202507312025 Idaho BPA ResEx Workpapers.pdf

Avista Corporation
Residential Exchange- State of Idaho
Proposed Rate
October 1, 2025 - September 30, 2026
Idaho portion of 2024 fiscal year benefit amount -$3,122,771
Estimated under-refunded balance at end of existing rate -117,237
Net benefit for rate adjustment -$3,240,007
Conversion factor 0.995661
Revenue requirement -$3,254,127
Projected kWh 10/1/25- 9/30/26 1,398,509,554
Proposed rate -$0.00233
Rate Impact
Proposed rate credit above -$0.00233 -36%
Existing rate credit -$0.00366
Difference $0.00133
Bill for 939 kWh at present rates with all adders
Basic charge $20.00
First 600 kWh 600 $0.08569 51.41
Over 600 kWh 339 $0.09703 32.89
Total 104.30
Proposed rate Increase 939 $0.00133 $1.25 105.55
Percent rate Increase 1.20%
Proposed ResEx Rate

Change in Benefit
Proposed Present
Idaho portion of benefit amount $ (3,258,527) $ (5,118,545) $ 1,860,018

Avista Corporation
Idaho Residential Exchange Account
Actual and Projected
Interest Rate
Balance 5/31/2023 (Actual) -$106,018.35 5.0%
April credit received in June -412,972.51
Amortization 338,857.96
Interest -441.75
Balance 6/30/2023 (Actual) -$180,574.65
May credit received in July -355,463.46
Amortization 399,563.73
Amortization Adjustment-June unbilled 134,191.09
Interest -752.39
Balance 7/31/2023 (Projected) -$3,035.69
June credit received in August -348,806.42
Amortization 371,736.39
Interest -12.65
Balance 8/31/2023 (Projected) $19,881.63
July credit received in September -435,429.30
Amortization 298,228.24
Interest 82.84
Balance 9/30/2023 (Projected) -$117,236.59
Check
Balance 5/31/25 (Actual) -$106,018.35
Credits to be received -1,552,671.69
Amortization 1,542,577.40
Interest -1,123.95
Balance at 9/30/25 -$117,236.59
Idaho ResX Balances

Avista Corporation
Projected Residential Exchange Program Benefits
Total Oct-24 thru Sep-25 KWH 1 Percent Credit
ID Credit Amount 1,419,441,313 33.81% $3,122,771
WA Credit Amount 2,778,935,475 66.19% $6,113,658
Total 4,198,376,787 100.00% $9,236,429
Purchase at ASC 67.2900
Sale at PF Exchange Rate 65.0900
2.2000
Projected Loads 4,198,376,787
Total Credit $9,236,429
(1)Average of 2023 and 2024 qualifying kilowatt-hours by state.
Projected Benefits

Purchase at ASC Rate:
ASC Utility Filings- Bonneville Power Administration
Table 2.4-1: Exchange Period FY 2026-2028 ASC ($/MWh)
With No Major Resource Additions or Removals
July 1, 2024 July 24, 2025 Final
Date As-Filed ASC Report
FY 2026-2028 $71.39 $67.29
Sale at PF Exchange Rate:
Appendix D.Final Proposal Power Rate Schedules and GRSPs.BP-26-A-01-AP01
6.1.Energy Rate
Rates in mills/kWh
Investor-Owned Utilities Base PF 7(b)(3) PF Exchange
Exchange Rates Surcharge Rates
Avista 58.93 6.16 65.09
Idaho Power 58.93 1.14 60.07
NorthWestern 58.93 22.48 81.40
PacifiCorp 58.93 33.14 92.07
Portland General 58.93 25.76 84.68
Puget Sound Energy 58.93 17.17 76.10
Consumer-Owned Utilities Base Tier 1 PF 7(b)(3) PFExchange
Ekchange Rates Surcharge Rates
Snohomish County PUD No 1 1 58.12 0.86 58.97
Projected Benefits

Avista Utilities
Projected Kilowatt-hours
and Residential Exchange Amortization
State of Idaho
kwh(000's)
$(000's)
Oct-25 Nov-25 Dec-25 Jan-26 Feb-26 Mar-26 Apr-26 May-26 Jun-26 Jul-26 Aug-26 Sep-26 Total
Total
ID001 85,503 126,216 160,434 154,460 136,214 117,196 106,142 88,885 86,561 105,074 99,774 79,147 1,345,606
ID012 2,596 3,838 4,762 4,816 4,459 3,861 3,100 2,559 2,412 2,731 2,617 2,330 40,080
ID022 568 618 795 808 782 633 548 518 506 587 610 540 7,512
ID032 212 202 252 276 233 209 197 283 465 876 879 428 4,514
ID048 66 66 66 66 66 66 66 66 66 66 66 66 797
Total 88,945 130,941 166,309 160,426 141,755 121,965 110,054 92,312 90,009 109,335 103,946 82,511 1,398,510
Jul-25 Aug-25 Sep-25
Total
ID001 105,440 97,963 78,536
ID012 2,671 2,498 2,256
ID022 587 600 547
ID032 882 882 432
ID048 66 66 66
Total 109,646 102,010 81,838
Rate -$0.00366 -$0.00366 -$0.00366
Revenue -$401,305 -$373,356 -$299,528
CF 0.995661 0.995661 0.995661
Amort -$399,564 -$371,736 -$298,228
Note:The projected kilowatt-hours Included above contain both billed and unbilled customer loads.In past filings,prorations had been included for October and November to capture the unbilled
loads in the following month when they are billed to customers. Because both billed and unbilled are included above,no proration is needed.
Note that either method would inlcude one calandar year's worth of loads.
Projected kWhs

Avista Corp.
BPA Residential Exchange Load Calculation
2023 2024 Average
Per Verification E- Immaterial
ID WA Total ID WA Total Average mail sent to BPA Difference ID WA Total
January 173,670,430 344,136,616 517,807,046 172,706,387 325,664,428 498,370,815 508,088,930 508,088,930 (0) 173,188,408 334,900,522 508,088,930
February 139,907,355 259,991,928 399,899,283 151,469,852 297,159,077 448,628,929 424,264,106 424,264,106 0 145,688,603 278,575,502 424,264,106
March 152,903,566 305,479,922 458,383,488 130,483,508 252,471,886 382,955,393 420,669,441 420,669,441 0 141,693,537 278,975,904 420,669,441
April 111,857,306 213,603,965 325,461,271 110,963,183 215,997,057 326,960,239 326,210,755 326,210,755 (0) 111,410,244 214,800,511 326,210,755
May 97,852,906 196,230,690 294,083,596 93,252,810 178,689,435 271,942,245 283,012,920 283,012,920 0 95,552,858 187,460,063 283,012,920
June 91,921,733 184,926,082 276,847,815 89,320,660 169,738,376 259,059,036 267,953,426 267,953,426 0 90,621,196 177,332,229 267,953,426
July 109,606,827 215,133,291 324,740,118 109,111,648 214,200,296 323,311,945 324,026,031 324,026,031 (0) 109,359,238 214,666,794 324,026,031
August 115,889,177 238,478,928 354,368,105 - 354,368,105 354,368,105 (0) 115,889,177 238,478,928 354,368,105
September 96,299,055 199,192,478 295,491,533 - 295,491,533 295,491,533 - 96,299,055 199,192,478 295,491,533
October 82,626,849 165,486,514 248,113,362 - 248,113,362 248,113,363 (0) 82,626,849 165,486,514 248,113,362
November 113,719,840 216,613,670 330,333,510 - 330,333,510 330,333,510 0 113,719,840 216,613,670 330,333,510
December 143,392,307 272,452,361 415,844,668 - 415,844,668 415,844,668 (0) 143,392,307 272,452,361 415,844,668
1,429,647,351 2,811,726,444 4,241,373,794 857,308,047 1,653,920,555 2,511,228,602 4,198,376,787 4,198,376,788 (0) 1,419,441,313 2,778,935,475 4,198,376,787
33.81% 66.19% 100%
ID WA
1,419,441,313 2,778,935,475
CLEG ADJUSTMENTS
Load Calculation

AVISTA CORPORATION
JUNE 2025 IDAHO ELECTRIC
RESIDENTIAL& FARM ENERGY RATE ADJUSTMENT CREDIT
JUNE UNBILLED
Credit Rate
On/After On/After
Schedule kWh 1/Oct/22 1/Oct/22
(a) (b) (c)
a*b=c
1 35,554,121 (0.3660) (130,128.08)
12 933,669 (0.3660) (3,417.23)
22 201,576 (0.3660) (737.77)
32 134,646 (0.3660) (492.80)
48 0 (0.3660) -
Schedule Totals 36,824,012 (134,775.88)
Conversion factor 0.995661
Amortization (134,191.09)
June Unbilled

AVISTA UTILITIES
Settlement Revenue Conversion Factor
Idaho- Electric System
TWELVE MONTHS ENDED JUNE 30, 2024
Line
No. Description Factor
1 Revenues 1.000000
Expenses:
2 Uncollectibles 0.002212
3 Commission Fees 0.002127
4 Idaho Income Tax 0.000000
5 Total Expenses 0.004339
6 Net Operating Income Before FIT 0.995661
Case No.AVU-E-25-01: Per Final Stipulation &Settlement
Copy of 2025 Idaho BPA ResEx Workpapers.xlsx
Conversion Factor Page 9 of 9