Optimization of Resilient, Reliable, and Renewable Energy Infrastructure for Large-Scale Essential Services in Urban Environments

Op imiza ion o Resilien , Reliable, and Renewable Ene gy
In as uc u e o La ge-Scale Essen ial Se ices in U ban
En i onmen s
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Submi ed o: Joe Lei a
Resea ch, De elopmen & Demons a ion
Sou he n Cali o nia Gas Company
555 Wes 5 h S ee ,
Los Angeles, CA 90013
Submi ed by: P o esso Jacob (Jack) B ouwe , Di ec o
Vic o Klumpe
D . Robe Flo es, Senio Scien is
Clean Ene gy Ins i u e
Uni e si y o Cali o nia, I ine
I ine, Cali o nia 92697-3550
Tel: (949) 824-1999 x221
Fax: (949) 824-7423
jb ou[email p o ec ed]ci.edu
Oc obe 03, 2025
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Table o Con en s
Table o Con en s ........................................................................................................................... i
Lis o Figu es ............................................................................................................................... i
Lis o Tables ............................................................................................................................... ii
Execu i e Summa y ................................................................................................................... iii
1 In oduc ion ........................................................................................................................... 1
1.1 Pu pose ............................................................................................................................. 1
1.2 Li e a u e Re iew ............................................................................................................. 2
1.3 Cu en Wo k and Con ibu ions ...................................................................................... 5
2 Key Assump ions ................................................................................................................... 6
3 Scena ios ................................................................................................................................. 6
4 Resiliency Analysis ................................................................................................................ 8
4.1 Wild i e/PSPS E en Zones ............................................................................................. 8
4.2 Resiliency o he Exis ing Elec ical G id/Model Ve i ica ion ...................................... 12
4.2.1 Zone 1 – Lowe Palm Sp ings Co ido .................................................................. 13
4.2.2 Zone 2 – Uppe Palm Sp ings Co ido .................................................................. 14
4.2.3 Zone 3 – Vic o ille Co ido ................................................................................. 15
4.2.4 Zone 4 – San a Cla i a Co ido .............................................................................. 16
4.2.5 Zone 5 – Cen al Co ido ....................................................................................... 19
4.2.6 Conclusions on Exis ing G id Resiliency Unde Full Loads .................................. 20
4.3 Residen ial & Comme cial Building S ock C i ical Loads ............................................ 20
4.3.1 Residen ial Load P o ile ......................................................................................... 21
4.3.2 Comme cial Load P o ile ........................................................................................ 21
4.3.3 Adjus ing Load P o iles .......................................................................................... 21
4.3.4 Zone 3 ..................................................................................................................... 22
4.3.5 Zone 4 ..................................................................................................................... 23
4.3.6 Zone 5 ..................................................................................................................... 24
4.3.7 Conclusions on C i ical Load Resiliency ................................................................ 24
5 Pipeline Hyd ogen as a Resiliency Augmen a ion ............................................................ 25
5.1 Combining Models ......................................................................................................... 25
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5.2 Sys em Response o Remo al o Non-Renewables ....................................................... 26
5.3 Le e aging Pipeline Hyd ogen....................................................................................... 27
5.3.1 Segmen 1 – Palm Sp ings o Comp esso S a ion ................................................. 30
5.3.2 Segmen 2 – Comp esso S a ion o Basin .............................................................. 32
5.4 Simula ing he Inclusion o Hyd ogen Wi hin OpenDSS .............................................. 32
5.5 Including Na u al Gas Demand ...................................................................................... 37
5.6 Fuel Cell Sizing P oblem ............................................................................................... 39
5.7 Resiliency o Resul ing Sys em...................................................................................... 41
5.7.1 Zone 1 – Pipeline Included ..................................................................................... 41
5.7.2 Zone 2 – Pipeline Included ..................................................................................... 47
5.7.3 Zones 1 AND 2 – Pipeline Included ....................................................................... 49
5.7.4 Zone 3 – Pipeline Included ..................................................................................... 52
5.7.5 Zone 4 – Pipeline Included ..................................................................................... 54
5.7.6 Zone 5 – Pipeline Included ..................................................................................... 57
5.7.7 Conclusions on Hyd ogen-Rein o ced Sys em Resiliency ..................................... 60
6 Pe o mance Unde Comple e Elec i ica ion o End-Uses ............................................. 60
6.1 Resiliency Analysis ........................................................................................................ 62
6.2 Commen s on T anspo a ion Elec i ica ion ................................................................. 65
7 Technoeconomic Analysis ................................................................................................... 65
7.1 Base Sys em Resiliency Analysis Resul s ...................................................................... 65
7.1.1 Base Sys em - Zone 3 Disabled Upg ade Cos ....................................................... 66
7.1.2 Base Sys em – Zone 4 Disabled Upg ade Cos ...................................................... 67
7.1.3 Base Sys em – Zone 5 Disabled Upg ade Cos ...................................................... 68
7.1.4 Base Sys em – To al Upg ade Cos ........................................................................ 68
7.2 Hyd ogen-Augmen ed Sys em Resiliency Analysis Resul s ......................................... 69
7.2.1 Hyd ogen-Augmen ed Sys em – Zone 3 ................................................................. 69
7.2.2 Hyd ogen-Augmen ed Sys em – Zone 4 ................................................................. 69
7.3 Hyd ogen-Augmen ed Sys em Addi ional Pipeline Cos ............................................... 69
8 Conclusion ............................................................................................................................ 69
9 Re e ences ............................................................................................................................. 71
Appendix A – Da a Collec ion o Elec ic G id Model .......................................................... 72
Geospa ial Da a ......................................................................................................................... 72
Cali o nia Elec ical T ansmission Lines .............................................................................. 72
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Sou he n Cali o nia Edison Dis ibu ed Ene gy Resou ce In e connec ion Map .................. 73
Cali o nia Powe Plan s ......................................................................................................... 74
Load & Gene a ion P o ile Da a ............................................................................................... 76
Cali o nia Independen Sys em Ope a o .............................................................................. 76
Residen ial & Comme cial Building S ock ........................................................................... 77
Appendix B - Model De elopmen & Simula ion Me hodology ............................................. 79
OpenDSS Elec ical G id Model ............................................................................................... 79
Language Fo ma & Requi emen s o Model ...................................................................... 79
Py hon Algo i hm .................................................................................................................. 79
Public Use Mic oda a A eas & Subs a ion Selec ion ............................................................ 80
T ansmission In as uc u e Model ....................................................................................... 82
Es ablishmen & Ve i ica ion o a Base Case ....................................................................... 83
Load P o ile Assignmen ....................................................................................................... 83
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Lis o Figu es
Figu e 1: A e age eliabili y and ou age a e me ics o he elec ical and na u al gas ne wo ks
ac oss he Uni ed S a es .................................................................................................................. 3
Figu e 2:Map o he Sou he n Cali o nia elec ical ansmission g id wi h majo subs a ions.
Subs a ions ...................................................................................................................................... 7
Figu e 16: Sou he n Cali o nia gas ne wo k ................................................................................... 7
Figu e 3: PSPS E en s in 2023 ....................................................................................................... 9
Figu e 4: Sou he n Cali o nia Fi e Haza d A eas ......................................................................... 10
Figu e 5: Pa i ioned Fi e Zones ................................................................................................... 10
Figu e 6: Base Loads & Gene a ion O e load Plo (Zone 1 Disabled) ........................................ 13
Figu e 7: Base Loads & Gene a ion O e load Plo (Zone 2 Disabled) ........................................ 14
Figu e 8: Base Loads & Gene a ion O e load Plo (Zone 3 Disabled) ........................................ 15
Figu e 9: Base Loads & Gene a ion O e load Plo (Zone 4 Disabled) ........................................ 16
Figu e 10: Base Loads & Gene a ion O e load Plo (Zones 3 and 4 Disabled) ........................... 18
Figu e 11: Base Loads & Gene a ion O e load Plo (Zone 5 Disabled) ...................................... 19
Figu e 12: Base & C i ical Load P o ile Compa ison .................................................................. 22
Figu e 13: Zone 3 Pe o mance Unde C i ical Loads, O e load Plo ......................................... 22
Figu e 14: Zone 4 Pe o mance Unde C i ical Loads, O e load Plo ......................................... 23
Figu e 15: Zone 5 Pe o mance Unde C i ical Loads, O e load Repo ..................................... 24
Figu e 17: Sou he n Cali o nia Gas Pipeline & Elec ical In as uc u e ..................................... 26
Figu e 18: Remo al o Na u al Gas Gene a ion O e load Plo (Base Loads) .............................. 27
Figu e 19: Line 3568 Ampaci y Plo ............................................................................................ 28
Figu e 20: O e loaded Line Ampaci ies ....................................................................................... 29
Figu e 21: Hyd ogen Mass Flow Ra e .......................................................................................... 30
Figu e 22: Pipeline Segmen 1 Pe o mance, Full Mass Flow Ra e ............................................. 31
Figu e 23: Pipeline Segmen 1 Pe o mance, Di ided Mass Flow Ra e ....................................... 32
Figu e 24: Pipeline Segmen 2 Pe o mance, Di ided Mass Flow Ra e ....................................... 32
Figu e 25: Elec ical G id, Na u al Gas Pipelines, Na u al Gas Plan s ........................................ 33
Figu e 26: Remaining O e loads .................................................................................................. 34
Figu e 27: Addi ional Hyd ogen o Add ess O e loads ............................................................... 34
Figu e 28: P e iously O e loaded Lines A e Hyd ogen Implemen a ion.................................. 35

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Figu e 29: Pipeline Sys em Pe o mance Wi h Final Hyd ogen Mass Flow Ra e, Di ided ......... 36
Figu e 30: Hyd ogen P o iles........................................................................................................ 37
Figu e 31: Sys em Pe o mance Unde Full Hyd ogen Load ....................................................... 38
Figu e 32: Base Sys em Hyd ogen P o ile.................................................................................... 40
Figu e 33: Zone 1 Disabled – Sys em O e load Plo ................................................................... 42
Figu e 34: Hyd ogen Mass Flow Ra e o Full Load Zone 1 ....................................................... 44
Figu e 35: Pipeline Pe o mance Repo , Full Loads, Zone 1 ...................................................... 45
Figu e 36: Pipeline Pe o mance Repo , C i ical Loads, Zone 1 ................................................. 46
Figu e 37: Zone 2 Disabled – Sys em O e load Plo ................................................................... 47
Figu e 38: Pipeline Pe o mance Repo , Full Loads, Zone 2 ...................................................... 48
Figu e 39: Pipeline Pe o mance Repo , Full Loads, Zones 1 and 2 ........................................... 49
Figu e 40: Comple e Pipeline Pe o mance Repo , Full Loads, Zones 1 and 2 .......................... 50
Figu e 41: Pipeline Pe o mance Repo wi h One Addi ional Pipe, Base Loads, Zones 1 & 2 .. 51
Figu e 42: Zone 3 Disabled – Sys em O e load Plo ................................................................... 52
Figu e 43: Pipeline Pe o mance Repo , Full Loads, Zone 3 ...................................................... 53
Figu e 44: Zone 4 Disabled – Sys em O e load Plo ................................................................... 54
Figu e 45: Zone 4 Disabled – Pipeline Hyd ogen Applied ........................................................... 55
Figu e 46: Pipeline Pe o mance Repo , Full Loads, Zone 4 ...................................................... 56
Figu e 47: Zone 5 Disabled – Pipeline-Included Sys em Plo ...................................................... 57
Figu e 48: Zone 5 Disabled – Pipeline Hyd ogen Applied ........................................................... 58
Figu e 49: Pipeline Pe o mance Repo , Full Loads, Zone 5 ...................................................... 59
Figu e 50: Whole-Home Elec i ica ion Package, Min E iciency – Residen ial ......................... 61
Figu e 51: Base & Whole-Home Elec i ica ion Load Compa ison ............................................. 61
Figu e 52: Hyd ogen P o ile Compa isons ................................................................................... 62
Figu e 53: Pipeline Pe o mance Repo , Elec i ica ion Package, Base Sys em ......................... 63
Figu e 54: Pipeline Pe o mance Repo , Elec i ica ion Package, Zones 1 and 2 Disabled ........ 64
Figu e 55: Cali o nia Elec ical T ansmission Lines geospa ial map ........................................... 73
Figu e 56: DERiM subs a ion geospa ial map .............................................................................. 74
Figu e 57: Powe Plan s ................................................................................................................ 75
Figu e 58: CAISO O e all Gene a ion P o iles ............................................................................ 76
Figu e 59: CAISO Renewable Gene a ion P o iles ...................................................................... 76
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Figu e 60: ResS ock agg ega e load p o ile .................................................................................. 77
Figu e 61:ComS ock agg ega e load p o ile ................................................................................. 78
Figu e 62: Key Subs a ions (Buses) .............................................................................................. 81
Figu e 63: Map o All Subs a ions in PUMA delinea ions ........................................................... 81
Figu e 64: G id In as uc u e ....................................................................................................... 82
Figu e 65: CAISO load p o ile compa ed wi h DERiM agg ega ed load p o ile ......................... 84
Figu e 66: Final Load P o iles o PUMA egion G0606503 ....................................................... 84
Figu e 67: Gene a ion Plan Map .................................................................................................. 85
Figu e 68: Augus 8 h Load & Gene a ion P o iles ....................................................................... 86
Figu e 69: Adjus ed Load & Gene a ion P o iles ......................................................................... 87
Figu e 70: Base Case Vol age P o ile ........................................................................................... 90
Figu e 71: Base Case O e load Plo ............................................................................................. 90
Figu e 72: Adjus ed Reac ance Vol age P o ile ............................................................................ 95
Figu e 73: Adjus ed Reac ance O e load Plo .............................................................................. 95
Figu e 74: Ini ial OpenDSS Ne Load .......................................................................................... 97
Figu e 75: I e a ions o ne load p o iles....................................................................................... 98
Figu e 76: I e a ions o Na u al Gas Du y Cycle .......................................................................... 98
Figu e 77: Final Na u al Gas P o iles ........................................................................................... 99
Figu e 78: Ze o Ne Load O e load Plo ...................................................................................... 99
Figu e 79: Final Base Case O e load Plo .................................................................................. 102
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Lis o Tables
Table 1: Reliabili y s. Resiliency [2] ............................................................................................ 2
Table 2: Base Loads & Gene a ion Vol age Repo (Zone 3 Disabled) ....................................... 15
Table 3: Base Loads & Gene a ion O e load Repo (Zone 3 Disabled) ..................................... 15
Table 4: Base Loads & Gene a ion O e load Repo (Zone 4 Disabled) ..................................... 17
Table 5: Base Loads & Gene a ion Vol age Repo (Zone 4 Disabled) ....................................... 17
Table 6: Base Loads & Gene a ion O e load Repo (Zone 5 Disabled) ..................................... 19
Table 7: Base Loads & Gene a ion Vol age Repo (Zone 5 Disabled) ....................................... 19
Table 8: Residen ial End Uses ...................................................................................................... 21
Table 9: Zone 3 Pe o mance Unde C i ical Loads, O e load Repo ........................................ 22
Table 10: Zone 4 Pe o mance Unde C i ical Loads, O e load Repo ...................................... 23
Table 11: Remo al o Na u al Gas Gene a ion O e load Repo (Base Loads) ........................... 27
Table 12: Zone 1 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 43
Table 13: Zone 2 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 47
Table 14: Zone 3 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 52
Table 15: Zone 4 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 54
Table 16: Zone 4 Disabled – Pipeline Hyd ogen Applied, O e load Repo ............................... 55
Table 17: Zone 5 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 57
Table 18: Zone 5 Disabled – Pipeline-Included Elec ical Pe o mance Repo .......................... 58
Table 19: Base Sys em - Zone 3 Disabled O e load Repo ........................................................ 66
Table 20: Base Sys em – Zone 3 Upg ade Cos ........................................................................... 66
Table 21: Base Sys em – Zone 4 Upg ade Cos ........................................................................... 67
Table 22: Base Sys em – Zone 5 Upg ade Cos ........................................................................... 68
Table 23: Zone 4 sys em de ails.................................................................................................... 69
Table 24: Base Case Vol age Repo ............................................................................................ 91
Table 25: Base Case O e load Repo .......................................................................................... 91
Table 26: Base Case Vol age Repo ............................................................................................ 93
Table 27: Adjus ed Reac ance Vol age Repo ............................................................................. 95
Table 28: Adjus ed Reac ance O e load Repo ........................................................................... 96
Table 29: Ze o Ne Load O e load Repo ................................................................................. 100
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Execu i e Summa y
Resilien , eliable, and enewable ene gy in as uc u e is essen ial o c i ical applica ions such as
da a cen e s, hospi als, and mili a y acili ies, which demand s ic ene gy se ice up ime despi e
he challenges o u ban space cons ain s and he in e mi en na u e o enewable ene gy sou ces
like sola and wind. Mo eso, ou ages ex ending beyond a ew hou s educe quali y o li e in ways
ha spu a ec ed esiden s o pu sue back-up gene a ion.
Solu ions o inc easing esiliency include 1) ha dening ene gy in as uc u e, 2) de eloping
dis ibu ed gene a ion, and 3) inc easing demand esponse capabili ies. Ha dening ene gy
in as uc u e, in many cases, includes expanding and unde g ounding ene gy ansmission
sys ems, bo h o which a e expensi e p ocesses. Likewise, de eloping dis ibu ed gene a ion based
on sola and ba e y ene gy s o age is di icul due o sola capaci y size cons ain s based on
building oo op a ea coupled wi h he high expense backup ba e y ene gy sys ems ha a e a ely
u ilized in o de o ensu e eliabili y. An al e na e solu ion could be o u ilize exis ing he gas
ansmission sys em coupled wi h dis ibu ed gene a ion o inc ease he capaci y o locally si ed
uel cells. This app oach has po en ial because he exis ing na u al gas ansmission in as uc u e
is subs an ially mo e eliable han he elec ic ansmission sys em. Addi ionally, in oducing
enewable hyd ogen in o he gas ansmission sys em would educe and elimina e ca bon
emissions associa ed wi h gas pipeline ope a ion, esul ing in ca bon neu al backup gene a ion.
This wo k aims o demons a e ha enewable hyd ogen, in eg a ed wi h a o dable, enewable
g id powe , o e s a obus solu ion o achie e 100% enewable ene gy goals while mee ing
s ingen eliabili y and esiliency s anda ds. Th ough comp ehensi e modeling o Sou he n
Cali o nia's elec ical and gas ne wo ks, his e o analyzes he dynamic in e ac ion o hyd ogen
sys ems—including uel cells, elec olyze s, and ba e ies—wi h local and emo e enewable
ene gy sou ces, he elec ic g id, and gas ne wo ks o add ess g id ou ages and imp o e ene gy
sys em esilience. This epo ocuses on how he exis ing gas ansmission sys em can i m up
elec ici y supply in he ace o a less esilien and eliable elec ic ansmission sys em. Resiliency
is examined om wo pe spec i es: 1) when mee ing he en i e Sou he n Cali o nia elec ical load,
and 2) when mee ing a educed Sou he n Cali o nia elec ical load based on c i ical loads om a
socie al and indi idual esiden le el. Subsequen wo k will educe loads u he , ocusing on
socie al c i ical loads only (hospi als, communica ion, anspo a ion, heal h and sa e y, wa e , and
o he c i ical in as uc u e/loads).
The esiliency e en s conside ed in his wo k ocus on examining he disabling o majo elec ical
ansmission lines ha powe Sou he n Cali o nia. The main mo i a ion o conside ing hese
ansmission lines a e public sa e y powe shu o (PSPS) e en s, and wild i es. A a less likely
cause is equipmen ailu e un ela ed o PSPS and wild i e e en s. Gas ansmission ou ages a e no
conside ed in his wo k because he gas ansmission sys em has his o ically achie ed esiliency
and eliabili y me ics ha a e o de s o magni ude be e han elec ic ansmission sys ems.
This wo k makes a key assump ion ha he gas ansmission has been con e ed om ca ying
na u al gas o hyd ogen. P io wo k has shown ha he cu en na u al gas ansmission has
su icien capaci y o powe gas powe plan s in and a ound Los Angeles, O ange, San Be nadino,
and Ri e side coun ies ha make up he G ea e Los Angeles A ea, boos ing sys em esiliency and
eliabili y. Howe e , he main in e es o his wo k is in examining he elec ic and gas
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1.3 Cu en Wo k and Con ibu ions
This wo k ocuses on he elec ical and na u al gas ne wo ks in Los Angeles, O ange Coun y, and
pa s o Ri e side and O ange Coun y. Geog aphical dema ca ion is based on he loca ion o i e
isk zones su ounding he majo popula ion cen e s in Sou he n Cali o nia. Gi en he ac s
summa ized in he p io sec ion, he opic o in e es o his epo is ec ui ing na u al gas
in as uc u e o coope a e wi h elec ical in as uc u e o le e age i s supe io eliabili y. Speci ic
o he issue o wild i es, i would be di icul o come up wi h a si ua ion whe e na u al gas pipeline
in as uc u e could be esponsible o igni ing a i e. Thus, gas in as uc u e could be used as a
backup dis ibu ion sys em when pa o he elec ical in as uc u e ei he ails o needs o be
disabled. To achie e his, we can conside powe ing uel cells using H2 ha is anspo ed om
poin s o p oduc ion ac oss Cali o nia o poin s o use inside he G ea e Los Angeles A ea using
exis ing gas ansmission lines.
In essence, he me hodology o his s udy will be o analyze he beha io o he Sou he n Cali o nia
elec ical g id unde a ious ope a ing condi ions, and hen e alua e he abili y o he na u al gas
pipeline in as uc u e o help in deli e ing adequa e ene gy o all demand nodes using hyd ogen.
A majo con ibu ion o his wo k is he de elopmen o an elec ic ansmission model o
Sou he n Cali o nia. Publicly a ailable da a sou ces we e use o de elop a highly de ailed
al e na ing cu en powe low ep esen a ion o his sys em, including he magni ude and loca ion
o esiden ial, comme cial, and indus ial elec ical loads h oughou Sou he n Cali o nia.
To pe o m his s udy, a model p e iously de eloped o simula e ansmi ing H2 using na u al gas
pipelines unning on hyd ogen was used [7]. This e e ence ully de ails he physics and execu ion
o his gas pipeline model.
The con en s o his epo ocus on he di e en esiliency analyses pe o med du ing his wo k.
A comple e desc ip ion o he da a collec ion me hods and model de elopmen is p o ided in he
Appendix.

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2 Key Assump ions
The key assump ions made in his wo k a e:
• Exis ing na u al gas ansmission and dis ibu ion pipes ha e been epu posed o ca y
100% H2. This implici ly assumes ha :
o Cali o nia egula ions ha e been amended o allow he injec ion and ansmission
o H2 in o exis ing gas pipelines
o Gas ansmission pipeline componen s can sa ely ansmi H2
o Gas ansmission componen s ha canno sa ely o eliabily ansmi H2 ha e been
eplaced
o U ili y cus ome s can sa ely use H2 a hei acili ies/ esidences
o The e is a consis en and s eady supply o enewable H2 ha can be injec ed in o
pipelines ha se e he Sou he n Cali o nia Gas se ice e i o y
o H2 can be p oduced and deli e ed o pipelines a a ela i ely low cos ha would
enable consume use
• U ili y cus ome s ha e he abili y o shed load du ing a esiliency e en . We do no esol e
how load shedding occu s – i he e is a echnology (i.e., sma panel o sma
appliance/load) ha enables au oma ic load shedding, o i indi idual u ili y cus ome s
ac ua e hei loads o educe demand du ing a esiliency e en (i.e., unplug appliances, u n
o ai condi ione , u n o ligh s).
• Fuel cells a e used as he H2 dis ibu ed gene a ion ins alled ac oss he G ea e Los Angeles
A ea o imp o e sys em esiliency and eliabili y.
• Na u al gas powe plan s inside he G ea e Los Angeles A ea ha e been shu down.
Speci ic scena ios assume ha hese powe plan s ha e been e o i ed o use H2 o ha e
been eplaced wi h H2 uel cells.
• T anspo a ion elec i ica ion is no conside ed
3 Elec ic and Na u al Gas T ansmission In as uc u e
This s udy is ocused on in as uc u e in he Sou he n Cali o nia a ea – bo h elec ical and na u al
gas. Maps showing he in as uc u e ha is conside ed a e shown in Figu e 2 and Figu e 3 o he
elec ical and na u al gas ansmission sys ems espec i ely. Figu e 2 also indica es majo
subs a ions cap u ed in he elec ical ansmission sys ems. These subs a ions a e loca ed a poin s
whe e he high ol age elec ical ansmission sys em in e aces wi h lowe ol age ansmission
and dis ibu ion ci cui s. Elec ical loads ac oss he Sou he n Cali o nia Edison e i o y a e
agg ega ed a ound hese majo subs a ions indica ed in Figu e 2. The subs a ions in Figu e 2 a e
spli be ween subs a ions ha a e also connec ed o u ili y scale na u al gas elec ici y gene a ion,
and subs a ions ha a e no .
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Figu e 2: Map o he Sou he n Cali o nia elec ical ansmission g id wi h majo subs a ions. All
subs a ions se e elec ical u ili y cusom e s ei he di ec ly o h ough o he subs a ions ha a e connec ed
h ough lowe ol age ansimisison and dis ibu ion ci cui s no cap u ed in his map. Subs a ions a e
di e en ia ed be ween subs a ions ha a e connec ed o u ili y scale na u al gas elec ici y gene a ion, and
subs a ions ha a e no .
Figu e 3: Sou he n Cali o nia gas ansmission ne wo k
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4 Resiliency Analysis
To e alua e he esiliency o he elec ical g id as i s ands, we e e o Table 1, which s a es ha
esiliency can be pa ially quan i ied by a me ic o desc ibe he agili y/su i abili y o he
elec ical g id, speci ically in unusual condi ions. I has been demons a ed in p ac ice ha he g id
is capable o ope a ing when all lines a e ac i e, and he model e lec s his. Howe e , when
subjec ed o a ‘dis up i e e en ’ as e e ed o by IEEE in [1] in which no mal ope a ion o he
g id is a ec ed in ways ha can lead o powe ou ages, ol age ins abili ies, o sys em ailu es, he
g id may be unable o espond depending on he magni ude o he e en . Common ypes o
dis up i e e en s include na u al disas e s and ex eme wea he , cybe secu i y and physical
a acks, equipmen ailu es, unexpec ed o excessi e elec ic demand, and ope a ional/human
e o s.
The key esul p esen ed in his sec ion is ha he loss o majo elec ic ansmission lines has he
po en ial o educe he eliabili y o he Sou he n Cali o nia elec ic g id, po en ially leading o a
esiliency e en . Unde cu en load condi ions, addi ional demand esponse is absolu ely
necessa y i o he measu es a e no aken o ensu e g id esiliency and eliabili y agains wild i es
and o he PSPS causing e en s.
4.1 Wild i e/PSPS E en Zones
In 2023, he e we e a o al o 13 Public Sa e y Powe Shu o (PSPS) e en s. A leas one PSPS
e en occu ed in Augus o 2023. In Los Angeles, Augus saw he highes a e age empe a u e o
all mon hs in 2023 ([8]), meaning he cooling loads we e likely highe han no mal. The e o e,
analysis o PSPS e en s coupled wi h he ele a ed Augus load p o iles is mos pe inen o he
e alua ion o he g id’s esiliency, as i p o ides esul s o a ‘wo s -case’ scena io.
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Figu e 4: PSPS E en s in 2023
The DERiM esou ce as discussed in Appendix B p o ides a map o a eas ha ha e high i e isk.
T ansmission lines unning h ough hese a eas a e he e o e candida es o shu o s. Figu e 5
shows a map o he i e haza d a eas su ounding he LA basin, as well as he elec ical
in as uc u e unning h ough hese a eas. The i e a eas we e pa i ioned in o 5 zones. Figu e 6
shows hese pa i ioned i e isk a eas. All ansmission lines in he model ha un h ough hese
a eas we e g ouped oge he based on zone. To simula e PSPS e en s, he lines unning h ough
each zone could be disabled depending on which zone was lagged o be a wild i e h ea . While
PSPS e en s a e ou ages scheduled o p e en he igni ion o a wild i e by ansmission
in as uc u e, his zone analysis doubles as a po en ial scena io whe e a wild i e does occu in
hese zones, leading o he des uc ion o he co esponding ansmission in as uc u e. In
analyzing he esiliency o he sys em o PSPS e en s, he model will be un wi h bo h indi idually
disabled as well as combina ions o disabled zones.
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Figu e 5: Sou he n Cali o nia Fi e Haza d A eas
Figu e 6: Pa i ioned Fi e Zones
A a ie y o ou age scena ios a e conside ed in his wo k. These scena ios also conside di e en
gene a ion scena ios whe e he na u al gas elec ical gene a o s loca ed inside Los Angeles,
O ange, Ri e side, and San Be nadino coun y a e kep ope a ional using na u al gas o con e ed
o hyd ogen. These di e en scena ios a e lis ed in Table 2. This able also p o ides a high le el
summa y on simula ion esul s, indica ing i elec ic ansmission o e loads occu in he simula ion

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and i exis ing gas pipelines could ca y he necessa y quan i y o hyd ogen. Addi ional
in o ma ion in his able include:
• Elec ic Load De ini ion: This desc ibes he elec ic load scena io ac oss Sou he n
Cali o nia. “Base” indica es elec ic loads based on cu en elec ici y use in Sou he n
Cali o nia. “C i ical” indica es ha a esiliency e en is occu ing and elec ic loads ha e
been cu ailed o “c i ical loads only”. “100% Elec i ied” indica es ha mos esiden ial,
comme cial, and indus ial na u al gas loads ha e been elec i ied and ha e been added o
he no mal elec ic load de ined in he “Base” scena io.
• Gene a ion Fuel: This indica es he ype o uel used o powe he cu en na u al gas
gene a ion loca ed a subs a ions as indica ed wi h ed do s in Figu e 2. In he “H2”
scena io, we assume ha hese gene a o s can be epowe ed wi h hyd ogen.
• Disabled Zones: Zones e e o i e zones shown in Figu e 6. I a zone is disabled, we
assume ha all majo ansmission lines unning h ough his i e zone a e deene gized.
• O e loads: This indica es esul s om ou simula ions o he elec ic ansmission
sys em. A “Yes” indica es ha he elec ical ansmission sys em expe iences an o e load
somewhe e in he sys em wi hin his scena io.
• Pipeline Success: This indica es i he exis ing na u al gas in as uc u e can sa ely handle
he gas ha is equi ed o mee cus ome and powe plan uel demand. A “N/A” indica es
ha he scena io assumes na u al gas is lowing h ough he pipelines. Since he cu en
na u al gas sys em can handle cus ome and powe plan demand, hese scena ios a e
assumed o be iable and a e no simula ed. A “Yes” indica es ha na u al gas in all
pipelines has been eplaced wi h hyd ogen, and he pipelines can handle he hyd ogen
demand. A “No” indica es ha na u al gas in all pipelines has been eplaced wi h hyd ogen,
and he cu en sys em does no ha e su icien gas ca ying capaci y o supply he desi ed
uel ene gy low a e. A “Pa ially” indica es ha na u al gas in all pipelines has been
eplaced wi h hyd ogen, and ha he gas pipeline sys em can handle he uel ansi ion
h ough mos hou s o he day, bu mus be augmen ed wi h uel s o age nea o a he
cus ome o success ully mee demand. In o he wo ds, he gas pipeline sys em in he
“Pa ially” case can handle he a e age gas demand, bu canno handle peak gas demand.
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Table 2: De ini ion o di e en gene a ion and ou age scena ios. The able also indica es i elec ic
ansmission sys em o e loads occu , i he pipeline is capable o ca ying he desi ed hyd ogen, and he
sec ion ha desc ibes he scena io
Scena io
Index
Elec ic
Load
De ini ion
Gene a ion
Fuel
Disabled
Zones O e loads Pipeline
Success
Repo
Sec ion
1 Base Base None No N/A N/A
2
Base
Base
1
No
N/A
4.2.1
3 Base Base 2 No N/A 4.2.2
4
Base
Base
3
Yes
N/A
4.2.3
5 Base Base 4 Yes N/A 4.2.4
6
Base
Base
3,4
Yes
N/A
4.2.5
7 Base Base 5 Yes N/A 4.2.6
8
C i ical
Base
3
Yes
N/A
4.3.4
9 C i ical Base 4 Yes N/A 4.3.5
10
C i ical
Base
5
No
N/A
4.3.6
11 Base H2 None Yes N/A 5.2
12
Base
H2
1
Yes
Yes
5.7.1
13 Base H2 2 Yes Yes 5.7.2
14
Base
H
2
1,2
Yes
No
5.7.3
15 Base H2 3 Yes Yes 5.7.4
16
Base
H
2
4
Yes
Pa ially
5.7.5
17 Base H2 5 Yes Pa ially 5.7.6
18
100%
Elec i ied
H2 1,2 Yes No 6.1
4.2 Resiliency o he Exis ing Elec ical G id/Model Ve i ica ion
The base sys em, which includes Augus load and gene a ion p o iles, mus i s be assessed o
esiliency o hese PSPS e en s. Fi s , each o he i e p e iously speci ied zones will be disabled,
leading o i e simula ions whe e a majo ansmission pa hway is o line. A e his, combina ions
o wo disabled zones will be simula ed. OpenDSS equi es he speci ica ion o a “sou ce bus”,
which compensa es o any ne load in he sys em by p o iding impo a ion o expo a ion as i he
sys em is a mic og id connec ed o a la ge g id. In all simula ions, his sou ce bus has been
selec ed o be he eas e nmos bus in Palm Sp ings. This bus was chosen because o he
implica ions o po en ially placing enewable gene a ion in he adjacen dese and e alua ing he
abili y o he ansmission co ido s he e o anspo his gene a ion o he basin. Each o he i e
es ablished i e isk zones will be disabled indi idually and he esul ing ci cui will be e alua ed
based on pe o mance.
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4.2.1 Zone 1 – Lowe Palm Sp ings Co ido
Zone 1 is he lowe Palm Sp ings co ido . Figu e 7 shows ha disabling i has no signi ican
impac on he G ea e Los Angeles a ea ci cui s, as he e a e no epo ed cu en o e loads, no
ol age anomalies. This is a easonable esul , as he ansmission lines in he Palm Sp ings
co ido a e obus , bu no esponsible o much powe ansmission wi hin his con igu a ion, as
he e is less han 2GW o gene a ion in he a ea. The key d i e o his esul is ha o he elec ic
ansmission lines ha e su icien cu en -ca ying capaci ies o supply he elec ici y ha would
ha e o he wise been supplied h ough he lowe Palm Sp ings co ido wi hou inducing a line
o e load o expe iencing unaccep able ol age d op h oughou he elec ic ansmission sys em.
Figu e 7: Base Loads & Gene a ion O e load Plo (Zone 1 Disabled)
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4.2.2 Zone 2 – Uppe Palm Sp ings Co ido
Figu e 8 shows ha disabling Zone 2, he uppe ansmission co ido in Palm Sp ings, leads o no
o e load o ol age anomaly epo s.
Figu e 8: Base Loads & Gene a ion O e load Plo (Zone 2 Disabled)
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4.3.1 Residen ial Load P o ile
The ResS ock esiden ial load p o ile can be b oken down in o a se o end-uses, o which se e al
could be conside ed c i ical. Below is a able o each end use, whe he i is o is no conside ed
c i ical in he analysis, and a a ionale.
Table 9: Residen ial End Uses
END USE
CRITICAL?
REASONING
CEILING FAN
Y
Some buildings may no be equipped wi h A/C, an is las eso o
cooling
CLOTHES
DRYER
N
Clo hes can be hang-d ied
CLOTHES
WASHER
N
Clo hes can be washed in ba h ub
COOLING
Y
Li able indoo empe a u e is c i ical
DISHWASHER
N
Dishes can be washed in sink
FREEZER
Y
S o age o ood is essen ial
HEATING
Y
Tempe a u e con ol is essen ial
HOT TUB
N
Rec ea ional i em
HOT WATER
Y
Necessa y o washing
EXTERIOR
LIGHTING
Y
Ex e io isibili y a nigh p omo es sa e y
INTERIOR
LIGHTING
Y
Visibili y in home p omo es sa e y
GARAGE
LIGHTING
Y
Same as in e io ligh ing
MECHANICAL
VENTS
Y
May be impo an o be able o close en s in he case o wild i es
a ec ing ai quali y
PLUG LOADS
50%
In e ne connec ion, as well as some c i ical end uses, may be ied o his
POOL HEATING
N
Rec ea ional i em
RANGE OVEN
Y
Abili y o cook ood is essen ial
REFRIGERATOR
Y
S o age o ood is essen ial
WELL PUMP
Y
Abili y o pump wa e is essen ial
4.3.2 Comme cial Load P o ile
As wi h ResS ock’s b eakdown, ComS ock can be b oken down in o end uses. All end uses a e
assumed o be c i ical because hei naming indica es hey a e all ied o ei he ligh ing, hea ing,
cooling, o some o he sys em whose impo ance o ope abili y is ambiguous.
4.3.3 Adjus ing Load P o iles
To gene a e a c i ical load p o ile o each subs a ion, he exis ing base load p o ile o ha
subs a ion is mul iplied by a ac o a each hou . Fo each hou , he pe cen age o he o al load
deemed c i ical, based on he asse ions made in sec ions 4.3.1 and 4.3.2, is close o 80%. This

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20% educ ion may be enough o alle ia e some o he o e loads expe ienced when disabling he
zones. Figu e 13 shows he esul ing c i ical load p o ile o one o he subs a ions. The e is a
consis en dec ease in he load o each hou . Zones 3, 4 and 5 showed o cause p oblems when
disabled in he ull load case examined. They will again be es ed unde he educed c i ical load.
Figu e 13: Base & C i ical Load P o ile Compa ison
4.3.4 Zone 3
Figu e 14: Zone 3 Pe o mance Unde C i ical Loads, O e load Plo
Table 10: Zone 3 Pe o mance Unde C i ical Loads, O e load Repo
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Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
5743
500
0
TRUE
3125
114
4
385
5741
500
0
FALSE
3125
114
4
385
5742
500
0
FALSE
3125
114
4
385
3622
220
8
FALSE
3894
112
3
414
3654
500
7
TRUE
3108
113
3
368
5744
220
10
TRUE
2497
108
2
177
Despi e he educ ion in load, he same lines a e o e loaded, al hough in compa ison wi h he
esul s o Zone 3 in 4.2.3, he o e loads a e educed sligh ly in pe cen age and signi ican ly in
du a ion.
4.3.5 Zone 4
Figu e 15: Zone 4 Pe o mance Unde C i ical Loads, O e load Plo
Table 11: Zone 4 Pe o mance Unde C i ical Loads, O e load Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3597
500
76
FALSE
3112
114
6
372
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3598
500
76
FALSE
3110
114
6
370
3892
500
20
TRUE
4678
114
4
568
3893
500
2
TRUE
3134
114
4
394
3894
500
1
FALSE
6270
114
4
790
3889
500
26
FALSE
3106
113
4
366
3890
500
31
FALSE
3062
112
4
322
3891
500
26
FALSE
3120
114
4
380
As wi h he pe o mance o Zone 3, he e is a ma ginal educ ion in he o e load pe cen age and a
signi ican dec ease in he o e load du a ion.
4.3.6 Zone 5
Figu e 16: Zone 5 Pe o mance Unde C i ical Loads, O e load Repo
Unde c i ical loads, disabling Zone 5 no longe leads o o e loads.
4.3.7 Conclusions on C i ical Load Resiliency
Despi e he 20% educ ion in loads, he e a e s ill signi ican o e loads ha occu when Zones 3
and 4 a e disabled. To ully a oid o e loads in such a scena io, he educed elec ical load would
ha e o be dec eased u he beyond he c i ical esiden ial and comme cial loads ou lined in
Sec ion 4.3.1, which could be a ealis ic s a egy as 80% is a gene ous es ima e o wha po ion o
loads should be conside ed c i ical.
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5 Pipeline Hyd ogen as a Resiliency Augmen a ion
Cali o nia aims o ansi ion o 100% enewable ene gy by 2045. A scena io o in e es is
he e o e one whe e he non- enewable gene a ion in he model is disabled en i ely. In he model,
his implies he emo al o all na u al gas gene a ion. Can his los gene a ion be eplaced by
enewable gene a ion si ed in loca ions ou side o he G ea e Los Angeles A ea? Mo e
speci ically, will he elec ical ansmission in as uc u e be able o suppo he added s ain
esul ing om he emo al o in-basin gene a ion? I no , how can he na u al gas in as uc u e be
le e aged o accomplish his?
The analysis in his sec ion di e s om he p io because he p io sec ion only conside ed
i he cu en elec ical ansmission sys em can success ully handle ansmission line ou ages. In
many ins ances, he elec ic ansmission sys em expe iences o e loads and ol age issues. This
sec ion in oduces a emedy o ansmission issues du ing a esiliency e en whe e he gas
ansmission sys em is used o del e hyd ogen o uel cells and ze o emission gene a o s loca ed
ac oss he G ea e Los Angeles A ea.
5.1 Combining Models
To in oduce hyd ogen as a enewable ene gy ansmission medium, he exis ing na u al gas
in as uc u e could be le e aged o deli e hyd ogen o key poin s in he elec ical ansmission
g id. Since he s a e o Cali o nia is pushing i s cons i uen s o ansi ion om non- enewable o
enewable ene gy, a mos logical s ep is o eplace all na u al gas gene a ion wi h hyd ogen uel
cells, supplied wi h hyd ogen h ough he pipeline ne wo k. The Cali o nia S a e Geopo al,
men ioned in 4, p o ides a geospa ial da ase o he na u al gas pipeline in as uc u e in Sou he n
Cali o nia.
Figu e 17 shows he na u al gas pipeline ne wo k o e laid on he elec ical ansmission
ne wo k o he model. The yellow subs a ions hos all na u al gas gene a ion in he model. As can
be seen, he na u al gas pipelines un close o many o hese subs a ions. The e o e, o conduc an
analysis on he esiliency o he sys em when hyd ogen ansmission is included, all na u al gas
plan s will be emo ed om he model, and a subse o he yellow subs a ions ha un closes o
na u al gas pipelines will be equipped wi h uel cells o mee he du y cycle o he now inac i e
na u al gas plan s. The pipeline model will be used o e alua e whe he he pipelines can ansmi
he necessa y olume o hyd ogen o powe hese uel cells. Only pipes 1, 2, 3, 4, and 5 in will be
simula ed as hey co e he pa h om Palm Sp ings o a se o junc ions in he basin ha b anch
o in o many o he pipelines. Once he hyd ogen is anspo ed o hese junc ions, i is assumed
ha he pipeline in as uc u e wi hin he basin can dis ibu e i .
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Figu e 17: Sou he n Cali o nia Gas Pipeline & Elec ical In as uc u e
5.2 Sys em Response o Remo al o Non-Renewables
To e alua e he abili y o phase ou non- enewable gene a ion and eplace i wi h hyd ogen,
i is impo an o de e mine he sys em esponse o he emo al o na u al gas gene a ion. Na u al
gas is esponsible o a signi ican po ion o gene a ion, hus i s emo al will ha e a majo impac
on he delica ely balanced sys em.

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Figu e 18: Remo al o Na u al Gas Gene a ion O e load Plo (Base Loads)
Table 12: Remo al o Na u al Gas Gene a ion O e load Repo (Base Loads)
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3568
500
67
FALSE
4235
155
7
1495
5698
500
66
FALSE
4288
156
7
1548
3653
500
65
FALSE
6011
146
6
1901
3569
220
69
FALSE
2464
106
2
144
3553
220
68
TRUE
2515
108
2
195
Wi h he du ess o he ull loads as de i ed om CAISO his o ical da a, emo ing in-basin na u al
gas plan s pu s signi ican s ess on he Palm Sp ings ansmission co ido s when his missing
gene a ion is supplied by he sou ce bus. Be o e unning a mo e complica ed app oach, we can
de e mine simply whe he he pipelines ha un pa allel o hese ansmission lines a e able o
alle ia e hese o e loads.
5.3 Le e aging Pipeline Hyd ogen
The o e loaded lines a e no cons an ly o e loaded. Below is an example o he ampaci y
p o ile on one o he o e loaded lines. Figu e 19 shows ha line 3568 is o e loaded om hou
13.5 onwa ds, peaking a hou 20.
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Figu e 19: Line 3568 Ampaci y Plo
To alle ia e his o e load om he line, we con e his ampe age i s o powe , hen o hyd ogen.
𝑃𝑃=𝐼𝐼𝐿𝐿∙𝑉𝑉𝐿𝐿−𝐿𝐿 ∙√3 (1)
𝑚𝑚󰇗𝐻𝐻2=
𝑃𝑃∙𝑆𝑆𝑆𝑆
𝐿𝐿𝐿𝐿𝑉𝑉
𝐻𝐻2
∙𝜂𝜂
𝐺𝐺𝐺𝐺𝐺𝐺
(2)
Equa ion (1) con e s single-phase cu en o h ee-phase powe using he line-line (base)
ol age. To ob ain hyd ogen mass low a e, Equa ion (2) hen akes his h ee-phase powe and
di ides i by he lowe hea ing alue o hyd ogen gas, as well as a con e sion e iciency cons an .
I is hen mul iplied by a sa e y ac o , o ensu e ha he line is no ope a ing exac ly a i s ope a ing
capaci y o hose hou s. These equa ions a e applied o he p o iles o each o he o e loaded
lines ha un in pa allel. Fo example, he lines om 339 o 347 in Figu e 18 (3568, 5698, 3569,
3553 and 3554 in Figu e 20) a e included in his calcula ion, bu he line om 347 o 367 is no ,
because his would be double coun ing he o e load unning h ough ha b anch. The lowe
hea ing alue used is 120MJ/kg. A sa e y ac o o 1.1 is assigned. A gas- o-powe e iciency o
50% is assumed, based on known elec ical e iciency da a on PEMFCs ([9]). The e o e, he
necessa y powe is con e ed o a heo e ical hyd ogen mass low a e ha would p oduce an equal
powe ou pu when sen h ough a uel cell.
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Figu e 20: O e loaded Line Ampaci ies
Figu e 21 shows he esul ing necessa y hyd ogen p o ile o alle ia e he o e loaded lines. This
p o ile se es as a di ec inpu in o he pipeline model. Based on Figu e 17, a simple ne wo k o a
hand ul o pipes will be able o desc ibe he pipeline sys em unning in pa allel wi h he o e loaded
lines. sugges s he p esence o pipes 1, 2, and 3 ha mee a a comp esso s a ion, om whe e
pipes 4 and 5 con inue in o he basin. I can be assumed ha once he hyd ogen has success ully
passed h ough his se o pipes, he pipeline in as uc u e in he basin, which hos s signi ican ly
mo e pipes as seen in Figu e 17, can ansmi he hyd ogen o he di e en subs a ions equipped
wi h uel cells. Assuming he abili y o injec hyd ogen in o pipes 1, 2, and 3 in Palm Sp ings, we
can use he MATLAB model discussed in sec ion 1.3 coupled wi h co esponding pipeline
pa ame e s aken om o de e mine whe he he pipeline ne wo k can ansmi he hyd ogen mass
low a e p o ile.
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Uni e si y o Cali o nia, I ine 30
Clean Ene gy Ins i u e
Figu e 21: Hyd ogen Mass Flow Ra e
5.3.1 Segmen 1 – Palm Sp ings o Comp esso S a ion
The leng h o he pipeline segmen be ween he Palm Sp ings injec ion poin and he comp esso
s a ion was assumed o be 100km, a ound 40% o he o al leng h o he h ee pipelines acco ding
o . This assump ion was made conse a i ely based on an obse a ion o he dis ance be ween
Palm Sp ings and he comp esso s a ion. Each o he h ee pipes can indi idually ansmi he
en i e hyd ogen mass low a e, al hough he peak does app oach he ope a ional pipe p essu e
limi in pipes 1 and 3. These igu es indica e he maximum p essu e allowable in he pipe, he
ou le p essu e equi ed a poin o deli e y, and he inle p essu e, o he p essu e a which he gas
in injec ed in o he pipe.
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Uni e si y o Cali o nia, I ine 37
Clean Ene gy Ins i u e
5.5 Including Na u al Gas Demand
I canno be assumed ha he pipelines a e comple ely emp y and only need o ansmi he
hyd ogen p o ile ob ained in 5.4. While he need o na u al gas in u ili y gene a ion has been
elimina ed wi h he emo al o na u al gas plan s in he basin, esiden ial and comme cial demand
o na u al gas s ill exis s. ResS ock & ComS ock, as discussed in 4, ha e simula ed na u al gas
demand p o iles o bo h sec o s on an a e age Augus day. These p o iles a e p o ided in
equi alen kWh o ene gy, making hei con e sion o hyd ogen s aigh o wa d. Since his da a
ep esen s he en i e s a e o Cali o nia, i is di ided by h ee o ep esen an es ima e o he demand
o he a ea o he s udy. These esiden ial and comme cial na u al gas kWh p o iles a e summed
up and con e ed o hyd ogen, assuming a gas- o-powe e iciency o 30%. This low e iciency is
a conse a i e es ima e o how he end uses no mally se iced by na u al gas would pe o m on a
100% hyd ogen inpu . The esul ing hyd ogen p o ile is added on op o he p e ious p o ile, and
he sys em is eassessed. Figu e 30 shows ha he esiden ial and comme cial na u al gas
equi alen hyd ogen demand a e ela i ely small compa ed o he equi ed hyd ogen ou pu o he
o e loaded lines.
Figu e 30: Hyd ogen P o iles
A e combining hese p o iles, hey a e ed h ough he pipeline sys em.

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Uni e si y o Cali o nia, I ine 38
Clean Ene gy Ins i u e
Figu e 31: Sys em Pe o mance Unde Full Hyd ogen Load
The sys em can easily suppo he comple e hyd ogen mass low a e p o ile ha includes
esiden ial and comme cial na u al gas demand. In conclusion, he na u al gas pipeline
in as uc u e would be able o suppo he necessa y hyd ogen ansmission o powe uel cells o
ully eplace he na u al gas gene a ion in he G ea e Los Angeles A a. I Segmen 2 can
success ully ansmi he hyd ogen, his means ha Segmen 1 au oma ically can as well. Since
Pipes 4 and 5 a e assumed o ha e iden ical physical p ope ies, we can assess he en i e sys em
pe o mance om jus one o hese pipes alone. Thus, om he e onwa ds, only Pipe 4 will be
plo ed o analysis pu poses.
0 5 10 15 20 25
Time (h)
500
1000
P essu e (psi-g)
Pipe 1 (Segmen 1)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
0 5 10 15 20 25
Time (h)
500
1000
P essu e (psi-g)
Pipe 2 (Segmen 1)
0 5 10 15 20 25
Time (h)
500
1000
P essu e (psi-g)
Pipe 3 (Segmen 1)
0 5 10 15 20 25
Time (h)
500
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
0 5 10 15 20 25
Time (h)
500
1000
P essu e (psi-g)
Pipe 5 (Segmen 2)
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Uni e si y o Cali o nia, I ine 39
Clean Ene gy Ins i u e
5.6 Fuel Cell Sizing P oblem
We ha e es ablished ha he pipeline in as uc u e can ca y he necessa y hyd ogen o
he subs a ions. Howe e , o con e his hyd ogen back in o elec ici y o be injec ed in o he g id,
adequa e uel cell capaci y is necessa y. Based on he simula ed hyd ogen gene a ion p o ile
es ablished o he base sys em in sec ion 5.5, each o he subs a ions equi es 10s 0 1000s o MW
uel cell capaci y. Acco ding o he Fuel Cell & Hyd ogen Ene gy Associa ion (FCHE, [10]),
s a iona y uel cell echnology can p oduce a ound 10MW pe ac e o land. Assuming a linea
ela ionship be ween powe ou pu and he a ea equi ed, he subs a ions would each equi e ens
o hund eds o ac es o space, land which is no eadily a ailable in he ci y. Fu he mo e, his is
only conside ing he base ci cui , no he added s ain o disabling Zones, which would inc ease
he equi ed uel cell powe ou pu e en mo e.
Ins ead o assuming he use o uel cells, a nea e m solu ion would be o swi ch o H2
powe ed combined cycles using con en ional gas u bine and s eam u bine sys ems. Con en ional
combined cycles can ope a e a peak uel o elec ici y con e sion e iciencies exceeding 60%.
Long e m solu ions could include highe e iciency uel cell – gas u bine cycles whe e a high
empe a u e uel cell is he mally in eg a ed wi h a gas u bine, using hea om he uel cell p ocess
o eplace combus ion in a gas u bine. Theo e ical analysis o his nex gene a ion powe plan
p edic uel o elec ici y con e sion e iciencies in excess o 70% on a lowe hea ing alue basis
([11]). Se e al expe imen al uel cell-gas u bine hyb ids ha e success ully demons a ed
e iciencies app oaching and exceeding hese heo e ical alues ([12]). Fo his wo k, we assume
ha powe plan s wi h a uel o elec ici y con e sion e iciency o 55% a e used. This lowe alue
is selec ed based on a) exis ing gene a o s in he G ea e Los Angeles A ea ha could be epowe ed
using hyd ogen, and b) o e lec ha powe plan s ope a ing on a elec ic g id wi h high
pene a ion o in e mi en enewable esou ces a e egula ly ope a ed a pa load whe e ac ual
e iciency d ops below a ed e iciency.
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Uni e si y o Cali o nia, I ine 40
Clean Ene gy Ins i u e
Based on his new e iciency assump ion, he inal hyd ogen p o ile needed o supply he sys em a e na u al gas
is comple ely emo ed is plo ed below.
Figu e 32: Base Sys em Hyd ogen P o ile
As Pipe 4 can ansmi i s sha e o he hyd ogen mass low p o ile, we can conclude ha he en i e pipeline sys em does as
well.
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
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Uni e si y o Cali o nia, I ine 41
Clean Ene gy Ins i u e
5.7 Resiliency o Resul ing Sys em
Now ha he pipeline has an ac i e ole in he ene gy ansmission sys em, we can conduc
he same analysis done in Sec ion 4. Each o he i e i e isk zones is disabled, he esul ing
o e loads a e plo ed, and he ques ion o whe he he pipeline can suppo enough hyd ogen o
alle ia e hese o e loads by supplying combined cycle hyd ogen plan s is answe ed, o bo h he
ull elec ical loads as well as he c i ical loads es ablished in 4.3. The esul s in his sec ion
conside he addi ion o H2 in he gas ansmission sys em as a uel ha can be used in backup
gene a ion and o he sys ems ha can be used o send elec ici y back o he g id du ing an ad e se
elec ic ansmission e en .
5.7.1 Zone 1 – Pipeline Included
Figu e 33 shows o e loads a e expe ienced in he uppe Palm Sp ings co ido unde ull elec ical
loads when zone 1 is disabled. In his si ua ion, he pipelines unning in pa allel o he ansmission
lines a e ideal o add essing he o e loads. Taking he same app oach as be o e, he ampe age
o e loads on he ansmission lines abula ed in
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Uni e si y o Cali o nia, I ine 42
Clean Ene gy Ins i u e
Table 12 a e con e ed o an equi alen hyd ogen mass low a e and hen sen h ough he
pipelines, on op o he mass low a e es ablished in sec ion 5.5. By doing his, ideally he
elec ical o e loads a e add essed by he addi ional hyd ogen mass low in o he basin. Figu e 33
shows he ci cui esponse o he emo al o he lowe ansmission co ido , when he e is no
na u al gas gene a ion in he basin. Na u ally, since ha na u al gas gene a ion is eplaced by
enewable gene a ion o igina ing om bus 339, an elec ical o e load occu s in he o he
ansmission co ido . Sec ions 5.7.1.1 and 5.7.1.2 show he abili y o he pipeline o add ess his
issue o ull elec ical loads and c i ical loads espec i ely.
Figu e 33: Zone 1 Disabled – Sys em O e load Plo

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Clean Ene gy Ins i u e
Table 13: Zone 1 Disabled – Pipeline-Included Elec ical Pe o mance Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3896
220
8
TRUE
2546
110
1
226
3876
220
7
FALSE
2705
117
1
385
3555
220
25
TRUE
2949
127
2
629
3556
220
25
TRUE
2913
126
2
593
3873
220
24
FALSE
3010
130
2
690
3569
220
69
FALSE
3494
151
2
1174
3553
220
68
TRUE
3565
154
2
1245
3554
220
72
TRUE
3353
145
2
1033
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Uni e si y o Cali o nia, I ine 44
Clean Ene gy Ins i u e
5.7.1.1 Disabling Zone 1 Unde Full Elec ical Loads
Fi s , he sys em is e alua ed based on i s abili y o ansmi adequa e hyd ogen o mee
ull elec ical loads. Figu e 34 shows he esul ing necessa y hyd ogen mass low a e ha
elimina es he o e loads in he ci cui ha a ise when Zone 1 is disabled, unde ull elec ical loads.
Logically, he emo al o ansmission in as uc u e unning pa allel o he pipelines has inc eased
he in ol emen o he pipelines in ene gy ansmission. This o al p o ile will be sen h ough he
pipeline sys em.
Figu e 34: Hyd ogen Mass Flow Ra e o Full Load Zone 1
Figu e 35 shows he pe o mance o he pipeline sys em on he necessa y hyd ogen mass low a e
unde ull elec ical loads. Since Pipe 4 can ansmi i s po ion o he hyd ogen mass low, Pipe 5
is also capable, and he e o e Pipes 1, 2 and 3 a e as well.
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Uni e si y o Cali o nia, I ine 45
Clean Ene gy Ins i u e
Figu e 35: Pipeline Pe o mance Repo , Full Loads, Zone 1
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
Final Repo
Uni e si y o Cali o nia, I ine 46
Clean Ene gy Ins i u e
5.7.1.2 Disabling Zone 1 Unde C i ical Loads
Since he pipelines can suppo hyd ogen unde ull elec ical loads, he abili y o se ice
c i ical loads is implied. As Figu e 36 shows, unde c i ical loads he pipeline is e en mo e capable
o ansmi ing he necessa y hyd ogen o he basin.
Figu e 36: Pipeline Pe o mance Repo , C i ical Loads, Zone 1
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
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Uni e si y o Cali o nia, I ine 53
Clean Ene gy Ins i u e
Figu e 43: Pipeline Pe o mance Repo , Full Loads, Zone 3
Again, as he pipeline sys em can suppo he o e loads c ea ed by he ull elec ical loads in his
case, i is in e ed ha c i ical loads can also easily be me using his app oach.
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e

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Uni e si y o Cali o nia, I ine 54
Clean Ene gy Ins i u e
5.7.5 Zone 4 – Pipeline Included
Figu e 44: Zone 4 Disabled – Sys em O e load Plo
Table 16: Zone 4 Disabled – Pipeline-Included Elec ical Pe o mance Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3622
220
8
FALSE
5081
146
9
1601
5744
220
10
TRUE
3256
140
9
936
304
138
3
TRUE
2515
108
4
195
3597
500
76
FALSE
3252
119
6
512
3598
500
76
FALSE
3250
119
6
510
5698
500
66
FALSE
2877
105
2
137
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Clean Ene gy Ins i u e
The ci cui expe iences some elec ical o e loads downs eam o he main pipeline sys em we a e
modelling. These o e loads a e no easily add essed by adding mo e hyd ogen, as his addi ional
hyd ogen has no e ec on ansmission in as uc u e ha does no un in pa allel o he pipeline
sys em. A e applying he algo i hm o de e mine he necessa y hyd ogen low a e, he ci cui is
eassessed.
Figu e 45: Zone 4 Disabled – Pipeline Hyd ogen Applied
Table 17: Zone 4 Disabled – Pipeline Hyd ogen Applied, O e load Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3597
500
76
FALSE
3186
116
7
446
3598
500
76
FALSE
3184
116
7
444
3892
500
20
TRUE
4408
107
3
298
3893
500
2
TRUE
2953
108
3
213
3894
500
1
FALSE
5909
108
3
429
3889
500
26
FALSE
2930
107
3
190
3890
500
31
FALSE
2889
105
3
149
3891
500
26
FALSE
2944
107
3
204
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Clean Ene gy Ins i u e
Figu e 46: Pipeline Pe o mance Repo , Full Loads, Zone 4
Wi h he inclusion o hyd ogen, he o e loads ha e shi ed om whe e hey we e occu ing in
Figu e 44 o a single ansmission b anch. These o e loads occu because he e a e loads in he
no h-wes e n pa o he a ea whe e he e a e no gene a o s. The hyd ogen compensa ion
algo i hm is unable o con e ge on a solu ion whe e he e a e no o e loads in he sys em, meaning
he esul o he analysis o his pa icula case should be conside ed inconclusi e. We suspec ha
he pipeline sys em can add ess hese o e loads since he pe o mance epo (Figu e 46) shows
he sys em is below capaci y. Mos likely, a limi a ion in he model is p e en ing con e gence.
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
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Uni e si y o Cali o nia, I ine 57
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5.7.6 Zone 5 – Pipeline Included
Figu e 47: Zone 5 Disabled – Pipeline-Included Sys em Plo
Table 18: Zone 5 Disabled – Pipeline-Included Elec ical Pe o mance Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3880
220
8
TRUE
4143
179
6
1823
3941
220
8
FALSE
4135
178
6
1815
304
138
3
TRUE
2936
127
6
616
3569
220
69
FALSE
2594
112
2
274
3553
220
68
TRUE
2647
114
2
327
3554
220
72
TRUE
2490
107
2
170
3599
220
11
TRUE
2713
117
3
393
3600
220
11
TRUE
2768
119
3
448
Disabling Zone 5 leads o majo o e loads bo h in he uppe Palm Sp ings co ido as well as
downs eam wi hin he basin. By including pipeline hyd ogen, all hese o e loads a e add essed,
excep a new o e load is c ea ed in he ansmission in as uc u e in I ine:
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Uni e si y o Cali o nia, I ine 58
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Figu e 48: Zone 5 Disabled – Pipeline Hyd ogen Applied
Table 19: Zone 5 Disabled – Pipeline-Included Elec ical Pe o mance Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3691
220
13
TRUE
2549
110
3
229

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Uni e si y o Cali o nia, I ine 59
Clean Ene gy Ins i u e
Figu e 49: Pipeline Pe o mance Repo , Full Loads, Zone 5
Since he ansmission lines be ween s a ion 2133 and 381 do no un pa allel o he pipeline, and
since he only o he elec ical pa h o s a ion 381 is cu o when Zone 5 is disabled, hese lines
become o e loaded and canno be helped by he pipeline in as uc u e. The model does no
accoun o gene a ion sou h o he a ea, so in he eal sys em i is likely ha hese o e loads would
no occu because powe can s ill be ansmi ed o s a ion 381 om he Sou h.
0 5 10 15 20 25
Time (h)
200
300
400
500
600
700
800
900
1000
P essu e (psi-g)
Pipe 4 (Segmen 2)
Inle p essu e
Ou le p essu e
Maximum pipe p essu e
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Uni e si y o Cali o nia, I ine 60
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5.7.7 Conclusions on Hyd ogen-Rein o ced Sys em Resiliency
When compa ing he pe o mance o he exis ing base sys em (sec ion 4.2) o his sec ion, he
inclusion o he pipeline ne wo k signi ican ly inc eases sys em esiliency. Mos impo an ly, i
achie es his while simul aneously elimina ing he need o na u al gas based elec ici y gene a ion
in he basin.
Wi hou disabling any zones, he pipeline ne wo k can easily suppo he base sys em on ull
elec ical loads. Disabling Zones 1 o 2 leads o o e loads in he uppe and lowe Palm Sp ings
co ido s espec i ely, and we ha e demons a ed ha hese o e loads can be ully alle ia ed by
he pipeline ne wo k in sec ions 5.7.1 and 5.7.2. All loads can be me by he pipeline sys em i
Zone 3 is disabled. Disabling Zones 1 and 2 simul aneously, which is a ealis ic scena io as hey
a e physically connec ed, would equi e he pipeline ne wo k o anspo hyd ogen exceeding i s
capaci y. Speci ically, Pipes 4 and 5 would no be able o anspo adequa e hyd ogen o add ess
he sys em’s elec ical needs. An addi ional pipeline iden ical o Pipes 4 and 5 would need o be
buil .
Disabling Zones 4 and 5 bo h lead o a sys em con igu a ion whe e he hyd ogen compensa ion
algo i hm does no con e ge on a solu ion whe e he g id has no elec ical o e loads. An AC powe
low model is highly dynamic, and ce ain esul s a e di icul o p ope ly diagnose, so i is likely
ha some limi a ion in he way he model is se up is p e en ing his algo i hm om con e ging.
Howe e , we a e con iden ha he exis ing pipeline in as uc u e would be capable o add essing
he o e loads seen when Zones 4 and 5 a e disabled, based on he inspec ion o he pe o mance
epo s.
6 Pe o mance Unde Comple e Elec i ica ion o End-Uses
The s udy pe o med in sec ion 5 was conduc ed on he assump ion ha he elec ical load
p o ile aken om CAISO his o ical da a accu a ely ep esen s he comple e ene gy demand in he
a ea. Howe e , hese loads a e pu ely elec ical and do no accoun o al e na i e ene gy sou ces,
p ima ily na u al gas. To accoun o na u al gas, sec ion 5.5 con e ed i s demand o a hyd ogen
demand p o ile, bu he law wi h his app oach is ha i assumes ha all na u al gas end uses can
be e o i ed o use hyd ogen. I we ins ead assume ha all na u al gas end uses a e con e ed o
elec ical loads, we can again un an analysis de e mining whe he he pipeline ne wo k can
suppo he addi ional loads.
ResS ock and ComS ock p o ide comple e elec i ica ion load p o iles, anging om low-
o high-e iciency, whole-home elec i ica ion packages. This is only a ailable a he s a e le el,
so we mus le e age ou o he da a o inc ease he esolu ion and assign new, comple e
elec i ica ion load p o iles o he subs a ions. To achie e his, we can de e mine he hou ly a io
be ween he baseline elec ical load and he comple e elec i ica ion package load, hen apply his
hou ly a io o each o he subs a ions’ cu en elec ical load p o iles, like how we de e mined
c i ical load p o iles in sec ion 4.3.
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Figu e 50: Whole-Home Elec i ica ion Package, Min E iciency – Residen ial
The upg ade package we a e using assumes whole-home elec i ica ion a minimum e iciency.
This was chosen o de e mine he sys em pe o mance in he mos conse a i e e iciency case.
As an equi alen package is no p o ided o he comme cial end uses in ComS ock, his esiden ial
package will be used exclusi ely o adjus all loads.
Figu e 51: Base & Whole-Home Elec i ica ion Load Compa ison
Figu e 51 demons a es he inc eased elec ical loads because o he whole-home elec i ica ion
package. Howe e , because we a e now accoun ing o he esiden ial and comme cial na u al gas
end uses in he elec ical p o iles, we can elimina e he na u al gas demand om he pipeline
sys em.
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Clean Ene gy Ins i u e
6.1 Resiliency Analysis
Figu e 52 shows he inc ease in hyd ogen ansmission necessa y due o he con e sion o whole-
home elec i ica ion. While na u al gas end uses we e con e ed o elec ical demand and his
dec eased he hyd ogen p o ile be ween hou s 2 and 8 (when he elec ical g id expe iences no
o e loads), o he es o he day he esul ing elec ical o e loads demand mo e hyd ogen
ansmission o e all.
Figu e 52: Hyd ogen P o ile Compa isons
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7.2 Hyd ogen-Augmen ed Sys em Resiliency Analysis Resul s
Fo he ew cases whe e he hyd ogen compensa ion algo i hm was unable o con e ge on
a solu ion whe e none o he elec ical ansmission lines we e o e loaded, i is bene icial o
de e mine he po en ial cos s o upg ading hese speci ic ansmission lines as an al e na i e. To
ei e a e, in his case, i is assumed ha all na u al gas powe plan s in he LA basin a e epu posed
o use hyd ogen, making i a highly enewable case.
7.2.1 Hyd ogen-Augmen ed Sys em – Zone 3
In he hyd ogen-augmen ed sys em, he pipeline comple ely add esses all elec ical
o e loads. Thus, no upg ade is necessa y.
7.2.2 Hyd ogen-Augmen ed Sys em – Zone 4
Table 24: Zone 4 sys em de ails
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe
Phase)
Pe cen age
o
Capaci y
Time Spen
O e loaded
(Hou s)
Addi ional
Requi ed
Capaci y
Pe Phase
(Amps)
3597
500
76
FALSE
3186
116
7
446
3598
500
76
FALSE
3184
116
7
444
3892
500
20
TRUE
4408
107
3
298
3893
500
2
TRUE
2953
108
3
213
3894
500
1
FALSE
5909
108
3
429
3889
500
26
FALSE
2930
107
3
190
3890
500
31
FALSE
2889
105
3
149
3891
500
26
FALSE
2944
107
3
204
7.3 Hyd ogen-Augmen ed Sys em Addi ional Pipeline Cos
In one ex eme case, pa o he pipeline sys em was unable o handle he hyd ogen
ansmission load. In oducing a new pipeline add essed his p oblem. Thus, i is impo an o
de e mine he possible cos s o building such a new pipeline, and o compa e hese cos s o ha o
elec ical ansmission econduc o ing discussed in sec ion 7.2.
8 Conclusion
This epo analyzed he esiliency and eliabili y o he Sou he n Cali o nia ene gy in as uc u e,
ocusing on he po en ial o hyd ogen augmen a ion h ough na u al gas pipelines o enhance

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sys em pe o mance unde s ess. Below a e he key indings and quan i ied esul s om he
analysis:
• Baseline Sys em Resiliency:
o The Sou he n Cali o nia g id expe ienced o e loads exceeding 120% o ope a ional
limi s du ing simula ed ou ages in majo ansmission zones. These occu ed o
du a ions anging om 2 o 9 hou s.
o Upg ading he elec ical in as uc u e o handle hese o e loads would cos an
es ima ed $66 million, assuming ins alla ion cos s a e en imes he conduc o cos s.
• Hyd ogen-Augmen ed Sys em Pe o mance:
o Inclusion o hyd ogen ansmission ia pipelines signi ican ly imp o ed sys em
esiliency.
o Hyd ogen pipelines e ec i ely mi iga ed o e loads in Zones 1, 2, and 3 du ing ull
load scena ios, wi hou exceeding ope a ional pipeline limi s.
o When Zones 1 and 2 we e simul aneously disabled, he exis ing pipelines we e
insu icien . Adding one new 36-inch pipeline would enable hyd ogen ansmission
o mee sys em demand a an es ima ed capaci y inc ease o 45%.
• C i ical Load Managemen :
o Wi h loads educed by 20%, mos o e loads we e alle ia ed, demons a ing he
sys em's abili y o p io i ize essen ial se ices du ing ou ages.
o Unde ull elec i ica ion scena ios, pipeline limi s we e app oached bu no
exceeded o single-zone ou ages. Howe e , simul aneous ou ages o Zones 1 and
2 equi ed addi ional pipeline in as uc u e.
• Fu u e Ou look:
o T ansi ioning na u al gas pipelines o hyd ogen anspo o e s a dual bene i :
educing dependency on ossil uels and enhancing g id esiliency.
o Howe e , he comple e elec i ica ion o end-uses and anspo a ion would
inc ease elec ical loads by up o 70%, necessi a ing signi ican in as uc u e
in es men s in ei he hyd ogen o elec ical sys ems.
This analysis suppo s he easibili y and economic ad an age o using hyd ogen in as uc u e as
a esiliency measu e o c i ical u ban ene gy sys ems. Fu he in eg a ion o enewable hyd ogen
and s a egic pipeline expansion is ecommended o u u e-p oo he Sou he n Cali o nia ene gy
g id agains inc easing demand and ex eme e en s.
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9 Re e ences
[1] S anko ic A, Tomso ic K, Mili ( L, Pan eli M, Ka icky J, Thomas K, e al. Commen s on he De ini ion and
Quan i ica ion o Resilience IEEE Task Fo ce on De ini ion and Quan i ica ion o Resilience. 2018.
[2] Chi Y, Xu Y, Hu C, Feng S. A S a e-o - he-A Li e a u e Su ey o Powe Dis ibu ion Sys em Resilience
Assessmen . 2018 IEEE Powe & Ene gy Socie y Gene al Mee ing (PESGM), 2018, p. 1–5.
h ps://doi.o g/10.1109/PESGM.2018.8586495.
[3] Liss W, Rowley P. Assessmen o na u al gas and elec ic dis ibu ion se ice eliabili y. Gas Technology
Ins i u e 2018.
[4] Williams AP, Aba zoglou JT, Ge shuno A, Guzman-Mo ales J, Bishop DA, Balch JK, e al. Obse ed Impac s
o An h opogenic Clima e Change on Wild i e in Cali o nia. Ea hs Fu u e 2019;7:892–910.
h ps://doi.o g/h ps://doi.o g/10.1029/2019EF001210.
[5] CPUC. Public Sa e y Powe Shu o s. H ps://WwwCpuc.caGo /Psps/ n.d.
[6] US Depa men o Ene gy. Cali o nia Ene gy Sec o Risk P o ile 2015.
[7] Heyda zadeh Z, McVay D, Flo es R, Thai C, B ouwe J. Dynamic modeling o cali o nia g id-scale hyd ogen
ene gy s o age. ECS T ans 2018;86:245.
[8] Los Angeles Almanac. High/Low & A e age Tempe a u es By Mon h & Yea Down own Los Angeles.
H ps://WwwLaalmanacCom/Wea he /We04aPhp n.d.
[9] Lohse-Busch H, S u enbe g K, Duoba M, Ilie S. Technology assessmen o a uel cell ehicle: 2017 Toyo a
Mi ai. No ANL/ESD-18/12 A gonne Na ional Lab 2017.
[10] Fuel Cell & Hyd ogen Ene gy Associa ion. S a iona y Powe . H ps://WwwFcheaO g/S a iona y n.d.
[11] D.F. Chuahy F, Kokjohn SL. Solid oxide uel cell and ad anced combus ion engine combined cycle: A
pa hway o 70% elec ical e iciency. Appl Ene gy 2019;235:391–408.
h ps://doi.o g/h ps://doi.o g/10.1016/j.apene gy.2018.10.132.
[12] an Bie L, Wouds a T, Godje ac M, Visse K, A a ind P V. A he modynamic compa ison o solid oxide
uel cell-combined cycles. J Powe Sou ces 2018;397:382–96.
h ps://doi.o g/h ps://doi.o g/10.1016/j.jpowsou .2018.07.035.
[13] U.S. Ene gy In o ma ion Adminis a ion. Cali o nia S a e Ene gy P o ile.
H ps://WwwEiaGo /S a e/P in Php?Sid=CA 2023.
[14] P o Wi e & Cable. ACSR Conduc o P icing. H ps://P owi eandcableCom/Building-
Wi e/Aluminum/Acs /?S sl id=A mBOo G4GU KmR6qVwCLqCeSBz6EFSdKOb9_ JHQiBe85U9Uu5uPoL
n n.d.
[15] Cali o nia Ene gy Commission. Cali o nia Ene gy S o age Sys ems Su ey.
H ps://WwwEne gy.caGo /Da a-Repo s/Ene gy-Almanac/Cali o nia-Elec ici y-Da a/Cali o nia-
Ene gy-S o age-Sys em-Su ey 2024.
[16] LaFo es JJ, Gene al Elec ic Co. PMALTDi ; GECo, SNYEUS. T ansmission Line Re e ence Book - 345kV and
abo e. EPRI, NTRL; 1981.
[17] Indulka CS, Ramalingam K. Es ima ion o ansmission line pa ame e s om measu emen s. In e na ional
Jou nal o Elec ical Powe & Ene gy Sys ems 2008;30:337–42.
h ps://doi.o g/h ps://doi.o g/10.1016/j.ijepes.2007.08.003.
[18] Dixon J, Mo an L, Rod iguez J, Domke R. Reac i e Powe Compensa ion Technologies: S a e-o - he-A
Re iew. P oceedings o he IEEE 2005;93:2144–64. h ps://doi.o g/10.1109/JPROC.2005.859937.
[19] Aspen En i onmen al G oup, CPUC. T ansmission S uc u es.
H ps://IaCpuc.caGo /En i onmen /In o/Aspen/Cl p/A chi e/Files_8_26_14/_4T ansmissionS uc u es
Fac Shee Pd n.d.
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[20] Dwigh HB, Fa me EB. Double Conduc o s o T ansmission Lines. T ansac ions o he Ame ican Ins i u e
o Elec ical Enginee s 1932;51:803–8. h ps://doi.o g/10.1109/T-AIEE.1932.5056167.
Appendix A – Da a Collec ion o Elec ic G id Model
Geospa ial Da a
Da a ha desc ibes he loca ion and speci ica ions o impo an in as uc u e was necessa y o
he de elopmen o a model o he elec ical and na u al gas g ids.
Cali o nia Elec ical T ansmission Lines
The “Cali o nia Elec ic T ansmission Lines” da ase p o ided by he Cali o nia Ene gy
Commission con ains all elec ical ansmission lines in he s a e o Cali o nia and abula es a se
o ea u es o each line. Among hese ea u es, hose lis ed below a e mos signi ican o ou
model:
• Line ID numbe
• Line coo dina es (all segmen s)
• Line ol age a ing (in kV)
• U ili y ha owns he line
• Ope a ional s a us
• Whe he he line is a single o double ci cui
• Line leng h (in miles & ee )
Figu e 55 shows a subsec ion o he da ase in ou a ea o in e es : he LA basin and i s su ounding
egions.
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Figu e 55: Cali o nia Elec ical T ansmission Lines geospa ial map
Sou he n Cali o nia Edison Dis ibu ed Ene gy Resou ce In e connec ion Map
Subs a ions a e key componen s o he elec ical g id. F om a modelling s andpoin , hey a e nodes,
in e connec ed by ansmission lines. An a ea’s powe gene a ion, as well as load p o iles
pe aining o he a ea’s popula ion, can be assigned o hese nodes. Sou he n Cali o nia Edison has
a publicly a ailable geospa ial da ase , known as he Dis ibu ed Ene gy Resou ce In e connec ion
Map (DERiM). This da ase con ains he de ails desc ibing all subs a ions in he Sou he n
Cali o nia a ea, including hose owned by o he u ili ies. Like he ansmission line da a se , his
da a se p o ides a lis o ea u es o each subs a ion:
• Subs a ion ID
• Subs a ion coo dina es
• “Sys em” o which he subs a ion belongs
• DER exis ing gene a ion (in MW)
• P ojec ed load (in MW)
• Maximum and minimum loads expe ienced du ing e e y hou o e e y day in a yea
Figu e 56 shows he plo ed subs a ion da a aken om DERiM.
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Figu e 56: DERiM subs a ion geospa ial map
Accompanying his geospa ial da a is a se o comma-sepa a ed alues desc ibing minimum and
maximum expe ienced loads (in MW) o e e y subs a ion. E e y mon h is desc ibed by a
minimum and maximum 24-hou load p o ile, whe e he alues a e based on he minimum and
maximum loads expe ienced a each hou in he en i e mon h. Fo example, i Janua y 3 d
expe ienced he lowes load a 13:00, while Janua y 20 h expe ienced he highes load a 13:00,
hey would be selec ed o desc ibe Janua y’s minimum and maximum loads a 13:00 espec i ely.
While his da a is no physical as i is an agg ega ion o da a collec ed o e mon h-long pe iods
a he han desc ibing eal indi idual days, i will be use ul in scaling and assigning eal, physical
da a o he nodes.
By combining he ansmission line da ase wi h his subs a ion da ase , i will be possible o build
an A/C powe low model ha ea s he subs a ions as nodes, and he ansmission lines as
connec ions be ween hese nodes.
Cali o nia Powe Plan s
Alongside geospa ial da a o he physical in as uc u e ha cons i u es he elec ical g id, ou
model necessi a es geospa ial da a desc ibing he magni ude, loca ion, and ype o powe
gene a ion in he sys em. The Cali o nia S a e Geopo al p o ides a da ase o all powe plan s in
Cali o nia, wi h he ollowing se o ea u es desc ibing each:
• Cali o nia Ene gy Commission Plan ID
• Plan Name
• S a e o e i emen (0 o 1)

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• Ope a o Company
• Coun y
• Capaci y (in MW)
• Uni s
• P ima y Ene gy Sou ce (SUN, NG, WIND…)
While his da ase does no con ain in o ma ion ega ding gene a ion p o iles o any o hese
plan s, he capaci y and loca ion da a will be use ul in scaling and assigning such p o iles o
subs a ions in hei icini ies. Figu e 57E o ! Re e ence sou ce no ound. shows a plo o his
da ase , again in ou a ea o in e es .
Figu e 57: Powe Plan s
No e ha his da ase desc ibes u ili y-scale gene a ion and does no accoun o DER esou ces
such as oo op sola , meaning ha he DER da a collec ed om SCE’s DERiM is independen
om his da ase . The e o e, we can be con iden ha no gene a ion will be double coun ed in he
model.
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Load & Gene a ion P o ile Da a
Cali o nia Independen Sys em Ope a o
To es ablish a wo king model ha accu a ely desc ibes he eal ansmission sys em in Sou he n
Cali o nia, eal demand and gene a ion da a is equi ed. The Cali o nia Independen Sys em
Ope a o (CAISO) is a powe ul esou ce ha p o ides in o ma ion on he ope a ion o
Cali o nia’s elec ic powe ansmission. In i s lib a y, i con ains elec ical demand and gene a ion
da a o e e y day since Ap il 10 h, 2018. The gene a ion da a is b oken down by esou ce
( enewables, na u al gas, hyd oelec ic, e c.) in 5 minu e inc emen s, and he enewable gene a ion
is u he b oken down by enewable ca ego y (sola , wind, geo he mal, e c.). Figu e 58 and Figu e
59 show his gene a ion da a as i is p esen ed on he CAISO websi e, o Augus 8 h, 2023.
Figu e 58: CAISO O e all Gene a ion P o iles
Figu e 59: CAISO Renewable Gene a ion P o iles
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This da a ep esen s he o al s a ewide gene a ion bu canno be sepa a ed based on u ili ies. I is
he e o e no possible o know how much o he o al gene a ion is p o ided by SCE and LADWP,
he u ili ies o in e es in his s udy.
Load p o ile da a is p o ided by he Cali o nia ISO ia i s Open Access Same- ime In o ma ion
Sys em (OASIS) on an hou ly basis, b oken down based on u ili ies. As a esul , we can ob ain a
load p o ile ha adequa ely ep esen s ou a ea o in e es (se ed by mos o SCE and LADWP).
The limi a ion o his CAISO da a is he ac ha i is agg ega ed da a (s a ewide o gene a ion,
u ili y-based o loads). This limi a ion can be compensa ed o using ce ain p ope ies o he
geospa ial da a.
Residen ial & Comme cial Building S ock
The Na ional Renewable Ene gy Labo a o y p o ides building simula ion da a in wo ca ego ies
o building s ock – esiden ial (ResS ock) and comme cial (ComS ock). Bo h ca ego ies con ain
da a a he s a e le el, which a e pa i ioned in o end uses. ‘Upg ade packages’, which simula e he
p edic ed elec ical loads o building s ock ha is pa ially o en i ely elec i ied, a e also a ailable.
Mon hly da a can be downloaded, whe e he use can ob ain a 24-h p o ile in uni s o kWh.
Figu e 60: ResS ock agg ega e load p o ile
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Figu e 61:ComS ock agg ega e load p o ile
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he same app oach as aken in assigning load p o iles o he subs a ions in 0, each subs a ion is
assigned a se o powe plan s based on hei p oximi y.
Figu e 67 shows all powe gene a ion plan s ha a e included in he model and assigned o
hei nea es subs a ions. Wi h a gene a ion capaci y alue o e e y ype o gene a ion a ached o
each subs a ion, he gene a ion p o iles can be di ided amongs he subs a ions acco dingly. Fo
example, i he e is a o al o 20GW o na u al gas gene a ion in he egion, and a subs a ion has a
na u al gas gene a ion capaci y alue o 2GW, i will be esponsible o 10% o he o al na u al
gas gene a ion p o ile. The o al gene a ion capaci y o each gene a ion ype was ound and
abula ed. The gene a ion p o iles p o ided by CAISO in 0 a e no pa i ioned by u ili y, bu he
load p o iles p o ided by CAISO OASIS a e. By aking he a io be ween he SCE + LADWP
loads and he s a ewide loads a each hou , we a i e a an a ay o a ios a each hou ha can be
mul iplied elemen wise by he gene a ion p o iles o ob ain an app oxima ion o he local
gene a ion p o iles.
Figu e 67: Gene a ion Plan Map

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𝑆𝑆𝐿𝐿 (7)
In obse a ion o Figu e 68, no ice ha u ili y sola , he sola gene a ion p o ided by he CAISO
p o ile, has been scaled such ha i s maximum ou pu does no exceed he sola gene a ion
capaci y. Wind, hyd oelec ic, geo he mal and impo ed p o iles a e un ouched. Roo op sola
gene a ion is he gene a ion p o ided by he DERiM esou ce, which p o ides exis ing cus ome -
side sola gene a ion capaci y o each subs a ion. This p o ile was cons uc ed using hese
capaci y numbe s coupled wi h a sola gene a ion p o ile o he Los Angeles a ea in Augus ,
downloaded om he NREL PVWa s ool. Two High-Vol age DC ansmission lines known as
Pa h 27 and Pa h 65 a e esponsible o a signi ican amoun o impo ed powe in o he basin.
Wi h capaci ies o 2.4GW and 3.1GW espec i ely, hey a e mo e han capable o ansmi ing he
impo a ion p o ile seen in Figu e 68, and hus will be inse ed in o he model o he pu pose o
supplying all impo a ion o he sys em. No e ha hey a e single-phase HVDC lines ha will be
ea ed as h ee-phase AC lines wi h he same capaci y o a oid adding complexi y o he model.
The impo s p o ile was adjus ed such ha he e is cons an impo a ion o powe a 50% o he
maximum capaci y o hese wo HVDC lines, a conse a i e es ima e o simplici y and o a oid
needing o amp up he na u al gas du y cycle o un easonable le els. Figu e 69 displays his
adjus ed impo gene a ion p o ile.
Figu e 68: Augus 8 h Load & Gene a ion P o iles
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Figu e 69: Adjus ed Load & Gene a ion P o iles
Wi h a o al gene a ion p o ile o each ype o gene a ion es ablished o he a ea co e ed by he
model, his gene a ion can be di ided among he subs a ions using he gene a ion capaci y alues
assigned o each subs a ion.
On Ene gy S o age
This model o a base case will no include ba e y ene gy s o age due o he sizing and
placemen o he exis ing s o age in he s a e. Acco ding o he Cali o nia Ene gy S o age Sys em
Su ey ([15]), he s a e has a o al ene gy s o age capaci y o 10.383GW. Mos o his capaci y is
owned by u ili y companies. Because he gene a ion p o iles we e aken di ec ly om CAISO, he
dynamics o s o age and dispa ch a e al eady in eg a ed. As such, o he base case, which aims
only o simula e a eal day, o mally including ba e y ene gy s o age as a gene a ion p o ile was
deemed unnecessa y.
T ansmission Line Pa ame e s
The pa ame e s go e ning ansmission line dynamics in OpenDSS, namely ope a ing
ampaci y, esis ance, capaci ance and esis ance, a e all de ined in a ‘linecode’. A linecode needs
o be de ined o each ype o ansmission line included in he model – 500kV, 220kV and o he
high- ol age lines a e buil using di e en ly sized conduc o s and hus will no ha e he same
elec ical p ope ies. Sou he n Cali o nia Edison declined o p o ide de ails on he conduc o s used
in hei ansmission lines, and he e o e some es ima es mus be made o p oceed.
To make an ini ial es ima e on he physical pa ame e s o he ansmission lines in he
ci cui , ansmission line conduc o da a was necessa y. Aluminum Conduc o , S eel Rein o ced
(ACSR) conduc o s a e he s anda d conduc o s used in ansmission line in as uc u e. In he
T ansmission Line Re e ence Book [16] published by EPRI, a able con aining c i ical in o ma ion
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on ACSR conduc o s is p o ided. F om his able, which con ains dozens o di e en conduc o s,
a se o conduc o s we e selec ed o be assigned o he di e en ansmission lines in he model.
These conduc o s we e chosen based on he assump ion ha highe - ol age lines will ha e
highe cu en -ca ying capaci ies, hough his is no e i iable. The alues shown in he able
apply o indi idual conduc o s, o which he e a e h ee in a h ee-phase ansmission line. Some
ansmission lines ca y double ci cui s, meaning he e a e wo sepa a e h ee-phase ci cui s wi h
a conduc o each, a o al o six conduc o s. The ansmission line da ase discussed in 0 accoun s
o his, as i s a es o e e y line in he da ase whe he ha line is a single o double ci cui .
Double-ci cui ansmission lines will be ea ed as wo iden ical single-ci cui ansmission lines
in pa allel. OpenDSS linecode equi es capaci ance speci ica ions which a e no included in he
able aken om [16]. Ins ead, physical measu emen s o capaci ance o a 220kV line we e aken
om [17], hen applied o he o he ol ages simply using nume ical a ios be ween he ol ages
o inc ease o dec ease he capaci ance. Wi h his conduc o da a and he knowledge o he numbe
o conduc o s in e e y ansmission line, we ha e a i s wo king model o he elec ical
ansmission sys em and can begin o adjus pa ame e s acco ding o whe he he model beha es
as expec ed.
Upon esol ing a ci cui , OpenDSS p o ides analy ics ha allow he use o de e mine
whe he he ci cui is ope a ing co ec ly. Among hese analy ics, he pe -uni (pu) ol age sys em
and he ampaci y o e load sp eadshee a e he mos indica i e o issues. The p.u. ol age sys em
shows whe he he ci cui componen s a e ope a ing a hei speci ied ol ages, wi hou signi ican
unde - o o e - ol ages. Ideally, he p.u. ol age is equal o 1 h oughou he en i e ci cui , al hough
in p ac ice he ag eed-upon accep able ange is om 0.95 o 1.05, a 5% e o . Thus, i a
ansmission line is a ed o ope a e a 500kV, bu d ops o below 475kV, his is conside ed an
unde ol age.
O e - and unde - ol ages a e caused by signi ican e en s. A ligh ning s ike hi ing a
ans o me would be one example o a cause o an o e - ol age, while an unde - ol age can
occu when he demand o powe in a ci cui exceeds he a ed powe o a componen in he
ci cui , leading o a ol age d op. In he base case ci cui , i is assumed ha such e en s do no
occu , and ha he ci cui is ully capable o ansmi ing he powe gene a ed and demanded.
Thus, o e - and unde - ol ages indica e ha ansmission line pa ame e s a e no p ope ly
speci ied.
Ampaci y o e loads occu when lines in he ci cui a e equi ed o ansmi cu en s ha
exceed hei ope a ing capaci ies. O e loads lead o he deg ada ion o he ansmission
in as uc u e and should be a oided. Lines ope a ing a o e 105% o hei capaci y will be
o e loaded. OpenDSS p o ides an o e load epo on he ci cui , showing he o e loaded lines,
hei ampaci ies, and he hou s in which hese o e loads occu ed. Using hese me ics o desc ibe
he sys em’s pe o mance, a i s un o he model can be conduc ed and e alua ed.
Final Repo
Uni e si y o Cali o nia, I ine 89
Clean Ene gy Ins i u e
The chosen pa ame e s o he ansmission lines do no lead o wha would be conside ed an
accep able ol age p o ile in p ac ice. The wo ed lines in Figu e 70 ma k he accep able p.u.
ol age ange (0.95-1.05), and he blue lines deno e he ansmission lines in he model, s a ing a
Palm Sp ings on he le whe e he sou ce bus is si ua ed (no e ha he lines mo e om le o igh
on he g aph, while on he map hey a e eally mo ing om Eas o Wes ). F om inspec ion, Figu e
70 shows a signi ican ol age d op ac oss he powe lines.
Final Repo
Uni e si y o Cali o nia, I ine 90
Clean Ene gy Ins i u e
Table 26 shows a minimum unde ol age o 0.63 pu, wi h a o al o 19 unde ol age buses. This is
a below he accep able minimum.
Figu e 70: Base Case Vol age P o ile
Figu e 71: Base Case O e load Plo

Final Repo
Uni e si y o Cali o nia, I ine 91
Clean Ene gy Ins i u e
Table 25: Base Case Vol age Repo
Maximum
O e -
ol age
Maximum
Hou
Numbe o
O e -
ol ages
a Max
Hou
Minimum
Unde -
ol age
Minimum
Hou
Numbe o
Unde -
ol ages a
Min Hou
1.006711
5
0
0.619941
19
249
Table 26: Base Case O e load Repo
Final Repo
Uni e si y o Cali o nia, I ine 92
Clean Ene gy Ins i u e
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
3564
500
25
FALSE
1486
108
2
3694
220
10
TRUE
1740
150
3
3622
220
8
FALSE
2941
254
12
3685
220
16
TRUE
2116
182
3
3664
220
16
TRUE
2099
181
3
3892
500
20
TRUE
2671
195
1
3893
500
2
TRUE
1782
130
1
3894
500
1
FALSE
3564
260
1
3895
500
12
FALSE
2190
160
2
3703
220
9
TRUE
3112
268
3
3896
220
8
TRUE
1459
126
2
3876
220
7
FALSE
1550
134
2
297
500
10
FALSE
1510
110
1
298
500
11
FALSE
1500
109
1
3555
220
25
TRUE
1425
123
3
3556
220
25
TRUE
1408
121
3
3873
220
24
FALSE
1455
125
3
3903
220
6
TRUE
1530
132
3
3699
220
6
TRUE
1516
131
3
3569
220
69
FALSE
1420
122
4
3553
220
68
TRUE
1450
125
4
3889
500
26
FALSE
1775
130
1
3890
500
31
FALSE
1776
130
1
3891
500
26
FALSE
1783
130
1
3653
500
65
FALSE
3440
251
3
3916
220
37
TRUE
1414
122
1
3696
220
5
TRUE
1376
119
3
3568
500
67
FALSE
1785
130
6
5698
500
66
FALSE
1809
132
6
3554
220
72
TRUE
1362
117
3
3691
220
13
TRUE
1339
115
2
3697
220
5
TRUE
1335
115
2
3860
220
1
TRUE
1278
110
1
Final Repo
Uni e si y o Cali o nia, I ine 93
Clean Ene gy Ins i u e
Table 27: Base Case Vol age Repo
Maximum
O e -
ol age
Maximum
Hou
Numbe o
O e -
ol ages
a Max
Hou
Minimum
Unde -
ol age
Minimum
Hou
Numbe o
Unde -
ol ages a
Min Hou
1.006711
5
0
0.619941
19
249
The pa ame e ha has he mos impac on his ol age d op was de e mined h ough ial
and e o o be he eac ance in he linecodes. Despi e he assump ion ha he conduc o eac ance
speci ica ions p o ided by he ACSR da a able in [16] a e accu a e, i was ound ha he model
could only p oduce an accep able ol age p o ile when he eac ance was educed by an o de o
magni ude. While no sou ce in he li e a u e uses line eac ance alues below hose in he ACSR
able, he e is no o he simple way o p oduce accep able ol age p o iles in he model han by
educing he eac ance.
An explana ion o his disc epancy be ween he eal sys em and he model is he lack o
eac i e powe compensa ion in he model. Acco ding o a e iew o Reac i e Powe
Compensa ion published in IEEE [18], eac i e powe compensa ion is used o “[inc ease] he
maximum ac i e powe ha can be ansmi ed. I also helps o main ain a subs an ially la ol age
p o ile a all le els o powe ansmission” ([18], page 1). One me hod used o achie e eac i e
powe compensa ion is known as ‘Se ies Compensa ion’, whe e capaci o s a e ins alled in se ies
o “dec ease he equi alen eac ance o a powe line a a a ed equency” ([18], page 2 sec ion
B). Thus, he di ec manual educ ion o eac ance leads o he same esul as Se ies Compensa ion
(being educed eac ance along he powe lines). Ul ima ely, he need o eac i e powe
compensa ion in he eal ansmission ci cui a ises om he ac ha he ansmission line
eac ance is a ixed physical pa ame e . I is he e o e essen ial as a physical way o educe
equi alen eac ance and a oid ol age d ops. Howe e , in he simula ed model o he sys em, he
line eac ance is no ixed, and can be manipula ed di ec ly, achie ing he same esul as, and
elimina ing he need o , eac i e powe compensa ion.
Final Repo
Uni e si y o Cali o nia, I ine 94
Clean Ene gy Ins i u e
Adjus ing he ansmission line eac ance pa ame e s ac oss all linecodes by an o de o
magni ude, OpenDSS yields he ollowing esul s. While Figu e 72 shows ha he o de o
magni ude educ ion in he line eac ance has p oduced an accep able ol age p o ile, and Figu e
73 shows ewe o e loaded ansmission lines han Figu e 71, he e a e s ill unde ol ages and
many o e loaded lines in he ci cui . Table 28: Adjus ed Reac ance O e load Repo
Line
Vol age
(kV)
Leng h
(km)
Double
Ci cui
Highes
Ampe age
(Pe Phase)
Pe cen age
o Capaci y
Time Spen
O e loaded
(Hou s)
3564
500
25
FALSE
2566
187
3
3694
220
10
TRUE
2341
202
6
3622
220
8
FALSE
4433
382
11
3685
220
16
TRUE
2346
202
4
3664
220
16
TRUE
2327
201
4
3892
500
20
TRUE
2836
207
3
3893
500
2
TRUE
1891
138
3
3894
500
1
FALSE
3783
276
3
3895
500
12
FALSE
2681
196
4
3703
220
9
TRUE
2936
253
3
297
500
10
FALSE
1649
120
4
298
500
11
FALSE
1637
119
4
3889
500
26
FALSE
1877
137
3
3890
500
31
FALSE
1878
137
3
3891
500
26
FALSE
1886
138
3
3653
500
65
FALSE
2168
158
4
3912
220
14
TRUE
1306
113
3
3568
500
67
FALSE
1873
137
3
5698
500
66
FALSE
1897
138
3
3691
220
13
TRUE
1676
144
4
3903
220
6
TRUE
1452
125
2
3699
220
6
TRUE
1439
124
2
3687
220
9
TRUE
1459
126
2
3688
220
9
TRUE
1454
125
2
3690
69
9
TRUE
1459
126
2
3860
220
1
TRUE
1495
129
2
3742
220
6
TRUE
1246
107
2
3916
220
37
TRUE
1269
109
2
shows he se o ansmission lines in he ci cui ha expe ience o e loads a leas once in
he 24 hou simula ion. Lines o which he ‘Double Ci cui ’ en y is TRUE should be coun ed
wice, as hey ha e iden ical lines unning in pa allel ha expe ience he same o e load. No e ha
hese lines a e expe iencing ampe ages be ween 100% and 500% o no mal ope a ing capaci y.
Be o e hese o e loads can be add essed, i s he loads and gene a ion mus be comple ely
balanced in he ci cui .
Final Repo
Uni e si y o Cali o nia, I ine 101
Clean Ene gy Ins i u e
sou ce ci ing he p e alence o bundled conduc o s could be ound, he CPUC co obo a es he
s a emen ha he phases o lines a ed abo e 200kV “can consis o mul iple (bundled)
conduc o s” [19]. Fu he mo e, ‘double’ conduc o s (bundles con aining wo conduc o s) ha e
been discussed in li e a u e as ea ly as 1932 [20]. Mos impo an ly, he poo pe o mance o he
cu en model sugges s he exis ence o bundled conduc o s in he eal sys em.
To add ess he cu en o e loads, all o e loaded lines will be assigned new linecodes based
on how much hey a e ansmi ing o e hei ope a ing capaci y. Double, iple and quad uple
conduc o bundles will ha e double, iple and quad uple cu en ca ying capaci ies espec i ely.
Addi ionally, hei esis ances will be di ided by wo, h ee and ou espec i ely based on he
pa allel esis o law:
1
𝑅𝑅𝐺𝐺𝑇𝑇𝐺𝐺
= �
1
𝑅𝑅𝑝𝑝
(5)
Reac ance and capaci ance may no be a ec ed as simply as esis ance, as sugges ed by [20],
which s a es double conduc o s lead o me ely a 20% dec ease in eac ance and a 20% inc ease in
capaci ance. I will be assumed ha double conduc o s abide by hese changes, and ha iple and
quad uple conduc o s ha e he same eac ance and capaci ance as double conduc o s, o
simplici y.
As a i s adjus men o he sys em, i will be assumed ha all lines a ed 220kV and o e
will be equipped wi h double conduc o s a minimum. O e loads ha pe sis a e his adjus men
will be add essed as ollows:
• Lines equipped wi h single conduc o s ha expe ience o e loads be ween 100-200% will
be assigned double conduc o s.
• Lines equipped wi h double conduc o s ha expe ience o e loads be ween 100-150% will
be assigned iple conduc o s.
• Lines equipped wi h double conduc o s ha expe ience o e loads exceeding 150% will be
assigned quad uple conduc o s.

Final Repo
Uni e si y o Cali o nia, I ine 102
Clean Ene gy Ins i u e
A e making his adjus men , he sys em expe iences no o e loads and no ol age anomalies,
con i med by Figu e 79. Thus, wi h he sys em ully mee ing elec ical loads wi hou cu en
o e loads anywhe e in he ci cui , we ha e es ablished a base case ep esen a i e o he eal
elec ical ansmission sys em and can now p oceed wi h analyzing i s pe o mance.
Figu e 79: Final Base Case O e load Plo