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Available Flowgate Capacity (AFC)

Market Training Session on AFC

Cameron WarrenTransmission Business Operations

Houston, TXMarch 9th, 2004

Entergy Services, Inc

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Topics of Discussion

Changes to the OASIS

Redirects

Scenario Analyzer

Market trials

Live demonstration of request submittal

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Contract path TTC/ATC, GOL values no longer posted or used to evaluate reservations Flowgate AFC Values will be used to evaluate reservations

Flowgate AFC values can be viewed using the Query Offerings hyperlink under the Transmission Service section of OASIS

Scenario Analyzer will be used to obtain estimate of ATC/AFC

Several source names will be changed Ownership no longer required with source name on

Reservations

What will change on OASIS?

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Three of the current PORs and PODs will change to reflect registered names on TSIN website CSW will change to CSWS LAF will change to LAFA OGE will change to OKGE

Must choose Source/Sink, POR/POD, but no longer have to pick the path

Typical status flow change Current status change for a typical reservation is QUEUED to RECEIVED to

COUNTEROFFER, ACCEPTED, REFUSED

Future status change for a typical reservation is QUEUED to RECEIVED to STUDY to COUNTEROFFER, ACCEPTED, REFUSED

OASIS Changes (Continued)

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Current practice A redirect is evaluated as a new request, with the original’s effects

removed, if contract path ATC is unavailable, the request is refused

Redirect policy

CSWS SOCORequest #1: 100 MW confirmed Original

LAGN SOCORequest #2: 100 MW received Redirect of #1

If contract ATC was zero, even with request #1 removed,Request #2 would be refused

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Future Practice A redirect is evaluated to see if there is a larger impact on the original

reservation flowgates or any constraints on new flowgates

Redirect policy

CSWS SOCORequest #1: 100 MW confirmed Original

LAGN SOCORequest #2: 100 MW received Redirect of #1

Flowgates B and C do not have any greater constraints.Flowgate D does not have a constraint.Request #2 is approved.

Impacts flowgates A,B,C

Impacts flowgates B,C,D

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The Scenario Analyzer is an OASIS module that allows Transmission Customers to evaluate availability for a Source and Sink pair, providing a “what if” scenario, but does not decrement ATC since no request has been submitted

Scenario Analyzer uses the same form as the normal reservation submittal process Enter the following information:

Source / Sink name POR / POD name Capacity type Begin time / End time (for each time segment) Capacity value (for each time segment)

The Scenario Analyzer notifies the customer if sufficient AFC

exists, displays the limiting flowgate, the hour(s) when the limit exists, the amount of flowgate capacity available and the transfer capability that is available

Scenario Analyzer

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Scenario Analyzer cont.

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Scenario Analyzer cont.

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Market trials

Market trails will be from March 10 at 9:00 AM CST until March 16, 2004 at 1:00 PM CST

Test site: https://oasis.entergytransmission.com/oasis/eesCustomers will be able to submit test requests to get a feel

for the AFC processSupport contact provided from 9:00 AM until 1:00 PM

CST each weekday during trial at (870) 543-5497Email support at OASISSupport@entergy.comMarket encouraged to submit realistic requests to maximize

benefits gained from the trial

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QUESTIONS?

Available Flowgate Capacity (AFC)

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Available Flowgate Capacity (AFC)

Market Training Session on AFC

Uma GangadharanTransmission Operational Planning

Houston, TXMarch 9th, 2004

Entergy Services, Inc

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ATC (Available Transfer Capability) calculated on each of the 15 control area

interfaces with Entergy focus of transfer study is on regional

constraints transfer capability defined by most limiting

element under single contingency

Current Process to Evaluate Reservations

GOL (Generator Operating Limit) generator specific deliverability study instituted to address local area limitations addresses simultaneous impact of generators in

close electrical proximity using local area calculation

alternative to, not a replacement for system impact studies

CLECO

LAFA

AMERENEDE

SPA

OG&E

CSW

AECI

LAGN

LEPA

SOUCO

SMEPA

BATESVILLE

Entergy

TVA

DENL

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• Every study can be source/sink transaction specific• Accurately captures effect of interactions between transactions• Requests evaluated in order and impacts on flowgates continuously

updated• Assesses the impact of each source/sink pair on each monitored

flowgate• Can monitor all critical flowgates on the Entergy system

For a request of 100 MW from Source A to Sink B, response factors will be

calculated for every monitored flowgate and the impact of the transaction on

each flowgate will be evaluated before the

request can be approved

100 MW100 MWSource A Sink B

Flowgate #1

0.20.2

0.10.1

Base Flow + 20 MWBase Flow + 20 MW

Base Flow + 10 MWBase Flow + 10 MW

RFRF

RFRF

Flowgate #2

Net flow increase on flowgate as a

result of transaction

Available Flowgate Capacity (AFC) method

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Graphical Representation of AFC

Transfer 1: 1000 MW SRC1 to SNK1 (2.5%, 5%, 10%)

Transfer 2: 500 MW SRC2 to SNK2 (10%, 8%, 3%)

Transfer 3: 600 MW SRC3 to SNK3 (15%, 15%, 10%)

Flowgate 1 – 300 MW Rating Flowgate 2 – 250 MW Rating Flowgate 3 – 150 MW Rating

100

200

300250

150

50

150

100

50100 50 25

+25 +50 +100+50 +40

+15+ 15 +15

)/()( factorresponseBaseflowRatingATC scommitmentprioreffective

Effective ATC (150-140)/(0.1)

= 100 MW

Approved

Counter Offer – 100 MW

Approved

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Horizons in AFC Calculation

• Operating (12 – 36 Hours)

• Planning (End of Operating – Day 31)

• Study (Month 2 – 18)

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Benefits of AFC Utilization

• More accurate representation of system transfer capability

• Maximizes throughput and enhances system reliability

• Process lends itself to more efficient short-term market operation

• Each request evaluation is like an SIS

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How will AFC improve accuracy of transfer capability determinations?

• Transfer capability determinations are based on power flows from specific generator sources rather than control areas.

• Evaluation of service requests based on actual impact on specific transmission facilities.

• Simultaneous impacts of other transmission reservations and schedules are more appropriately accounted for.

• Use of frequently updated data inputs derived from real-time or near-term system conditions.

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How will AFC facilitate the short-term market?

• System Impact Study no longer necessary to evaluate transfer capability for short-term requests.

• The speed of the analysis is vastly improved over current ATC/GOL methods.

• AFC does not depend upon a pre-calculated contract path non-simultaneous value.

• Capacity that is withdrawn is reclaimed and made available to the market quickly.

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Differences between AFCs and GOL/ATCs

• GOL/ATC restricted to lowest of transacted path, otherwise SIS. AFC is source/sink based, therefore more accurate and consistent with SIS process.

• GOL/ATC is based upon daily/monthly models. AFC will be based upon hourly/daily/monthly models.

• Models for GOL/ATC include monthly and yearly reservations. With AFC, increased automation allows for daily/weekly reservations/schedules to also be modeled.

• Coordination of GOL/ATC models are performed quarterly/monthly with neighbors. Continue coordination of models with AFC, in addition near real-time data will allow for improved accuracy of parallel flow impacts on flowgates.

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Differences between AFCs and GOL/ATCs

• Predetermined GOL/ATC values posted on OASIS. AFC values on monitored flowgates will be posted on OASIS and available capability obtained through scenario analyzer.

• GOL is an alternative to, not a replacement for SIS. With AFC, TSR is evaluated with most up-to-date model, therefore AFC evaluation is much like SIS.

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• OASIS automation provides interface for granting and reserving transmission service based on calculated AFC values

• Scenario Analyzer provides an instant “study” of the request

• Scenario Analyzer is a study tool – service is granted only for actual requests on OASIS

• OASIS automation evaluates each request sequentially – automatic impact study process

Overview of OASIS Automation

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Implementation Timeframe

• Compliance filing due on March 12

• Market trials will start on March 10

• AFCs go live on April 1

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QUESTIONS?

Available Flowgate Capacity (AFC)