20180216Vail Exhibit 51.pdf

Case No.PAC-E-17-07
Exhibit No.5 l
Witness:Rick A.Vail
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
O ROCKY MOUNTAIN POWER
Exhibit Accompanying Second Supplemental Testimony of Rick A.Vail
Q0712 SIS Report
February 2018
O
Rocky Mountain Power
PACIFICORP
ExhiCb o 51 e1o7f423
Large Generator Interconnection
System Impact Restudy Report
Completed for
Orion Wind Resources,LLC
("InterconnectionCustomer")
Q0712
Cedar Springs 1
Proposed Point of Interconnection
Windstar substation at 230 kV
February8,2018
O
Rocky Mountain Power
V PACIFI CORP
ExhiCbitNo51 e2o 3
O System Impact Study Report
TABLE OF CONTENTS
l.0 DESCRIPTION OF THE GENERATING FACILITY .....................................................2
2.0 SCOPE OF THE STUDY ..........................................................2
3.0 TYPE OF INTERCONNECTION SERVICE ....................................................3
4.0 DESCRIPTION OF PROPOSED INTERCONNECTION.....................................................3
4.1 Other Options Considered.......................................................4
5.0 STUDY ASSUMPTIONS........................................................................................4
6.0 ENERGY RESOURCE (ER)INTERCONNECTION SERVICE....................................................5
6.1 Requirements .........................................................6
6.1.1 Generating Facility Modifications 6
6.1.2 Transmission System Modifications 8
6.1.3 Transmission/Distribution Line Modifications 8
6.1.4 Existing Circuit Breaker Upgrades -Short Circuit 9
6.1.5 Protection Requirements 9
6.1.6 Data (RTU)Requirements 9
6.1.7 Substation Requirements 12
6.1.8 Communication Requirements 13
6.1.9 Metering Requirements 13
7.0 COST ESTIMATE (ER)......................................................14
8.0 SCHEDULE............................................................................................................................16
8.1.1 Maximum Amount of Power that can be delivered into Network Load,with No Transmission
Modifications (for informational purposes only)16
8.1.2 Additional Transmission Modifications Required to Deliver 100%of the Power into Network
Load (for informational purposes only)16
9.0 PARTICIPATION BY AFFECTED SYSTEMS......................................................16
O 10.0 APPENDICES ...............................................................16
10.1 Appendix 1:Higher Priority Requests .......................................................17
10.2 Appendix 2:Property Requirements........................................................18
10.3 Appendix 3:Study Results....................................................20
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Orion Wind Resources,LLC Page i February 8,2018
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PAciFI CORP
ExhiCbitNo51 e3o93
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1.0 DESCRIPTIONOF THE GENERATINGFACILITY
Orion Wind Resources,LLC ("InterconnectionCustomer")proposed interconnecting 520 MW of
new generation to PacifiCorp's ("Transmission Provider")Windstar substation at 230 kV located
in Converse County,Wyoming.The Cedar Springs 1 project ("Project")will consist of two
hundred eight (208)GE 127 2.5 MW wind turbines for a total output of 520 MW.The requested
commercial operation date is December 31,2020.
The restudy of this Project is performed due to the staging of the Energy Gateway West project.
Specifically,while the entire Gateway West project has a longer development timeline,the Aeolus-
Bridger/Anticline D.2 segment of the project (500 kV segment from the planned Aeolus substation
to the planned Anticline substation)now has an expected 2020 in-service date.The earlier
availability of the D.2 segment materially changescertain modeling assumptions that could impact
the cost or timing of the interconnection of certain projects whose previous studies depended on
Gateway West in its entirety.
Interconnection Customer will NOT operate this generator as a Qualified Facility as defined by
the Public Utility Regulatory Policies Act of 1978 (PURPA).
Transmission Provider has assigned the Project "Q0712."
2.0 SCOPE OF THE STUDY
O The interconnection system impact study shall evaluate the impact of the proposed interconnection
on the reliability of the transmission system.The interconnection system impact study will
consider Base Case as well as all generating facilities (and with respect to (iii)below,any identified
network upgrades associated with such higher queued interconnections)that,on the date the
interconnection system impact study is commenced:
(i)are directly interconnected to the transmission system;
(ii)are interconnected to Affected Systems and may have an impact on the interconnection
request;
(iii)have a pending higher queued interconnection request to interconnect to the transmission
system;and
(iv)have no Queue Position but have executed an LGIA or requested that an unexecuted
LGIA be filed with FERC.
This interconnection system impact restudy will consist of a short circuit analysis,a stability
analysis,and a power flow analysis.The study will state the assumptions upon which it is based;
state the results of the analyses;and provide the requirements or potential impediments to
providing the requested interconnection service,including preliminary indication of the cost and
length of time that would be necessary to correct any problems identified in those analyses and
implement the interconnection.The study will also provide a list of facilities that are required as a
result of the Interconnection Request and a non-binding good faith estimate of the cost
responsibility and a non-bindinggood faith estimated time to construct.
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Based on the engineering judgement,the stability results for this project are not expected to change
and hence the restudy of stability analysis was not performed.
3.0 TYPE OF INTERCONNECTIONSERVICE
Interconnection Customer has elected to have the interconnection studied as an Energy Resource
(ER).
4.0 DESCRIPTIONOF PROPOSED INTERCONNECTION
Interconnection Customer's proposed Generating Facility is to be interconnected through two new
bay positions on the southeast corner of the existing Windstar substation.Figure 1 below,is a one-
line diagram that illustrates the interconnection of the proposed Generating Facility to
Transmission Provider's system.
Interconnection Customer will be responsible for the installation of two (2)new 230 kV circuit
breakers and associated switches at the Windstar 230 kV substation to interconnect the Generating
Facility.Based on the data provided by Interconnection Customer,the Project consists of two
different phases,Phase A and Phase B.The Project's Phase A will interconnect to Windstar
substation through one of the 20-mile 230 kV double circuit line.Phase B of the Project will
connect to Windstar substation through the second 230 kV line on the double circuit tie-line.Phase
B of the Project is four additional miles farther than Phase A,making that 230 kV line 24 miles
long.Each 230 kV circuit will be constructed using 954 kemil ACSR (aluminum conductor steel
reinforced)conductor.
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'
Windstar Substation
Points of
230 kV interconnection
Q0712 A Collector---Change of Ownership Substation atskv
4 MiksQ0712
B Collector
Substation
Figure 1:SimplifiedSystem One Line Diagram
4.1 Other Options Considered
The following alternative options were considered as potential Points of Interconnection for
this Project:None per Interconnection Customer.
5.0 STUDYASSUMPTIONS
All active higher priority transmission service and/or generator interconnection requests with
an in-service date of December 2020 or earlier will be considered in this study and are listed
in Appendix 1.If any of these requests are materially modified or withdrawn,Transmission
Provider reserves the right to restudy this request,and the results and conclusions could
significantly change.O Orion Wind Resources,LLC Page 4 February 8,2018
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Transmission Provider reserves the right to restudy this Project should Interconnection
Customer request a change in status to a Qualifying Facility,there is a change in system
topology,or assumed facility improvements are not in-service.
For study purposes there are two separatequeues:
o Transmission Service Queue:to the extent practical,all network upgrades that are required
to accommodate active transmission service requests will be modeled in this study.
o Generation Interconnection Queue:Interconnection Facilities associated with higher
queued interconnection requests with an in-service date of December 2020 or earlier will
be modeled in this study.
Interconnection Customer's request for energy or network resource interconnection service
in and of itself does not convey transmission service.Onlya Network Customer may make
a request to designate a generating resource as a Network Resource.The provision of
transmission service may require additional studies and the construction of additional
upgrades.
Under normal conditions,Transmission Provider does not dispatch or otherwise directly
control or regulate the output of generating facilities.Therefore,the need for transmission
modifications,if any,which are required to provide Network Resource Interconnection Service
will be evaluated on the basis of 100 percent deliverability (i.e.,no displacement of other
resources in the same area).
This study assumes the Project will be integrated into Transmission Provider's system at the
Windstar substation (Point of Interconnection,or "POI").
Interconnection Customer will construct and own any facilities required between the Point of
Change of Ownership and the Project unless specifically identified by Transmission Provider.
Generator tripping will be required for certain outages.
All facilities will meet or exceed the minimum Western Electricity Coordinating Council
("WECC"),North American Electric Reliability Corporation ("NERC"),and Transmission
Provider's performance and design standards (Policy 139).
The Energy Gateway West,Aeolus-Bridger/Anticline D.2 500 kV line from the proposed
Aeolus substation to the proposed Anticline substation and ancillary projects are assumed in
service in 2020
o All existing and proposed Remedial Action Schemes ("RAS")associated with prior
queue generation facilities are assumedto be in service for this study.
A RAS that will arm approximately 640 MW of generation for the Energy Gateway D.2
outages was assumed to be in-service.
It is assumed that a new 230 kV line from Shirley Basin -Aeolus constructed with 2-1557
Potomac ACSR/TW as identified as mitigation for the Q0707 Project is in-service.
This report is based on information available at the time of the study.It is Interconnection
Customer's responsibility to check Transmission Provider's web site regularly for
Transmission System updates at http://www.pacificorp.com/tran.html
6.0 ENERGY RESOURCE (ER)INTERCONNECTIONSERVICE
Energy Resource Interconnection Service allows Interconnection Customer to connect its
Generating Facility to Transmission Provider's Transmission System and to be eligible to deliver
electric output using firm or non-firm transmission capacity on an as available basis.Energy
resource interconnection service in and of itself does not convey transmission service.O Orion Wind Resources,LLC Page 5 February 8,2018
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Y PACIFI CORP
Exhibi o 51 P e7o7f23
O System Impact Study Report
6.1 Requirements
6.1.1 Generating Facility Modifications
All interconnecting synchronous and non-synchronous generators are required to design
their generating facilities with reactive power capabilities necessary to operate within the
full power factor range of 0.95 leading to 0.95 lagging.This power factor range shall be
dynamic and can be met using a combination of the inherent dynamic reactive power
capability of the generator or inverter,dynamic reactive power devices and static reactive
power devices to make up for losses.For synchronous generators,the power factor
requirement is to be measured at the POI.For asynchronous generators,the power factor
requirement is to be measured at the high-side of the generator substation.
The Generating Facility must provide dynamic reactive power to the system in support of
both voltage scheduling and contingency events that require transient voltage support,and
must be able to provide reactive capability over the full range of real power output.If the
Generating Facility is not capable of providing positive reactive support (i.e.,supplying
reactive power to the system)immediately following the removal of a fault or other
transient low voltage perturbations,the Generating Facility must be required to add
dynamic voltage support equipment.These additional dynamic reactive devices shall have
correct protection settings such that the devices will remain on line and active during and
immediatelyfollowinga fault event.Generators shall be equipped with automatic voltage-
control equipment and normally operated with the voltage regulationcontrol mode enabled
unless written authorization from the Grid Operator is given to operate in other control
mode (e.g.constant power factor control).The control mode of the generating units shall
be accurately represented in operating studies.The generators shall be capable of operating
continuously at their maximum power output at its rated field current within +/-5%of its
rated terminal voltage.
As required by NERC standard VAR-001-la,Transmission Provider will provide a voltage
schedule for the POI.In general,Generating Facilities should be operated so as to maintain
the voltage at the POI,or other designated point as deemed appropriated by Transmission
Provider,between 1.00 per unit to 1.04 per unit.Transmission Provider may also specify a
voltage and/or reactive power bandwidth as needed to coordinate with upstream voltage
control devices such as on-load tap changers.At Transmission Provider's discretion,these
values might be adjusted depending on operating conditions.Generating Facilities capable
of operating with a voltage droop are required to do so.Voltage droop control enables
proportionatereactive power sharing among generating facilities.Studies will be required
to coordinate voltage droop settings if there are other facilities in the area.It will be
Interconnection Customer's responsibility to ensure that a voltage coordination study is
performed,in coordinationwith Transmission Provider,and implemented with appropriate
coordinationsettings prior to unit testing.
For areas with multiple generating facilities additional studies may be required to
determine whether or not critical interactions,including but not limited to control systems,
exist.These studies,to be coordinated with Transmission Provider,will be the
responsibility of Interconnection Customer.If the need for a master controller is identified,
the cost and all related installation requirements will be the responsibility of
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Interconnection Customer.Participation by the Generating Facility in subsequent
interaction/coordinationstudies will be required pre-and post-commercial operation in
order ensure system reliability.
To facilitate collection and validation of accurate modeling data to meet NERC modeling
standards,PacifiCorp,as the Planning Coordinator,requires Phasor Measurement Units
(PMUs)at all new Generating Facilities with an individual or aggregate nameplate capacity
of 75 MVA or greater.In addition to owning and maintaining the PMU,the Generating
Facility will be responsible for collecting,storing and retrieving data as requested by the
Planning Coordinator.Data must be collected and be able to stream to Planning
Coordinatorfor each of the Generator Facility's step-up transformers measured on the low
side of the GSU at a sample rate of at least 30 samples per second and synchronized within
+/-2 milliseconds of the Coordinated UniversalTime (UTC).Initially,the followingdata
must be collected:
Three phase voltage and voltage angle (analog)
Three phase current (analog)
Data requirements are subject to change as deemed necessary to comply with local and
federal regulations.
All generators must meet the Federal Energy Regulatory Committee ("FERC")and WECC
low voltage ride-through requirements as specified in the interconnection agreement.As
Transmission Provider cannot submit a user written model to WECC for inclusion in base
O cases,a standard model from the WECC Approved Dynamic Model Library is required
180 days prior to trial operation.The list of approved generator models is continually
updated and is available on the http://www.WECC.biz website.
Based on the data provided by Interconnection Customer,the wind turbines do not
have the capability to deliver 100%of the power to the POI within the range of +/-
0.95 power factor.The data provided indicates that the wind turbines have the power
factor capability of 0.98 capacitive and 0.96 inductive at rated power.The study showed
that the collector system injects approximately31.8 MVAr (see Figure 2 in Appendix 3)
when it is connected to the transmission system without the wind turbines being online.
Interconnection Customer will be required to ensure that there is minimum reactive
interchange under these conditions and that the collector system of the Project is not
contributing excessive MVArs into the system increasing voltage under light load
conditions.Failure of the Project to minimize the reactive interchange under these
conditions may result in the opening of the POI breakers for the Project by Transmission
Provider.
At low or zero output levels,the Project must not have reactive power interchange outside
of the +/-0.95 power factor requirement at the POI.Transmission Providerhas experienced
high voltages in this area of its system when the transmission system is lightly loaded with
low wind conditions.With low wind conditions the wind farms tend to supply reactive
power into the transmission system increasing the voltage.
O Orion Wind Resources,LLC Page 7 February 8,2018
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The Interconnection Customer is responsible for the protection of the transmission line
between the Generating Facility and the POI substation.In order to provide this protection
the Interconnection Customer shall construct and own a tie-line substation to be located at
the change of ownership (separate fenced facility adjacent to the Transmission Provider's
POI substation)and include an Interconnection Customer owned protective device and
associated transmission line relaying/communications.The ground grids of the
Transmission Provider's POI substation and the Interconnection Customer's tie-line
substation will be connected to support the use of a bus differential protection scheme
which will protect the overhead bus connection between the two facilities.
6.1.2 Transmission System Modifications
The followingtransmission system modifications are required:
Rebuild the Standpipe-Freezeout-Aeolus 230 kV line with bundled 2-1272 ACSR
conductor,approximately 15 miles.
Two (2)230 kV 3000 ampere breakers and line positions with associated switches
at Windstar substation.
Rebuild the existing Aeolus-Shirley Basin #1 line with 2-1557 ACSR,
approximately 16 miles.
6.1.3 Transmission/Distribution Line Modifications
Rebuild the existing 230 kV transmission line from Aeolis to Shirley Basin using double
bundled 1557 ACSR conductor.The line will be approximately 16.23 miles long.Of this
mileage,1.88 miles (Loop-in to Shirley Basin)is existing double bundled 1272 ACSR
Conductor which will be re-conducted with 1557.4 ACSS/TW Conductor.
Rebuild the approximately 15 miles of 230 kV transmission line between Standpipe,
Freezeout and proposed Aeolus substation with bundled 2-1272 ACSR conductor.
The Interconnection Customer shall construct the tie line from the collector substations to
the tie-line substations.
The Interconnection Customer is required to build tie-line substations adjacent to the
Windstar substation which will house the tie-line breakers.The Transmission Provider
shall review the design of the tie-line spans between the tie-line substation deadend towers
and the Windstar substation deadend towers.The Interconnection Customer shall coil
conductor,OPGW,shield wire,and line hardware with sufficient quantities to span
between the tie-line substation towers and the Windstar substation towers.
The Transmission Provider will construct the span between the tie-line substation towers
and the Windstar substation towers.
If any Transmission Provider lines are crossed by Interconnection Customer tie-line,the
Interconnection Customer line will cross under Transmission Provider's line with at least
NESC plus 3 foot clearance under all sag conditions of both lines.
O Orion Wind Resources,LLC Page 8 February 8,2018
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6.1.4 Existing Circuit Breaker Upgrades-Short Circuit
The increase in the fault duty on the system as a result of the addition of the Generating
Facility with 208 GE 127 2.5 MW wind turbine generators fed through 208 -2600 kVA
34.5 kV -690 V transformers with 9.0%impedance then fed through four 230 -34.5kV
90/120/150 MVA step up transformers with 8.0%impedance will not push the fault duty
above the interrupting rating of any of the existing fault interruptingequipment.
6.1.5 Protection Requirements
The ground mats of the tie-line substations and Windstar substation must be tied together
so that metallic control cables can be used between the two facilities.Bus differential relays
will be applied to detect faults on these connections.With this arrangement the
Interconnection Customer must install line relays systems that will detect and clear all
faults on the tie lines in 5 cycles or less.Sets of non-pilot step distance line relays that will
detect faults on the tie lines will also be applied at Windstar substation.Should the
Interconnection Customer desire a potential alternative to the tie-line substations in order
to provide adequate protection to its tie lines,the Interconnection Customer may petition
the Transmission Provider for an exemption to this arrangement.The Transmission
Provider must review and approve the Interconnection Customer's proposed
alternative.Without approval of the proposed alternative the tie-line substation
configuration will be required.The Interconnection Customer will need to supply and
maintain sets of line relays to be installed at Q0712 collector substations that will detect
faults on the 230 kV line back to Windstar substation.These line relays can be time
coordinated with the relays detecting faults on the transmission network and will not
communicate with the line relays to be installed at Windstar substation for the tie line.
Protective relay elements in the line relays at Windstar substation will monitor voltage and
frequency.If the voltage,magnitude,or frequency is outside of the normal operation range,
this relay will trip the 230 kV breakers at the tie line substations.
New line relay settings will need to be developed for the Standpipe -Freezeout 230 kV
line to adjust for the new phase conductor.
6.1.6 Data (RTU)Requirements
Data for the operation of the power system will be needed from the Generating Facility.
This data can be acquired by installing an Interconnection Customer owned data
concentrator at the collector substations.The data will be transferred to the RTU in
Windstar substation via Interconnection Customer owned fiber on the tie from the collector
substations.
In addition to the control and indicationof the new 230 kV breaker in Windstar substation,
the followingdata will be acquired through the substation RTU.Also listed is the data that
will be acquired from the collector substations and tie line substations.
From Windstar substation:
Analows:O Orion Wind Resources,LLC Page 9 February 8,2018
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ExhibLNo51 Pag 11
O System Impact Study Report
Q0712 A Net Generation MW
Q0712 A Net Generator MVAr
Q0712 A Energy Register
Q0712 B Net Generation MW
Q0712 B Net Generator MVAr
Q0712 B Energy Register
From the Q0712 A collector substation:
Analogs:
Transformer l Real power
Transformer l Reactive power
Transformer 2 Real power
Transformer 2 Reactive power
34.5 kV Real power 52 AAl &AA2 &AB1
34.5 kV Reactive power 52 AAl &AA2 &ABl
34.5 kV Real power 52 AE
34.5 kV Reactive power 52 AE
34.5 kV Real power 52 AF
34.5 kV Reactive power 52 AF
34.5 kV Real power 52 AG
34.5 kV Reactive power 52 AG
34.5 kV Real power 52 AI
O 34.5 kV Reactive power 52 AI
34.5 kV Real power 52 AJ
34.5 kV Reactive power 52 AJ
34.5 kV Real power 52 AK
34.5 kV Reactive power 52 AK
34.5 kV Real power 52 AL
34.5 kV Reactive power 52 AL
34.5 kV Real power 52 AM
34.5 kV Reactive power 52 AM
34.5 kV Real power 52 AN2 &AB2
34.5 kV Reactive power 52 AN2 &AB2
34.5 kV Reactive power 52 CAP 1
34.5 kV Reactive power 52 CAP 2
A phase 230 kV transmission voltage
B phase 230 kV transmission voltage
C phase 230 kV transmission voltage
Average Wind speed
Average Plant Atmospheric Pressure (Bar)
Average Plant Temperature (Celsius)
Status:
230 kV Transformer Breaker 1
230 kV Transformer Breaker 2
34.5 kV breaker 52 AAl &AA2 &ABl
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34.5 kV breaker 52 AE
34.5 kV breaker 52 AF
34.5 kV breaker 52 AG
34.5 kV breaker 52 AI
34.5 kV breaker 52 AJ
34.5 kV breaker 52 AK
34.5 kV breaker 52 AL
34.5 kV breaker 52 AM
34.5 kV breaker 52 AN2 &AB2
34.5 kV breaker 52 CAP 1
34.5 kV breaker 52 CAP 2
34.5 kV breaker Bus Tie
From the Q0712 B collector substation:
Analogs:
Transformer 1 Real power
Transformer 1 Reactive power
Transformer 2 Real power
Transformer 2 Reactive power
34.5 kV Real power 52 AAl &AA2 &ABl
34.5 kV Reactive power 52 AAl &AA2 &AB1
34.5 kV Real power 52 AE
O 34.5 kV Reactive power 52 AE
34.5 kV Real power 52 AF
34.5 kV Reactive power 52 AF
34.5 kV Real power 52 AG
34.5 kV Reactive power 52 AG
34.5 kV Real power 52 AI
34.5 kV Reactive power 52 AI
34.5 kV Real power 52 AJ
34.5 kV Reactive power 52 AJ
34.5 kV Real power 52 AK
34.5 kV Reactive power 52 AK
34.5 kV Real power 52 AL
34.5 kV Reactive power 52 AL
34.5 kV Real power 52 AM
34.5 kV Reactive power 52 AM
34.5 kV Real power 52 AN2 &AB2
34.5 kV Reactive power 52 AN2 &AB2
34.5 kV Reactive power 52 CAP l
34.5 kV Reactive power 52 CAP 2
A phase 230 kV transmission voltage
B phase 230 kV transmission voltage
C phase 230 kV transmission voltage
Average Wind speed
Average Plant Atmospheric Pressure (Bar)
Orion Wind Resources,LLC Page 11 February 8,2018
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AveragePlant Temperature (Celsius)
Status:
230 kV Transformer Breaker 1
230 kV Transformer Breaker 2
34.5 kV breaker 52 AAl &AA2 &AB1
34.5 kV breaker 52 AE
34.5 kV breaker 52 AF
34.5 kV breaker 52 AG
34.5 kV breaker 52 AI
34.5 kV breaker 52 AJ
34.5 kV breaker 52 AK
34.5 kV breaker 52 AL
34.5 kV breaker 52 AM
34.5 kV breaker 52 AN2 &AB2
34.5 kV breaker 52 CAP l
34.5 kV breaker 52 CAP 2
34.5 kV breaker Bus Tie
Tie Line Substations
Status:
230 kV Breaker 1
230 kV Breaker 2
6.1.7 Substation Requirements
90712 Collector Station A
Interconnection Customer will provide a separategraded,grounded and fenced area along
the perimeter of Interconnection Customer's Generating Facility for Transmission Provider
to install a control house for any required metering,protection or communication
equipment.This area will share a fence and ground grid with the Generating Facility and
have separate,unencumbered access for Transmission Provider.DC power for the control
house will be supplied by Transmission Provider.AC station service power for the control
house will be provided by Interconnection Customer.A CDEGS grounding analysis is
required by Interconnection Customer.Six 230 kV CT/VT combined metering units and
four 230 kV group operated switches will be installed.
90712 Collector Station B
Interconnection Customer will provide a separategraded,grounded and fenced area along
the perimeter of Interconnection Customer's Generating Facility for Transmission Provider
to install a control house for any required metering,protection or communication
equipment.This area will share a fence and ground grid with the Generating Facility and
have separate,unencumbered access for Transmission Provider.DC power for the control
house will be supplied by Transmission Provider.AC station service power for the control
house will be provided by Interconnection Customer.A CDEGS grounding analysis is
required by Interconnection Customer.Six 230 kV CT/VT combined metering units and
four 230 kV group operated switches will be installed.
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Windstar substation
The substation yard and fence will need to be expanded to allow for an additional 230 kV
bay to be constructed.New ground grid and conduit will be installed.The ground grid at
Windstar will be connected to the ground grids at the Interconnection Customer owned tie
line substations.A CDEGS grounding analysis will be required.New relay panels will be
installed in the control house.The followingstation equipment will be installed:
(2)-230 kV circuit breaker
(6)-230 kV combined CT/VT metering unit
(2)-230 kV group operated switch,breaker disconnect
(2)-230 kV group operated switch,line disconnect,with motor operator,with
ground blade
(2)-230 kV group operated switch,meter disconnect
(6)-144 kV MCOV surge arrester
6.1.8 Communication Requirements
6.1.8.1 Interconnection of 90712 (A-B)substations
Interconnection Customer is to install OPGW fiber on the new 20 mile line from the
tie line substation near Windstar to the Q0712A and Q0715B collector substations.
ADSS fiber is to be installed from the tie line substation into Windstar substation's
O building.Interconnection Customer is to supply 2 SCADA circuits with the required
points using DNP3 protocol over the fiber to the Windstar substation control building
where it will be routed over the Transmission Provider's existing network to the control
centers.
6.1.9 Metering Requirements
6.1.9.1 Interchange Metering
The POI will be at Transmission Provider's Windstar substation:Revenue metering
will be located at Windstar substation on each of the two transmission lines between
Windstar and the Q0712 tie line substations.Metering will be designed bidirectional
and rated for the total net generation of the Project.The bidirectional metering will also
include the retail load (per tariff)delivered to Interconnection Customer.Transmission
Provider will specify and order all interconnection revenue metering,including the
instrument transformers,metering panels,junction box and secondary metering wire.
The primary metering transformers shall be combination 2000:5 CT/VT extended
range for high accuracy metering.
The metering design package will include two revenue quality meters,test switch,with
DNP real time digital data terminated at a metering interpositionblock.One meter will
be designated a primary SCADA meter and a second meter will be used designated as
backup with metering DNP data delivered to the alternate control center.The metering
data will include bidirectional KWH KVARH,revenue quantities including
instantaneous PF,MW,MVAR,MVA,including per phase voltage and amps data.
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An Ethernet connection is required for retail sales and generation accounting via
the MV-90 translation system.
6.l.9.2 90712 Substation A metering:
Revenue metering is required for each of the two customer power transformers and will
be located on the high side of each of the step-up transformers.The primary metering
transformers shall be combination 230kV,1000:5 CT/VT extended range for high
accuracy metering.
Transmission Provider will design and procure the collector revenue metering panels.
The panels shall be located inside the collector control house.The collector substation
metering panel shall include two revenue quality meters,test switches,and all SCADA
metering data terminated at a metering interpositionblock.
A second,independent communication path from that used for the Q0712 substation A
is required for retail sales and generation accounting via the MV-90 translation system.
6.l.9.3 90712 Substation B metering:
Revenue metering is required for each of the two customer power transformers and will
be located on the high side of each of the step-up transformers.The primary metering
transformers shall be combination 230kV,1000:5 current ratio,CT/VT extended range
for high accuracy metering.
Transmission Provider will design and procure the collector revenue metering panels.
The panels shall be located inside the collector control house.The collector substation
metering panel shall include two revenue quality meters,test switches,and all SCADA
metering data terminated at a metering interpositionblock.
An Ethernet phone line is required for retail sales and generation accounting via the
MV-90 translation system.
6.l.9.4 Station Service/Construction Power
The Project is within the Transmission Provider's service territory.Please note that
prior to back feed,Interconnection Customer must arrange transmission retail meter
service for electricity consumed by the Project and arrange back-up station service for
power that will be drawn from the transmission or distribution line when the Project is
not generating.Interconnection Customer must call the PCCC Solution Center 1-800-
625-6078 to arrange this service.Approval for back feed is contingent upon obtaining
station service.
7.0 CosT ESTIMATE (ER)
The following estimate represents only scopes of work that will be performed by Transmission
Provider.Costs for any work being performed by Interconnection Customer are not included.O Orion Wind Resources,LLC Page 14 February 8,2018
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ExhibLNo.51PaA E6of23
O System Impact Study Report
Direct Assigned
Q0712 Collector substation A $1,012,000
Add metering and control house
Q0712 Collector substation B $1,085,000
Add metering and control house
Windstar substation $840,000
Project Line Termination &Metering
Tie line substations $124,000
Add communications
Total Direct Assigned $3,061,000
Network Upgrades
Windstar substation $4,193,000
Expand yard,add line positions and breakers
Shirley Basin substation $250,000
Update protection &control and communications
Aeolus substation $250,000
Update protection &control and communications
Aeolus Shirley Basin #1 Transmission Line $19,501,000
Reconductor 16 miles of230 kV line
Standpipe-Freezeout-Aeolus Transmission Line $19,788,000
Rebuild 16 miles of230 kV line
Freezeout Substation $4,758,000
Rebuildsubstation
Total Network Upgrade $48,740,000
Grand Total $51,801,000
*Any distribution line modifications identified in this report will require a field visit analysis in
order to obtain a more thorough understanding of the specific requirements.The estimate provided
above for this work could change substantially based on the results of this analysis.Until this field
analysis is performed Transmission Provider must develop the Project schedule using conservative
assumptions.Interconnection Customer may request that Transmission Provider perform this field
analysis,at Interconnection Customer's expense,prior to the execution of an Interconnection
Agreement in order to obtain more cost and schedule certainty.
Note:Costs for any excavation,duct installation and easements shall be borne by Interconnection
Customer and are not included in this estimate.This estimate is as accurate as possibly given the
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ExhibLNo51 Pag 17of23
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level of detailed study that has been completed to date and approximates the costs incurred by
Transmission Provider to interconnect this Generating Facility to Transmission Provider's
electrical distribution or transmission system.A more detailed estimate will be calculated during
the Facilities Study.Interconnection Customer will be responsible for all actual costs,regardless
of the estimated costs communicated to or approved by Interconnection Customer.
8.0 SCHEDULE
Transmission Provider estimates it will require approximately 24-36 months to design,procure
and construct the facilities described in the Energy Resource sections of this report followingthe
execution of an Interconnection Agreement.The schedule will be further developed and optimized
during the Facilities Study.
Please note,the time required to perform the scope of work identified in this report as well as the
contingent requirements for higher queued projects results in a timeframe that may support
Interconnection Customer's requested Commercial Operation date of December 31,2020.
8.1.1 Maximum Amount of Power that can be delivered into Network Load,with
No Transmission Modifications (for informational purposes only)
Zero (0)MW can be delivered on a firm basis to the Transmission Provider's network loads
with additional transmission modifications.
8.1.2 Additional Transmission Modifications Required to Deliver 100%of the
Power into Network Load (for informational purposes only)
In order to deliver 100%of the power into Network Load,in addition to the mitigation
identified in section 6.1.2,the completion of additional Transmission Provider Energy
Gateway projects and other system improvements would also be required.
9.0 PARTICIPATION BY AFFECTEDSYSTEMS
Transmission Provider has identified the following affected systems:WAPA,Black Hills,Tri-
state,Basin Electric
A copy of this report will be sharedthe each Affected System.
10.0APPENDICES
Appendix 1:Higher Priority Requests
Appendix 2:Property Requirements
Appendix 3:Study Results
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ExhibLNo51 Pag 18 o 3
O System Impact Study Report
10.1 Appendix 1:HigherPriority Requests
All active higher priority transmission service and/or generator interconnection requests with an
in-service date of December 2020 or earlier were considered in this study and are identified below.
If any of these requestsare materially modified,Transmission Provider reserves the right to restudy
this request,as the results and conclusions contained within this study could significantly change.
Transmission/Generation Interconnection Queue Requests considered:
Q0720 (80 MW TSR -Q2060)
Q0542 (240 MW)
Q0706 (250 MW)
Q0707 (250 MW)
Q0708 (250 MW)
O
O Orion VVind Resources,LLC Page 17 February 8,2018
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ExhibLNo51Pa 19of23
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10.2 Appendix 2:PropertyRequirements
Property Requirements for Point of Interconnection Substation
Requirements for rights of way easements
Rights of way easements will be acquired by Interconnection Customer in Transmission Provider's
name for the construction,reconstruction,operation,maintenance,repair,replacement and
removal of Transmission Provider's Interconnection Facilities that will be owned and operated by
PacifiCorp.Interconnection Customer will acquire all necessary permits for the Project and will
obtain rights of way easements for the Project on Transmission Provider's easementform.
Real Property Requirements for Point of Interconnection Substation
Real property for a POI substation will be acquired by an Interconnection Customer to
accommodate Interconnection Customer's Project.The real property must be acceptable to
Transmission Provider.Interconnection Customer will acquire fee ownership for interconnection
substation unless Transmission Provider determines that other than fee ownership is acceptable;
however,the form and instrument of such rights will be at Transmission Provider's sole discretion.
Any land rights that Interconnection Customer is planning to retain as part of a fee property
conveyance will be identified in advance to Transmission Provider and are subject to Transmission
Provider's approval.
Interconnection Customer must obtain all permits required by all relevant jurisdictions for the
planned use including but not limited to conditional use permits,Certificates of Public
O Convenience and Necessity,California Environmental Quality Act,as well as all construction
permits for the Project.
Interconnection Customer will not be reimbursed through network upgrades for more than the
market value of the property.
As a minimum,real property must be environmentally,physically,and operationallyacceptable to
Transmission Provider.The real property shall be a permitted or able to be permitted use in all
zoning districts.Interconnection Customer shall provide Transmission Provider with a title report
and shall transfer property without any material defects of title or other encumbrances that are not
acceptable to Transmission Provider.Property lines shall be surveyed and show all encumbrances,
encroachments,and roads.
Examples of potentially unacceptable environmental,physical,or operational conditions could
include but are not limited to:
1.Environmental:known contamination of site;evidence of environmental
contamination by any dangerous,hazardous or toxic materials as defined by any
governmental agency;violation of building,health,safety,environmental,fire,land
use,zoning or other such regulation;violation of ordinances or statutes of any
governmental entities having jurisdiction over the property;underground or above
ground storage tanks in area;known remediation sites on property;ongoing
mitigation activities or monitoring activities;asbestos;lead-based paint,etc.A
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phase I environmental study is required for land being acquired in fee by
Transmission Provider unless waived by Transmission Provider.
2.Physical:inadequate site drainage;proximity to flood zone;erosion issues;wetland
overlays;threatened and endangered species;archeological or culturallysensitive
areas;inadequate sub-surface elements,etc.Transmission Provider may require
Interconnection Customer to procure various studies and surveys as determined
necessary by Transmission Provider.
Operational:inadequate access for Transmission Provider's equipment and vehicles;existing
structures on land that require removal prior to building of substation;ongoing maintenance for
landscaping or extensive landscape requirements;ongoing homeowner's or other requirements or
restrictions (e.g.,Covenants,Codes and Restrictions,deed restrictions,etc.)on property which are
not acceptable to Transmission Provider.
O
O Orion Wind Resources,LLC Page 19 February 8,2018
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10.3 Appendix 3:Study Results
A Western Electricity Coordinating Council (WECC)approved 2021-22 Heavy Winter case was
used to perform the power flow studies using PSS/E version 33.7.The study was performed
assuming the Energy Gateway,D.2 500 kV segment from the planned Aeolus substation to the
planned Anticline substation was in-service.The local 500 kV,345 kV,230 kV,and 115 kV
transmission system outages were considered during the study.
N-0 Results:Assuming the Energy Gateway,Segment D.2 projects are in service,along with the
mitigation required by Q0707 and Q0708,the study did not indicate any thermal overload or
voltage issues.
The data provided by Interconnection Customer indicated that the generator does not have
adequate reactive capability to deliver 100%of its power output at +/-0.95 power factor.Hence,
external shunt compensation which is dynamic in nature will be required in order to control the
voltage and provide adequate reactive capability to maintain the voltage at the POI with a +/-0.95
power factor on the high side of the step-up transformer.
As shown in Figure 2,the study indicated that if the collector system is connected to the
transmission system without the generator being online,the collector system contributes
approximately 31.8 MVAr to the transmission system.The addition of 31.8 MVAr on the
transmission system under light load conditions could cause high voltages.The Interconnection
Customer will have to minimize the reactive interchange under these conditions.
O Orion Wind Resources,LLC Page 20 February 8,2018
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PACIFICORP
ExhibLNo.51Pa k2E2o3
System Impact Study Report
GO712 Phase A and Phase B Interconnection to Windstar 230 kV Substation
99714 1.035OO712_A_CLC2 35.71
99715
QC712_A_GEN 2 8 8
------0.00
0.00 --
99713 8 1.035
8
QD712_A_CLC 6 "35.70
1.035
0.71
99712
1 0.00 00712POI
5.90
0.00 0.010.00
-590
99725 99724 99723 99716
00712_B_GEN 00712_B_CLC2 00712_B_CLC 00712 PH_B 1.030
23s.so
O ___
0.00 -0.00 0.00 0.00 5 59 -5.564.00 -0.00 -0.00 -11.17 -0.00 0.01
1.034 -0 00 0.00
0.71 5.59 -5.56
1.034 1.033 1.02935.66 35.65 236.56 1.025
235.73
O
Figure 2:Chargingfrom Q0712 Collector System
N-1 Results:
Assuming the Energy Gateway D.2 projects are in service,along with the mitigation identified for
senior queue projects,an outage of the Aeolus -Shirley Basin #2 230 kV line resulted in an
overload on the Aeolus -Shirley Basin 230 kV #1 line of 152%.The mitigation for this issue is to
rebuild the existing Shirley Basin #1 230 kV line,approximately16 miles,with 2-1272 ACSR.
An outage of the Aeolus -Anticline 500 kV line,Aeolus 230/500 kV transformer or Anticline
345/500 kV transformer results in an overload on the Standpipe-Freezeout 230 kV line (109%),
the Freezeout -Aeolus 230 kV line (102%)230 kV and the Standpipe-Platte 230 kV line (106%).
The mitigation for this overload is to rebuild the existing lines,approximately 15 miles,from
Standpipe to Freezeout to Aeolus with bundled 2xl272 ACSR.
N-1-1 Results:
Based on operating conditions in real time,generation curtailment may be required for certain N-
1-1 conditions that may limit the transmission capacity in the Wyoming area.No mitigation is
identified for N-1-1 outages as manual curtailment of the Project would be performed post first
contingency such that no thermal overload would occur for the second contingency.
Orion Wind Resources,LLC Page 21 February 8,2018
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ExhibitaN51 Page 2E3o93
System Impact Study Report
N-2 Results:
Assuming Energy Gateway,Segment D.2 and mitigation required by Q0707 and Q0708 Projects
are in service,no N-2 thermal overloads or voltage issues were observed in the study.
O
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