feasibility study for the hamilton county 115kv 75 mw solar project · 2019-12-23 · the hamilton...

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Feasibility Study for the

Hamilton County 115kV

75 MW Solar Project

August 11, 2016

Bulk Transmission Planning, Florida

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This document and any attachments hereto (“document”) is made available by

Duke Energy Florida upon and subject to the express understanding that: (a)

neither Duke Energy Florida nor any of its officers, directors, affiliates, agents, or

employees makes any warranty, assurance, guarantee, or representation with

respect to the contents of the document or the accuracy or completeness of the

information contained or referenced in the document, and (b) Duke Energy

Florida, its officers, directors, affiliates, agents, and employees shall not have

any liability or responsibility for inaccuracies, errors , or omission in, or any

business or policy decisions made by any direct or indirect recipient in reliance

on, this document or the information contained or referenced therein; all such

liability is expressly disclaimed.

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Table of Contents 1. Executive Summary ............................................................................................................................... 3

2. Point of Interconnection (POI) .............................................................................................................. 4

3. Model Development ............................................................................................................................. 7

3.1. Power Flow Models....................................................................................................................... 7

3.2. Interface Models ........................................................................................................................... 7

3.3. Short Circuit Models ..................................................................................................................... 7

3.4. Generator Interconnection Queue Considerations ...................................................................... 7

3.5. Transmission Service Request Priority List Considerations .......................................................... 7

4. Analyses Performed .............................................................................................................................. 7

4.1. Power flow analyses ..................................................................................................................... 7

4.2. Short circuit analyses .................................................................................................................... 8

5. Screening Criteria .................................................................................................................................. 8

6. Study Results Option 1 .......................................................................................................................... 9

6.1. Thermal Results ............................................................................................................................. 9

6.2. Voltage .......................................................................................................................................... 9

6.3. Short Circuit ................................................................................................................................ 10

6.4. Third-party Impacts ..................................................................................................................... 10

6.5. Costs ............................................................................................................................................ 10

7. Study Results Option 2 ........................................................................................................................ 11

7.1. Thermal Results ........................................................................................................................... 11

7.2. Voltage ........................................................................................................................................ 11

7.3. Short Circuit ................................................................................................................................ 11


7.5. Costs ............................................................................................................................................ 12

8. Study Results Option 3 ........................................................................................................................ 12

8.1. Thermal Results ........................................................................................................................... 12

8.2. Voltage ........................................................................................................................................ 12

8.3. Short Circuit ................................................................................................................................ 12


8.5. Costs ............................................................................................................................................ 13

Appendix A - Summary of Thermal Analysis Results .............................................................................. 14

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Option 1 .................................................................................................................................................. 14

Option 2 .................................................................................................................................................. 14

Option 3 .................................................................................................................................................. 15

Appendix B - Short Circuit Analysis Results ............................................................................................ 16

Option 1 .................................................................................................................................................. 16

Option 2 .................................................................................................................................................. 16

Option 3 .................................................................................................................................................. 17

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1. Executive Summary

The Hamilton County Solar Project customer has submitted an Interconnection Request on

Duke Energy Florida’s (DEF’s) system for a Solar PV station, capable of 75 MW net output. The

facility will be located in Hamilton County, Florida with options connecting to the Suwannee to

Hanson 115 KV Line and the Suwannee to Jasper 115 kV line.

The customer has requested this generation facility be evaluated for Energy Resource

Interconnection Service (ERIS) and Network Resource Interconnection Service (NRIS) with a

requested Commercial Operating Date (COD) of January 2018. Delay of that COD may require

additional study or resubmittal of an interconnection request. The customer has also

requested that three options be evaluated as potential interconnection configurations, as

referenced in this report as Option 1, Option 2, and Option3.

The study identified potential network upgrades to DEF’s transmission network to

accommodate the full capacity of the Hamilton County Solar Project. In this level of study there

were no potential Third Party Impacts identified. The cost estimates in this report are based on

the facilities that are identified as directly impacted by the generator under study, and do not

take into account results that exceed screening criteria. Additional detailed study is required to

determine any change of scope. The estimates from this Feasibility Study are very high level

and may change significantly due to additional information determined from a more detailed

System Impact Study to follow.

The estimated cost for a new facility (interconnecting substation) required to interconnect the

Hamilton County Solar Project using Option 1 is $5,000,000, for Option 2 is $5,000,000, and for

Option 3 is $7,000,000. When more probable network upgrades are included, the costs are

estimated to increase to $25,250,000 for Option 1 and $28,050,000 for Option 2. No addition

facilities, other than those required for interconnection, are required for Option 3.

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2. Point of Interconnection (POI) There are three POIs requested for study by interconnection customer:

Option 1 – A new three (3) Breaker Ring Bus Substation1 connecting to DEF’s Suwanee – Hanson 115 kV line. The connection point is approximately 5.18 miles from the Suwanee 115kV Substation.

Figure 1: Diagram of Hamilton County Solar Interconnection Option 1

1 A three breaker ring bus configuration was chosen over a single breaker point of interconnection because of the

projected fiber construction cost needed to implement high speed tripping for a single breaker configuration.

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Option 2 – A new three (3) Breaker Ring Bus Substation1 connecting to DEF’s Suwanee – Jasper 115 kV line. The connection point is approximately 5.18 miles from the Suwanee 115kV Substation.


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Option 3 – A new five (5) Breaker Ring Bus Substation connecting to DEF’s Suwanee – Hanson 115 kV line and DEF’s Suwanee – Jasper 115 kV line. The connection point on each line is approximately 5.18 miles from the Suwanee 115kV Substation.


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3. Model Development

3.1. Power Flow Models

Power flow models were built using the Siemens PSS/E power system simulation program and were based on the FRCC 2016 series cases, which were the most recent models available at the time of the study. The model years studied for power flow impacts were 2017/18 winter and 2018 summer. The base case models were adjusted for additional prior queued generation not already incorporated into the base case and therefore adjustments were made to reflect the additional transmission facilities and dispatch resulting from the integration of the Hamilton County Solar Project. The study case models utilized the adjusted base models with the addition of the Hamilton County Solar Project generation and the required basic interconnection facilities for each option.

3.2. Interface Models

No interface analyses were performed as part of this evaluation.

3.3. Short Circuit Models

Short circuit analyses performed utilized the FRCC 2015 short circuit model (y15_18sr1aSCd.sav).

The model year studied for short circuit analysis was2018.

3.4. Generator Interconnection Queue Considerations Prior queued generation in the FRCC coordinated queue was reviewed. It was determined that none of the prior queued generation would have significant impact on this study.

Generator Interconnect Studies for prior queued generation interconnection requests in the form of Feasibility and System Impact Studies are currently conducted in accordance with FERC rules and are prioritized by their queue positions to determine the assignment of required interconnection facilities and transmission upgrades to accommodate their requested interconnections. In the instances where these studies are not sufficiently complete, the facilities and upgrades required for these earlier queued requests might not be included in the base cases used in this study. To the extent that one or more of these requests completes, are modified or withdrawn, the results presented in this analysis may no longer be valid and/or may change materially. DEF will advise the customer of any changes associated with the preceding GIS requests that may require a re-study of this GIS request.

3.5. Transmission Service Request Priority List Considerations A review of transmission service requests in the FRCC coordinated priority list was performed, and it was determined that there are no relevant transmission service requests in the study area that were not already built into the FRCC cases.

4. Analyses Performed

4.1. Power flow analyses Power flow analyses of the cases were performed using the PowerGEM TARA software (TARA)

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to determine the impact of interconnecting the queued generation to the transmission system

in the area. The base and interconnection study cases were compared to determine if the

interconnection option created thermal overloads or voltage violations or exacerbated existing

thermal overloads or voltage violations. All 69 kV and above branch flows and bus voltages in

the FRCC region were monitored.

The following contingencies were observed in this study:

Selected Category P1, P2, P4 and P7 contingencies within the FRCC region as previously

defined by FRCC transmission owners. Selection variations include:

o All single element contingencies (69 kV and above) in the FRCC region

4.2. Short circuit analyses

Short circuit analyses were performed using PSS/E activity ASCC. All local generators were

online for the analysis. Activity FLAT was used to set up the network conditions corresponding

to classical fault analysis assumptions. Three phase and single line-to-ground faults were

applied at all buses within FRCC and were analyzed using a 3% cutoff criterion. The final results

represent all buses within FRCC with a difference between the base case and study case study

greater than 3% plus one additional bus.

5. Screening Criteria

The following criteria were used for screening thermal results.

Unrelated GSU transformers were excluded from results.

Transmission system elements operated at less than 69 kV nominal voltage were excluded.

System-intact overloads must be greater than 100% of rate A.

Post-contingency overloads must be greater than 100% of rate A.

Post-contingency overloads that are improved by the interconnection were excluded.

Post-contingency overloads must have been made worse than the base case by 3% of the

affected element’s rating or greater.

The following criteria were used for screening voltage results.

Buses in DEF and SECI were monitored for values outside of the range 0.9-1.05 p.u.

FPL 69, 115, 138, and 230 kV buses were monitored for values outside the range 0.95-1.07 p.u.

FPL 500 kV buses were monitored for values outside the range 0.95-1.10 p.u.

TECO 69 kV buses were monitored for values outside the range 0.925-1.05 p.u.

TECO 138 and 230 kV buses were monitored for values outside the range 0.95-1.06 p.u.

Turkey Point bus voltage was monitored for values outside the range of 1.01 p.u. and 1.06 p.u.

St. Lucie bus voltage was monitored for values outside the range of 1.00 p.u. and 1.06 p.u.

All other monitored areas were monitored for values outside of the range 0.95 and1.05 p.u.

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Generator buses and buses with nominal voltage below 69 kV were excluded from

consideration.

Absolute change in bus voltage between base case and the interconnection case must have

been greater than 0.02 p.u.

The following screening criteria were used for screening the ASCC short circuit results.

Three phase and single line-to-ground fault current on the DEF system had to exceed the

interrupting rating of the breaker.

Three phase and single line-to-ground fault current results are provided to third parties close to

this area for their acceptance or rejection of the results based on their own breaker rating

criteria.

6. Study Results Option 1

6.1. Thermal Results

NRIS

The NRIS evaluation identified potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project. These potential

overloads are shown in Appendix A. Further analysis and evaluation will be performed in the

associated future System Impact Study to assess the financial impact and subsequent assignable

cost to the Hamilton County Solar Project on these facilities.

ERIS

The ERIS evaluation identified potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project. Due to overloads on

DEF’s facilities, without any transmission upgrades, the additional generation could be limited to 67

MW or lower as observed from the overload in the table below:

Season Overloaded Facility (Continuous Rating) Contingency 67 MW 75 MW

Summer SONNIE TP TO WEST LAKE 1 115kV Line P2-1:SUW TRANS TO HAMCO POI

100.0% 112.47%

6.2. Voltage

There were no identified voltage violations that were attributable to the interconnection of the

Hamilton County Solar Project interconnection.

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6.3. Short Circuit

Short circuit analyses revealed that the proposed interconnection would cause impacts greater than

3% at several DEF Substations. The short circuit results are tabulated in Appendix B.

6.4. Third-party Impacts

The thermal analysis revealed no potential third-party impacted facilities to third parties. Short

circuit analysis revealed some third-party substations with short-circuit impacts greater than 3%.

Additional analysis for third-party impacts will be studied in future studies.

6.5. Costs

These estimates are preliminary planning estimates, and details specific to this project discovered in

the System Impact Study and Facilities (design engineering) Study phases may significantly increase

or decrease these estimates.

Required upgrades for basic physical interconnection: Est. Costs

Three terminal 115 kV ring bus substation $5,000,000

Identified network facility upgrades for NRIS:

Rebuild of the Hanson to Sonnie Tap 115 kV line segment (6.6 miles) $10,500,000

Rebuild of the Sonnie Tap to West Lake 1 115 kV line segment (6.2 miles) $9,750,000

Total Estimated NRIS Cost: $25,250,000

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NRIS

The NRIS evaluation identified potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project. These potential

overloads are shown in Appendix A. Further analysis and evaluation will be performed in the

associated future System Impact Study to assess the financial impact and subsequent assignable

cost to the Hamilton County Solar Project on these facilities.

ERIS

The ERIS evaluation identified potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project. Due to overloads on

DEF’s facilities, without any transmission upgrades, the additional generation could be limited to 58

MW or lower as observed from the overload in the table below:

Season Overloaded Facility (Continuous Rating) Contingency 58 MW 75 MW

Summer JASPER TO BURNHAM TP 115KV Line P2-1: SUW TRANS TO HAMCO POI.

100.0% 120.43%

7.2. Voltage



7.3. Short Circuit

Short circuit analyses revealed that the proposed interconnection would cause impacts greater than 3% at several DEF substations. The short circuit results are tabulated in Appendix B.


The thermal analysis revealed additional no potential third-party impacted facilities in various areas.

Short circuit analysis revealed some third-party substations with short-circuit impacts greater than

3%.


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7.5. Costs






NRIS The NRIS evaluation identified no potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project.

ERIS

The ERIS evaluation identified no potential network upgrades to DEF’s transmission network to

accommodate the full capacity (75 MW) of the Hamilton County Solar Project.

8.2. Voltage



8.3. Short Circuit

Short circuit analyses revealed that the proposed interconnection would cause impacts greater than 3% at several DEF Substations. The short circuit results are tabulated in Appendix B.


Three terminal 115 kV ring bus substation $5,000,000


Rebuild of the Jasper to Burnham Tap 115 kV line segment (~13 miles) $2,800,000

Rebuild of the Burnham Tap to West Lake 2 115 kV line segment (~2

miles)

$20,250,000


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The thermal analysis revealed no potential third-party impacted facilities to third parties. Short

circuit analysis revealed some third-party substations with short-circuit impacts greater than 3%.


8.5. Costs





Five terminal 115 kV ring bus substation. $7,000,000


No Additional Facilities $ 0


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Appendix A - Summary of Thermal Analysis Results

Option 1

Winter 2017 Results Meeting Impact Criteria – % Loading

Monitored Facility Contingency Name Base Study Delta N/A N/A N/A N/A N/A

Summer 2018 Results Meeting Impact Criteria – % Loading

Monitored Facility Contingency Name Base Study Delta 3111 HANSON 115 3131 SONNIE TP 115 1 P2-1:3133-SUW TRANSM -115-3181-HamCO Op1 -115-1 12.43 102.07 89.64 3131 SONNIE TP 115 3137 WEST LAKE 1 115 1 P2-1:3133-SUW TRANSM -115-3181-HamCO Op1 -115-1 2.47 112.47 110

Results potentially impacting 3rd parties to be resolved under the FRCC process.





Option 2




Monitored Facility Contingency Name Base Study Delta 3113 JASPER 115 3148 BURNHAM TP 115 1 P2-1:3133-SUW TRANSM -115 3182-HamCO Op2 -115-1 10.94 120.43 109.5 3138 WEST LAKE 2 115 3148 BURNHAM TP 115 1 P2-1:3133-SUW TRANSM -115 3182-HamCO Op2 -115-1 0.63 102.71 102.1






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Option 3










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Appendix B - Short Circuit Analysis Results

Option 1

PSS®E ASCC SHORT CIRCUIT CURRENTS (V @ 1 .0 pu) Base Case Study Case

Bus # Bus Name kV 3φ (I1) Amps

SLG (3I0) Amps

3φ (I1) Amps

SLG (3I0) Amps % 3 % SLG

7058 BLUESPRG 115 DEF 4498.9 2724.7 4550 2805.9 1.14 2.98

3181 HAMCOSOLAR1 115 DEF #N/A #N/A 10690.8 8385.2 #N/A #N/A

3111 HANSON 115 DEF 7127.5 4425.3 7206.4 4544.3 1.11 2.69

7063 SONN_BKR 115 DEF 6304.1 3944.8 6405 4117.2 1.60 4.37

7064 SONN_SW 115 DEF 5030.8 3070.9 5094.7 3174.4 1.27 3.37

3131 SONNIE TP 115 DEF 6317.8 3953.3 6419.1 4126.4 1.60 4.38

3157 SUW 115 CT 115 DEF 24052.4 22391.8 24485.5 23022.9 1.80 2.82

3133 SUW TRANSM 115 DEF 24632.6 23289 25092.1 23992.8 1.87 3.02

3132 SUWAN PLT A 115 DEF 22784.5 21638.1 23141.3 22059.3 1.57 1.95

3158 SUWAN PLT B 115 DEF 22784.5 21638.1 23141.3 22059.3 1.57 1.95

3137 WEST LAKE 1 115 DEF 7310.8 4701.2 7506.3 5153.7 2.67 9.63

Base Case: "y15_18sr1aSCd.sav” with all FRCC generation in-service.

Study Case: Base case plus 115kV Option 1 Interconnection.

Option 2



SLG (3I0) Amps

3φ (I1) Amps


6986 BURHAM 115 DEF 4953.4 3110 5094.1 3444.3 2.84 10.75

3148 BURNHAM TP 115 DEF 4961.3 3115.1 5102.5 3450.6 2.85 10.77

3182 HAMSOLAR2 115 DEF #N/A #N/A 9634.2 7589.4 #N/A #N/A

3157 SUW 115 CT 115 DEF 24052.4 22391.8 24504.8 23049.4 1.88 2.94

3133 SUW TRANSM 115 DEF 24632.6 23289 25112.5 24022.3 1.95 3.15

3138 WEST LAKE 2 115 DEF 5601.7 3530.7 5781 3967.5 3.20 12.37



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Option 3



SLG (3I0) Amps

3φ (I1) Amps


7058 BLUESPRG 115 DEF 4498.9 2724.7 4741.7 2896.9 5.40 6.32

6986 BURHAM 115 DEF 4953.4 3110 6199.4 4091.1 25.15 31.55

3148 BURNHAM TP 115 DEF 4961.3 3115.1 6211.8 4100 25.21 31.62

7048 CHERRY 115 DEF 5050.9 3108.9 5163.8 3207.2 2.24 3.16

3183 HAMSOLAR3 115 DEF #N/A #N/A 14520.6 11646.2 #N/A #N/A

3111 HANSON 115 DEF 7127.5 4425.3 7360.1 4628.8 3.26 4.60

7052 MADISON 115 DEF 7261.9 4411.1 7442.9 4562.5 2.49 3.43

3116 MADISON 115 DEF 7336.2 4448.5 7513.9 4596.6 2.42 3.33

3118 MADISON TP 115 DEF 7294.5 4431 7477.3 4583.8 2.51 3.45

7063 SONN_BKR 115 DEF 6304.1 3944.8 6791 4315.9 7.72 9.41

7064 SONN_SW 115 DEF 5030.8 3070.9 5336.4 3291.5 6.07 7.18

7056 SONNIE 115 DEF 3416.7 2029.3 3555 2123.4 4.05 4.64

3131 SONNIE TP 115 DEF 6317.8 3953.3 6806.9 4326.1 7.74 9.43

3157 SUW 115 CT 115 DEF 24052.4 22391.8 24503.2 23101.1 1.87 3.17

3133 SUW TRANSM 115 DEF 24632.6 23289 25110.9 24080.7 1.94 3.40

3132 SUWAN PLT A 115 DEF 22784.5 21638.1 23155.8 22106.1 1.63 2.16

3137 WEST LAKE 1 115 DEF 7310.8 4701.2 8624.7 5855.8 17.97 24.56

3138 WEST LAKE 2 115 DEF 5601.7 3530.7 7247.7 4851.3 29.38 37.40



feasibility study for the hamilton county 115kv 75 mw solar project · 2019-12-23 · the hamilton...

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