Generator
Interconnection
Studies &
Agreements
Charles Hendrix
Generator Interconnection Service
•
Energy Resource Interconnection Service – allows a
generator to be eligible to use the existing firm or
non-firm capacity of the Transmission System on an
“as available” basis
– Customer must still request Transmission Service
•
Network Resource Interconnection Service – allows
the Transmission Owner to construct the necessary
upgrades to integrate the generator into the
Transmission System in a manner comparable with
other Network Resources
– Customer must still request Transmission Service
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Generator Interconnection Service
•
Neither Energy Resource Interconnection Service
or Network Resource Interconnection Service gives
the generator any right to deliver energy to any
customer or point of delivery
3
Generator Interconnection Studies Process
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Definitive Interconnection System Impact Study
(DISIS) – Studied in Clusters
•
Facility Study
•
Limited Operation Study
•
Interconnection Agreement
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DISIS – Powerflow Analysis
• Models built from the Integrated Transmission
Planning Models
• Includes all upgrades with NTC
• Includes a look over the 10 year planning
horizon so no short term outages accounted for
• SPP Footprint divided into 12 sub-regions
(groups) for interconnection study purposes
5
DISIS – Powerflow Analysis
• Distinct dispatch for each interconnection
request in the cluster study for each season
• All Energy studied to be sunk in SPP footprint
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DISIS – Powerflow Analysis
•
AC Contingency Analysis
•
Constraints Identified and transmission
reinforcements required for
– ERIS – overloads with 20% sensitivity factor
– NRIS – overloads with 3% sensitivity factor
•
Neither ERIS nor NRIS conveys right to deliver
•
Upgrade Costs shared on a MW impact basis
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DISIS – Transmission Upgrades
•
If long lead time upgrades with NTC are found to
mitigate the constraints identified in the DISIS
Study, this is documented in the study as a
required upgrade for the Generator
•
This requirement also documented in the
Generator Interconnection Agreement (GIA)
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Facility Studies
•
Performed by the transmission owner
•
+/- 20% estimate of interconnection facilities and
network upgrades
•
Short Circuit Analysis – verify circuit breaker duty
ratings
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Limited Operation Impact Study (LOIS)
•
Customer may request to interconnect before the
completion of long lead time upgrades identified
in the DISIS
•
An additional study (LOIS) is evaluated taking the
following into consideration
– Customer’s requested COD
– Higher-queued generation in service

Neglecting generators that haven’t built
– Existing transmission infrastructure
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Limited Operation Impact Study (LOIS)
•
AC Contingency Analysis
•
Constraints Identified – LOIS may be denied (or
temporary cap identified) for
– Overloads with 20% sensitivity factor
•
Otherwise Generator can interconnect on ‘as
available’ basis until higher queued generator
comes into service
•
Conditions documented in GIA
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Interconnection Agreement
•
Draft GIA presented to Customer after completion
of Facility Study
•
Customer given 60 days to negotiate with
transmission owner for construction milestones
•
GIA is finalized, executed, and filed at FERC if
necessary
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Questions
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