′= 𝑯𝒚𝒅𝒓𝒐 𝑮𝒆𝒏(𝒂𝒗𝒈 𝒅𝒂𝒊𝒍𝒚 𝐦𝐚𝐱 −𝒂𝒗𝒈 𝒅𝒂𝒊𝒍𝒚 𝐦𝐢𝐧⁡) 𝑯𝒚𝒅𝒓𝒐 𝑮𝒆𝒏(𝒂𝒗𝒈)
𝑯𝒚𝒅𝒓𝒐 𝑲′= 𝑯𝒚𝒅𝒓𝒐 𝑮𝒆𝒏(𝑶𝒑𝑹𝒂𝒏𝒈𝒆 (𝑴𝑾)) 𝑯𝒚𝒅𝒓𝒐 𝑮𝒆𝒏(𝒂𝒗𝒈)
𝑲(𝑺𝒍𝒐𝒑𝒆)= 𝑯𝒚𝒅𝒓𝒐 𝑲′ 𝑳𝒐𝒂𝒅 𝑲′
Load K’ is calc in the same way as Hydro K’

11. c p ∗C=𝑂𝑝𝑅𝑎𝑛𝑔𝑒(𝑀𝑊)*HTC(Share) → p= OpRange(MW)∗HTC(𝑆ℎ𝑎𝑟𝑒) 𝑐 𝑝 ∗𝐶
Calc HTC p
HTC reshapes a share of PLF Hydro generation based on LMP
The original equation for HTC
Where:
C – Plant Capacity
A – Plant Operating Range (OpRange)
This assumes a 50/50 split between PLF/HTC hence ½
Re-writing where
HTC(Share) + PLF(Share) = 1 (Share of operating range)
A/2:= Range of Plant Gen for HTC:= OpRange(MW)*HTC(Share)
4:= c(p) = Constant based on HTC method used: Rectangle method c(p) = 4 (2 passes with +/- = 4) and Triangle method c(p) = 2 (1 pass with +/- = 2)
4pC = 𝐴 2 → p= 𝐴 8𝐶
c p ∗C=𝑂𝑝𝑅𝑎𝑛𝑔𝑒(𝑀𝑊)*HTC(Share) → p= OpRange(MW)∗HTC(𝑆ℎ𝑎𝑟𝑒) 𝑐 𝑝 ∗𝐶

12. Calc K and p Consolidate K and p Calc where
OpRange = Average Daily Operating range for Hydro and Load
Avg monthly Hydro generation and load
PLF(Share) + HTC(Share) = 1 (Share of operating range)
c(p) = If HTC method is ‘Rectangle’ = 4 or 2 of ‘Triangle’
Max rating: Modeled (MW)
Min rating: Modeled [ROR] (MW)
𝑲(𝑺𝒍𝒐𝒑𝒆)= 𝑯𝒚𝒅𝒓𝒐 𝑲′ 𝑳𝒐𝒂𝒅 𝑲′
𝑯𝒚𝒅𝒓𝒐 𝑲′= 𝑯𝒚𝒅𝒓𝒐 𝑶𝒑𝑹𝒂𝒏𝒈𝒆 ∗𝑷𝑳𝑭(𝑺𝒉𝒂𝒓𝒆) 𝑯𝒚𝒅𝒓𝒐 𝑮𝒆𝒏(𝒂𝒗𝒈)
𝑳𝒐𝒂𝒅 𝑲′= 𝑳𝒐𝒂𝒅 𝑶𝒑𝑹𝒂𝒏𝒈𝒆 𝑳𝒐𝒂𝒅(𝒂𝒗𝒈)
𝒑= 𝑯𝒚𝒅𝒓𝒐 𝑶𝒑𝑹𝒂𝒏𝒈𝒆 ∗𝑯𝑻𝑪(𝑺𝒉𝒂𝒓𝒆) 𝒄 𝒑 ∗𝑴𝒐𝒅𝒆𝒍𝒆𝒅 𝑴𝒂𝒙

13. Modeling the Core Columbia River

14. Operational Change Starting in 2011
Slide was originally present 11/3/2015
Starting in 2011 the annual average daily operating range decrease by 2,224 MW (38%)
Any forecast run should reflect this reduction in operational flexibility
Take-a-way: To calc 2009 Hydro the OpRange needs to be calc based on post 2011 operation ( used)

15. Example Historic Operations
Slide was originally present 8/31/2015
Example operation for January 2010 through 2013
Aggregated and some individual projects Hydro generation are proportional to load
Take-a-way: Hydro gen from individual projects are not always proportional to load but the aggregate Net Columbia, Upper Columbia and Lower Columbia are
Load Used:=
100% of BPA
+ 100% of MidC
+ 6% of CAISO
Per unit of generation the operating range of Upper Columbia is greater than the Lower Columbia

16. Summary of Calc Procedure
Columbia River operation were split into aggregate system (Upper & Lower Columbia)
OpRange: Calc based on average OpRange based on operation for 2009 monthly generation w/2008 used for Jun-Aug
Hydro K’ calc based on allocated OpRange *PLF(Share) and avg monthly generation
Calc p based on allocated OpRange *HTC(Share)

17. Modeling Changes for Columbia River

18. Provided to WECC All Core Columbia River units converted to PLF
Hydro data for 2009 w/ 2008 used for Jun-Aug.
When appropriate a PLF/HTC split of 50/50
Calc based on region load equal the sum of 100% of BPA, MidC (CHPD, DOPD, GCPD) + 5% CAISO
Provided: Annual load weighting of BPA 60.7%, CHPD 4.3%, DOPD 2%, GCPD 5.9% + CAISO 27.1%

19. Current Modeling of Columbia River
Provided monthly PLF/HTC variable for all plants
None of the fixed hourly shapes were converted to PLF
This results in a mismatch of input assumption used in the dataset
Propose WECC completing the modeling change on the Core Columbia by changing the fixed hourly shapes to PLF

20. Hydro Dispatch to Multi Regions
Hydro dispatch to multi regions uses a scaled unit against the region load
This makes it difficult to calc an appropriate K when load factor of the regions are not similar
A clean relationship exist of historic Hydro operation to BPA load. See posted file ‘ Columbia Riv Gen HTC PLF Compare v01’
Propose WECC eliminate multi regions assignment for NW entities with regions outside of the NW

21. Propose Lowering HTC on the Columbia River

22. Core Columbia with 50/50 PLF/HTC
From posted spreadsheet ‘ Columbia Riv Gen HTC PLF Compare v01’
50% HTC shifts morning ramp energy to afternoon ramp in most months
PLF only misses the afternoon ramp in when NW peaks in the morning (Mar)
20% HTC is a reasonable compromise that balances 50% HTC with 0% HTC (100% PLF)

23. Core Columbia with 50/50 PLF/HTC
Posted spreadsheet ‘ Columbia Riv Gen HTC PLF Compare v01’ compares average weekday Hydro generation shape vs. historic Hydro operation and load
For both absolute and unitized values
Overall the 50/50 PLF/HTC results in a significate shift in avg hourly generation shape when compared to historic
Propose WECC lowers PLF/HTC modeling assumption on the Core Columbia River from 50/50 to 80/20
Long term: Work with BPA to determine what an appropriate Hydro flexibility exist and provide to the HMTF with updates when new information becomes available

24. Hydro Dispatch Against Load – Wind - Solar

25. Hydro Dispatch Load - Wind
Slide was originally present 8/31/2015
Relative to load, wind generation serves up to 64% of BPA daily load in or 20% of annual load
Changing from “Load” to “Load – Wind” increases the deviation in daily a factor of 2.7
The expanded daily StDev directly impacts the daily allocation of Hydro generation. This impact can be amplified when K is > 1
Installed Wind Capacity in BPA for ,515 MW

26. Summary Load – Wind for BPA
Issues occur if wind/solar is intermittent and a high percentage of area load
The relationship for K breaks down

27. Region Load – Wind - Solar
Conceptually Hydro is dispatched against net load
In CA daily wind generation is stable relative to PNW wind
In CA daily solar generation is stable relative stable except for some days in the winter intra monthly allocation of load – Solar should not be a problem

28. Hydro Dispatch
Propose WECC test or implement the use of “Region Load – Wind –Solar” with the following setting:
In all case BPA Wind Coefficient Factor:= 0.0 (0%)
Option 1: Solar/wind Coefficient Factor of 50/50%
Option 2: Solar/wind Coefficient Factor of 100/50%
Option 3: Solar/wind Coefficient Factor of 100/100%

29. Convert Select Daily Dispatchable Hydro from Fixed Hourly Shape to PLF

30. Hourly Shape Hydro Dispatch
Previously (3/14/2017) we covered the advantages of converting Hydro that has daily shaping capability from fixed hourly shape, based on 2005, to PLF
The primary advantage is when Hydro is dispatching against “Load – Solar” the daily peak generation shifts in response to the net load
The posted spreadsheet from the 3/14/2017 meeting was in PDF format
This format is difficult to review

31. Hourly Shape Hydro Dispatch
Propose the following:
Convert the listed units in “Convert Fixed to PLF 2026CC1.7 v02.xlsx” from fixed hourly shapes to PLF
For any plant the owner/operator disagrees with will not be converted

32. Other Hydro Suggestion?
(503)