1. MWG Recommended Hydro Improvement March 14, 2017
Kevin Harris, ColumbiaGrid
TEPPC\Model Work Group - Chair

2. Overview Correct HTC p Factor
Complete modeling change for the Core Columbia River
Propose Hydro dispatch option to be set to “Load – Solar –Wind” by region
Wind Coefficient Factor: ?
Solar Coefficient Factor: 100%
Revise PLF for Load- Solar
Review proposed plants to be converted from “Hourly” to “PLF”
PS Changes: Castaic, Oroville, and Thermalito

3. Hydro Issues

4. HTC p Factor
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%
Correction: Mult all “p” factors by 2

5. Modeling Core Columbia River
The Core Columbia River are the 11 projects between Grand Coulee and Bonneville and Lower Snake River
2024 data set assumed some of the projects used a fixed hourly shape
Data provided to WECC assumed all projects using PLF with a couple of HTC
Recommendation: Complete modeling change of Core Columbia and Lower Snake to PLF/HTC

6. Model Core Columbia by Plant
I have a scenario that aggregates the Core Columbia river plus Lower Snake River units by plant
This eliminates ~195 units from the dataset
Recommendation: Apply aggregation scenario for Core Columbia and Lower Snake River to WECC dataset

7. FYI: Review Core Columbia River
HTC has a tendency to create average daily generation profile skewed to the afternoon/evening peak
This profile is outside of historic operation for
I have received 2014 and 2015 hourly generation and will be review resent operation for skewed afternoon generation shift
I will also be reviewing Hydro modeling of Core Columbia River with BPA
New HTC modeling recommendation with be coming for Core Columbia and Lower Snake

8. Hydro Dispatch to Multi Regions
Do not use multi regions assignment for NW Hydro
Hydro dispatch to multi regions does not create a proxy load by summing the modeled percentage of each regions load
Not knowing what the load the Hydro is being PLF with makes it difficult to calc the appropriate K Factor
Until this method is adjusted use it at you on risk

9. Hydro Dispatch
“Hydro Dispatch Option” for Proportional Load Following (PLF) needs to be re-set to “Region Load – Wind – Solar”
If proper GridView version is available the percent of wind and solar can be set by region
Recommendation: Use “Region Load – Wind –Solar”
Region temporal setting to:
Solar Coefficient Factor:= 1 (100%)
Wind Coefficient Factor
In the Northwest:=0 (0%)
Outside the Northwest:= ?
Revise PLF for Load - Solar

10. Hourly Shape Hydro Dispatch
Many units in California are modeled with a hourly shape but the are capable of daily shaping Hydro generation daily
Fixed hourly shapes use 2005 do not take into account Hydro dispatching against “Load – Solar”
Converting these units to PLF would support the California afternoon ramp instead of contribute to the problem
Example: WAPA’s Judge F Carr, Spring Creek, Folsom, Hetch Hetchy Project, DWR, ID,..

11. Example Hourly Shape Hydro Dispatch
Currently these WAPA projects are on a fixed hourly shape: Judge F Carr, Spring Creek, & Folsom
Changing to PLF shifts the summer mid-day peak to the evening
Fixed hourly shape is based on 2005
Adjusted to 2009 monthly Hydro generation
Resulting PLF Hydro generation
May & Dec mid-day gen?

12. Benefit of PLF Dispatch
Difference in PLF – Fixed Hourly generation
Overall a mid-day is neutral or a drop on Hydro generation
This mid-day drop shift generation to the evening peak
Hydro dispatched to
● JF Carr: CAISO
● Spring Crk: CAISO
● Folsom: BANC
The combination of low monthly generation with high K factor at JF Carr in both May and Dec resulting in surplus generation of 47% and 146% (HTC required to adhere to gen)

13. Consider Run-Off River (ROR) as PLF
Many small Hydro projects are ROR
No regulation exist therefore what ever flow in flows out
Regulation exist but down stream requirement allow little flexibility in daily peak
Recommendation: Consider modeling generation with a flat profile as PLF with K Factor set to zero or small value
When changing water years only monthly generation needs updating

14. Hourly Shape Hydro Dispatch
Recommendation: Converting select fixed hourly shape Hydro plants to PLF
A list of current plants modeling and recommended changes will be provided
The “Convert Fixed to PLF 2026CC1.7 v01.xlsx” shows units converted from fixed to PLF with annual average “K” value
One week to for participants to review and make comments

15. Castaic PS Current PS efficiency 85%, 75% and 65%
Notes from CEC the average operational PS efficiency is 70%
Recommendation: Lowering PS efficiency to 71%, 66% and 61%

16. Is Oroville and Thermalito PS
Currently some units at Oroville (Edward Hyatt) and Thermalito are PS capable and modeled as PS
EIA-923 show no pumping load after 2007
Minor pumping in 2/2002 & 3/2007
Recommendation: Model as 100% Hydro plant, no PS

17. Summary of Recommendations
Correct HTC coefficient by multiplying by 2
Complete modeling change of Core Columbia and Lower Snake to PLF/HTC
Apply aggregation scenario for Core Columbia and Lower Snake River to WECC dataset
New HTC modeling recommendation with be coming for Core Columbia and Lower Snake
Recommendation: Use “Region Load – Wind –Solar”
Recommend converting some fixed hourly shapes to PLF
Change Castaic PS eff to: 71%, 66%, or 61%
Convert Oroville and Thermalito PS to Hydro PLF

18. Other Hydro Suggestion?