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Entergy Transmission's Facility Connection Requirements Document

Entergy Transmission's Facility Connection Requirements Document (pdf)

January 13, 2003 Revision

Revision Details

Entergy Transmission's Facility Connection Requirements document was created in response to NERC Planning Standard section I.C. This document applies to all generation, transmission, and end-use customers wishing to interconnect to Entergy's transmission system. As stated in the introduction of the standard,

All facilities involved in the generation, transmission, and use of electricity must be properly connected to the interconnected transmission systems to avoid degrading the reliability of the electric systems to which they are connected. To avoid adverse impacts on reliability, generation and transmission owners and electricity end-users must meet facility connection and performance requirements as specified by those responsible for the reliability of the interconnected transmission systems.

This document includes:

  • Procedures and requirements for generation interconnection
  • Non-Utility Generator Interconnection Requirements Standard
  • Customer-Owned Substation Guideline
  • Voltage Fluctuations Operations Guideline
  • Typical Interconnection and Operating Agreement
  • Typical Operating Agreement for Customer-Owned Substations

Download Files

Facility Connection Requirements (pdf)

   Standard Forms (Included in PDF file above but offered in Word below)

  • Interconnection Study Letter Agreement ( Word)
  • Facilities Study Letter Agreement (Word)
  • Partial Facilities Study Letter Agreement (Word)
  • Reimbursement Agreement (Word)
  • Network Resource Interconnection Study Letter Agreement ( Word)

Interconnection Study Data Requirements


FAQs for Generation Interconnection Requests

Getting Started

Deposit Policy

Interconnection Study

Interconnection Study Results

Other Required Studies

Next Steps


Getting Started

Q. Who do I contact to request an interconnection?

A. Thomas Lanigan, Manager of Transmission Project Development. E-mail address: tlaniga@entergy.com.  Phone (504) 310-5866


Q. What are the required studies?

A. An Interconnection Study will be performed upon request by the customer. The Interconnection Study has two phases. Phase one is the Feasibility Study, which is a quick look study that determines the local area transmission constraints for various generation output levels up to the customer specified generation output level. Phase two is the Detailed Interconnection Study, which includes AC load flow, short circuit, and stability analyses. This study identifies any additional transmission constraints for a fixed level of generation output as specified by the customer.

Following the Interconnection Study is the Facilities Study, which will further refine the solutions proposed in the Interconnection Study. A scope document will be provided with the customer requirements, estimated projected schedule, and refined cost estimates.

The successful completion of either the Interconnection Study or the Facilities Study does not guarantee the customer the right to transmission service. Transmission service can only be obtained from the customer's request on Entergy's OASIS web site
http://oasis.e-terrasolutions.com/OASIS/EES and upon the completion of a System Impact Study, if required.


Q. What steps do I have to follow to request the Interconnection Study?

A. The customer must first sign the Interconnection Study Letter Agreement and provide the required study data. This Agreement should be sent to the Manager of the Transmission Project Development group, whose phone number and e-mail address are given above.


Q. What are the deliverables of the Feasibility Study?

A. The deliverable of the Feasibility Study is a report that identifies the transmission constraints with various generation output levels up to the customer specified generation level. A rough cost estimate for relieving each constraint will also be provided.


Q. What are the deliverables of the Interconnection Study?

A. The deliverable of the Interconnection Study is a report that compiles results from the AC Load Flow, Short Circuit/Breaker Rating, and Transient Stability analyses. It will also contain a description of the necessary upgrades (required and optional) along with high level cost estimates. This report will build upon the results of the Feasibility Study.


Deposit Policy

Q. What is Entergy Transmission’s policy on generator interconnection study deposits?

A. In evaluation of the deposit policy at Entergy for customers engaged in interconnecting generation to the transmission grid, the following deposits will be required effective May 23, 2002. This requirement is due to the current business climate and the decision by Entergy management not to accept financial risk during the performance of these studies. Entergy will enforce this policy for all studies going forward:


Interconnection Study - Feasibility Study Phase $10,000

Interconnection Study - Detailed Study Phase Estimated full cost of study

Partial Facilities Study or Facilities Study $50,000


During a Partial Facilities Study or a Facilities Study, customers will be billed monthly on actual costs accrued, provided at least $10,000 of cost have accrued in a given month.


Interconnection Study

Q. Why are interconnection studies needed?

A. The interconnection studies are performed to ensure the security and adequacy of the Entergy transmission system. The addition of a generator onto the Entergy transmission system may have a significant impact on the operation of the system. Several factors may be affected and must be analyzed prior to the addition of generation. These include system stability, fault duty of existing equipment, overloading problems, and voltage violations.


Q. What are the steps in performing an interconnection study?

A. The customer must first request the study to be performed by signing an Interconnection Study Letter Agreement. Then, the customer must provide complete and accurate data to Entergy. Entergy will execute phase one of the Interconnection Study, the Feasibility Study. The Feasibility Study results will be provided to the customer within 20 days. The customer must then confirm in writing whether to proceed with the Detailed Interconnection Study, which is phase two of the Interconnection Study. If the customer chooses to proceed, Entergy will perform the Detailed Interconnection Study and provide the customer with refined results.  The customer's failure to notify or submit detailed data within 20 days of receipt of the Feasibility Study report will cause Entergy to place customer's project on hold for an additional 30 days and provide the customer with notice thereof.  If the customer is placed on hold for failing to provide either detailed data or notification to proceed with the Detailed Interconnection Study, Entergy will cancel the study at the end of the 30-day hold period, and the customer will have to submit another study request to establish a new queue position.

Q. What are the models used? Can we get those models?

A. For the load flow and transient stability analyses, Entergy uses an internal model that is both load flow and transient stability compatible. The models are modified to reflect the projected load for the expected in-service year. Firm transmission transactions are also modeled.

Entergy will not provide these internal study models to the customer. However, the customer can obtain the SERC model, which contains the Entergy system, from the SERC office.

Q. Are the Interconnection Studies performed independently? Why?

A. Yes. Under Entergy's study process, once a project has been studied and an Interconnection and Operating Agreement has been executed, it is included in the base case, assuming no power is flowing across the Entergy Transmission System. Once transmission service has been reserved, then the project and the flow of power is included in the base case. Such a study approach is in conformance with the FERC's requirements in New England Power Pool, 85 FERC 61,141 (1998) ("NEPOOL"), reh'g denied, 87 FERC 61,347 (1999). In that proceeding, NEPOOL proposed additions to its tariff establishing procedures for new generators to interconnect to the NEPOOL grid. The procedures proposed by NEPOOL required that the interconnection studies include an assumption that (1) "each planned generator must be guaranteed an exclusive and unconstrained firm transmission path to reach every load serving entity in NEPOOL;" and (2) "all proposed projects already in the queue for service under the NEPOOL Tariff are completed and placed in operation." NEPOOL, 85 FERC at 61,550-51. The Commission rejected NEPOOL's proposed tariff language and stated that

[If all of these generation projects [NEPOOL new generation requests] are developed, there would be a surplus of generating capacity within NEPOOL. Accordingly, it is unlikely that all of these generation projects will be constructed and, if constructed, it is likely that many will displace more expensive resources in serving existing load. If transmission expansion were based on the unrealistic assumption that all planned projects will be constructed and that all need a separate and exclusive firm transmission path to reach all load in NEPOOL, the transmission system would be significantly oversized.  Id.

The FERC then went on to state that the "ISO-New England may limit its analysis to the system reliability, stability and operating considerations of the actual interconnection." Id. (emphasis added).

Q. Can other applicants "leap frog" me in the study queue?

A. The only instance in which one customer may "leap frog" another in the study process is when a customer does not provide adequate data to Entergy to initiate a study. Customers with incomplete data will be placed on hold until the required information is provided. Accordingly, a customer that is on hold because it has failed to provide adequate information may receive its final interconnection study report later than the subsequent customer(s) in the queue. Utilizing this process allows those customers that have provided the necessary information not to be delayed by those customers that have not yet provided such information.

Q. How much does the interconnection study cost?

A. The approximate cost of performing the interconnection study is $60,000. However, the customer will be paying for actual costs.

Q. Can I perform the studies myself?

A. No. Entergy accepts only those studies that are performed by Transmission personnel and Entergy-approved contractors.

Q. How long does it take to perform a Detailed Interconnection Study?

A. At present, once a study is initiated and complete study data are provided, an Interconnection Study can be completed within six to eight weeks.

Q. What are the data requirements for the Interconnection Study?

A. The preliminary data requirements can be found in the Entergy's "Facility Connection Requirements" document. More detailed data will be requested from the customer before the study can be initiated. The detailed data will include generator, governor, exciter, and stabilizer modeling information. These data sheets can be obtained from the Manager of the Transmission Project Development Group.

Q. Will the study requests and study results be kept confidential? When will they be made public?

A. Yes. In order to ensure compliance with the Entergy Corporation Standards of Conduct Regarding the Relationship Between Transmission System Operations and the Wholesale Merchant Function ("Entergy's Transmission Standards of Conduct"), the Entergy Operating Companies have maintained as confidential the customer-specific information acquired from parties requesting to interconnect to the Entergy transmission system. Consistent with paragraph 2(c) of Entergy's Transmission Standards of Conduct, only that customer-specific information that is required to be posted on the OASIS or that is contained in Interconnection and Operating Agreements that have been executed by the customer and filed with the FERC is made public by the Entergy Transmission Organization.

Q. After I have submitted an interconnection study request, can I still retain the same queue position if I decide to increase the generator output, change the site, or voltage level (i.e., 230kV connection versus 138kV connection)?

A. No. If a customer wishes to increase the generation output level, change the site, or voltage level, a separate interconnection study must be requested. This will be added to the end of the queue. Each request has to be generation level, site, and voltage level specific.

Q. If I decide to cancel an interconnection study request in which Entergy has to yet to start, can I move another one of my requests, which is further down in the queue, to the cancelled position?

A. No. To ensure fairness to all applicants in the queue, such a move cannot be accommodated.

Interconnection Study Results

Q. What are optional costs and direct costs?

A. Direct costs are costs for upgrading those facilities that need to be replaced, upgraded, or installed as a direct result of interconnecting the customer facility to the Entergy transmission system. Such facilities are the interfacing facilities, or they may be circuit breakers that are determined to be under-rated due to the addition of the customer's additional generation.

Optional costs are those upgrades that are load flow related. For example, the reconductoring of a line may be required only if the customer's production exceeds a certain level. However, the customer may choose to restrict its production to a level such that the limiting line is not overloaded. In this case, the customer is taking a risk in limiting its generation to a certain level because Entergy will not allow the customer to produce above this limit.

Q. If I make local upgrades based on the Interconnection Study results, what exactly is it buying me?

A. The capabilities of the transmission system are available to all market participants on a first come, first serve basis.  For every dollar the customer contributes toward optional upgrades, the customer receives transmission credits.   These credits can be applied toward future transmission service.

Q. What are transmission credits? How do I use them?

A. System Upgrades that are committed to and paid for by the Customer that are optional (load flow related) will be eligible for transmission credits. A credit will be established for each customer in an amount equal to the investment in system upgrades paid for by the customer. These credits can be used for transmission service originating from the customer's facility.

Other Required Studies

Q. Can a Facilities Study be performed concurrent with the Interconnection Study?

A. Yes. If the customer wishes to obtain preliminary engineering and cost estimates for connecting to Entergy's system, they can initiate this study by signing a "Partial Facility Study Letter Agreement". The main focus of the Partial Facilities Study is the interconnection of the customer facility to the Entergy system. The results provided by the Partial Facilities Study will not be as comprehensive as those of the complete Facilities Study, which is dependent on the outcome of the Interconnection Study. The Partial Facilities Study will only use information that is available at the time of the study. Therefore, a complete Facilities Study is required before the customer can interconnect its facility to the Entergy transmission system.

Q. What's a System Impact Study?

A. The System Impact Study determines if available transfer capability (ATC) is available to accommodate the transfer of power from the generator to the sink as specified in the request. The study identifies regional constraints that might restrict the transfer. For this study, the generator must specify a specific source and sink combination and the requested time period. The results of the study will be available 60 days from the date of the request. Please contact Ollie Burke for further information.

Q. If I wish to interconnect to Entergy's Distribution system, what procedures do I need to follow?

A. Entergy Transmission can direct the customer to the correct contact in Entergy's Distribution Organization, which has its own process for evaluating such a request. Requirements for non-utility generators wishing to interconnect to Entergy's system at 34.5kV and below are governed by Entergy's Distribution Standard DR07-01-0895, which can be provided upon request.

Next Steps

Q. Does signing an Interconnection and Operating Agreement provide any rights to transmission service?

A. No. An Interconnection and Operating Agreement only provides for the connection of a generating facility to the transmission system. Transmission service is requested under a separate process utilizing OASIS.

Q. Can transmission service be granted before the interconnection study is completed? What are my obligations?

A. No. However, the customer can submit a request through OASIS. Entergy will complete a System Impact Study within 60 days as required by the FERC. The service will be granted under the condition that the customer is committed to signing the interconnection agreement.