20240731Application.pdf

1,
RECEIVED
Avista Corp. 2024 July 31 AM 11:14
1411 East Mission P.O. Box 3727 IDAHO PUBLIC
Spokane, Washington 99220-0500 UTILITIES COMMISSION
Telephone [phone]
Toll Free 800-727-9170
July 31, 2024
Commission Secretary
State of Idaho
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Building 8, Suite 201-A
Boise, Idaho 83714
Case No. AVU-G-24-02
I.P.U.C. No. 27—Natural Gas Service
The Company has attached for electronic filing with the Commission are the following revised tariff sheets:
Thirty-Fourth Revision Sheet 150 canceling Thirty-Third Revision Sheet 150
Twenty-Sixth Revision Sheet 155 canceling Twenty-Fifth Revision Sheet 155
The Company requests that the proposed tariff sheets be made effective November 1, 2024. These tariff sheets
reflect the Company's annual Purchased Gas Cost Adjustment ("PGA"). If approved, the Company's annual
revenue will decrease by approximately $32.3 million or approximately 27.9%. The proposed changes have no
effect on the Company's earnings.Detailed information related to the Company's request was filed electronically
along with the attached Application and supporting workpapers.
If the PGA filing is approved,residential natural gas customers in Idaho using an average of 64 therms per month
would see their monthly bills decrease from$78.03 to $57.62, a decrease of$20.41 per month, or approximately
26.2%. The proposed natural gas rate changes would be effective November 1, 2024.
If you have any questions regarding this filing,please contact Marcus Garbarino at(509)495-2567.
Sincerely,
/s/Patrick D. Ehrbar
Patrick D. Ehrbar
Director of Regulatory Affairs

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION OF )
AVISTA UTILITIES FOR AN ORDER APPROVING ) CASE: AVU-G-24-02
A CHANGE IN RATES FOR PURCHASED GAS )
COSTS AND AMORTIZATION OF GAS-RELATED )
DEFERRAL BALANCES )
Application is hereby made to the Idaho Public Utilities Commission for an Order approving a revised
schedule of rates and charges for natural gas service in the state of Idaho. The Applicant requests that
the proposed rates included in this Purchased Gas Cost Adjustment("PGA")filing be made effective on
November 1,2024. If approved as filed,the Company's annual revenue will decrease by approximately
$32.3 million or about 27.9%. In support of this Application, Applicant states as follows:
I.
The name of the Applicant is AVISTA CORPORATION, doing business as AVISTA UTILITIES
(hereinafter Avista,Applicant or Company), a Washington corporation,whose principal business office
is 1411 East Mission Avenue, Spokane,Washington,and is qualified to do business in the state of Idaho.
Applicant maintains district offices in Moscow, Lewiston, Coeur d'Alene, Sandpoint, and Kellogg,
Idaho. Communications in reference to this Application should be addressed to:
Patrick D. Ehrbar
Director of Regulatory Affairs
Avista Utilities
1411 E. Mission Avenue
Spokane, WA 99220-3727
Phone: [phone]
Pat.ehrbarnavistacorp.com
Dockets(&,avistacorp.com
II.
Attorney for the Applicant and his address is as follows:
David J. Meyer
Vice President and Chief Counsel for Regulatory
And Governmental Affairs
Avista Utilities
1411 E. Mission Avenue
Spokane, WA 99220-3727
Phone: [phone]
David.meyergavistacorp.com
Case No.AVU-G-24-02 Page 1 of 5

III.
The Applicant is a public utility engaged in the distribution of natural gas in certain portions of Northern
Idaho, Eastern and Central Washington, and Southwestern and Northeastern Oregon, and further
engaged in the generation, transmission, and distribution of electricity in Northern Idaho and Eastern
Washington.
IV.
Thirty-Fourth Revision Sheet 150,which Applicant requests the Commission approve, is filed herewith
as Exhibit "A". Additionally, Twenty-Sixth Revision Sheet 155, which Applicant requests the
Commission approve, is also filed herewith as Exhibit "A". Also included in Exhibit "A" is a copy of
Thirty-Fourth Revision Sheet 150 and Twenty-Sixth Revision Tariff Sheet 155 with the changes
underlined and a copy of Thirty-Third Revision Sheet 150 and Twenty-Fifth Revision Tariff Sheet 155
with the proposed changes shown by lining over the current language or rates.
V.
The existing rates and charges for natural gas service on file with the Commission and designated as
Applicant's Tariff IPUC No. 27, which will be superseded by the rates and charges filed herewith, are
incorporated herein as though fully attached hereto.
VI.
Notice to the Public of Applicant's proposed tariffs is to be given simultaneously with the filing of this
Application by posting, at each of the Company's district offices in Idaho, a Notice in the form attached
hereto as Exhibit "B" and by means of a press release distributed to various informational agencies, a
draft copy attached hereto in Exhibit"C". In addition, Exhibit"C"to this Application also contains the
form of customer notice that the Company will send to its customers in its monthly bills in the August
timeframe.
VII.
The circumstances and conditions relied on for approval of Applicant's revised rates are as follows:
Applicant purchases natural gas for customer usage and transports it over Williams Northwest Pipeline,
Gas Transmission Northwest (GTN), TC Energy - Alberta, TC Energy - BC and Enbridge Energy
Pipeline systems, and defers the effect of timing differences due to implementation of rate changes and
differences between Applicant's actual weighted average cost of gas ("WACOG") purchased and the
WACOG embedded in rates. Applicant also defers various pipeline refunds or charges and
miscellaneous revenue received from natural gas related transactions including pipeline capacity
releases. Workpapers for all proposed Commodity, Demand and Amortization costs are provided with
this filing as Exhibit"D".
VIII.
This filing reflects the Company's proposed annual PGA to: 1) pass through changes in the estimated
cost of natural gas for the period of November 2024 through October 2025 (Schedule 150),and 2)revise
Case No.AVU-G-24-02 Page 2 of 5

the amortization rate(s) to refund or collect the balance of deferred natural gas costs (Schedule 155).
Below is a table summarizing the proposed rate changes reflected in this filing:
Commodity Demand Total Amortization Total PGA
Sch. Change Change Sch. 150 Change Rate Change
Service No. per the per the Change per the per the
General 101 $ (0.04984) $ 0.00111 $ (0.04873) $ (0.27015) $ (0.31888)
Lg. General 111 $ (0.04984) $ 0.00111 $ (0.04873) $ (0.27015) $ (0.31888)
Lg General 112 $ (0.04984) $ 0.00111 $ (0.04873) $ - $ (0.04873)
Interruptible 131 $ (0.04984) $ - $ (0.04984) $ - $ (0.04984)
Transportation 146 $ - $ - $ - $ - $ -
IX.
Schedule 150/Purchase Gas Cost- Commodity Costs
As shown in the table above, the estimated WACOG change is a decrease of$0.04984 per therm; the
proposed WACOG of $0.23850 per therm compared to the present WACOG of $0.28834 per therm
included in rates. The decrease is a result of current forward prices being lower compared to when the
Company filed its PGA in the prior year.
The natural gas market in the western US experienced significant price volatility early in the most recent
winter (2023/2024) culminating in a 5-day period over the Martin Luther King Jr. (MLK) holiday
weekend, when regional prices topped $20/dth at several locations. The volatility was driven mainly by
temperatures with the higher priced periods coinciding with below average temperatures. Since MLK
weekend however, volatility has declined, and prices have trended lower through the late winter and
spring. Mild temperatures are the main cause of the falling prices as demand for heating has
underperformed expectations during this period. The weak demand has led to historically high storage
balances at all the regional storage facilities.
Nationally, prices for most of the past year have mirrored the regional market. Henry Hub prices and
volatility were elevated prior to the MLK weekend and then began to trend lower due to mild weather
and a growing storage balance. Since early May however, Henry Hub and the regional hubs have
diverged. Henry Hub spot prices have risen over$1 during this period while regional prices have mostly
stayed flat, or fallen, in the case of the AECO hub. The strength in Henry Hub is likely due to a
combination of reduced production and increased demand nationally. Demand for power generation has
ramped up recently due to above average temperatures in many parts of the country. Production
meanwhile has fallen since early February.
Avista has been hedging natural gas on both a periodic and discretionary basis throughout the previous
thirty-six months for the forthcoming PGA year. Approximately 40% of the annual load requirements
for this year's PGA period (November 2024 through October 2025) have been hedged at a fixed-price
derived from the Company's Plan. Through June, the hedge volumes for the PGA period have been
executed at a weighted average price of$3.20 per dekatherm ($0.32041 per therm).
Available underground storage capacity at the Jackson Prairie Natural Gas Storage Facility represents
approximately 22% of annual load requirements (30% of load requirements during the November to
March withdrawal period). The estimated WACOG for all storage volumes is $1.38 per dekatherm
Case No.AVU-G-24-02 Page 3 of 5

($0.1376 per therm). The Company utilizes its underground storage to capture seasonal price spreads
(differentials), improve the reliability of supply, increase operational flexibility and mitigate peak
demand price spikes.
The Company used a 30-day historical average of AECO forward prices (ending June 30, 2024) to
develop an estimated cost associated with index purchases. These index purchases represent
approximately 38% of estimated annual load requirements for the coming year. The annual weighted
average price for these volumes is $2.19 per dekatherm ($0.2186 per therm).
X.
Schedule 150/Purchase Gas Cost-Demand Costs
Demand costs reflect the cost of pipeline transportation to the Company's system, as well as fixed costs
associated with natural gas storage. As shown in the table above, demand costs are expected to increase
for residential customers by approximately $0.00111 per therm. This increase is related to a variety of
factors including Canadian exchange rate, updated demand forecast, and new pipeline rates in effect
during the upcoming PGA year.
XI.
Schedule 155/Amortization Rate Change
As shown in the table above, the proposed amortization rate change for Schedule 101 and Schedule I I I
is a decrease in revenue of$0.27015 per therm. The current rate applicable to Schedule 101 and Schedule
I I I is $0.25281 per therm in the surcharge direction; the proposed rate is $0.01734 per therm in the
rebate direction.
In this PGA filing, the Company has used the deferral and amortization balances as of June 30, 2024,
inclusive of the residual amortization balance from the prior PGA, and proposed amortizing the balance
over 12-months which is consistent with historical PGA filings. The company included forecasted
amortization of the prior year surcharge deferral balance from July 1, 2024 through October 31, 2024
being collected through Schedule 155, which reduced the balance to be collected in the upcoming PGA
year by approximately$3.6 million. The result is a rebate amortization rate to collect approximately$1.7
million from customers. On a per therm basis,the net impact of the expiring amortization surcharge and
the new amortization rebate is a change in the amortization rate of$0.27015 per therm.
XII.
If approved as filed, the Company's annual revenue will decrease by approximately $32.3 million or
27.9% effective November 1, 2024. Residential or small commercial customers using an average of 64
therms per month would see a decrease of$20.41 per month, or approximately 26.2%. The present bill
for 64 therms is $78.03 while the proposed bill is $57.62.
XIII.
Exhibit "D" attached hereto contains support workpapers for the Proposed Tariff Rates proposed by
Applicant contained in Exhibit "A".
Case No.AVU-G-24-02 Page 4 of 5

XIV.
Avista requests that the rates proposed in this filing be approved to become effective on November 1,
2024, and requests that the matter be processed under the Commission's Modified Procedure rules
through the use of written comments. Avista stands ready for immediate consideration on its
Application.
XV.
WHEREFORE, Avista requests the Commission issue its Order finding its proposed rates to be just,
reasonable, and nondiscriminatory and to become effective for all natural gas service on and after
November 1, 2024. The overall decrease is approximately $32.3 million or 27.9%. The Company
requests that the matter be processed under the Commission's Modified Procedure rules through the use
of written comments.
Dated at Spokane, Washington, this 31St day of July 2024.
AVISTA UTILITIES
BY
/s/ David J. Meyer
David J. Meyer
Vice President and Chief Counsel for
Regulatory& Governmental Affairs
Avista Corporation
Case No.AVU-G-24-02 Page 5 of 5