fifth forward capacity auction transmission security analysis requirements

Reliability Committee MeetingJanuary 18, 2011Marianne Perben

Fifth Forward Capacity Auction Transmission Security Analysis Requirements

Reliability Committee Meeting – 01/18/2011FCA #5 TSA Requirements

© 2011 ISO New England Inc.

Purpose of the Discussion

• Review the assumptions, methodology and Transmission Security Analysis (TSA) requirements for the 2014-2015 Capacity Commitment Period (FCA #5)– Based on the same methodology that was used for FCA #4

• Details available at http://www.iso-ne.com/committees/comm_wkgrps/relblty_comm/relblty/mtrls/2010/mar172010/index.html

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FCA #5 TSA Requirements - Model

• The calculation of the FCA #5 local capacity requirements, including the TSA requirements, rely on the latest available data– Load forecast, resource data and resource availability were

presented to the Power Supply Planning Committee on 12/06/2010; details are available at:

http://www.iso-ne.com/committees/comm_wkgrps/relblty_comm/pwrsuppln_comm/mtrls/2010/dec62010/index.html

– The transmission topology that was certified for FCA #5 was introduced at the 09/20/10 RC; details are available at:

http://www.iso-ne.com/markets/othrmkts_data/fcm/qual/models/index.html

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FCA #5 TSA Requirements and Transfer Limits

• Transfer limits are updated to reflect the impact of a new major transmission project when all of the following conditions are met

– All portions of the major transmission project have been certified– They have been certified to be in-service by June 1 of the Capacity Commitment Period

under consideration– Certification has occurred before the network model for the FCA was built– Studies to reflect the impact of the project on the transfer limits have been completed– The ISO has approved the certifications for all portions of the project pursuant to Section

III.12.6 of Market Rule 1

• Based on the certified transmission topology for FCA #5, only the Connecticut import limits were changed

• The N-1 and N-1-1 Boston import limits remained at 4,900 and 3,700 MW respectively; the N-1 Maine-New Hampshire export limit remained at 1,600 MW

• Transfer limits for FCA #5 do not reflect the impact of the Maine Power Reliability Program (MPRP) as the conditions listed under bullet 1 were not all met

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Interface2014-2015 Capacity Commitment Period

Transfer Limit in MW Comment

Connecticut Import (N-1) 2,600 Includes the impact of the Greater Springfield Reliability ProjectConnecticut Import (N-1-1) 1,400



FCA #5 TSA Requirements and Related Analysis

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FCA #5 TSA Requirements and Related Analysis, cont

• As detailed in the appendix, TSA requirements were calculated for both a “Line-Gen” and “Line-Line” scenario

• As a worst-case sensitivity analysis, TSA requirements were also calculated for the New Hampshire, Rhode Island, SEMASS, WCMASS and Vermont Load Zones; a worst-case assumption of 0 MW of N-1 and N-1-1 import transfer capability was initially assumed for these Load Zones– As further sensitivity, a Capacity Zone determination was performed

• It was assumed that in every Load Zone, the Local Sourcing Requirement would be set by the TSA requirement

• The determination was based on the methodology described in section III.12.4 of Market Rule 1

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1 Connecticut

NEMA/Boston(Salem Harbor

assumed "in" in the TSA analysis)


assumed "out" in the TSA analysis)New Hampshire Rhode Island SEMASS WCMASS Vermont

2 Zone 2014 90/10 Load 8240 6325 6325 2815 2170 4065 4215 1160

3 Reserves (Largest unit or loss of import capability) 1225 1360 1360 1247 529 682 326 604

4 Sub-area Transmission Security Need 9465 7685 7685 4062 2699 4747 4541 17645 Existing Resources** 9502 4017 3269 4427 2889 6471 4409 13276 Assumed Unvailable Capacity -779 -345 -176 -152 -229 -423 -268 -527 Sub-area N-1 Import Capability* 2600 4900 4775 0 0 0 0 0

8 Sub-area Available Resources 11323 8572 7868 4275 2660 6048 4141 1274

9 TSA Margin 1858 887 183 213 -38 1301 -400 -490

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11 LSR (=TSA requirement, assuming TSA>LRA) 7478 3046 3075 4206 2931 5079 4835 1837

12 +Export Bid or Admin. Export De-List Bid with a path going through the zone 100 0 0 0 0 0 0 0

13 = Export-Adjusted LSR 7578 3046 3075 4206 2931 5079 4835 1837

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15 Existing Capacity Resource in the Load Zone** 9502 4017 4017 4427 2889 6471 4409 132716 - Admin. Export De-List Bids in the Load Zone 0 0 0 0 0 0 100 017 - Non-Price Retirements in the Load Zone 0 0 0 0 0 0 0 0

18 =First Amount of capacity to be compared to the Export-Adjusted LSR 9502 4017 4017 4427 2889 6471 4309 1327

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First Amount of capacity to be compared to the Export-Adjusted LSR 9502 4017 4017 4427 2889 6471 4309 1327

21 - Permanent De-List Bids 0 749 749 0 0 0 0 022 - Export Bids from non-FCM Pivotal Suppliers 0 0 0 0 0 0 0 0

23 - Static De-List Bids from non-FCM Pivotal Suppliers 0 0 0 0 0 127 16 40

24 =Revised Amount of capacity to be compared to the Export-Adjusted LSR 9502 3269 3269 4427 2889 6344 4293 1287

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26 Revised Amount Minus Export-Adjusted LSR 1924 222 193 221 -42 1265 -542 -550

* Import Capability on the AC Ties

** Includes 39 MW of Existing Import Resources over Phase I/II in WCMASS and 194 MW of Existing Import Resources over Highgate in Vermont

FCA #5 TSA Requirements – Line-Gen

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All values in MW



1 Connecticut


assumed "in" in the TSA analysis)


assumed "out" in the TSA analysis)New Hampshire Rhode Island SEMASS WCMASS Vermont

2 Zone 2014 90/10 Load 8240 6325 6325 2815 2170 4065 4215 1160

3 Reserves (Largest unit or loss of import capability) 1200 1200 1400 0 0 0 0 0

4 Sub-area Transmission Security Need 9440 7525 7725 2815 2170 4065 4215 11605 Existing Resources** 9502 4017 3269 4427 2889 6471 4409 13276 Assumed Unvailable Capacity -800 -371 -202 -174 -231 -467 -280 -637 Sub-area N-1 Import Capability* 2600 4900 4775 0 0 0 0 0

8 Sub-area Available Resources 11302 8546 7841 4253 2658 6004 4130 1264

9 TSA Margin 1862 1021 116 1438 488 1939 -85 104

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11 LSR (=TSA requirement, assuming TSA>LRA) 7469 2892 3145 2930 2359 4381 4500 1218

12 +Export Bid or Admin. Export De-List Bid with a path going through the zone 100 0 0 0 0 0 0 0

13 = Export-Adjusted LSR 7569 2892 3145 2930 2359 4381 4500 1218

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15 Existing Capacity Resource in the Load Zone** 9502 4017 4017 4427 2889 6471 4409 132716 - Admin. Export De-List Bids in the Load Zone 0 0 0 0 0 0 100 017 - Non-Price Retirements in the Load Zone 0 0 0 0 0 0 0 0

18 =First Amount of capacity to be compared to the Export-Adjusted LSR 9502 4017 4017 4427 2889 6471 4309 1327

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First Amount of capacity to be compared to the Export-Adjusted LSR 9502 4017 4017 4427 2889 6471 4309 1327

21 - Permanent De-List Bids 0 749 749 0 0 0 0 022 - Export Bids from non-FCM Pivotal Suppliers 0 0 0 0 0 0 0 0

23 - Static De-List Bids from non-FCM Pivotal Suppliers 0 0 0 0 0 127 16 40

24 =Revised Amount of capacity to be compared to the Export-Adjusted LSR 9502 3269 3269 4427 2889 6344 4293 1287

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26 Revised Amount Minus Export-Adjusted LSR 1933 376 124 1497 530 1962 -207 69

* Import Capability on the AC Ties

** Includes 39 MW of Existing Import Resources over Phase I/II in WCMASS and 194 MW of Existing Import Resources over Highgate in Vermont

FCA #5 TSA Requirements – Line-Line

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All values in MW



FCA #5 TSA Requirements - Results

• The Load Zone sensitivity analysis show that– Regardless of their N-1 or N-1-1 import capability, there is no need to form

separate Capacity Zones for New Hampshire or SEMASS, because the revised amount of capacity to be compared to the export-adjusted LSR can not be lower than the export-adjusted LSR

– Under the worst-case assumption where the N-1 or N-1-1 import capability into Rhode Island, WCMASS and Vermont is below the required import capability shown below, the revised amount of capacity to be compared to the export –adjusted LSR can be less than the export-adjusted LSR; however, these Load Zones’ interfaces are such that they include many 345kV, 230kV or 115kV ties; therefore, there is still no need to form separate Capacity Zones for Rhode Island, WCMASS and Vermont

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Load Zone Required Import Capability (MW) Load Zone Interface Characteristics

Rhode Island N-1: 38 MW 3 345kV and 8 115kV paths into the load pocket

WCMASS N-1: 509 MWN-1-1: 194 MW

8 345kV, 2 230kV and 15 115kV paths into the load pocket

Vermont N-1: 528 MW 2 345kV, 1 230kV and 7 115kV paths into the load pocket



FCA #5 TSA Requirements – Results, cont.

• The results of the NEMA/Boston sensitivity analysis show that with or without the Salem Harbor units, there is no need to form a separate Capacity Zone for NEMA/Boston

• The final FCA #5 TSA requirement for NEMA/Boston is set by the Line-Gen scenario and is 3,046 MW

• The final FCA #5 TSA requirement for Connecticut is set by the Line-Gen scenario and is 7,478 MW

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Questions

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AppendixMethodology and Additional Assumptions Behind the TSA Values for the

2014/15 FCA

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Background

• The methodology and assumptions used to determine the 2014/15 TSA requirements were developed in accordance with section III.12.2.1.2. of Market Rule 1, and section 6 of ISO Planning Procedure 10 – Planning Procedure to Support the Forward Capacity Market

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Methodology

• The TSA determines the requirement of the sub-area to meet its load through internal generation and import capability

• It stems from ISO Planning Procedure 3 - Reliability Standards for the New England Area Bulk Power Supply System key transmission security requirements– Integrate all resources and serve area load under N-1 and N-1-1 conditions– Perform review under reasonably stressed conditions (“With due allowance

for generator maintenance and forced outages”)

• It is performed via a series of transmission load flow studies– In performing the analysis, static transmission interface transfer limits may

be established as a reasonable representation of the transmission system’s capability to serve sub-area load with available existing resources

• Results may be presented in the form of a deterministic operable capacity analysis

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Methodology, cont.

• When presented in the form of a deterministic operable capacity analysis, the TSA compares need with available resources

– Needs include• Load + Loss of Generator (“Line-Gen” scenario), or

• Load + Loss of import capability (going from an N-1 import capability to an N-1-1 import capability; “Line-Line” scenario)

– Resources include• N-1 Import capability

• Regular generation

• Operating actions (fast start units, demand response…)

– Resource unavailability is applied by de-rating capacity

• ExampleSubarea 90/10 Load 8 300Reserves (Largest unit or loss of import capability) 1 200

Subarea Transmission Security Need 9 500Existing Resources 10 000Assumed Unavailable Capacity 500Subarea N-1 Import Capability 2 500

Subarea Available Resources 12 000

Subarea Transmission Security Margin 2 500

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Methodology, cont.

• For each of the potential import constrained Capacity Zones, the TSA requirement (resource requirement that will be compared to the Local Resource Adequacy Requirement) is the amount of internal resources (generators and Demand Resources) needed in the zone, so that the Line-Line or Line-Gen requirements can be met after proper accounting for resource unavailability

• The TSA requirement can be approximated by using the following formula

• The TSA requirement ensures that the zone’s transmission security margin remains close to zero

(Need – Import Limit)

1 - ( Assumed Unavailable Capacity / Existing Resources)TSA Requirement

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Methodology, cont.

• Example:

• The proposed TSA requirement formula is based on the assumption that the amount of assumed unavailable capacity, prior to the N-1 or N-1-1 state, is proportional to the amount of existing resources

– In the prior example, it is assumed that 500/10,000=5% of the resources will be unavailable on forced or maintenance outage, prior to the N-1 or N-1-1 state. This assumption is maintained regardless of the amount of existing resources that is assumed in the sub-area

Subarea 90/10 Load 8 300Reserves (Largest unit or loss of import capability) 1 200

Subarea Transmission Security Need 9 500Existing Resources 10 000Assumed Unavailable Capacity 500Subarea N-1 Import Capability 2 500

Subarea Available Resources 12 000

Subarea Transmission Security Margin 2 500

(9 500 – 2 500)

1 - (500/ 10 000)TSA Requirement 7 368 MW

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Methodology, cont.

• The TSA requirement calculation is an approximation, due to:– The use of static transmission interface transfer limits

– The reliance on specific scenarios (“Line-Gen”) and (“Line-Line”)

– The nature of the calculation• The term [Assumed Unavailable Capacity / Existing Resource] in the above

equation depends on the actual proportion of regular generation, peaking generation, intermittent resources, Real-Time Emergency Generation (RT-EG), active non-RTEG Demand Resources (DR) and passive DR

– The fact that the energy Load Zones boundaries do not exactly correspond to the real operating boundaries

• Real operating boundaries are based on the limiting constraints that define a zone’s import capability and the ability of the generation within the zone to alleviate those constraints

• The TSA requirement is calculated based on the zone’s real operating boundaries and is an approximation for what the requirement would be for the energy Load Zone

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FCA 2014/15 TSA Assumptions

• Load Forecast Data

– 2010 CELT forecast

• Connecticut sub-area 90/10 peak load*: 8,240 MW

• Boston sub-area 90/10 peak load*: 6,325 MW

• Resource Data**

– Generating Capacity

• Connecticut sub-area existing qualified capacity: 8,408 MW

– Includes 6,686 MW of regular generation resources, 193 MW of intermittent generation resources and 1,529 MW of peaking generation resources

• Boston sub-area existing qualified capacity: 3,351 MW

– Includes 3,047 MW of regular generation resources, 70 MW of intermittent generation resources and 234 MW of peaking generation resources

*The 90/10 peak load for the sub-area differs slightly from the 90/10 peak load for the Load Zone.** Totals are approximate as they may include rounding and/or minimal changes due to data collection timing.

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FCA 2014/15 TSA Assumptions, cont.

• Resource Data*

– Passive Demand Resources

• Connecticut sub-area existing qualified capacity: 423 MW

• Boston sub-area existing qualified capacity: 236 MW

– Non-RTEG Active Demand Resources



– Real-Time Emergency Generation



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* Totals are approximate as they may include rounding and/or minimal changes due to data collection timing.



FCA 2014/15 TSA Assumptions, cont.

• Resource Unavailability Assumptions

– Regular Generation Resources - Weighted average EFORd

• Connecticut sub-area: 5%

• Boston sub-area: 7%

– Peaking Generation Resources - Operational de-rating factor

• Connecticut and Boston sub-areas: 20%

– Passive Demand Resources: 0%

– Non-RTEG Active Demand Resources - De-rating based on performance factors



– Real-Time Emergency Generation - De-rating based on performance factors



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fifth forward capacity auction transmission security analysis requirements

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