APPLICATION.tif

APPLICATION - 1
MEGAN GOICOECHEA ALLEN (ISB No. 7623)
DONOVAN E. WALKER (ISB No. 5921)
Idaho Power Company
1221 West Idaho Street (83702)
P.O. Box 70
Boise, Idaho 83707
Telephone: [phone]
Facsimile: [phone]
[e-mail]
[e-mail]

Attorneys for Idaho Power Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION

IN THE MATTER OF THE
APPLICATION OF IDAHO POWER FOR
APPROVAL OF REVISED
DEPRECIATON RATES FOR
ELECTRIC PLANT-IN-SERVICE AND
REQUEST FOR ACCOUNTING ORDER

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CASE NO. IPC-E-26-23

APPLICATION

Idaho Power Company (“Idaho Power” or “Company”), in accordance with Idaho
Code §§ 61-524 and 61-525 and Idaho Public Utilities Commission (“Commission”) Rule
of Procedure 52 hereby makes this Application respectfully requesting that the
Commission issue an Order by mid-February 2027: (1) approving updated depreciation
rates for electric plant-in-service effective January 1, 2028; and (2) authorizing
amortization accounting treatment for new accounts established as a result of Federal
Energy Regulatory Commission ("FERC") Order No. 898. The Company is not seeking to
change retail electric rates in this proceeding, only to update depreciation rates. Approval
of the revised depreciation rates by mid-February 2027 would provide regulatory certainty
APPLICATION - 2
regarding depreciation expense and permit the Company to incorporate the approved
rates in a general rate case filed in 2027, should the Company elect to do so. In the
absence of a 2027 general rate case, the Company will file a separate application seeking
Commission approval of any change in retail electric rates necessary to reflect the new
level of annual depreciation expense resulting from this case. Accordingly, no increase to
retail electric rates is requested or proposed in this Application.
In support of this Application, Idaho Power has filed the Direct Testimony of John
J. Spanos ("Spanos Testimony"). In further support of this Application, Idaho Power states
as follows:
I. DEPRECIATION STUDY
1. The Commission last approved comprehensive revisions to Idaho Power’s
depreciation rates in Order No. 35272, issued December 27, 2021, in Case No. IPC-E-
21-18, which approved the Settlement Stipulation entered by the parties to that case and
adopted the agreed-upon rates effective January 1, 2022. The revised rates were based
on the Company's electric plant-in-service as of December 31, 2020, and represented a
compromise of the differing depreciation methodologies, theories, and opinions
presented in that case. Since that time, Idaho Power has continued to invest in and retire
utility plant, operating expectations have evolved, and additional plant classes have been
placed in service or are anticipated to be placed in service.
2. Idaho Power has conducted a new, detailed depreciation study of its electric
plant-in-service as of December 31, 2025 (the “2025 Depreciation Study”) and hereby
seeks Commission approval of the resulting revised depreciation rates. The 2025
Depreciation Study was prepared under the direction and supervision of John J. Spanos,
APPLICATION - 3
President of Gannett Fleming Valuation and Rate Consultants, LLC (“Gannett Fleming”),
and is presented as Exhibit No. 2 to the Spanos Testimony filed contemporaneously with
this Application. The study develops annual depreciation accrual rates by account and
subaccount and evaluates appropriate average service lives and net salvage
percentages.
3. Once approved in Case No. IPC-E-21-18, Idaho Power's current
depreciation rates were applied to investments in the applicable plant accounts and
subaccounts. The 2025 Depreciation Study evaluates those rates using plant account
data as of December 31, 2025, and develops recommended depreciation rates based on
the straight-line remaining-life method of depreciation and the average service-life
procedure. For selected plant accounts and certain assets reclassified in connection with
FERC Order No. 898,1 the study uses straight-line remaining-life amortization. The
service-life analysis incorporates historical additions, transfers, retirements, surviving
plant balances, retirement rate analyses, survivor curves, management and operating
information, and field observations. The net salvage analysis incorporates the Company's
historical net salvage data, Company operating information, industry practices, and
expected future decommissioning costs.
4. A summary schedule detailing the results of the study, as applied to the
original cost of electric plant as of December 31, 2025, including the original plant cost
and book depreciation reserve balances, is set forth in Part VI “Results of Study” of Exhibit

1 FERC Order No. 898, final rule amending the Uniform System of Accounts to create new accounts for
renewable generating assets, establish a functional class for energy storage accounts, codify the
accounting treatment of environmental credits, create accounts for computer hardware, software, and
communication equipment, and amend related FERC forms; effective January 1, 2025.

APPLICATION - 4
No. 2 to the Spanos Testimony and is also provided as Attachment No. 1 to this
Application. The study results in revised depreciation rates across the Company’s plant
functions. On a functional basis, the current and proposed composite rates are
summarized as follows:
Function Existing % Proposed %
Miscellaneous Intangible Plant 3.38% 3.98%
Steam Production Plant 3.46% 3.17%
Hydraulic Production Plant 2.42% 2.91%
Solar Production Plant 5.56% 5.54%
Other Production Plant 3.19% 3.86%
Transmission Plant 1.96% 2.21%
Distribution Plant 2.22% 2.45%
Energy Storage Plant 6.71% 7.23%
General Plant 5.92% 6.88%

The proposed depreciation rates, when applied to plant-in-service presently
authorized for recovery in current rates, are expected to result in an approximately $32.3
million annual increase over the level of depreciation expense currently approved in
customer rates.
5. The principal drivers of the changes vary by function. As explained by Mr.
Spanos, the change for Steam Production Plant is principally associated with longer life
spans; the Hydraulic Production Plant change is driven primarily by necessary future net
salvage costs; the Other Production Plant change is driven primarily by net salvage; the
Distribution Plant increase is primarily attributable to somewhat more negative net
salvage percentages for certain accounts; and the General Plant increase is primarily
attributable to shorter lives for several accounts.
6. The 2025 Depreciation Study also includes a decommissioning component
in net salvage for steam, hydraulic, other production, and energy storage facilities. The
decommissioning component is part of the overall net salvage for each location
APPLICATION - 5
associated with these assets.
7. As recommended by and described in the testimony of Mr. Spanos, the
Company is proposing a reserve adjustment specific to Account 391.20, Computer
Hardware - EDP Equipment. Currently, the amortization rate that is consistent with the
account's five-year amortization period for plant in service today, and for future additions,
does not align with the existing book reserve balance. As of December 31, 2025, Account
391.20 had plant in service of $26,080,850. Based on the ages of the surviving plant, a
reserve balance of $12,630,744 is required to produce the 20 percent amortization rate
associated with a five-year amortization period. However, the current book reserve is
$10,818,556, resulting in an unrecovered reserve amount of $1,812,188. If a reserve
adjustment is not made, the amortization rate applied going forward would need to exceed
20 percent in order to fully amortize the existing plant over its remaining life. However, an
amortization rate greater than 20 percent would result in future investments being fully
amortized in less than five years.
8. To correct this mismatch and ensure that the amortization rate remains
consistent with the account's five-year amortization period for both existing and future
investment, Mr. Spanos recommends a reserve adjustment of $1,812,188 to Account
391.20, Computer Hardware - EDP Equipment. Idaho Power proposes to amortize this
amount over a five-year period, resulting in additional amortization expense of
approximately $362,438 annually.
9. The 2025 Depreciation Study also develops depreciation rates for new or
separately identified asset classes, including certain miscellaneous power plant
equipment, assets associated with Jim Bridger Unit 3 and Valmy Natural Gas Unit 1, and
APPLICATION - 6
Accounts 357.00, Underground Conduit, and 358.00, Underground Conductors and
Devices. These proposed rates reflect the proposed life parameters, net salvage
percentages, and probable retirement dates described in the Spanos Testimony and the
2025 Depreciation Study.
10. The revised depreciation rates are intended to more accurately match the
recovery of plant investment and future net salvage costs with the periods in which the
associated assets will provide utility service. The Company believes that the revised
depreciation rates for electric plant-in-service will promote rate accuracy and ensure
intergenerational equity by recovering the service value of utility assets from customers
receiving service from those assets and are just, fair, reasonable, and in the public interest
and should therefore be approved by the Commission.
11. A Commission order received by mid-February 2027 would provide
regulatory certainty regarding depreciation expense and permit the Company to
incorporate the updated rates in the event the Company elects to file a general rate case
in 2027. In the absence of a 2027 general rate case, the Company will file a separate
application seeking Commission approval of any change in retail electric rates necessary
to reflect the new level of annual depreciation expense resulting from this case.
II. ACCOUNTING ORDER
12. The Company is requesting an accounting order to allow amortization
accounting (to track and retire plant at the vintage level) for the following accounts or
subaccounts resulting from FERC Order 898:

APPLICATION - 7
FERC Account Account Description
Steam Production Plant
315.1 Computer hardware
315.2 Computer software
315.3 Communication equipment
Hydraulic Production Plant
334.1 Computer hardware
334.2 Computer software
334.3 Communication equipment
335 Misc. power plant equipment *
Solar Production Plant
338.9 Computer hardware
338.10 Computer software
338.11 Communication equipment
Other Production Plant
345.1 Computer hardware
345.2 Computer software
345.3 Communication equipment
Transmission Plant
351.1 Computer hardware
351.2 Computer software
351.3 Communication equipment
Distribution Plant
363.1 Computer hardware
363.2 Computer software
363.3 Communication equipment
Energy Storage Plant
387.8 Computer hardware
387.9 Computer software
387.10 Communication equipment

* Limited to Idaho Power subaccounts 33510 for Office Equipment and
33520 for Furniture.
13. These accounts represent less than one percent of depreciable plant. The
requested accounting treatment would allow Idaho Power to track and account for plant
additions and retirements at the vintage level for each account, rather than at the
individual asset level, consistent with the accounting treatment previously authorized by
APPLICATION - 8
the Commission in IPC-E-97-4, Order No. 26937.
III. MODIFIED PROCEDURE
14. Idaho Power believes a hearing is not necessary to consider the issues
presented herein and respectfully requests that this Application be processed under
Modified Procedure pursuant to Commission Rules of Procedure 201, et seq., i.e., by
written submissions rather than by hearing. If, however, the Commission determines that
a technical hearing is required, the Company stands ready to present its testimony and
support the Application in such hearing.
IV. COMMUNICATIONS AND SERVICE OF PLEADINGS
15. Communications and service of pleadings, exhibits, orders, and other
documents relating to this proceeding should be sent to the following:
Megan Goicoechea Allen
Donovan Walker
Regulatory Dockets
Idaho Power Company
1221 West Idaho Street (83702)
P.O. Box 70
Boise, Idaho 83707
[e-mail]
[e-mail]
[e-mail]

Tim Tatum
Connie Aschenbrenner
Kelley Noe
Idaho Power Company
1221 West Idaho Street (83702)
P.O. Box 70
Boise, Idaho 83707
[e-mail]
[e-mail]
[e-mail]

V. REQUEST FOR RELIEF
16. For the reasons set forth above, Idaho Power respectfully requests that the
Commission issue an Order by mid-February 2027: (1) approving the updated
depreciation rates for electric plant-in-service effective as of January 1, 2028; and (2)
authorizing the amortization accounting for new accounts established as a result of FERC
Order No. 898.

APPLICATION - 9
DATED at Boise, Idaho, this 19th day of August 2026.

________________________________
MEGAN GOICOECHEA ALLEN
Attorney for Idaho Power Company

BEFORE THE

IDAHO PUBLIC UTILITIES COMMISSION

CASE NO. IPC-E-26-23

IDAHO POWER COMPANY

ATTACHMENT 1
PROPOSED DEPRECIATION RATES

IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
ELECTRIC PLANT
MISCELLANEOUS INTANGIBLE PLANT
303.00 303.80 MISCELLANEOUS INTANGIBLE PLANT - SPECTRUM 30-SQ 0 3,557,837.65 227,293 3,330,545 141,725 3.98 23.5
TOTAL MISCELLANEOUS INTANGIBLE PLANT 3,557,837.65 227,293 3,330,545 141,725 3.98
STEAM PRODUCTION PLANT
310.00 310.20 LAND AND WATER RIGHTS
JIM BRIDGER COMMON 12-2045 75-R4 *0 148,899.77 133,228 15,672 894 0.60 17.5
TOTAL LAND AND WATER RIGHTS 148,899.77 133,228 15,672 894 0.60 17.5
311.00 311.00 STRUCTURES AND IMPROVEMENTS
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 100-S0.5 *(16)7,771,727.46 7,208,873 1,806,331 96,218 1.24 18.8
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 100-S0.5 *(16)6,445,347.62 5,954,214 1,522,389 81,123 1.26 18.8
JIM BRIDGER UNIT 4 12-2045 100-S0.5 *(17)91,270.65 2,778 104,009 5,248 5.75 19.8
JIM BRIDGER COMMON 12-2045 100-S0.5 *(17)23,698,542.06 19,768,644 7,958,650 401,546 1.69 19.8
VALMY NATURAL GAS UNIT 1 12-2049 100-S0.5 *(24)24,709,901.61 (828)30,641,106 1,292,874 5.23 23.7
VALMY NATURAL GAS UNIT 2 12-2049 100-S0.5 *(23)701,194.18 4,457 858,012 36,222 5.17 23.7
VALMY NATURAL GAS COMMON 12-2049 100-S0.5 *(24)1,411,546.09 25,639 1,724,678 72,837 5.16 23.7
TOTAL STRUCTURES AND IMPROVEMENTS 64,829,529.67 32,963,777 44,615,175 1,986,068 3.06 22.5
312.00 312.10 BOILER PLANT EQUIPMENT - SCRUBBERS
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 60-R2.5 *(16)30,474,042.77 21,238,661 14,111,229 763,478 2.51 18.5
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 60-R2.5 *(16)30,289,132.39 20,874,336 14,261,058 772,078 2.55 18.5
JIM BRIDGER UNIT 4 12-2045 60-R2.5 *(17)1,088,308.75 19,653 1,253,668 63,670 5.85 19.7
JIM BRIDGER COMMON 12-2045 60-R2.5 *(17)10,619,433.74 5,921,655 6,503,082 330,273 3.11 19.7
TOTAL BOILER PLANT EQUIPMENT - SCRUBBERS 72,470,917.65 48,054,305 36,129,037 1,929,499 2.66 18.7
312.00 312.20 BOILER PLANT EQUIPMENT - OTHER
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 50-R1.5 *(16)45,488,714.82 22,989,039 29,777,870 1,631,488 3.59 18.3
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 50-R1.5 *(16)49,457,533.32 25,463,948 31,906,791 1,752,303 3.54 18.2
JIM BRIDGER UNIT 3 12-2045 50-R1.5 *(17)73,858.88 2,525 83,890 4,397 5.95 19.1
JIM BRIDGER UNIT 4 12-2045 50-R1.5 *(17)3,802,991.25 114,360 4,335,140 227,209 5.97 19.1
JIM BRIDGER COMMON 12-2045 50-R1.5 *(17)35,055,478.24 13,438,262 27,576,648 1,445,317 4.12 19.1
VALMY NATURAL GAS UNIT 1 12-2049 50-R1.5 *(24)27,187.64 (52,990)86,703 3,836 14.11 22.6
VALMY NATURAL GAS UNIT 2 12-2049 50-R1.5 *(23)1,501,124.45 10,983 1,835,400 81,459 5.43 22.5
VALMY NATURAL GAS COMMON 12-2049 50-R1.5 *(24)88,344.12 17,695 91,852 4,072 4.61 22.6
TOTAL BOILER PLANT EQUIPMENT - OTHER 135,495,232.72 61,983,822 95,694,294 5,150,081 3.80 18.6
312.00 312.30 BOILER PLANT EQUIPMENT - RAILCARS
JIM BRIDGER COMMON 12-2045 35-R2.5 *0 1,694,302.58 1,472,738 221,565 19,642 1.16 11.3
TOTAL BOILER PLANT EQUIPMENT - RAILCARS 1,694,302.58 1,472,738 221,565 19,642 1.16 11.3
314.00 314.00 TURBOGENERATOR UNITS
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 45-S1 *(16)23,600,853.29 19,078,077 8,298,913 470,814 1.99 17.6
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 45-S1 *(16)30,437,381.25 24,392,205 10,915,157 609,359 2.00 17.9
JIM BRIDGER UNIT 3 12-2045 45-S1 *(17)225,080.15 1,627 261,717 13,428 5.97 19.5
JIM BRIDGER UNIT 4 12-2045 45-S1 *(17)433,919.70 14,008 493,678 25,330 5.84 19.5
JIM BRIDGER COMMON 12-2045 45-S1 *(17)3,479,251.93 1,920,257 2,150,468 110,337 3.17 19.5
VALMY NATURAL GAS UNIT 1 12-2049 45-S1 *(24)9,786,702.97 (10,028)12,145,540 526,921 5.38 23.1
VALMY NATURAL GAS UNIT 2 12-2049 45-S1 *(23)1,769,556.74 36,897 2,139,658 93,857 5.30 22.8
VALMY NATURAL GAS COMMON 12-2049 45-S1 *(24)66,416.50 (17,147)99,503 4,374 6.59 22.7
TOTAL TURBOGENERATOR UNITS 69,799,162.53 45,415,896 36,504,634 1,854,420 2.66 19.7
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
315.00 315.00 ACCESSORY ELECTRIC EQUIPMENT
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 60-S1.5 *(16)5,975,294.43 5,109,739 1,821,603 111,152 1.86 16.4
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 60-S1.5 *(16)4,942,370.43 4,345,537 1,387,613 86,141 1.74 16.1
JIM BRIDGER UNIT 4 12-2045 60-S1.5 *(17)24,260.72 806 27,579 1,389 5.73 19.9
JIM BRIDGER COMMON 12-2045 60-S1.5 *(17)6,281,837.74 4,861,829 2,487,921 125,273 1.99 19.9
VALMY NATURAL GAS UNIT 2 12-2049 60-S1.5 *(23)270,495.91 4,975 327,735 13,852 5.12 23.7
VALMY NATURAL GAS COMMON 12-2049 60-S1.5 *(24)49,996.56 72 61,924 2,612 5.22 23.7
TOTAL ACCESSORY ELECTRIC EQUIPMENT 17,544,255.79 14,322,958 6,114,375 340,419 1.94 18.0
316.00 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT
JIM BRIDGER NATURAL GAS UNIT 1 12-2045 35-S0 *(16)391,002.10 268,559 185,003 19,313 4.94 9.6
JIM BRIDGER NATURAL GAS UNIT 2 12-2045 35-S0 *(16)258,626.04 169,072 130,934 13,732 5.31 9.5
JIM BRIDGER UNIT 4 12-2045 35-S0 *(17)65,376.96 1,414 75,077 4,112 6.29 18.3
JIM BRIDGER COMMON 12-2045 35-S0 *(17)4,275,759.53 1,870,596 3,132,043 171,525 4.01 18.3
VALMY NATURAL GAS UNIT 2 12-2049 35-S0 *(23)1,739,667.58 36,668 2,103,123 100,446 5.77 20.9
VALMY NATURAL GAS COMMON 12-2049 35-S0 *(24)90,707.87 3,787 108,691 5,179 5.71 21.0
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT 6,821,140.08 2,350,096 5,734,871 314,307 4.61 18.3
316.00 316.10 MISCELLANEOUS POWER PLANT EQUIPMENT - AUTOMOBILES
JIM BRIDGER COMMON 13-L2.5 20 242,168.38 99,004 94,731 7,578 3.13 12.5
VALMY NATURAL GAS COMMON 13-L2.5 20 95,012.14 21,227 54,783 5,198 5.47 10.5
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - AUTOMOBILES 337,180.52 120,231 149,514 12,776 3.79 11.7
316.00 316.40 MISCELLANEOUS POWER PLANT EQUIPMENT - SMALL TRUCKS
JIM BRIDGER COMMON 13-L2.5 20 98,953.52 79,163 0 0 - **-
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - SMALL TRUCKS 98,953.52 79,163 0 0 --
316.00 316.50 MISCELLANEOUS POWER PLANT EQUIPMENT - MISCELLANEOUS
JIM BRIDGER COMMON 13-L2.5 20 23,360.90 18,689 0 0 - **-
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - MISCELLANEOUS 23,360.90 18,689 0 0 --
316.00 316.70 MISCELLANEOUS POWER PLANT EQUIPMENT - LARGE TRUCKS
JIM BRIDGER COMMON 12-L2.5 15 289,272.84 48,228 197,654 17,187 5.94 11.5
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - LARGE TRUCKS 289,272.84 48,228 197,654 17,187 5.94 11.5
316.00 316.80 MISCELLANEOUS POWER PLANT EQUIPMENT - POWER OPERATED EQUIPMENT
JIM BRIDGER COMMON 19-L0 25 2,920,517.95 (1,443,931)3,634,319 195,499 6.69 18.6
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - POWER OPERATED EQUIPMENT 2,920,517.95 (1,443,931)3,634,319 195,499 6.69 18.6
316.00 316.90 MISCELLANEOUS POWER PLANT EQUIPMENT - TRAILERS
JIM BRIDGER COMMON 17-L2 15 9,532.34 3,330 4,772 289 3.03 16.5
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT - TRAILERS 9,532.34 3,330 4,772 289 3.03 16.5
TOTAL STEAM PRODUCTION PLANT 372,482,258.86 205,522,530 229,015,882 11,821,081 3.17
HYDRAULIC PRODUCTION PLANT
331.00 331.00 STRUCTURES AND IMPROVEMENTS
HAGERMAN MAINTENANCE SHOP 12-2040 105-R2.5 *(10)3,573,121.87 1,934,327 1,996,107 134,184 3.76 14.9
MILNER DAM 06-2067 105-R2.5 *(10)814,224.25 480,233 415,414 10,680 1.31 38.9
NIAGARA SPRINGS HATCHERY 12-2077 105-R2.5 *(45)35,147,466.00 8,098,845 42,864,981 861,695 2.45 49.7
HELLS CANYON MAINTENANCE SHOP 12-2077 105-R2.5 *(30)4,027,592.10 1,321,328 3,914,542 79,383 1.97 49.3
RAPID RIVER HATCHERY 12-2077 105-R2.5 *(45)9,496,498.08 2,777,419 10,992,503 222,176 2.34 49.5
AMERICAN FALLS 12-2056 105-R2.5 *(8)12,764,629.73 9,140,989 4,644,811 158,280 1.24 29.3
BROWNLEE 12-2077 105-R2.5 *(28)52,087,498.90 26,671,842 40,000,157 827,406 1.59 48.3
BLISS 07-2034 105-R2.5 *(3)1,997,158.09 1,550,281 506,792 59,267 2.97 8.6
CASCADE 01-2061 105-R2.5 *(9)7,341,639.22 5,134,662 2,867,725 87,409 1.19 32.8
CLEAR LAKE 06-2041 105-R2.5 *(1)377,290.42 241,913 139,150 9,024 2.39 15.4
HELLS CANYON 12-2077 105-R2.5 *(30)12,381,533.83 2,228,515 13,867,479 278,368 2.25 49.8
LOWER MALAD 03-2035 105-R2.5 *(2)1,270,670.27 753,194 542,890 59,076 4.65 9.2
LOWER SALMON 07-2034 105-R2.5 *(2)3,656,019.83 2,630,539 1,098,601 128,647 3.52 8.5
MILNER 11-2068 105-R2.5 *(10)9,897,282.26 5,526,598 5,360,412 133,338 1.35 40.2
OXBOW HATCHERY 12-2077 105-R2.5 *(16)31,301,006.81 1,392,480 34,916,688 694,666 2.22 50.3
OXBOW 12-2077 105-R2.5 *(20)30,738,927.68 7,935,125 28,951,588 591,787 1.93 48.9
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
OXBOW COMMON 12-2077 105-R2.5 *(21)111,952.27 119,297 16,165 389 0.35 41.6
PAHSIMEROI ACCUMULATING PONDS 12-2077 105-R2.5 *(45)19,130,219.89 7,491,852 20,246,967 409,405 2.14 49.5
PAHSIMEROI TRAPPING 12-2077 105-R2.5 *(45)1,361,283.91 756,314 1,217,548 25,412 1.87 47.9
SHOSHONE FALLS 12-2040 105-R2.5 *(1)10,802,497.02 2,203,988 8,706,534 584,824 5.41 14.9
STRIKE 07-2034 105-R2.5 *(3)14,811,898.30 6,997,284 8,258,971 967,146 6.53 8.5
SWAN FALLS 08-2042 105-R2.5 *(2)28,432,265.28 20,177,690 8,823,221 537,679 1.89 16.4
TWIN FALLS 12-2040 105-R2.5 *(4)1,596,680.48 762,660 897,888 60,695 3.80 14.8
TWIN FALLS (NEW)12-2040 105-R2.5 *(3)10,704,390.00 7,895,073 3,130,449 211,538 1.98 14.8
THOUSAND SPRINGS 06-2041 105-R2.5 *(2)1,299,904.17 350,342 975,560 63,493 4.88 15.4
UPPER MALAD 03-2035 105-R2.5 *(1)11,751,462.74 689,088 11,179,889 1,213,773 10.33 9.2
UPPER SALMON A 07-2034 105-R2.5 *(2)1,468,747.80 1,020,473 477,650 56,075 3.82 8.5
UPPER SALMON B 07-2034 105-R2.5 *(2)2,046,704.30 788,475 1,299,163 152,059 7.43 8.5
UPPER SALMON COMMON 07-2034 105-R2.5 *(2)390,834.94 360,106 38,546 4,528 1.16 8.5
TOTAL STRUCTURES AND IMPROVEMENTS 320,781,400.44 127,430,932 258,348,391 8,622,402 2.69 30.0
332.00 332.10 RESERVOIRS, DAMS AND WATERWAYS - RELOCATION
BROWNLEE 12-2077 120-R4 *(28)8,639,663.66 7,117,740 3,941,029 87,578 1.01 45.0
HELLS CANYON 12-2077 120-R4 *(30)940,788.93 763,655 459,371 10,208 1.09 45.0
OXBOW 12-2077 120-R4 *(20)56,309.00 45,866 21,705 482 0.86 45.0
OXBOW COMMON 12-2077 120-R4 *(21)1,927,919.83 1,696,204 636,579 13,978 0.73 45.5
BROWNLEE COMMON 12-2077 120-R4 *(29)7,895,824.78 6,979,170 3,206,444 71,254 0.90 45.0
TOTAL RESERVOIRS, DAMS AND WATERWAYS - RELOCATION 19,460,506.20 16,602,635 8,265,128 183,500 0.94 45.0
332.00 332.20 RESERVOIRS, DAMS AND WATERWAYS
MILNER DAM 06-2067 120-R4 *(10)809,584.42 391,728 498,815 12,160 1.50 41.0
AMERICAN FALLS 12-2056 120-R4 *(8)5,226,794.90 3,292,926 2,352,012 76,869 1.47 30.6
BROWNLEE 12-2077 120-R4 *(28)59,381,993.08 45,370,727 30,638,224 642,744 1.08 47.7
BLISS 07-2034 120-R4 *(3)17,102,787.78 8,685,175 8,930,696 1,043,344 6.10 8.6
CASCADE 01-2061 120-R4 *(9)3,145,630.46 2,179,522 1,249,215 36,315 1.15 34.4
CLEAR LAKE 06-2041 120-R4 *(1)5,540,189.07 2,152,134 3,443,457 222,173 4.01 15.5
HELLS CANYON 12-2077 120-R4 *(30)55,130,575.09 41,117,118 30,552,630 643,363 1.17 47.5
LOWER MALAD 03-2035 120-R4 *(2)5,554,058.72 4,323,322 1,341,818 145,213 2.61 9.2
LOWER SALMON 07-2034 120-R4 *(2)8,195,132.42 7,244,338 1,114,697 130,258 1.59 8.6
MILNER 11-2068 120-R4 *(10)16,970,001.86 9,208,494 9,458,508 223,980 1.32 42.2
OXBOW 12-2077 120-R4 *(20)35,824,134.84 23,159,688 19,829,274 417,847 1.17 47.5
OXBOW COMMON 12-2077 120-R4 *(21)9,871.65 7,225 4,720 94 0.95 50.2
SHOSHONE FALLS 12-2040 120-R4 *(1)14,825,870.12 6,199,055 8,775,074 585,332 3.95 15.0
STRIKE 07-2034 120-R4 *(3)13,047,966.77 10,221,421 3,217,985 377,145 2.89 8.5
SWAN FALLS 08-2042 120-R4 *(2)15,870,087.46 11,359,593 4,827,896 290,623 1.83 16.6
TWIN FALLS 12-2040 120-R4 *(4)1,322,999.31 590,873 785,046 52,476 3.97 15.0
TWIN FALLS (NEW)12-2040 120-R4 *(3)7,708,705.14 5,554,616 2,385,350 159,335 2.07 15.0
THOUSAND SPRINGS 06-2041 120-R4 *(2)6,726,367.66 3,935,305 2,925,590 188,801 2.81 15.5
UPPER MALAD 03-2035 120-R4 *(1)2,044,277.36 1,467,235 597,485 64,820 3.17 9.2
UPPER SALMON A 07-2034 120-R4 *(2)3,533,146.24 864,517 2,739,292 319,953 9.06 8.6
UPPER SALMON B 07-2034 120-R4 *(2)12,237,485.10 3,132,692 9,349,543 1,091,995 8.92 8.6
UPPER SALMON COMMON 07-2034 120-R4 *(2)4,235,362.79 1,530,705 2,789,365 325,616 7.69 8.6
HELLS CANYON COMMON 12-2077 120-R4 *(30)3,723,168.70 3,408,278 1,431,841 29,248 0.79 49.0
TOTAL RESERVOIRS, DAMS AND WATERWAYS 298,166,190.94 195,396,687 149,238,533 7,079,704 2.37 21.1
332.00 332.30 RESERVOIRS, DAMS AND WATERWAYS - NEZ PERCE 12-2077 SQUARE *0 5,472,398.44 2,655,102 2,817,296 54,179 0.99 52.0
333.00 333.00 WATER WHEELS, TURBINES AND GENERATORS
MILNER DAM 06-2067 95-S1 *(10)1,274,307.36 563,891 837,847 22,316 1.75 37.5
AMERICAN FALLS 12-2056 95-S1 *(8)45,889,107.11 17,242,602 32,317,634 1,098,632 2.39 29.4
BROWNLEE 12-2077 95-S1 *(28)116,900,756.42 35,586,281 114,046,687 2,448,028 2.09 46.6
BLISS 07-2034 95-S1 *(3)15,469,242.89 6,883,123 9,050,197 1,063,887 6.88 8.5
CASCADE 01-2061 95-S1 *(9)9,349,089.56 5,175,640 5,014,868 160,457 1.72 31.3
CLEAR LAKE 06-2041 95-S1 *(1)1,726,956.97 664,233 1,079,994 70,169 4.06 15.4
HELLS CANYON 12-2077 95-S1 *(30)45,189,696.76 17,574,620 41,171,986 831,292 1.84 49.5
LOWER MALAD 03-2035 95-S1 *(2)5,003,997.94 2,466,994 2,637,084 286,905 5.73 9.2
LOWER SALMON 07-2034 95-S1 *(2)48,024,659.54 12,172,331 36,812,822 4,301,460 8.96 8.6
MILNER 11-2068 95-S1 *(10)23,813,111.10 10,855,261 15,339,161 405,577 1.70 37.8
OXBOW 12-2077 95-S1 *(20)13,538,283.63 8,677,771 7,568,169 182,501 1.35 41.5
SHOSHONE FALLS 12-2040 95-S1 *(1)16,495,814.34 3,483,644 13,177,128 884,841 5.36 14.9
STRIKE 07-2034 95-S1 *(3)9,256,577.76 7,180,567 2,353,708 277,728 3.00 8.5
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
SWAN FALLS 08-2042 95-S1 *(2)26,925,228.97 17,692,285 9,771,449 605,835 2.25 16.1
TWIN FALLS 12-2040 95-S1 *(4)1,588,050.84 966,137 685,436 46,973 2.96 14.6
TWIN FALLS (NEW)12-2040 95-S1 *(3)16,109,863.64 11,071,164 5,521,996 379,062 2.35 14.6
THOUSAND SPRINGS 06-2041 95-S1 *(2)4,125,686.85 2,502,819 1,705,382 110,970 2.69 15.4
UPPER MALAD 03-2035 95-S1 *(1)5,473,398.00 2,574,362 2,953,770 320,720 5.86 9.2
UPPER SALMON A 07-2034 95-S1 *(2)2,180,170.52 1,256,953 966,821 114,711 5.26 8.4
UPPER SALMON B 07-2034 95-S1 *(2)4,688,379.37 2,623,779 2,158,368 253,122 5.40 8.5
TOTAL WATER WHEELS, TURBINES AND GENERATORS 413,022,379.57 167,214,457 305,170,507 13,865,186 3.36 22.0
334.00 334.00 ACCESSORY ELECTRIC EQUIPMENT
MILNER DAM 06-2067 60-S0 *(10)581,471.90 266,379 373,240 11,633 2.00 32.1
AMERICAN FALLS 12-2056 60-S0 *(8)9,548,861.75 2,387,586 7,925,185 287,700 3.01 27.5
BROWNLEE 12-2077 60-S0 *(28)14,229,317.48 6,685,771 11,527,755 312,995 2.20 36.8
BLISS 07-2034 60-S0 *(3)4,522,454.96 2,791,440 1,866,689 224,146 4.96 8.3
CASCADE 01-2061 60-S0 *(9)2,879,959.95 1,252,274 1,886,882 69,006 2.40 27.3
CLEAR LAKE 06-2041 60-S0 *(1)214,421.68 172,647 43,919 2,919 1.36 15.0
HELLS CANYON 12-2077 60-S0 *(30)11,496,659.66 3,288,271 11,657,387 294,620 2.56 39.6
LOWER MALAD 03-2035 60-S0 *(2)1,875,072.78 1,111,301 801,273 89,395 4.77 9.0
LOWER SALMON 07-2034 60-S0 *(2)6,135,562.60 2,366,210 3,892,064 463,811 7.56 8.4
MILNER 11-2068 60-S0 *(10)3,782,516.36 1,010,166 3,150,602 92,005 2.43 34.2
OXBOW 12-2077 60-S0 *(20)9,735,502.49 3,134,193 8,548,410 218,455 2.24 39.1
SHOSHONE FALLS 12-2040 60-S0 *(1)1,765,659.36 1,267,842 515,474 36,467 2.07 14.1
STRIKE 07-2034 60-S0 *(3)4,113,932.36 2,852,266 1,385,084 166,906 4.06 8.3
SWAN FALLS 08-2042 60-S0 *(2)4,165,621.76 2,223,167 2,025,767 131,541 3.16 15.4
TWIN FALLS 12-2040 60-S0 *(4)1,742,847.08 663,428 1,149,133 80,435 4.62 14.3
TWIN FALLS (NEW)12-2040 60-S0 *(3)4,764,695.72 2,263,978 2,643,659 185,764 3.90 14.2
THOUSAND SPRINGS 06-2041 60-S0 *(2)953,716.26 724,055 248,736 16,490 1.73 15.1
UPPER MALAD 03-2035 60-S0 *(1)1,249,150.34 682,384 579,258 64,688 5.18 9.0
UPPER SALMON A 07-2034 60-S0 *(2)1,668,550.23 808,780 893,141 107,592 6.45 8.3
UPPER SALMON B 07-2034 60-S0 *(2)1,579,841.99 787,683 823,756 98,918 6.26 8.3
TOTAL ACCESSORY ELECTRIC EQUIPMENT 87,005,816.71 36,739,821 61,937,414 2,955,486 3.40 21.0
334.10 335.30 COMPUTER HARDWARE 15-SQ 0 804,828.65 154,000 650,829 53,667 6.67 12.1
334.20 334.21 SOFTWARE - LICENSES 5-SQ 0 45,699.24 4,575 41,124 9,139 20.00 4.5
334.20 334.22 SOFTWARE - NON-ERP 10-SQ 0 4,016,073.92 2,160,000 1,856,074 401,424 10.00 4.6
334.30 334.30 COMMUNICATION EQUIPMENT
FULLY ACCRUED 229,617.18 229,617 0 0 --
AMORTIZED 15-SQ 0 613,838.55 164,265 449,574 40,922 6.67 11.0
TOTAL COMMUNICATION EQUIPMENT 843,455.73 393,882 449,574 40,922 4.85 11.0
335.00 335.00 MISCELLANEOUS POWER PLANT EQUIPMENT
HAGERMAN MAINTENANCE SHOP 12-2040 85-R1 *(10)5,350,620.11 1,687,308 4,198,374 288,070 5.38 14.6
MILNER DAM 06-2067 85-R1 *(10)40,190.01 13,755 30,454 841 2.09 36.2
NIAGARA SPRINGS HATCHERY 12-2077 85-R1 *(10)150,830.09 18,837 147,076 3,240 2.15 45.4
HELLS CANYON MAINTENANCE SHOP 12-2077 85-R1 *(30)3,636,637.94 720,467 4,007,162 87,953 2.42 45.6
RAPID RIVER HATCHERY 12-2077 85-R1 *(10)41,477.28 17,665 27,960 633 1.53 44.2
AMERICAN FALLS 12-2056 85-R1 *(8)2,034,727.39 885,841 1,311,665 46,993 2.31 27.9
BROWNLEE 12-2077 85-R1 *(28)8,798,722.34 3,155,769 8,106,596 181,686 2.06 44.6
BLISS 07-2034 85-R1 *(3)694,416.68 309,580 405,669 48,427 6.97 8.4
CASCADE 01-2061 85-R1 *(9)1,317,867.44 687,202 749,274 24,078 1.83 31.1
CLEAR LAKE 06-2041 85-R1 *(1)52,234.79 34,866 17,891 1,188 2.27 15.1
HELLS CANYON 12-2077 85-R1 *(30)1,852,536.39 387,563 2,020,734 46,180 2.49 43.8
LOWER MALAD 03-2035 85-R1 *(2)428,858.33 155,242 282,193 31,265 7.29 9.0
LOWER SALMON 07-2034 85-R1 *(2)547,030.33 345,340 212,631 25,312 4.63 8.4
MILNER 11-2068 85-R1 *(10)830,330.33 244,888 668,475 17,697 2.13 37.8
OXBOW HATCHERY 12-2077 85-R1 *(16)26,990.13 5,541 25,768 571 2.12 45.1
OXBOW 12-2077 85-R1 *(20)1,948,092.87 197,484 2,140,227 48,440 2.49 44.2
PAHSIMEROI ACCUMULATING PONDS 12-2077 85-R1 *(10)33,131.88 12,571 23,874 523 1.58 45.6
PAHSIMEROI TRAPPING 12-2077 85-R1 *(10)28,346.60 9,115 22,066 491 1.73 44.9
SHOSHONE FALLS 12-2040 85-R1 *(1)995,809.63 474,882 530,886 36,408 3.66 14.6
STRIKE 07-2034 85-R1 *(3)1,782,701.78 644,336 1,191,847 141,525 7.94 8.4
SWAN FALLS 08-2042 85-R1 *(2)1,675,074.99 557,592 1,150,984 71,791 4.29 16.0
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
TWIN FALLS 12-2040 85-R1 *(4)333,322.16 134,025 212,630 14,710 4.41 14.5
TWIN FALLS (NEW)12-2040 85-R1 *(3)472,597.14 247,162 239,613 16,559 3.50 14.5
THOUSAND SPRINGS 06-2041 85-R1 *(2)425,502.01 333,942 100,070 6,662 1.57 15.0
UPPER MALAD 03-2035 85-R1 *(1)256,492.82 138,613 120,445 13,323 5.19 9.0
UPPER SALMON A 07-2034 85-R1 *(2)248,215.23 117,755 135,425 16,161 6.51 8.4
UPPER SALMON B 07-2034 85-R1 *(2)271,060.16 160,313 116,168 13,896 5.13 8.4
UPPER SALMON COMMON 07-2034 85-R1 *(2)59,815.64 9,055 51,957 6,143 10.27 8.5
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT 34,333,632.49 11,706,709 28,248,114 1,190,766 3.47 23.7
335.00 335.10 MISCELLANEOUS POWER PLANT EQUIPMENT - EQUIPMENT 15-SQ 0 193,667.39 78,904 114,763 10,684 5.52 10.7
335.00 335.20 MISCELLANEOUS POWER PLANT EQUIPMENT - FURNITURE 20-SQ 0 42,231.03 10,101 32,130 4,284 10.14 7.5
336.00 336.00 ROADS, RAILROADS AND BRIDGES
MILNER DAM 06-2067 90-R4 *(10)12,737.21 6,153 7,858 201 1.58 39.1
NIAGARA SPRINGS HATCHERY 12-2077 90-R4 *0 46,667.72 30,181 16,487 501 1.07 32.9
RAPID RIVER HATCHERY 12-2077 90-R4 *0 17,896.46 8,928 8,968 183 1.02 49.0
AMERICAN FALLS 12-2056 90-R4 *(8)1,282,164.91 634,685 750,053 24,956 1.95 30.1
BROWNLEE 12-2077 90-R4 *(28)2,820,133.63 611,335 2,998,436 60,994 2.16 49.2
BLISS 07-2034 90-R4 *(3)486,476.64 473,083 27,988 3,272 0.67 8.6
CASCADE 01-2061 90-R4 *(9)122,668.04 74,560 59,148 1,821 1.48 32.5
CLEAR LAKE 06-2041 90-R4 *(1)11,097.30 10,927 281 20 0.18 14.0
HELLS CANYON 12-2077 90-R4 *(30)1,357,863.54 719,155 1,046,068 24,726 1.82 42.3
LOWER MALAD 03-2035 90-R4 *(2)244,565.45 209,071 40,386 4,419 1.81 9.1
LOWER SALMON 07-2034 90-R4 *(2)88,693.04 85,518 4,949 581 0.66 8.5
MILNER 11-2068 90-R4 *(10)489,139.50 233,829 304,224 7,564 1.55 40.2
OXBOW HATCHERY 12-2077 90-R4 *(16)3,070.44 3,175 387 13 0.42 29.8
OXBOW 12-2077 90-R4 *(20)3,674,732.91 615,190 3,794,489 78,393 2.13 48.4
PAHSIMEROI ACCUMULATING PONDS 12-2077 90-R4 *0 59,333.89 21,142 38,192 800 1.35 47.7
PAHSIMEROI TRAPPING 12-2077 90-R4 *0 15,612.35 15,378 234 6 0.04 39.0
SHOSHONE FALLS 12-2040 90-R4 *(1)468,608.98 465,767 7,528 502 0.11 15.0
STRIKE 07-2034 90-R4 *(3)1,602,868.07 784,455 866,499 101,390 6.33 8.5
SWAN FALLS 08-2042 90-R4 *(2)2,342,571.85 663,315 1,726,108 104,081 4.44 16.6
TWIN FALLS 12-2040 90-R4 *(4)883,860.44 648,593 270,622 18,374 2.08 14.7
TWIN FALLS (NEW)12-2040 90-R4 *(3)1,754,223.73 570,708 1,236,142 82,660 4.71 15.0
THOUSAND SPRINGS 06-2041 90-R4 *(2)785,489.40 673,190 128,009 8,268 1.05 15.5
UPPER MALAD 03-2035 90-R4 *(1)1,356,748.13 587,593 782,723 84,662 6.24 9.2
UPPER SALMON A 07-2034 90-R4 *(2)1,650.89 1,370 314 37 2.24 8.5
UPPER SALMON COMMON 07-2034 90-R4 *(2)27,708.47 27,986 277 35 0.13 7.9
TOTAL ROADS, RAILROADS AND BRIDGES 19,956,582.99 8,175,287 14,116,370 608,459 3.05 23.2
TOTAL HYDRAULIC PRODUCTION PLANT 1,204,144,863.74 568,723,092 831,286,247 35,079,802 2.91
SOLAR PRODUCTION PLANT
338.20 341.10 STRUCTURES AND IMPROVEMENTS 35-R3 0 2,976.33 749 2,227 86 2.89 25.9
338.40 344.10 SOLAR PANELS 20-S2.5 0 79,330.62 29,109 50,222 4,620 5.82 10.9
338.12 346.10 MISCELLANEOUS POWER PLANT EQUIPMENT 25-S2.5 0 12,592.16 3,905 8,687 554 4.40 15.7
TOTAL SOLAR PRODUCTION PLANT 94,899.11 33,763 61,136 5,260 5.54
OTHER PRODUCTION PLANT
341.00 341.00 STRUCTURES AND IMPROVEMENTS
SALMON DIESEL 06-2012 50-R3 *(3)11,959.08 11,956 362 0 --
EVANDER ANDREWS/DANSKIN #2 06-2041 50-R3 *(5)5,170,216.60 2,700,342 2,728,385 185,951 3.60 14.7
BENNETT MOUNTAIN 06-2046 50-R3 *(5)1,928,449.83 849,494 1,175,378 60,948 3.16 19.3
EVANDER ANDREWS/DANSKIN #1 06-2048 50-R3 *(5)1,329,997.82 662,503 733,995 35,176 2.64 20.9
LANGLEY GULCH 06-2054 50-R3 *(5)150,004,159.45 49,310,885 108,193,482 4,062,857 2.71 26.6
TOTAL STRUCTURES AND IMPROVEMENTS 158,444,782.78 53,535,180 112,831,602 4,344,932 2.74 26.0
342.00 342.00 FUEL HOLDERS, PRODUCERS AND ACCESSORIES
SALMON DIESEL 06-2012 45-R3 *(3)61,306.39 61,306 1,840 0 --
EVANDER ANDREWS/DANSKIN #2 06-2041 45-R3 *(5)2,067,567.54 914,109 1,256,837 85,358 4.13 14.7
BENNETT MOUNTAIN 06-2046 45-R3 *(5)2,290,713.40 1,313,325 1,091,924 59,988 2.62 18.2
EVANDER ANDREWS/DANSKIN #1 06-2048 45-R3 *(5)716,289.45 359,017 393,087 19,407 2.71 20.3
LANGLEY GULCH 06-2054 45-R3 *(5)6,424,588.52 1,858,262 4,887,556 190,283 2.96 25.7
TOTAL FUEL HOLDERS, PRODUCERS AND ACCESSORIES 11,560,465.30 4,506,019 7,631,244 355,036 3.07 21.5
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
343.00 343.00 PRIME MOVERS
EVANDER ANDREWS/DANSKIN #2 06-2041 40-R1.5 *(5)43,075,052.03 19,100,133 26,128,672 1,850,101 4.30 14.1
BENNETT MOUNTAIN 06-2046 40-R1.5 *(5)40,963,895.22 (8,093,002)51,105,092 2,767,163 6.76 18.5
EVANDER ANDREWS/DANSKIN #1 06-2048 40-R1.5 *(5)56,689,741.85 (3,935,134)63,459,363 3,160,098 5.57 20.1
LANGLEY GULCH 06-2054 30-R2 *(5)140,283,957.40 9,075,994 138,222,161 6,842,627 4.88 20.2
TOTAL PRIME MOVERS 281,012,646.50 16,147,991 278,915,288 14,619,989 5.20 19.1
344.00 344.00 GENERATORS
SALMON DIESEL 06-2012 45-S2 *(3)541,644.95 541,645 16,249 0 --
EVANDER ANDREWS/DANSKIN #2 06-2041 45-S2 *(5)13,327,221.96 10,766,495 3,227,088 240,200 1.80 13.4
BENNETT MOUNTAIN 06-2046 45-S2 *(5)8,139,999.35 5,985,622 2,561,377 145,121 1.78 17.6
EVANDER ANDREWS/DANSKIN #1 06-2048 45-S2 *(5)14,111,726.31 2,470,288 12,347,025 599,616 4.25 20.6
LANGLEY GULCH 06-2054 45-S2 *(5)40,047,458.38 13,942,690 28,107,141 1,101,186 2.75 25.5
TOTAL GENERATORS 76,168,050.95 33,706,740 46,258,880 2,086,123 2.74 22.2
345.00 345.00 ACCESSORY ELECTRIC EQUIPMENT
SALMON DIESEL 06-2012 45-L3 *(3)467,105.00 661,114 (179,996)0 --
EVANDER ANDREWS/DANSKIN #2 06-2041 45-L3 *(5)2,793,727.28 1,254,116 1,679,298 121,915 4.36 13.8
BENNETT MOUNTAIN 06-2046 45-L3 *(5)12,389,840.55 6,460,635 6,548,698 360,701 2.91 18.2
EVANDER ANDREWS/DANSKIN #1 06-2048 45-L3 *(5)11,627,005.99 5,821,704 6,386,652 323,511 2.78 19.7
LANGLEY GULCH 06-2054 45-L3 *(5)68,073,787.23 25,661,529 45,815,948 1,816,269 2.67 25.2
TOTAL ACCESSORY ELECTRIC EQUIPMENT 95,351,466.05 39,859,098 60,250,600 2,622,396 2.75 23.0
345.10 345.10 COMPUTER HARDWARE 15-SQ 0 212,325.92 70,200 142,126 14,156 6.67 10.0
345.20 345.22 SOFTWARE - NON-ERP 10-SQ 0 264,896.35 66,250 198,646 26,486 10.00 7.5
345.30 345.30 COMMUNICATION EQUIPMENT
FULLY ACCRUED 8,740.65 8,741 0 0 --
AMORTIZED 15-SQ 0 138,969.17 99,950 39,019 9,272 6.67 4.2
TOTAL COMMUNICATION EQUIPMENT 147,709.82 108,691 39,019 9,272 6.28 4.2
346.00 346.00 MISCELLANEOUS POWER PLANT EQUIPMENT
SALMON DIESEL 06-2012 40-S0.5 *(3)1,004.50 2,290 (1,255)0 --
EVANDER ANDREWS/DANSKIN #2 06-2041 40-S0.5 *(5)1,749,755.03 912,791 924,452 68,031 3.89 13.6
BENNETT MOUNTAIN 06-2046 40-S0.5 *(5)1,556,339.88 488,861 1,145,296 64,263 4.13 17.8
EVANDER ANDREWS/DANSKIN #1 06-2048 40-S0.5 *(5)1,818,174.83 562,798 1,346,286 69,067 3.80 19.5
LANGLEY GULCH 06-2054 40-S0.5 *(5)3,688,466.92 900,669 2,972,221 126,717 3.44 23.5
TOTAL MISCELLANEOUS POWER PLANT EQUIPMENT 8,813,741.16 2,867,409 6,387,000 328,078 3.72 19.5
TOTAL OTHER PRODUCTION PLANT 631,976,084.83 150,867,578 512,654,405 24,406,468 3.86
TRANSMISSION PLANT
350.00 350.20 LAND RIGHTS AND EASEMENTS 85-R3 0 39,594,688.18 11,184,630 28,410,058 438,248 1.11 64.8
351.10 351.10 COMPUTER HARDWARE
FULLY ACCRUED 3,045,206.09 3,045,206 0 0 --
AMORTIZED 15-SQ 0 3,650,228.49 1,302,843 2,347,385 243,351 6.67 9.6
TOTAL COMPUTER HARDWARE 6,695,434.58 4,348,049 2,347,385 243,351 3.63 9.7
351.20 351.21 SOFTWARE - LICENSES 5-SQ 0 203,905.65 20,400 183,506 40,779 20.00 4.5
351.20 351.22 SOFTWARE - NON-ERP 10-SQ 0 266,696.13 156,400 110,296 26,678 10.00 4.1
351.30 351.30 COMMUNICATION EQUIPMENT
FULLY ACCRUED 6,114,867.06 6,114,867 0 0 --
AMORTIZED 15-SQ 0 10,763,631.45 5,610,000 5,153,631 718,303 6.67 7.2
TOTAL COMMUNICATION EQUIPMENT 16,878,498.51 11,724,867 5,153,631 718,303 4.26 7.2
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
352.00 352.00 STRUCTURES AND IMPROVEMENTS 70-R2.5 (45)151,189,185.83 39,429,645 179,794,674 3,060,164 2.02 58.8
353.00 353.00 STATION EQUIPMENT 52-S0 (20)529,501,603.23 130,403,324 504,998,600 12,510,738 2.36 40.4
354.00 354.00 TOWERS AND FIXTURES 80-R4 (25)273,825,652.08 86,850,066 255,431,999 3,972,789 1.45 64.3
355.00 355.00 POLES AND FIXTURES 61-R1.5 (75)275,774,061.72 86,210,907 396,393,701 8,027,633 2.91 49.4
355.00 355.10 POLES AND FIXTURES - TREATMENT 20-S3 0 5,798,796.06 1,929,931 3,868,865 260,187 4.49 14.9
356.00 356.00 OVERHEAD CONDUCTORS AND DEVICES 70-R1.5 (45)342,952,159.98 94,203,149 403,077,483 7,041,599 2.05 57.2
359.00 359.00 ROADS AND TRAILS 70-R3 0 405,090.98 304,337 100,754 2,898 0.72 34.8
TOTAL TRANSMISSION PLANT 1,643,085,772.93 466,765,705 1,779,870,952 36,343,367 2.21
DISTRIBUTION PLANT
361.00 361.00 STRUCTURES AND IMPROVEMENTS 70-R2.5 (50)72,346,684.68 19,487,804 89,032,223 1,561,972 2.16 57.0
362.00 362.00 STATION EQUIPMENT 63-S0 (20)404,645,674.77 75,818,822 409,755,988 7,863,271 1.94 52.1
363.10 363.10 COMPUTER HARDWARE
FULLY ACCRUED 665,213.82 665,214 0 0 --
AMORTIZED 15-SQ 0 426,036.57 174,200 251,837 28,423 6.67 8.9
TOTAL COMPUTER HARDWARE 1,091,250.39 839,414 251,837 28,423 2.60 8.9
363.20 363.21 SOFTWARE - LICENSES 5-SQ 0 439,186.03 166,250 272,936 87,830 20.00 3.1
363.20 363.22 SOFTWARE - NON-ERP 10-SQ 0 7,183,627.02 3,247,500 3,936,127 718,587 10.00 5.5
363.30 363.30 COMMUNICATION EQUIPMENT
FULLY ACCRUED 3,240,944.52 3,240,945 0 0 --
AMORTIZED 15-SQ 0 9,523,834.31 3,692,500 5,831,334 635,633 6.67 9.2
TOTAL COMMUNICATION EQUIPMENT 12,764,778.83 6,933,445 5,831,334 635,633 4.98 9.2
364.00 364.00 POLES, TOWERS AND FIXTURES 62-R0.5 (55)382,337,444.58 140,629,131 451,993,908 8,684,541 2.27 52.0
364.00 364.10 POLES, TOWERS AND FIXTURES - TREATMENT 20-S3 0 25,913,762.75 7,068,794 18,844,969 1,239,163 4.78 15.2
365.00 365.00 OVERHEAD CONDUCTORS AND DEVICES 50-R0.5 (30)185,902,496.40 60,647,616 181,025,629 4,707,319 2.53 38.5
366.00 366.00 UNDERGROUND CONDUIT 63-R1.5 (35)63,807,648.10 21,998,328 64,141,997 1,367,933 2.14 46.9
367.00 367.00 UNDERGROUND CONDUCTORS AND DEVICES 50-R1.5 (25)384,858,306.93 119,020,073 362,052,811 9,487,476 2.47 38.2
368.00 368.00 LINE TRANSFORMERS 50-O1 (20)885,241,876.89 211,819,231 850,471,021 19,597,082 2.21 43.4
369.00 369.00 SERVICES 55-R1 (45)77,771,811.21 46,581,046 66,188,080 1,564,821 2.01 42.3
370.00 370.00 METERS 25-O1 (10)23,053,306.31 6,307,579 19,051,058 1,427,812 6.19 13.3
370.00 370.10 METERS - AMI 20-R0.5 (2)108,770,402.12 38,414,431 72,531,379 4,853,803 4.46 14.9
371.00 371.20 INSTALLATIONS ON CUSTOMERS' PREMISES 19-R1 (10)4,634,677.45 (59,518)5,157,663 520,035 11.22 9.9
373.00 373.20 STREET LIGHTING AND SIGNAL SYSTEMS 25-L0.5 (30)6,651,589.01 393,694 8,253,372 477,498 7.18 17.3
TOTAL DISTRIBUTION PLANT 2,647,414,523.47 759,313,640 2,608,792,332 64,823,199 2.45
ENERGY STORAGE PLANT
387.20 387.02 STRUCTURES AND IMPROVEMENTS
BLACK MESA 12-2043 30-R3 *(7)5,677,195.17 542,114 5,532,485 319,982 5.64 17.3
FRANKLIN 12-2044 30-R3 *(8)2,426,103.11 149,422 2,470,769 135,236 5.57 18.3
HEMINGWAY 1 12-2043 30-R3 *(7)12,097,109.03 369,511 12,574,396 726,928 6.01 17.3
HEMINGWAY 2 12-2044 30-R3 *(7)6,632,549.58 1,362,756 5,734,072 313,852 4.73 18.3
HAPPY VALLEY 12-2045 30-R3 *(7)14,929,490.78 367,261 15,607,294 810,348 5.43 19.3
OTHER 30-R3 0 6,679,233.06 349,324 6,329,909 221,869 3.32 28.5
TOTAL STRUCTURES AND IMPROVEMENTS 48,441,680.73 3,140,388 48,248,925 2,528,215 5.22 19.1
387.30 387.03 ENERGY STORAGE EQUIPMENT
BLACK MESA 12-2043 15-S3 *(7)42,578,963.66 4,059,436 41,500,055 3,346,779 7.86 12.4
FRANKLIN 12-2044 15-S3 *(8)108,083,092.40 6,688,029 110,041,711 8,212,068 7.60 13.4
HEMINGWAY 1 12-2043 15-S3 *(7)87,435,434.22 2,764,767 90,791,148 7,318,637 8.37 12.4
HEMINGWAY 2 12-2044 15-S3 *(7)49,744,121.79 10,151,367 43,074,843 3,214,541 6.46 13.4
HAPPY VALLEY 12-2045 15-S3 *(7)82,799,720.23 2,010,670 86,585,031 6,012,849 7.26 14.4
OTHER 15-S3 (10)16,276,949.25 842,153 17,062,491 1,263,581 7.76 13.5
TOTAL ENERGY STORAGE EQUIPMENT 386,918,281.55 26,516,422 389,055,279 29,368,455 7.59 13.3
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
387.50 387.05 COLLECTOR SYSTEM
BLACK MESA 12-2043 20-S2 *(7)5,677,195.17 541,238 5,533,361 363,798 6.41 15.2
FRANKLIN 12-2044 20-S2 *(8)4,852,219.12 298,845 4,941,552 304,846 6.28 16.2
HEMINGWAY 1 12-2043 20-S2 *(7)11,617,872.83 368,636 12,062,488 793,063 6.83 15.2
HEMINGWAY 2 12-2044 20-S2 *(7)6,632,549.58 1,353,516 5,743,312 354,307 5.34 16.2
HAPPY VALLEY 12-2045 20-S2 *(7)3,700,236.16 86,199 3,873,054 225,047 6.08 17.2
OTHER 20-S2 0 4,240,156.39 220,977 4,019,179 217,253 5.12 18.5
TOTAL COLLECTOR SYSTEM 36,720,229.25 2,869,411 36,172,946 2,258,314 6.15 16.0
387.60 387.06 GENERATOR STEP UP
BLACK MESA 12-2043 30-R3 *(7)1,419,298.82 134,652 1,383,998 80,046 5.64 17.3
FRANKLIN 12-2044 30-R3 *(8)1,819,577.34 112,067 1,853,077 101,427 5.57 18.3
HEMINGWAY 1 12-2043 30-R3 *(7)2,945,871.63 91,502 3,060,581 177,015 6.01 17.3
HEMINGWAY 2 12-2044 30-R3 *(7)1,658,137.39 341,620 1,432,587 78,412 4.73 18.3
HAPPY VALLEY 12-2045 30-R3 *(7)5,914,265.73 145,878 6,182,386 320,996 5.43 19.3
OTHER 30-R3 (15)308,427.02 15,414 339,277 11,892 3.86 28.5
TOTAL GENERATOR STEP UP 14,065,577.93 841,133 14,251,906 769,788 5.47 18.5
387.70 387.07 INVERTERS
BLACK MESA 12-2043 15-L3 *(7)1,419,298.77 135,090 1,383,560 115,201 8.12 12.0
FRANKLIN 12-2044 15-L3 *(8)3,032,628.90 186,778 3,088,461 237,391 7.83 13.0
HEMINGWAY 1 12-2043 15-L3 *(7)2,945,871.60 91,940 3,060,143 254,800 8.65 12.0
HEMINGWAY 2 12-2044 15-L3 *(7)1,658,137.40 343,245 1,430,962 109,989 6.63 13.0
HAPPY VALLEY 12-2045 15-L3 *(7)5,914,265.73 145,878 6,182,386 441,284 7.46 14.0
OTHER 15-L3 0 905,825.63 47,010 858,816 63,616 7.02 13.5
TOTAL INVERTERS 15,876,028.03 949,941 16,004,328 1,222,281 7.70 13.1
387.80 387.08 COMPUTER HARDWARE 15-SQ 0 2,981,103.94 100,000 2,881,104 198,697 6.67 14.5
387.10 387.10 COMMUNICATION EQUIPMENT 15-SQ 0 615,397.64 20,000 595,398 41,062 6.67 14.5
387.11 387.11 MISCELLANEOUS ENERGY STORAGE EQUIPMENT
HEMINGWAY 1 12-2043 25-R3 *(7)101,342.09 760 107,676 6,271 6.19 17.2
HAPPY VALLEY 12-2045 25-R3 *(7)1,206,824.21 29,603 1,261,699 67,255 5.57 18.8
OTHER 25-R3 0 111,302.95 719 110,584 4,512 4.05 24.5
TOAL MISCELLANEOUS ENERGY STORAGE EQUIPMENT 1,419,469.25 31,082 1,479,959 78,038 5.50 19.0
387.90 387.91 SOFTWARE - LICENSES 5-SQ 0 1,182,853.15 118,500 1,064,353 236,523 20.00 4.5
387.90 387.92 SOFTWARE - NON-ERP 10-SQ 0 1,091,754.14 164,000 927,754 109,148 10.00 8.5
TOTAL ENERGY STORAGE PLANT 509,312,375.61 34,750,877 510,681,952 36,810,521 7.23
GENERAL PLANT
390.00 390.11 STRUCTURES AND IMPROVEMENTS - CHQ BUILDING 12-2056 65-S0 *(10)37,624,456.90 12,250,717 29,136,186 1,087,749 2.89 26.8
390.00 390.12 STRUCTURES AND IMPROVEMENTS - EXCLUDING CHQ BUILDING
BOISE CENTER WEST 06-2067 55-S0.5 *(10)15,666,714.93 3,589,690 13,643,696 407,575 2.60 33.5
BOISE OPERATIONS CENTER 06-2054 55-S0.5 *(10)17,723,981.73 4,630,525 14,865,855 586,105 3.31 25.4
BOISE MECHANICAL AND ENVIRONMENTAL CENTER 06-2054 55-S0.5 *(10)11,309,562.89 3,540,805 8,899,714 360,874 3.19 24.7
AMITY DISTRIBUTION CENTER 06-2073 55-S0.5 *(10)19,207,396.54 639,904 20,488,232 512,189 2.67 40.0
OTHER STRUCTURES 55-S0.5 (10)99,604,415.02 16,858,375 92,706,482 2,122,883 2.13 43.7
TOTAL STRUCTURES AND IMPROVEMENTS - EXCLUDING CHQ BUILDING 163,512,071.11 29,259,299 150,603,979 3,989,626 2.44 37.8
TOTAL STRUCTURES AND IMPROVEMENTS 201,136,528.01 41,510,016 179,740,165 5,077,375 2.52 35.4
391.00 391.10 OFFICE FURNITURE AND EQUIPMENT - FURNITURE 20-SQ 0 14,037,562.89 7,905,000 6,132,563 701,818 5.00 8.7
392.00 392.10 TRANSPORTATION EQUIPMENT - AUTOMOBILES 13-L2.5 20 734,883.20 314,949 272,958 40,598 5.52 6.7
392.00 392.30 TRANSPORTATION EQUIPMENT - AIRCRAFT 15-S1 40 9,732,611.32 (391,902)6,231,469 429,756 4.42 14.5
392.00 392.40 TRANSPORTATION EQUIPMENT - SMALL TRUCKS 13-L2.5 20 42,769,658.95 12,068,334 22,147,393 2,486,080 5.81 8.9
392.00 392.50 TRANSPORTATION EQUIPMENT - MISCELLANEOUS 13-L2.5 20 2,526,480.07 777,284 1,243,900 151,251 5.99 8.2
392.00 392.60 TRANSPORTATION EQUIPMENT - LARGE TRUCKS (HYD)12-L2.5 15 79,274,372.38 6,075,064 61,308,153 8,815,505 11.12 7.0
392.00 392.70 TRANSPORTATION EQUIPMENT - LARGE TRUCKS (NON-HYD)12-L2.5 15 11,999,150.07 3,833,056 6,366,222 1,302,521 10.86 4.9
392.00 392.90 TRANSPORTATION EQUIPMENT - TRAILERS 17-L2 15 12,953,876.75 1,717,545 9,293,250 853,626 6.59 10.9
393.00 393.00 STORES EQUIPMENT 25-SQ 0 10,720,822.30 2,260,000 8,460,822 428,956 4.00 19.7
394.00 394.00 TOOLS, SHOP AND GARAGE EQUIPMENT 20-SQ 0 17,110,168.94 6,541,000 10,569,169 855,408 5.00 12.4
395.00 395.00 LABORATORY EQUIPMENT 20-SQ 0 16,669,089.66 8,020,000 8,649,090 833,495 5.00 10.4
396.00 396.00 POWER OPERATED EQUIPMENT 19-L0 25 34,044,934.33 6,768,815 18,764,886 1,220,036 3.58 15.4
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
397.10 391.20 COMPUTER HARDWARE - EDP EQUIPMENT
FULLY ACCRUED 40,743.81 40,744 0 0 --
AMORTIZED 5-SQ 0 26,040,106.01 12,590,000 13,450,106 5,208,640 20.00 2.6
TOTAL COMPUTER HARDWARE - EDP EQUIPMENT 26,080,849.82 12,630,744 13,450,106 5,208,640 19.97 2.6
397.10 391.21 COMPUTER HARDWARE - SERVERS 8-SQ 0 2,550,327.18 1,948,000 602,327 318,756 12.50 1.9
397.20 303.00 COMPUTER SOFTWARE 10-SQ 0 18,548,171.35 12,296,141 6,252,030 1,854,817 10.00 3.4
397.20 303.05 COMPUTER SOFTWARE - LICENSES
FULLY ACCRUED 454,123.87 454,124 0 0 --
AMORTIZED 5-SQ 0 16,698,342.86 6,054,000 10,644,343 3,339,329 20.00 3.2
TOTAL COMPUTER SOFTWARE - LICENSES 17,152,466.73 6,508,124 10,644,343 3,339,329 19.47 3.2
397.20 303.10 COMPUTER SOFTWARE - NON-ERP 10-SQ 0 31,245,249.04 6,326,339 24,918,910 3,124,526 10.00 8.0
397.20 303.15 COMPUTER SOFTWARE - ERP 15-SQ 0 13,257,581.62 1,325,758 11,931,824 883,839 6.67 13.5
397.20 303.70 COMPUTER SOFTWARE - CLOUD 5-SQ 0 8,271,771.20 2,771,500 5,500,271 1,653,964 20.00 3.3
397.30 397.10 COMMUNICATION EQUIPMENT - TELEPHONES 15-SQ 0 2,904,337.92 874,000 2,030,338 193,749 6.67 10.5
397.30 397.20 COMMUNICATION EQUIPMENT - MICROWAVE 15-SQ 0 21,182,743.33 13,075,000 8,107,743 1,413,464 6.67 5.7
397.30 397.30 COMMUNICATION EQUIPMENT - RADIO 15-SQ 0 32,996,462.22 11,010,000 21,986,462 2,201,763 6.67 10.0
397.30 397.40 COMMUNICATION EQUIPMENT - FIBER OPTIC 15-SQ 0 23,798,677.87 14,010,000 9,788,678 1,587,015 6.67 6.2
397.30 397.50 COMMUNICATION EQUIPMENT - SATELLITE 20-SQ 0 5,251,939.78 1,045,818 4,206,122 262,597 5.00 16.0
398.00 398.00 MISCELLANEOUS EQUIPMENT 15-SQ 0 12,758,506.52 4,850,000 7,908,507 851,579 6.67 9.3
TOTAL GENERAL PLANT 669,709,223.45 186,070,585 466,507,701 46,090,463 6.88
UNRECOVERED RESERVE ADJUSTMENT FOR AMORTIZATION
397.10 391.20 COMPUTER HARDWARE - EDP EQUIPMENT (1,812,188)362,438 ***
TOTAL UNRECOVERED RESERVE ADJUSTMENT FOR AMORTIZATION (1,812,188)362,438
TOTAL DEPRECIABLE PLANT 7,681,777,839.65 2,370,462,875 6,942,201,152 255,884,324 3.33
GENERATING STATION - EARLY RETIREMENTS
JIM BRIDGER STEAM PLANT
310.20 310.20 LAND AND WATER RIGHTS 69,428.34 64,605
311.00 311.00 STRUCTURES AND IMPROVEMENTS 37,145,650.96 34,625,418
312.10 312.10 BOILER PLANT EQUIPMENT - SCRUBBERS 107,324,633.87 91,029,699
312.20 312.20 BOILER PLANT EQUIPMENT - OTHER 202,035,776.29 173,729,660
312.30 312.30 BOILER PLANT EQUIPMENT - RAILCARS 790,012.06 734,136
314.00 314.00 TURBOGENERATOR UNITS 46,500,201.64 41,940,638
315.00 315.00 ACCESSORY ELECTRIC EQUIPMENT 16,102,637.42 15,012,057
316.00 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT 3,908,811.83 2,820,811
316.10 316.10 MISCELLANEOUS POWER PLANT EQUIPMENT - AUTOMOBILES 112,917.22 78,444
316.70 316.70 MISCELLANEOUS POWER PLANT EQUIPMENT - LARGE TRUCKS 135,701.65 91,976
316.80 316.80 MISCELLANEOUS POWER PLANT EQUIPMENT - POWER OPERATED EQUIPMENT 2,334,591.44 747,179
316.90 316.90 MISCELLANEOUS POWER PLANT EQUIPMENT - TRAILERS 4,444.70 3,158
352.00 352.00 STRUCTURES AND IMPROVEMENTS 140,501.50 123,300
353.00 353.00 STATION EQUIPMENT 4,471,474.76 3,023,483
JIM BRIDGER STEAM PLANT 421,076,783.68 364,024,564
TOTAL GENERATING STATION - EARLY RETIREMENTS 421,076,783.68 364,024,564
IDAHO POWER COMPANY
TABLE 1. SUMMARY OF ESTIMATED SURVIVOR CURVE, NET SALVAGE PERCENT, ORIGINAL COST, BOOK DEPRECIATION RESERVE AND CALCULATED
ANNUAL DEPRECIATION ACCRUALS RELATED TO ELECTRIC PLANT AS OF DECEMBER 31, 2025
PROBABLE NET ORIGINAL COST BOOK CALCULATED ANNUAL COMPOSITE
FERC IPC RETIREMENT SURVIVOR SALVAGE AS OF DEPRECIATION FUTURE ACCRUAL ACCRUAL REMAINING
ACCOUNT ACCOUNT ACCOUNT DATE CURVE PERCENT DECEMBER 31, 2025 RESERVE ACCRUALS AMOUNT RATE LIFE
(1)(2)(3)(4)(5)(6)(7)(8)(9)=(8)/(5)(10)=(7)/(8)
NONDEPRECIABLE PLANT AND ACCOUNTS NOT STUDIED
301.00 301.00 ORGANIZATION COSTS 5,703.01
302.00 302.00 FRANCHISES AND CONSENTS 64,377,355.57 22,588,942
310.00 310.10 LAND 967,139.31
317.00 317.00 STEAM ARO 14,790,524.24
330.00 330.00 LAND 32,050,434.48
338.10 340.10 LAND AND LAND RIGHTS 9,787.49
340.00 340.00 LAND 2,690,006.46
350.00 350.00 LAND 4,302,423.01
350.00 350.22 RIGHTS OF WAY STUDIES 1,489,644.11 161,810
360.00 360.00 LAND 10,561,394.04
360.00 360.22 RIGHTS OF WAY STUDIES 873,576.40 311,419
387.10 363.01 LAND 427,672.57
389.00 389.00 LAND 21,226,656.94
TOTAL NONDEPRECIABLE PLANT 153,772,317.63 23,062,171
TOTAL ELECTRIC PLANT 8,256,626,940.96 2,757,549,610
* LIFE SPAN PROCEDURE IS USED. CURVE SHOWN IS INTERIM SURVIVOR CURVE.
** NEW ADDITIONS AS OF JANUARY 1, 2026 WILL UTILIZE AN ANNUAL ACCRUAL RATE AS FOLLOWS:
ACCOUNT RATE
ACCOUNT 316.40 MISCELLANEOUS POWER PLANT EQUIPMENT - SMALL TRUCKS 6.15
ACCOUNT 316.50 MISCELLANEOUS POWER PLANT EQUIPMENT - MISCELLANEOUS 6.15
NOTE: ANNUAL ACCRUAL RATE FOR NEW ASSETS AS OF JANUARY 1, 2026 ARE AS FOLLOWS:
NEW ASSET RATE
ACCOUNT 311.00 STRUCTURES AND IMPROVEMENTS
JIM BRIDGER NATURAL GAS UNIT 3 6.21
ACCOUNT 312.10 BOILER PLANT EQUIPMENT - SCRUBBERS
JIM BRIDGER NATURAL GAS UNIT 3 6.25
ACCOUNT 315.00 ACCESSORY ELECTRIC EQUIPMENT
JIM BRIDGER NATURAL GAS UNIT 3 6.20
VALMY NATURAL GAS UNIT 1 5.45
ACCOUNT 316.00 MISCELLANEOUS POWER PLANT EQUIPMENT
JIM BRIDGER NATURAL GAS UNIT 3 6.70
VALMY NATURAL GAS UNIT 1 6.05
ACCOUNT 357.00 UNDERGROUND CONDUIT 1.91
ACCOUNT 358.00 UNDERGROUND CONDUCTORS AND DEVICES 2.20
***5-YEAR AMORTIZATION OF UNRECOVERED RESERVE RELATED TO IMPLEMENTATION OF AMORTIZATION ACCOUNTING.