Download Q58 Generation Interconnection

A subsidiary of Pinnacle West Capital Corporation
Q58 Generation
Interconnection
Interconnection Facilities Study
APS Contract No. 52325
By
Arizona Public Service Company
Transmission Planning
February 3, 2012
Version 1-3
Q58 (99MW) - Facilities Study
FACILITIES STUDY
Q58 PROPOSED GENERATION
TABLE OF CONTENTS
1. Introduction ............................................................................................................................................ 3
2. 500kV Interconnection at Proposed Qx Switchyard .............................................................................. 4
2.1. Interconnection Facilities – Qx Switchyard ........................................................................................ 4
2.2. Summary of Cost Estimates ............................................................................................................... 6
2.3. Summary of Construction Time Estimates ......................................................................................... 7
2.4. System Reinforcements ..................................................................................................................... 9
LIST OF APPENDICES
Appendix A – Q58, Q59, & Q60 Generator Interconnection Projects: Material Modification Review
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Q58 (99MW) - Facilities Study
1. Introduction
Arizona Public Service (APS) performed this Generator Interconnection Facilities Study (FaS) in response
to a generator interconnection request by the Interconnection Customer (IC). The Customer is listed in
APS’s Active Generator Interconnection Queue as queue number 58 (Q58) and has already completed a
System Impact Study. The purpose of the study is to provide cost and construction schedule estimates
for the facilities needed to interconnect the IC’s proposed 99 MW solar generation facility located near
Hyder, Arizona in Yuma County. The IC’s requested in-service date for Q58 is for August of 2012.
The IC has requested interconnection into the jointly owned Hassayampa – North Gila 500kV line. The
Point of Interconnection (POI) for this project would be at the proposed future Qx 500kV switchyard. The
IC has chosen to interconnect as an Energy Resource. Delivery of the Q58 output beyond the POI would
be on an “as-available” basis only. There are three participants in the Hassayampa – North Gila 500kV
line; APS, Imperial Irrigation District (IID), and San Diego Gas and Electric (SDG&E). The delivery of the
Q58 output would be subject to the firm or non-firm transmission capacity that may be available when a
Transmission Service Request is made. A request may be made to any or all of the participants; subject
to each participants OATT1.
The IC has requested that the interconnection of the Q58 project would be joined with the interconnection
of the Q59 and Q60 projects. All three projects would collect at a common “off-site” 69KV switchyard and
jointly own a common 69/500kV transformer, which would then require a single 500kV connection to the
Hassayampa – North Gila 500kV line at the proposed Qx switchyard. Therefore, this report consists of a
single POI at the Qx switchyard, which would accommodate an interconnection for the Q58, Q59, and/or
Q60 project(s). Because all three projects have proposed to use common facilities, the cost sharing of
the estimates within this report will need to be determined between the ICs themselves.
Nothing in this report constitutes an offer of transmission service or confers upon the IC, any right to
receive transmission service. APS and other interconnected utilities may not have the Available Transfer
Capability (“ATC”) to support the Transmission Service for the interconnection described in this report.
The original interconnection request was for a 99MW CSP project. Prior to initiating the Facilities Study,
the customer requested APS to determine if changing the project to a 99MW PV project would constitute
a Material Modification. APS performed a Material Modification review and determined that the requested
change would not constitute a Material Modification. The results of that review can be found in Appendix
A.
POI Requirements
The APS Open Access Transmission Tariff (OATT) policy regarding power factor requires all
Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor
(typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT
also requires Interconnection Customers to be able to achieve +/- 0.95 power factor at the POI, with the
maximum "full-output" VAr capability available at all outputs. Furthermore, APS requires Interconnection
Customers to have dynamic voltage control and maintain the voltage as specified by the transmission
operator within the limitation of +/- 0.95 power factor, as long as the Project is online and generating. If
the Project’s equipment is not capable of this type of response, a dynamic reactive device will be
required. APS has the right to disconnect the Project if system conditions dictate the need to do so in
order to maintain system reliability.
1
SDG&E transmission rights are administered by CAISO.
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Q58 (99MW) - Facilities Study
2. 500kV Interconnection at Proposed Qx Switchyard
The IC has requested interconnection into the jointly owned Hassayampa – North Gila 500kV line.
Although this project is within approximately 10 miles of the new Hoodoo Wash 500kV switchyard this
project, along with other generator interconnection requests, has been studied with an
interconnection into a new 500kV switchyard; the Qx 500kV switchyard. It was determined that the
Qx switchyard was needed due to the number of interconnection request in this general vicinity.
Currently, APS has seven active Large Generator Interconnection requests into the Hassayampa –
North Gila 500kV line in this area. In evaluating the location of all of the interconnection requests, the
Hoodoo Wash switchyard will not have the physical room to be expanded to interconnect all of the
projects. Therefore, a second 500kV switchyard was determined to be needed in the area.
APS determined that the proposed location of the Qx switchyard demonstrated the best opportunities
for this new switchyard. The Qx switchyard is proposed to be a 40 acre site that is adjacent to, on the
south side, the existing Hassayampa – North Gila 500kV line and north of the Union Pacific Railroad
tracks. This proposed site would allow Qx to be cut into the existing 500kV line without having to
cross the railroad tracks. It also is nearby a new APS 69kV substation (expected in-service in 2011)
and near existing 69kV lines. This allows for the co-location of electrical facilities and aides in
mitigating the impacts to the area. This location also allows for future expansion of the Qx substation
as more generators and/or transmission lines are located in the area.
2.1. Interconnection Facilities – Qx Switchyard
Figure 1 is a one-line diagram of the initial phase of the proposed Qx 500kV switchyard. The
ultimate layout for Qx will be for a breaker and a half configuration. The initial build of Qx that is
required for the interconnection of the Q58, Q59, and Q60 projects is only a three breaker ring bus.
The three breaker ring will accommodate the terminations for the line back to Hassayampa, the line
back to Hoodoo Wash, and the single termination for the Q58, Q59, and Q60 projects. Figure 1
shows the ring bus in the blue color. The ring bus will be considered a Network Upgrade. Figure 1
also shows a small portion of Transmission Provider’s Interconnection Facilities (TPIF), shown in the
green color. This is the portion of the 500kV gen-tie line that will be within the Qx switchyard fence.
The Hassayampa-North Gila participants will own and APS, on behalf of the participants, will operate
and maintain the portion of that line from the 500kV bus up to the first structure outside of the
switchyard fence, at which point the IC would pick-up ownership and responsibility for the line.
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Q58 (99MW) - Facilities Study
HDW
Figure 1. Preliminary Qx Switchyard Design – Q58, Q59, and Q60 500kV Interconnection
POI
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Q58 (99MW) - Facilities Study
2.2. Summary of Cost Estimates
The estimated cost of the Q58 interconnection is summarized in the tables below and depicted in Figure 1.
The costs that are summarized below are the total costs for a single 500kV line terminating at a new Qx
500kV switchyard. The total costs are shown here because these costs would be applicable if the Q58
project was interconnecting as the only project. If the Q59 and Q60 projects share the interconnection, the
split of the costs summarized below will need to be determined by the ICs and not APS.
The costs described in Table 1 are the network upgrades needed and the Transmission Provider’s
Interconnection Facilities (TPIF).
Network Upgrades
The cost estimates for the network upgrades needed for the Q58 interconnection are included in Table 1
and consists of the new Qx switchyard, the communications needed for the new yard, the cut-in of the
Hassayampa-Hoodoo Wash 500kV line, changing the relays at the Hoodoo Wash switchyard, changing the
relays at Hassayampa, and updating the EMS system for the new Qx switchyard. The new Qx switchyard
will consist of approximately 40 acres of land, three new 500kV breakers, the associated switches and
misc. substation equipment, and all of the below grade and above grade construction. The electrical oneline can be seen in Figure 1, with the network upgrades shown in the blue color.
Along with the construction costs there will also be costs associated with the Transmission Siting efforts for
obtaining a Certicificate of Environmental Compatibility (CEC) for the Qx switchyard from the Arizona
Corporation Commission (ACC). The estimated cost for siting this proposed 500kV switchyard are also
included in Table 1. The costs are to account for hiring an environmental consultant, APS in house labor,
legal resources, and other fees associated with the CEC process. These costs assume that a National
Environmental Policy Act (NEPA) process is not required. If a NEPA process is required APS would need
to re-evaluate both the time and money estimates.
Transmission Provider’s Interconnection Facitilies (TPIF)
Also included in Table 1 is the estimate for the Transmission Provider’s Interconnection Facilities. The only
Interconnection Facility for this project is the 500kV transmission line and associated equipment from the
Qx 500kV bay to the first structure outside the switchyard fence, at which point the IC will be responsible for
the line back to the generator facility. It is depicted in Figure 1 in the green color.
Table 1. Cost Estimates – Q58 Interconnection
Network Upgrades for Q58 Q58 TPIF
Qx switchyard
$13,441,000
Communications
$1,000,000
Lines
$1,900,000
Hoodoo Wash Relays
$189,000
Hassayampa Relays
$145,000
Qx CEC siting
$300,000
$1,136,000
Qx 500kV bay
Subtotal
$16,975,000
$1,136,000
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Q58 (99MW) - Facilities Study
2.3. Summary of Construction Time Estimates
The IC’s requested in-service date for the Q58 project is for August of 2012. Figure 2 shows a preliminary
construction schedule and as shown in Figure 2 the estimated schedule to be able to design, permit,
procure, and construct the facilities is approximately 20 months. Figure 2 does not show the time estimates
needed for obtaining a CEC from the ACC and then acquiring the needed land. It is estimated that the
siting activities for obtaining a new CEC for the Qx switchyard and the land acquisition would be
approximately 9 to 12 months. Therefore, the estimated total time, after the required agreements and
deposits are in-place, for the proposed Qx substation to be in-service is between 29 and 32 months. The
desired in-service date of the Q58 project is thereby not feasible. APS and the IC must therefore discuss
and mutually agree to a new and acceptable projected In-Service Date as part of the Interconnection
Agreement negotiations.
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Q58 (99MW) - Facilities Study
Figure 2. Q58 Preliminary Construction Schedule
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Q58 (99MW) - Facilities Study
2.4. System Reinforcements
The Interconnection Customer has chosen to interconnect as an energy resource, with delivery of the
Q58 output beyond the POI on an “as-available” basis only, using firm and non-firm transmission capacity
that may be available when a transmission service request is made. This Facilities Study does not
include estimates for any system upgrades identified in the SIS, beyond the facilities required to
interconnect, as described in the section above. Any additional system upgrades that may be required
are dependant on the Transmission Service that is ultimately requested by the Q58 project and should be
evaluated as part of any Transmission Service Request that the customer would make.
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Q58 (99MW) - Facilities Study
Appendix A
Q58, Q59, & Q60 Generator Interconnection Projects
Material Modification Review
(Provided in a separate file upon request)
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