2023Annual Report Electric.pdf

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Avista Corp.
2023
IDAHO
State Electric Annual Report
(IC 61-405)

IDAHO STATE ELECTRIC ANNUAL REPORT
Name of Respondentl Avista Corporation
This report is(original, resubmission) Original
Date of report 4/17/2024
Year/period of report

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XK An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
STATEMENT OF UTILITY OPERATING INCOME-IDAHO
Instructions
1. For each account below,report the amount attributable to the state of Idaho based on Idaho jurisdictional Results of Operations.
2. Provide any necessary important notes regarding this statement of utility operating income in a footnote in the available space at the bottom of this
Line Refer to TOTAL SYSTEM-IDAHO
No. Account Form 1 Current Year Prior Year
Page
(a) (b) (C) (d)
1 UTILITY OPERATING INCOME
? 10peratinq Revenues 400 300-301 512,985.949 520,101.035
3 Operating Expenses
4 Operation Expenses 401 320-323 336.497.110 357.217,159
5 Maintenance Expenses(402) 320-323 26.436.728 30.289.738
6 Depreciation Expense(403) 336-337 59,081189 56,478,034
7 Depreciation Expense for Asset Retirement Costs(403.1) 336-337 - -
8 Amortization&Depletion of Utility Plant(404-405) 336-337 16,655.751 15.348,086
9 lAmortization of Utility Plant Acquisition Adjustment 406 336-337 - -
10 JAmort of Property Losses,Unrecov Plant and Regulatory Study Costs(407)
11 lAmortization of Conversion Expenses 407 _
12 Regulatory Debits(407.3) 4.166,247 3,282.261
13 Less Regulatory Credits 407.4 (15.806.967) (17.696,983)
14 Taxes Other Than Income Taxes(A.08.1) 262-263 17.147,479 19.620.560
15 Income Taxes-Federal(409.1) 262-263 (303,077) 1,332,381
16 -Other 409.1 262-263
17 Provision for Deferred Income Taxes(410.1) 234.272-277 9,010,501) (10.417.490)
18 Less Provision for Deferred Income Taxes-Cr. 411.1 234.272-277 -
19 1 Investment Tax Credit Adjustment-Net(411.4) 266 172,197) (172.585)
20 (Less)Gains from Disposition of UtilityPlant 411.6)
21 Losses from Disposition Of Utility Plant 411.7
22 (Less)Gains from Disposition of Allowances 411.8)
23 Losses from Disposition of Allowances 411.9
24 Accretion Expense(411.10) - _
25 TOTAL Utility Operating Expenses(Total of line 4 throuah 24) 434.692.362 452.616,399
26 Net Utility Operating Income(Total line 2 less 25) 78.293,587 67.484.636
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.114-115

` Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation X] An Original mm/dd/yyyy End of 2023/Q4
( F—] A Resubmission 4/17/2024
!� STATEMENT OF UTILITY OPERATING INCOME-IDAHO
l 1 Instructions
page or in a separate schedule.
3. Explain in a footnote if the previous year's figures are different from those reported in prior reports.
f
! ELECTRIC UTILITY GAS UTILITY OTHER UTILITY Line
{ Current Year Prior Year Current Year Prior Year Current Year Prior Year No.
!{
1
391,413,522 395.962.215 121,572,427 124,138,820 2
3
( 243,415,359 263.694.228 93,081,751 93,522,931 4
23.316.905 27,030.605 31119,823 3.259.133 5
49,909,930 47.881.160 9.171,859 8,596,874 6
7
13,551,081 12,812,222 3.104.670 2.535.3 6, 8
9
10
11
3,902,138 3,044,087 264.109 238,174 12
(12,808,982) 16,046.960) (2,997,985) (1,650,023) 13
13,765,709 16.257,241 3.381.770 3,363,319 14
( (594,238) (620.888) 291,161 (711,493) 15
16
` (8,745,603) (11.021.436) (264,898) 603,946 17
18
( (172,197) (172.585) 19
20
21
_ 22
23
24
325,540,102 342,857,674 109.152.260 109.758,725 _ 25
65.873.420 53,104,541 12,420,167 14.380.095 26
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IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID 114-115

Name of Respondent This Report is Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
SUMMARY OF UTILITY PLANT AND ACCUMULATED PROVISIONS FOR DEPRECIATION,AMORTIZATION AND DEPLETION-IDAHO
Instructions
1. Report below the original cost of utility plant in service necessary to furnish utility service to customers in the state of Idaho,and the
accumulated provisions for depreciation,amortization,and depletion attributable to that plant in service.
2. Report in column(c)the amount for electric function,in column(d)the amount for gas function,in columns(e),(f),and(g)report other(specify),
Line Total Company
No. Account End of Current Year Electric
(a) (b) (c)
1 Utility Plant
2 In Service
3 Plant in Service Classified 2.381.567,830 1,828,433,015
4 Property Under Capital Leases 20,693,174
5 Plant Purchased or Sold
6 Completed Construction nct Classified
7 lExperimental Plant Unclassified
8 JTotal Total lines 3 through 7) 2.402.261.004 1,828,433,015
9 Leased to Others _
10 Held for Future Use 1.605,077 1,424,181
11 Construction Work in Proqress 52.920.283 42.168.225
12 Acquisition Adjustments
13 Total Utility Plant(Total lines 8 through 12) 2.456.786.364 1,872,025,421
14 Accumulated Provision for Depreciation,Amortization,and Depletion 909.802.349 701.885.368
15 INet Utility Plant Line 13 less line 14 1.546.984.015 1,170,140,053
16 Detail of Accumulated Provision for Depreciation,Amortization,and Depletion
17 In Service
18 Depreciation 847.030,071 689.452.842
19 Amortization and Depletion of Producing Natural Gas Lands/Land Rights -
20 Amortization of Underground Storage Lands/Land Rights _
21 Amortization of Other Utility Plant 62,772 278 12,432.526
22 Total(Total lines 18 through 21) 909.802.349 701,885,368
23 1 Leased to Others
24 De reciation
25 Amortization and Depletion
26 Total Leased to Others
27 Held for Future Use
28 Depreciation
29 Amortization
30 Total Held for Future Use
31 Abandonment of Leases Natural Gas
32 Amortization of Plant Acquisition Adjustment
33 Total Accumulated Provision(Total lines 22,26,30.31,32) 909.802.349 701,885,368
(1)A small portion of the Company's electric distribution plant is located in Montana.For jurisdictional reporting purposes,those amounts are
included as Idaho plant.
(2)Common Property Under Capital Leases are comprised of ROU Assets
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.200-201

f
f
( Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
SUMMARY OF UTILITY PLANT AND ACCUMULATED PROVISIONS FOR DEPRECIATION,AMORTIZATION AND DEPLETION-IDAHO
Instructions
` and in column(h)common function.
3. In order to accurately reflect utility plant in service necessary to furnish utility service to customers in the state of Idaho,electric and gas
plant not directly assigned is allocated to the state of Idaho as appropriate and included in column(c)and(d).
Line
Gas Other(Specify) Other(Specify) Other(Specify) Common No.
(d) (e) (h)
( 1
2
343,939,061 209,195,754 3
1 - 20.693.174 4
5
6
7
343,939,061 229,888.928 8
9
180,896 10
849.875 9.902,183 11
12
344.969.632 239,791.111 13
119,590,830 88,326,151 14
225.379.002 151.464,960 15
16
17
119,335,451 38,241,778 18
- 19
20
255,379 50,084,373 21
119.590.830 - 88,326,151 22
23
24
25
26
27
28
29
30
31
/ 32
l 119,590,830 88,326,151 33
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IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID 200-201

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
❑ A Resubmission 4/17/2024
ELECTRIC PLANT IN SERVICE-IDAHO(Account 101,102,103 and 106)
Instructions
1. Report below the original cost of electric plant in service necessary to furnish electric utility service to customers in the state of Idaho.
Include electric plant not directly assigned as allocated to the state of Idaho.
2. In addition to Account 101,Electric Plant in Service(Classified),this page and the next include Account 102,Electric Plant Purchased or Sold;
Account 103,Experimental Electric Plant Unclassified;and Account 106,Completed Construction Not Classified-Electric.
3. Include in column(c)or(d),as appropriate,corrections of additions and retirements for the current or preceding year.
4. For revisions to the amount of initial asset retirement costs capitalized,include by primary plant account increases in column(c),additions,and
reductions in column(a),adjustments.
5. Enclose in parentheses credit adjustments of plant accounts to indicate the negative effect of such amounts.
6. Classify Account 106 according to prescribed accounts,on an estimated basis if necessary,and include the entries in column(c). Also to be included
in column(c)are entries for reversals of tentative distributions of prior year in column(b). Likewise,if the respondent has a significant amount of plant
retirements which have not been classified to primary accounts at the end of the year,include in column(d)a tentative distribution of such retirements,
on an estimated basis,with appropriate contra entry to the account for accumulated depreciation provision. Include also in column(d)distributions of
Line Balance
No Account Beginning of Year Additions
(a) (b) (c)
1 1.INTANGIBLE PLANT
2 301 Organization
3 302 Franchises and Consents 15,681,522
4 303 Miscellaneous Intangible Plant 15.513,153 2,527,936
5 TOTAL Intanqible Plant(Total of lines 2,3,and 4) 31.194,675 2.527,936
6 2.PRODUCTION PLANT
7 A.Steam Production Plant
8 310 Land and Land Rights 1,373,299 -
9 311 Structures and Improvements 49.102.734 84,147
10 312 Boiler Plant Equipment 80,850,375 87.378
11 313 Engines and Engine-Driven Generators (1.510) 84.139
12 314 Turboqenerator Units 20,262.277 84.139
13 1 315 Accessory Electric Equipment 10.7217745 84.139
14 316 Miscellaneous Power Plant Equipment 5.958.039 84.139
15 317 Asset Retirement Costs for Steam Production _
16 TOTAL Steam Production Plant Total of lines 8 through 15 168.266.959 508.081
17 B.Nuclear Production Plant
18 320 Land and Land Rights
19 321 Structures and Improvements
20 322 Reactor Plant Equipment
21 1 323 Turboqenerator Units
22 324 Accessory Electric Equipment
23 325 Miscellaneous Power Plant Equipment
24 326 Asset Retirement Costs for Nuclear Production
25 TOTAL Nuclear Production Plant(Total of lines 18 through 24) -
26 C.Hydraulic Production Plant
27 330 Land and Land Rights 23.456.476 2,346,228
28 331 Structures and Improvements 39,770,154 1.313.662
29 332 Reservoirs.Dams,and Waterways 91,304,573 3,477.510
30 333 Water Wheels.Turbines,and Generators 83,941,030 292,591
31 334 Accessory Electric Equipment 30.214845 343.286
32 _335 Miscellaneous Power Plant Equipment 7.889.637 575,133
33 336 Roads,Railroads,and Bridqes 1,298,905 219.970
34 337 Asset Retirement Costs for Hydraulic Production - _
35 TOTAL Hydraulic Production Plant Total of lines 27 through 34 277.875,620 8.568.380
36 D.Other Production Plant
37 340 Land and Land Rights 322.240 -
38 341 Structures and Improvements 6,270,581 21.464
39 342 Fuel Holders,Products,and Accessories 71501,244 41
40 343 Prime Movers 7.634.029 -
41 344 Generators 85.435,218 214.728
42 345 Accessory Electric Equipment 9.153.625 313,213
43 346 Miscellaneous Power Plant Equipment 584,818 21
44 347 Asset Retirement Costs for Other Production _
45 TOTAL Other Production Plant Total of lines 37 through 44 116,901,755 549,467
46 TOTAL Production Plant Total of lines 16,25,35.and 45 563,044,334 9.625.928
(1)A small portion of the Company's electric distribution plant is located in Montana. For jurisdictional reporting purposes,those amounts are
included as Idaho plant.
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E ID.204-205

' Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
I
ELECTRIC PLANT IN SERVICE-IDAHO(Account 101,102,103 and 106)
Instructions
F these tentative classifications in columns(c)and(d),including the reversals of the prior year's tentative account distributions of these amounts. Careful
observance of these instructions and the texts of Accounts 101 and 106 will avoid serious omissions of the reported amount of respondent's plant
actually in service at end of year.
7. Show in column(f)reclassifications or transfers within utility plant accounts. Include also in column(f)the additions or reductions of primary account
classifications arising from distribution of amounts initially recorded in Account 102;include in column(e)the amounts with respect to accumulated
provision for depreciation,acquisition adjustments,etc.,and show in column(f)only the offset to the debits or credits distributed in column(f)to primary
account classifications.
8. For account 399,state the nature and use of plant included in this account,and,if substantial in amount,submit a supplementary statement showing
subaccount classification of such plant conforming to the requirement of these pages.
9.For each account comprising the reported balance and changes in Account 102,state the property purchased or sold,name of vendor or purchase,and
date of transaction. If proposed journal entries have been filed as required by the Uniform System of Accounts,give also the date of such filing.
Balance Line
Retirements Adjustments Transfers End of Year No.
(d) (e) (f) (g)
1
2
(35,240) 15.646.282 3
1.120.428 (607.231) 16,313.430 4
1,120,428 - (642,471) 31.959.712 5
6
7
- (3,086) 1,370,213 8
2,502 80,732 49,265,111 9
69,445 372,936 81.241.244 10
191 82,820 11
10,385 20.356.801 12
(9,810) 10,796,074 13
(1,792) 6.040.386 14
15
71,947 449,556 169.152.649 16
17
18
19
20
21
22
23
24
25
26
- (1,455,429) 24,347,275 27
103,711 507,868 41,487,973 28
(199,754) 94,582,329 29
171,336 (223,492) 83,838,793 30
32,720 (23,156) 30.502.255 31
8,715 (3.350,788) 5,105,267 32
10,101 (127,700) 1.381.074 33
- 34
326,583 (4,872,451) 281,244,966 35
36
- (724) 321,516 37
20,955 (19,626) 6,251.464 38
16.857) 7,484,428 39
6,321 (15,846) 7,611.862 40
131.490 (170.477) 85.347,979 41
24,506 (8,116) 9,434,216 42
5,735 (1,315) 577,789 43
- 44
189,007 (232,961) 117,029,254 45
587.537 (4.655,856) 567,426,869 46
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E-ID-204-205

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation X❑ An Original mm/dd/yyyy End of 2023/Q4
❑ A Resubmission 4/17/2024
ELECTRIC PLANT IN SERVICE-IDAHO(Account 101,102,103 and 106)(Continued)
Line Balance
No. Account Beginning of Year Additions
(a) (b) (c)
47 3.TRANSMISSION PLANT
48 350 Land and Land Rights 10,706,800 82.780
49 352 Structures and Improvements 10.905.150 (16,458)
50 353 Station Equipment 129,862.553 5.501,218
51 354 Towers and Fixtures 57976,718 (18.868)
52 355 Poles and Fixtures 125,703,581 16,589,437
53 356 Overhead Conductors and Devices 65,018,940 4,656.149
54 357 Under.round Conduit 1.273.569 73,531
55 358 Under round Conductors and Devices 2,511.571 73.531
56 359 Roads and Trails 927.748 _
57 359.1 Asset Retirement Costs for Transmission Plant _
58 TOTAL Transmission Plant Total of lines 48 through 57 352,886.630 26,941,320
59 4.DISTRIBUTION PLANT
60 360 Land and Land Rights 4,483.126 145.221
61 361 Structures and Improvements 7.680.610 13,168
62 362 Station Equipment 54,862,869 637.192
63 363 Storage Battery Equipment _
64 364 Poles,Towers,and Fixtures 182,982,315 14.840.386
65 365 Overhead Conductors and Devices 128.860.194 7,471,005
66 366 Underground Conduit 53,693,647 5.097.800
67 367 Underground Conductors and Devices 90,884,768 7.530,868
68 368 Line Transformers 101,396,394 6,107,802
69 369 Services 75,104,953 4,831.119
70 370 Meters 24.709.874 169,040
71 371 Installations on Customer Premises
72 372 Leased Property on Customer Premises _
73 373 Street Lighting and Signal Systems 27.533,544 1.250.239
74 374 Asset Retirement Costs for Distribution Plant
75 TOTAL Distribution Plant CTotal of lines 60 through 74 752,192,294 48.093,840
76 5.REGIONAL TRANSMISSION AND MARKET OPERATION PLANT
77 1 380 Land and Land Rights
78 381 Structures and Improvements
79 382 Computer Hardware
80 383 Computer Software _
81 384 Communication Equipment
82 385 Miscellaneous Regional Transmission and Market Operation Plant -
83 386 Asset Retirement Costs for Regional Transmission and Operation Plant
84 TOTAL Transmission and Market Operation Plant(Total lines 77 through 83
85 6.GENERAL PLANT
86 389 Land and Land Rights 494.893 -
87 390 Structures and Improvements 6.131.250 424.756
88 391 Office Furniture and Equipment 690.527 121,753
89 392 Transportation Equipment 19,460,929 1.606.646
90 393 Stores Equipment 136.828 -
91 1 394 Tools,Shop and Gara a Equipment 2.561.057 274.070
92 395 Laboratory Equipment 945,708 27.919
93 396 Power Operated Equipment 10.493.403 22,329
94 397 Communication Equipment 14,924,735 128.347
95 398 Miscellaneous Equipment 97.370 13.052
96 SUBTOTAL(Total of lines 86 through 95) 55,936,700 2.618.872
97 399 Other Tangible Property
98 ,399.1 Asset Retirement Costs for General Plant
99 TOTAL General Plant(Total of lines 96,97 and 98) 55,936,700 2.618.872
100 TOTAL Accounts 101 and 106) 1,755,254.633 89.807.896
101 102 Electric Plant Purchased
102 102 Less Electric Plant Sold
103 103 Experimental Plant Unclassified
104 TOTAL Electric Plant in Service(Total of lines 100 through 103 1,755,254,633 1 89.807,896
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.206-207

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
0 A Resubmission 4/17/2024
ELECTRIC PLANT IN SERVICE-IDAHO(Account 101,102,103 and 106)(Continued)
Balance Line
Retirements Adjustments Transfers End of Year No.
(d) (e) (f) (g)
47
(47.320) 10,742,260 48
2,388.945 13,277,637 49
737.256 3.167.818 137.794,333 50
24,565 15.586 5,948,871 51
58.822 (6,783,806) 135,450.390 52
84,352 1,915,398 67,675,339 53
- (205,510) 1,141.590 54
208,291) 2.376,811 55
(2,024) 925.724 56
- 57
904.995 (3,590,000) 375.332.955 58
59
- 35,705 4.664,052 60
5,726 7.688,052 61
123,725 195,392) 55,180,944 62
- 63
375,821 380 197,447,260 64
42,257 380 136.289.322 65
25.321 17,465 58,783,591 66
111.346 136,679 98.440.969 67
23,850 9,873 107,490,219 68
16.986 - 79.919.086 69
84,053 24:794,861 70
- 71
- 72
103.133 282680,650 73
- 74
912,218 5,090 799.379,006 75
76
- 77
78
79
80
81
82
83
- 84
85
54,701 549.594 86
154,508 152,306 6.249.192 87
54.485 (36,350) 721.445 88
715,220 (384,591) 19,967,764 89
(7,285)) 129.543 90
62,252 (110.938) 2,661,937 1 91
3,646 49,510 920,471 92
1,049.580 (232.878) 9,233.274 93
2,539,313 1,301,823 13.815,592 94
19.945 (4,816) 85.661 95
4,598,949 377,850 54,334,473 96
97
- 98
4,598,949 377,850 54,334,473 99
8,124.127 (8.505.387) 1,828,433,015 100
101
102
103
8.124.127 (8,505,387) 1.828.433.015 104
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.206-207

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation X❑ An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
ELECTRIC OPERATING REVENUES-IDAHO
Instructions
1. Report below operating revenues attributable to the state of Idaho for each prescribed account in accordance with jurisdictional Results of
Operations. Report the portion of total operating revenue and megawatt hours which pertains to unbilled revenue and MWH pertaining unbilled
revenue in the lines provided.
2. Report number of customers(columns(f)and(g))on the basis of meters,in addition to the number of flat rate accounts;except that where separate
meter readings are added for billing purposes,one customer should be counted for each group of meters added. The average number of customers
means the average of twelve figures at the close of each month.
3. If increases or decreases from previous period(columns(c),(e),and(g))are not derived from previously reported figures,explain any inconsistencies
in a footnote in the available space at the bottom of the page,or in a separate schedule.
Line ELECTRIC OPERATING REVENUE
No. Account Current Year Prior Year
(a) (b) (c)
1 Sales of Electricity
2 440 Residential Sales 137,966,223 137.067,346
3 442 Commercial and Industrial Sales 3
4 Small(or Commercial) 92.845.693 94.517.021
5 Large or Industrial 54.423.619 55.146.486
6 444 Public Street and Highway Lighting 2.844.790 2,797,260
7 445 Other Sales to Public Authorities _
8 446 Sales to Railroads and Railways _
9 448 Interdepartmental Sales 251,933 265.262
10 TOTAL Sales to Ultimate Customers (1) 288.332.258 289,793,375
11 447 Sales for Resale 90,099,322 65.713.130
12 TOTAL Sales of Electricity 3787431,580 355,506.505
13 449.1 (Less)Provision for Rate Refunds
14 TOTAL Revenues Net of Provision for Refunds 378,431,580 355,506.505
15 Other Operating Revenues
16 450 Forfeited Discounts
17 1 451 Miscellaneous Service Revenues 85.026 82,490
18 453 Sales of Water and Water Power 244,496 131.011
19 454 Rent from Electric Property 3,267,433 1,633,492
20 455 Interdepartmental Rents
21 456 Other Electric Revenues (4) (11615,551) 27.808.105
22 456.1 Revenues from Transmission of Electricity for Others 11,000.538 10,800,733
23 457.1 Regional Control Service Revenues _
24 1 457.2 Miscellaneous Revenues
25
26 TOTAL Other Operating Revenues 12.981.942 40,455,830
27 TOTAL Electric Operating Revenues 1 391,413,522 395.962.335
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-406) E.ID.300-301

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
ELECTRIC OPERATING REVENUES-IDAHO
Instructions
4. Disclose amounts of$250,000 or greater in a footnote at the bottom of the page or in a separate schedule for accounts 451,456,and 457.2
5. Commercial and Industrial Sales,Account 442,may be classified according to the basis of classification(Small or Commercial,and Large or Industrial)
regularly used by the respondent if such basis of classification is not generally greater than 1000 Kw of demand. (See Account 442 of the Uniform
System of Accounts. Explain basis of classification in a footnote.)
6. See pages 108-109 in the FERC Form 1,Important Changes During Period,for important new territory added and important rate increases or
decreases.
7. Include unmetered sales Provide details of such Sales in a footnote in the available space at the bottom of this page or in a separate schedule.
MEGAWATT HOURS SOLD AVG.NO.OF CUSTOMERS PER MONTH Line
Current Year Previous Year Current Year Previous Year No.
(d) (e) M (9)
1
1,355,967 1,388,608 125 5757 123,061 2
3
1,033,272 1,040,976 18.934 18.536 4
1,169,757 1,183,286 364 368 5
6,816 6,943 187 188 6
7
8
2,764 2.905 50 49 9
(2) 3,568,576 3,622.718 144.592 142,202 10
1.250,834 1,119,437 - 11
4,819,410 4,742.155 144.592 142,202 12
13
4,819.410 4,742.155 144.592 142,202 14
(1)Includes ($2,"G 0;1 of unbilled revenues.
(2)Includes (39,150) MWH relating to unbilled revenues
(3)Segregation of Commercial and Industrial made on basis of utilization of energy and not on size of account
(4)Includes $ 62,791 associated with a special contract for wheeling over the distribution system on file with the IPUC,recorded
in sub-account 456700.
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E ID.300-301

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
ELECTRIC OPERATION AND MAINTENANCE EXPENSES-IDAHO
Instructions
1. For each prescribed account below,report operation and maintenance expenses as allocated by the Results of Operations model to the state of
Idaho.
2. If the amount for previous year is not derived from previously reported figures,explain in a footnote.
Line Amount for Amount for
No. Account Current Year Previous Year
(a) (b) (c)
1 1.POWER PRODUCTION EXPENSES
2 A.Steam Power Generation
3 Operation
4 500 Operation Supervision and Engineering 62,923 122,066
5 501 Fuel 16.357.776 14,847,885
6 502 Steam Expenses 1,499,649 1,308,116
7 503 Steam from Other Sources
8 504 Less Steam Transferred-Cr.
9 1 505 Electric Expenses 267.873 314,792
10 506 Miscellaneous Steam Power Expenses 2,290,138 2.096,238
11 507 Rents
12 509 Allowances 662.437
13 TOTAL Operation(Total of lines 4 through 12 21,140,796 18,689.097
14 Maintenance
15 510 Maintenance Supervision and Engineering 145.172 250.793
16 1 511 Maintenance of Structures 308.807 319,889
17 512 Maintenance of Boiler Plant 2,518,387 2.348.230
18 513 Maintenance of Electric Plant 301,701 314.369
19 514 Maintenance of Miscellaneous Steam Plant 477,934 279.957
20 TOTAL Maintenance(Total of Lines 15 through 19 3,752,001 3,513,238
21 TOTAL Steam Power Generation Expenses(Total lines 13&20 24,892.797 22,202,335
22 B.Nuclear Power Generation
23 Operation
24 517 O eration Supervision and Engineering _
25 518 Fuel
26 519 Coolants and Water _
27 520 Steam Expenses
28 521 Steam from Other Sources
29 522 (Less)Steam Transferred-Cr. _
30 1 523 Electric Expenses _
31 524 Miscellaneous Nuclear Power Expenses _
32 525 Rents _
33 TOTAL Operation Total of lines 24 through 32) _
34 Maintenance
35 528 Maintenance Supervision and Engineering
36 529 Maintenance of Structures
37 1 530 Maintenance of Reactor Plant Equipment
38 531 Maintenance of Electric Plant _
39 532 Maintenance of Miscellaneous Nuclear Plant _
40 TOTAL Maintenance Total of lines 35 through 39
41 TOTAL Nuclear Power Generation Expenses Total lines 33&40 _
42 C.Hydraulic Power Generation
43 Operation
44 1 535 Operation Supervision and Engineering 873.540 969,986
45 536 Water for Power 420,762 435.695
46 537 Hydraulic Expenses 3.430.590 3,303,051
47 538 Electric Expenses 2,354,819 2,430,562
48 539 Miscellaneous Hydraulic Power Generation Expenses 782,614 616.318
49 540 Rents 2.708.276 2-500,518
50 TOTAL Operation Total of lines 44 through 49 10.570,601 10.256:130
51 iMaintenance
52 541 Maintenance Supervision and Engineering 253.624 291,668
53 542 Maintenance of Structures 176,918 371.867
54 543 Maintenance of Reservoirs,Dams,and Waterways 176.724 316,230
55 544 Maintenance of Electric Plant 1,111,088 1.284,428
56 545 Maintenance of Miscellaneous Hydraulic Plant 235.635 268,002
57 TOTAL Maintenance Total of lines 53 through 57 1.953.989 2,532,195
58 ITOTAL Hydraulic Power Generation Expenses Total of lines 50&58 12,524,590 12.788.325
59
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.320

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation X❑ An Original mm/dd/yyyy End of 2023/Q4
A Resubmission 4/17/2024
ELECTRIC OPERATION AND MAINTENANCE EXPENSES-IDAHO
Instructions
1. For each prescribed account below,report operation and maintenance expenses as allocated by the Results of Operations model to the state of
Idaho.
2. If the amount for previous year is not derived from previously reported figures,explain in a footnote.
Line Amount for Amount for
No. Account Current Year Previous Year
(a) (b) (c)
60 D.Other Power Generation
61 Operation
62 546 Operation Supervision and Engineering 317.507 135.145
63 547 Fuel 41,283,882 61,183,693
64 548 Generation Expenses 1,385.197 915.894
65 549 Miscellaneous Other Power Generation Expenses 335,762 277,655 I
66 550 Rents 36,623 31.016
67 TOTAL Operation(Total of lines 62 through 66) 43.358,971 62,543,403
68 Maintenance
69 551 Maintenance Suoervision and Enaineerinq 273.010 267,687 I
70 552 Maintenance of Structures 49,370 33.393
71 553 Maintenance of Generating and Electric Plant 714.808 j 1,415,194
72 554 Maintenance of Miscellaneous Other Power Generation Plant 306,276 I 190.645
73 TOTAL Maintenance(Total of lines 69 through 72) 1.343.464 j 1,906,919
74 TOTAL Other Power Generation Expenses 44,702,435 64,450,322
75 E Other Power Supply Expenses
76 555 Purchased Power 83,602,959 75.066,068
77 556 System Control and Load Dispatching 271,609 371.926
78 557 Other Exoenses 22,732,536 27,556,260
79 TOTAL Other Power Supply Expenses(Total of lines 76 through 78) 106,607,104 102.994.254
80 TOTAL Power Production Expenses(Total of lines 21.41,59.74,&79) 188.726.926 202,435,236
81 2.TRANSMISSION EXPENSES
82 Operation _
83 560 Operation Supervision and Engineering 740,439 693.140
84 561 Load Dispatching 1.094.056 1,163754
85 561.1 Load Dispatch-Reliability
86 561.2 Load Dispatch-Monitor and Operation Transmission System
87 1561.3 Load Dispatch-Transmission Service and SchedulingI
88 1561.4 Scheduling.System Control and Dispatch Services
89 1561.5 Reliability,Planning and Standards Development
90 1561.6 Transmission Service Studies
91 1 561.7 Generation Interconnection Studies
92 561.8 Reliability, Planning and Standards Development Services
93 562 Station Exoenses 141,091 162,053
94 563 Overhead Lines Expenses 115.388 186.841
95 564 Underground Lines Exoenses
j 96 565 Transmission of Electricity by Others 6,771.333 1 7.198.544
97 566 Miscellaneous Transmission Expenses 1,507.004 1,574,831
98 567 Rents 34,749 31.917
99 TOTAL Operation(Total of lines 83 through 98) 10.404.060 11,011,080
100 Maintenance
101 1 568 Maintenance Supervision and Engineering 132.144 150,835
102 569 Maintenance of Structures 221,141 264.392
103 569.1 Maintenance of Computer Hardware
104 569.2 Maintenance of Computer Software
105 569.3 Maintenance of Communication Equipment
106 569.4 Maintenance of Miscellaneous Re, ional Transmission Plant j
107 570 Maintenance of Station Equi ment j 412,330 430.562
108 571 Maintenance of Overhead Lines 784.099 803,013 I
109 572 Maintenance of Underground Lines 343 275
110 573 Maintenance of Miscellaneous Transmission Plant j 23.890 28.551
111 TOTAL Maintenance Total of lines 101 through 110) 1,573.947 1,677,628
112 TOTAL Transmission Expenses Total of lines 99 and 111 11,978.007 12.688.708
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.321

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XD An Original mm/dd/yyyy End of 2023/Q4
❑ A Resubmission 4/17/2024
ELECTRIC OPERATION AND MAINTENANCE EXPENSES-IDAHO
Instructions
1, For each prescribed account below,report operation and maintenance expenses as allocated by the Results of Operations model to the state of
Idaho.
2. If the amount for previous year is not derived from previously reported figures,explain in a footnote.
Line Amount for Amount for
No. Account Current Year Previous Year
(a) (b) (c)
113 3.REGIONAL MARKET EXPENSES —
114 Operation
115 575.1 Operation Supervision _
116 575.2 Day-Ahead and Real-Time Market Facilitation
117 575.3 Transmission Rights Market Facilitation _
118 575.4 Capacity Market Facilitation _
119 575.5 Ancillary Services Market Facilitation
120 575.6 Market Monitoring and Compliance _
121 575.7 Market Facilitation,Monitorin ,and Compliance Services _
122 575.8 Rents
123 Total Operation(Total lines 115 through 122 _
124 Maintenance
125 576.1 Maintenance of Structures and Improvements _ _
126 576.2 Maintenance of Computer Hardware _
127 576.3 Maintenance of Computer Software _
128 576.4 Maintenance of Communication Equipment _
129 576.5 Maintenance of Miscellaneous Market Operation Plant
130 Total Maintenance(Total lines 125 through 129
131 TOTAL Regional Market Expenses(Total lines 123&130 _
132 4.DISTRIBUTION EXPENSES
133 Operation
134 580 Operation Supervision and Engineering 1.232.095 1,390.330
135 581 Load Dispatching
136 582 Station Expenses 316,065 333,497
137 583 Overhead Line Expenses 1,051,705 1.036.072
138 584 Underground Line Expenses 11029,933 690,685
139 585 Street Lighting and Signal System Expenses 222 3.264
140 586 Meter Expenses 332,041 331,662
141 587 Customer Installations Expenses 292.382 302,953
142 588 Miscellaneous Expenses 2,477,386 2,523.996
143 589 Rents 78.642 71,797
144 TOTAL Operation(Total of lines 134 through 143) 6,810,471 6.684.186
145 Maintenance
146 590 Maintenance Supervision and En. ineerinq 420,146 776.402
147 591 Maintenance of Structures 146.414 311,605
148 592 Maintenance of Station Equipment 283,674 299,975
149 593 Maintenance of Overhead Lines 8,713,113 10,451,684
1501 594 Maintenance of Underground Lines 236.566 225,147
151 595 Maintenance of Line Transformers 92,267 88.643
152 596 Maintenance of Street Lighting and Signal Systems 11.350 24,191
153 597 Maintenance of Meters 6,725 8,432
154 598 Maintenance of Miscellaneous Distribution Plant 303.008 342,255
155 TOTAL Maintenance(Total lines 146 through 154 10.213.263 12.528,334
156 TOTAL Distribution Expenses(Total of lines 144 and 155) 17,023,734 19,212.520
15715.CUSTOMER ACCOUNTS EXPENSES
158 Operation
159 901 Supervision 47,578 45,658 I
160 902 Meter Reading Expenses 212.114 209,077
161 903 Customer Records and Collection Expenses 3,084,888 2,976.148
162 904 Uncollectable Accounts 635.851 625.923
163 905 Miscellaneous Customer Accounts Expenses 97.575 90.592
164 1TOTAL Customer Accounts Expenses(Total of line 159 through 163 4,078,006 1 3,947,398
1DAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.322

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XI An Original mm/dd/yyyy End of 2023/Q4
0 A Resubmission 4/17/2024
ELECTRIC OPERATION AND MAINTENANCE EXPENSES-IDAHO
Instructions
1. For each prescribed account below,report operation and maintenance expenses as allocated by the Results of Operations model to the state of
Idaho.
2. If the amount for previous year is not derived from previously reported figures,explain in a footnote.
Line Amount for Amount for
No. Account Current Year Previous Year
(a) (b) (c) _
165 6.CUSTOMER SERVICE AND INFORMATIONAL EXPENSES
166 Operation
167 907 Supervision
168 908 Customer Assistance Expenses 6,636,366 10,256,787
169 909 Informational and Instructional Expenses 274,182 272.311
170 910 Miscellaneous Customer Service and Informational Expenses 80.482 43,375
171 TOTAL Customer Service and Informational Expenses(Total lines 167 through 170) 6,991,030 10.572.473
172 7.SALES EXPENSES
173 lOperation
174 911 Supervision -
175 912 Demonstrating and Selling Expenses
176 913 Advertisina Expenses
177 916 Miscellaneous Sales Expenses
178 TOTAL Sales Expenses(Total of lines 174 through 177) - -
179 8.ADMINISTRATIVE AND GENERAL EXPENSES
180 Operation_
181 920 Administrative and General Salaries 10.502,009 10,448,662
182 921 Office Supplies and Expenses 1,229,331 1.392,874
183 922 Less Administrative Expenses Transferred-Credit 35,685) (31,558)
184 923 Outside Services Employed 4,179,887 4.481.943
185 924 Property Insurance 878.413 805,191
186 925 Injuries and Dama es 3,451,813 3,389.925
187 926 Employee Pensions and Benefits 8.672.765 12,214,410
188 927 Franchise Requirements 1,200 1.200
1891 928 Regulatory Commission Expenses 2,535,519 2.304,556
1901 929 Less Duplicate Charges-Cr-
191 930.1 General Advertising Expenses
192 930.2 Miscellaneous General Expenses 1,734,342 1,726,160
193 931 Rents 304,726 262.844
194 TOTAL Operation Total of lines 181 through 193 33AK320 1 36.996,207
195 Maintenance
196 935 Maintenance of General Plant 4,480,241 4,872,291
197 1TOTAL Administrative and General Expenses(Total of lines 194 and 196) 37.934.561 41,868,498
198 ITOTAL Elec Op and Maint Expns(Total lines 80, 112,131.156,164,171,178,197) 266,732,264 290,724,833
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61.405) E ID 323

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation ] An Original mm/dd/yyyy End of 2023/Q4
❑ A Resubmission 4/17/2024
TRANSMISSION LINE STATISTICS-IDAHO
Instructions
1. Report information concerning transmission lines physically located in the state of Idaho,including the cost of lines,and expenses for the
year. List each transmission line having nominal voltage of 132 kilovolts or greater.
Transmission lines below this voltage should be grouped and totals reported for each group.
2.Transmission lines include all lines covered by the definition of transmission system plant as given in the Uniform System of Accounts. Do not report
substation costs and expenses on this page.
3. Report data by individual lines for all voltages if so required by the State commission.
4. Exclude from this page any transmission lines for which plant costs are included in Account 121,Nonutility Property.
5. Indicate whether the type of supporting structure reported in column(e)is:(1)single pole wood or steel;(2)H-frame wood,or steel poles;(3)tower;or
(4)underground construction. If a transmission line has more than one type of supporting structure,indicate the mileage of each type of construction
by the use of brackets and extra lines. Minor portions of a transmission line of a different type of construction need not be distinguished from the
remainder of the line.
6. Report in columns(f)and(g)the total pole miles of each transmission line. Show in column(f)the pole miles of line on structures the cost of which is
reported for the line designated;conversely,show in column(g)the pole miles of line on structures the cost of which is reported for another line. Report
pole miles of line on leased or partly-owned structures in column(g). In a footnote in the available space at the bottom of this page or in a separate
VOLTAGE(KV) LENGTH(Pole Miles)
Line DESIGNATION Indicate where otherthan Type of For underwound lines.reoort circuit miles Number
No. 60 cycle.3 phase Supporting On Structure On Structures of
From To Operating Designed Structure of Line Designated of Another Line Circuits
(a) (b) (c) I (d) (a) (f) (g) (h)
1 Group Sum-115kV 115.001 115.00 593.00
2
3 Beacon Cabinet Gorae Plant 230.00 230.00 Steel Tower 1.00 1
4 Beacon Cabinet Gorge Plant 230.00 230.00 Steel Pole 19.00 2
5 Beacon Cabinet Gorge Plant 230.00 230.00 H Type 52.00 1
6
7 Divide Creek Lolo Sub 230.00 230.00 H Type 10.00 1
8 Divide Creek Lolo Sub 230.00 230.00 H Type 33.00 1
9 Noxon Plant Pine Creek Sub 230.00 230.00 Steel Pole 15.00 1
10 Noxon Plant Pine Creek Sub 230.00 230.00 H Type 1.00 1
11 Noxon Plant Pine Creek Sub 230.00 230.00 H Tvoe 14.00 1
12 Cabinet Gorge Plant Noxon 230.00 230.00 H Type 2.00 1
13
14 Benewah Sw.Station Pine Creek Sub 230.00 230.00 H Tvpe 43.00 1
15
16 Beacon Sub Lolo Sub 230.001 230.00 Steel Pole 10.00 2
17 Beacon Sub Lolo Sub 230.001 230.00 H Type 63.00 1
18 Beacon Sub Lolo Sub 230.001 230.00 H Type 8.00 1
19
20 North Lewiston Walla Walla 230.00 230.00 H Type 8.00 1
21
22 North Lewiston Shawnee 230.00 230,00 H Type 1.00 1
23
24 Hatwai N.Lewiston Sub 230.00 230,00 H Tvpe 7.00 1
25
26
27
28
29
30
31
32
33
34
35
36
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.422-423

Name of Respondent This Report is: Date of Report Year/Period of Report
Avista Corporation XQ An Original mm/dd/yyyy End of 2023/Q4
0 A Resubmission 4/17/2024
TRANSMISSION LINE STATISTICS-IDAHO
Instructions
schedule,explain the basis of such occupancy and state whether these expenses with respect to such structures are included in the expenses reported
for the line designated.
7. Do not report the same transmission line structure twice. Report lower-voltage lines and higher-voltage lines as one line. Designate in a footnote if you
do not have include lower-voltage lines with higher-voltage lines. If two or more transmission line structures support lines of the same voltage,report the
pole miles of the primary structure in column(f)and the pole miles of the other line(s)in column(g).
8. Designate any transmission line or portion thereof for which the respondent is not the sole owner. If such property is leased from another company,give
name of lessor,date and terms of lease,and amount of rent for year. For any transmission line other than a leased line,or portion thereof,for which the
respondent is not the sole owner but which the respondent operates or shares in the operation of,furnish a succinct statement explaining the arrangement
and giving details of such matters as percent ownership by respondent in the line,name of c-owner,basis of sharing expenses of the line,and and how
expenses borne by the respondent are accounts for,and accounts affected. Specify whether lessor,co-owner,or other party is an associated company.
9. Designate any transmission line leased to another company and give name of lessee,date and terms of lease,annual rent for year,and how determined.
Specify whether lessee is an associated company.
10. Base the plant cost figures called for in columns 0)through(I)on the book cost at end of year associated with the physical lines reported.
COST OF LINE EXPENSES,EXCEPT DEPRECIATION AND TAXES
Size of Include in column 6)land,land rights,and clearing right-of--way Line
Conductor Construction Operation Maintenance Total No.
and Material Land and Other Costs Total Cost Expenses Expenses Rents Expenses
(i) (i) (k) (1) (m) (n) (o) (P)
5 328.564 127.141.047 132.469.611 363,844 938,590 1.302.434 1
2
1590 ACSS 3
1590 ACSS 4
1590 ACSR 1,042,7813 26,138.592 27.181.378 5
6
1590 ACSR 7
1272 AAC 167,484 21,687,001 21.854,485 73 73 8
1272 ACSR - 9
1590 ACS 10
954 AAC 693.774 10.658,617 11,352.391 11
954 AAC 138.327 1,099,356 1,237.683 8.8841 12.225 21.109 12
13
954 AAC 399.821 5,257,051 5,656,872 31.9031 31,903 14
15
1590 ACSS 16
1272 AAC 17
1272 ACSS 363.604 30.912,849 31,276,453 18
19
1272 AAC 25.818 1,132.530 1,158,348 13,018 13.018 20
- 21
1272 ACSR 10.015 316.837 326,852 128 128 22
- 23
1590 ACSR 155.244 2.221.191 2.376,435 24
25
26
27
28
29
30
31
32
33
34
35
36
IDAHO STATE ELECTRIC ANNUAL REPORT(IC 61-405) E.ID.422-423