www.spp.org
1
Concerns
Tag Non Firm
Option
October 10, 2010
Bert Bressers
***Confidential***
www.spp.org
2
Concern 1. Tag Non Firm Option

SPP doesn’t think it is possible to capture all the Non Firm within the SPP Market
footprint (15 BA’s) with Non Firm Tags.

SPP has an Energy Imbalance Market for 15 BA Areas in Nebraska, Kansas,
Oklahoma, part of Missouri, part of Texas, part of Arkansas, part of New Mexico.

The 15 BA’s are still Tagging imports and exports and besides that each BA submits
Firm Native Load schedules (not Tagged) from the DNR’s to the Native Load
supported by NITS reservations.
So basically all Load in the SPP Market footprint is covered with Schedules and Tags.

The SPP Market Software (SCED) runs every 5 minutes, takes the Tags and
Schedules, Load and Offercurves of Resources and calculates the best possible
(constrained) economic dispatch solution. The Systems sends out dispatch
instructions to all resources of the Market footprint (every 5 minutes) and sends out
an NSI EIS value (Energy Imbalance NSI) to the 15 BA Areas. The 15 BA’s have to add
the NSI EIS to their NSI value based on Tags for AGC and ACE Control of the BA.

The Energy imbalance that flows between the 15 BA’s of the SPP EIS Market is
considered Non Firm (NN6 on CF flow gates and NH2 and NN6 on RCF flow gates).
And the Non Firm Energy Imbalance exchanged between the 15 BA’s is most likely
Energy Imbalance between Firm DNR resources in different BA Areas. Although the
DNR’s by itself are Firm, the Energy Imbalance they supply to Neighboring BA’s or
absorb from Neighboring BA’s of SPP Market footprint is Non Firm.
***Confidential***
www.spp.org
Concern 1. Tag Non Firm Option
Firm Resource
Non Firm Resource
FirmTag
NonFirmTag
SPP Market footptrint
tag
OPPD
Non Firm EIS
Not scheduled
tag
NPPD
EIS
EIS
EIS
EIS
INDN
MPS
LES
tag
EIS
EIS
EIS
KACY
SECI
EIS
WR
tag
tag
EIS
WFEC
EIS
KCPL
EIS
GRDA
EIS
EDE
OKGE
SPS
EIS
tag
tag
tag
EIS
CSWS
Every BA of the Market imports or exports
Un-scheduled Non Firm Energy Imbalance (EIS)
***Confidential***
www.spp.org
tag
Concern 2. Tag Non Firm Option

The Tag Non Firm Option doesn’t put any limitation on DNR’s within Markets (that original
consisted of BA’s, now called Regulation Zones) to supply Load of other Regulation
Zones within that Market footprint and qualify all of that flow as Firm flow causing Firm
impacts on all flow gates.

During “low” load situations there is an excess of Firm DNR capacity within Markets (and
also within Non Market BA’s).
Using all Firm DNR Resources in the North as an example to serve a large part of Load in
South can cause a major parallel flow on flow gates of Neighboring RC’s. All of those
impacts would be considered Firm in the “Tag Non Firm option” because it is sourcing
from Firm DNR, however it might not be “deliverable” without over-loading a Neighboring
flow gate with Firm forcing a TLR Level 5 on that Neighbors flow gate.
This is an undesired situation.
The Firm rights on Neighboring flow gates should some how be limited to a “deliverable”
situation, to allow the TO and BA that owns the flow gate to use at least its Firm rights.

The current CMP process limits Firm rights to more or less a “deliverable situation”.
The CMP Allocation process splits up the Firm Rights on flow gates based on historical
impacts. In the example above, the CMP Allocation approach would allow a certain
amount of Firm on a flow gate while the remainder of the Firm flow from DNR’s in the
North serving Load in South would be reported as Non Firm. The loading of the
Neighboring flow gate would be most likely resolved and controlled with Non Firm
curtailments in TLR Level 3.
***Confidential***
www.spp.org
Concern 2. Tag Non Firm Option
Firm Resource on line
X
Example: excess of DNR Capacity
in North during low Load situation
Market Area
Firm Resource off line
Regulation Zone B
Regulation Zone B
High Firm
Parallel flow
From Market
Regulation Zone B
Regulation Zone B
X
Regulation Zone B
X
X
X
X
Note: A Regulation Zone was a separate BA Area pre-Market
***Confidential***
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Neighboring
flow gate
Concern 3. Tag Non Firm Option

It will be difficult to measure if Markets (and maybe Non Market BA’s) are
accomplishing their relief obligation in case of the Tag Non Firm option.
If a Non Firm Tag is curtailed the Tag Non Firm option assumes that the resource that
is the source on Non Firm Tag will be re-dispatched down to the curtailed level of the
Non Firm Tag. That is not the case in Markets and maybe it is not case for Non Market
BA’s either.

Markets are re-dispatching the most expensive resources first (either Firm or Non
Firm) when Non Firm relief is required, they don’t re-dispatch Non Firm resources
before Firm resources and they don’t dispatch a single resource down that is the
source of a Non Firm Tag that is curtailed. The SCED software used by Markets don’t
allow for that.

If a non Firm Tag is curtailed the Resource that is the source on that Tag might stay
on same output level while other Firm and maybe Non Firm resources within the
Market are accomplishing the relief obligation.
If during the TLR event the Load increases and as result the Firm impact of the Native
Load part on flow gates increases it will be difficult to determine if the Market is (still)
accomplishing its Non Firm relief obligation with Firm re-dispatch during TLR.

Also the impact of the Tag is calculated based on GLDF from resource to weighted
average load of the BA or Market area, while relief is accomplished by re-dispatching
2 or more resources within the Market or BA. So the relief accomplished by Non Firm
Tag curtailment should be translated into a Non Firm re-dispatch obligation and Firm
re-dispatch should be credited against Non Firm relief obligation.
***Confidential***
www.spp.org
Concern 3. Tag Non Firm Option
Market or non Market BA
200100 MW
200150 MW
200 MW
Tag
200 0 MW
200100 MW
Load
Flow gate in TLR Level 3
200250 MW
Tag
200 MW
200 MW
200400 MW
Firm Resource
Non Firm Resource
NonFirmTag
***Confidential***
TLR Called on flow gate.
IDC curtailed Non Firm Tag to 0
Relief accomplished with Firm
Re-dispatch
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200 MW
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