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

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

Hydro Issues

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

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

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

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 2011-14 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

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

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

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,..

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?

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)

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

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

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%

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

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

Other Hydro Suggestion?