20191210Comments.pdf

DAYN HARDIE
DEPUTY ATTORNEY GENERAL
IDAHO PUBLIC UTILITIES COMMISSION
PO BOX 83720
BOISE, IDAHO 81720-0074
[phone]
IDAHO BARNO,9917
RECEIVED
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Street Address for Express Mail:
I 133I W CHINDEN BVLD, BLDG 8, SUITE 20I-A
BOISE, ID 837I4
Attomey for the Commission Staff
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF ROCKY MOUNTAIN
POWER'S APPLICATION TO REVISE
ELECTRIC SERVICE REGULATION NO. 6 -
COMPANY'S INSTALLATION
CASE NO. PAC.E-I9-I2
COMMENTS OF THE
COMMISSION STAFF'
STAFF OF the Idaho Public Utilities Commission, by and through its Attorney of
record, Dayn Hardie, Deputy Attorney General, submits the following comments.
BACKGROUND
On September 13,2019, Rocky Mountain Power ("Company") applied for authority to
revise paragraph I of Electric Service Regulation No. 6 - Company's Installation-to include a
new option for customers to receive single-phase 2401480 volt secondary service. The Company
asked the Commission to review its Application under Modified Procedure.
The Company estimates 40% of its distribution lines are single phase 120/240 volt
service. The lack ofthree-phase service can make it difficult for customers to operate equipment
with large electric motors -such as irrigation pumps, sewage-lift stations, and mine-ventilation
equipment -because that equipment typically runs on three-phase power.l
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STAFF COMMENTS DECEMBER IO,2019
I Singlc-phase clectric motorc over 7.5 horsepower have limited commercial availability.
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Where capacity is available on existing single-phase 1201240 volt lines, a three-phase
supply can be derived from a variable frequency drive or rotary-phase converter to provide
240/480 volt service. On average, 480 volt converters and motors are I 00% to 25% less
expensive to operate than 240 volt converters. In situations where adding three-phase service
may be cost prohibitive, the option to add single-phase 240/480 volt service will not significantly
affect the Company's construction standards, practices, and inventory requirements
The upgrades proposed in the Application may benefit several current and emerging
industries in the Company's service territory including inigation, highway lighting, and electric
vehicle rapid-charging stations.
STAFF ANALYSIS
StalTreviewed and supports the Company's request to add single-phase ,240/480 volt,
3-wire, grounded secondary service to Electric Service Regulation No. 6. Electric Service
Regulation No. 6 defines the standard types of distribution level voltages, phases, and grounded
circuit configurations available to serve customers. The Company's request would add the new
single-phase, 2401480 volt, 3-wire grounded service to the existing distribution level services
available. The new, higher voltage, service is similar to the existing 120/240 volt single-phase
service already in place.
Customers will benefit from the new single-phase,240/480 volt, 3-wire grounded service.
The higher service level voltage will allow customers to directly benefit tiom reduced equipment
operation costs beyond the point ofdelivery for connecting a larger load compared to the
existing single-phase 1201240 volt service that is available. The higher voltage service would
also reduce customer line loss between the point of delivery and load. Likewise, in certain
circumstances where customers might need three-phase power for a new load, the higher service
level voltage could preclude the need for the Company to construct a new three-phase primary
distribution line which can range in cost from $60,000 to $150,000 per mile.
The cost ofproviding service at the new single-phase 2401480 volt level is estimated at
$3,284 which is $ 161 more than the existing single-phase 1201240 volt service. The Company
indicates that customers requesting the 240/480 volt service will not see a change under the
Company's line extension policy given the small diffcrence in cost between the service level
voltages. The company estimates that as f'ew as ten customers per year may request the new
2STAI;I] COMMENTS DECEMBER IO,2019
single-phase, 2401480 volt service. Consequently, there are no expected rate impacts for existing
customers.
STAFF RECOMMENDATION
StafT recommends the Commission approve the Company's request to revise the Electric
Service Regulation No. 6 to include a new option for customers to receive single-phase, 240/480
volt. 3-wire. grounded secondary service.
' ^]t-Respectfully submitted this \ L' ' duy of December 2019.
Dayn Hardie
Deputy Attomey General
Technical Stali Rick Keller
l'ravis Culbertson
Bentley Erdwurm
i: um isc/comments/pace I 9. I 2dhtncrkbe commenLs
JSTAFF COMMENTS DECEMBER IO,2OI9
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CERTIFICATE OF SERVICE
I HEREBY CERTIFY THAT I HAVE THIS IOfi DAY OF DECEMBER 2019,
SERVED THE FOREGOING COMMENTS OF'THE COMMISSION STAFF, IN CASE
NO. PAC-E.19-I2, BY MAILING A COPY THEREOF, POSTAGE PREPAID, TO THE
FOLLOWING:
TED WESTON
ROCKY MOUNTAIN POWER
1407 WN TEMPLE STE 330
SALT LAKE CITY UT 84I I6
E-MAIL: ted.weston(iDpacilicorp.qont
DATA REQUEST RESPONSE CENTER
E.MAIL ONLY:
datarcqucst@pacifi corD.com
snil.,
SECRETARY
CERTIFICA'II] OF SERVICb
DANIEL E SOLANDER
SENIOR COT]NSEL
ROCKY MOTINTAIN POWER
1407 WN TEMPLE STE 320
SALT LAKE CITY UT 84I16
E-MAIL: daniel.solander@pacifi corp.com