TRANSMISSION / DISTRIBUTION PROJECTS COMPANY:EAI CUSTOMER: MID AMERICAN ENERGY. FACILITIES STUDY EJO # F4PPAR0422 MID AMERICAN TRANSMISSION SERVICE REQUESTS OASIS 1468288 Revision: 4 Rev Issue Date Description of Revision Revised By 0 9/11/07 Final Draft Issued to ICT GWR Project Manager 1 9/20/07 Revised Draft for Review GWR 2 9/26/07 Revised Study GWR 3 10/9/07 Added comments Section 3.ii GWR 4 10/12/07 ICT Review JDL JH Entergy Transmission Business Page 1 of 8
AECI AFC AMRN ATC ICT EES MVA MW OASIS OATT SOCO TSR TTC Acronyms Used in this Study Associate Electric Cooperatives, Incorporated Allowable Flowgate Capacity Ameren Corporation Control Area Available Transfer Capability Independent Coordinator of Transmission Entergy Control Area Mega-Volt Amp Mega-Watt Online Access and Same-time Information System Open Access Transmission Tariff Southern Company Control Area Transmission Service Request Total Transfer Capability Entergy Transmission Business Page 2 of 8
Table of Contents Section Title Link to Page 1. EXECUTIVE SUMMARY...4 2. SAFETY AWARENESS...5 3. SCOPE SUMMARY...5 I. Contract Path Allocation Modification... 5 II. New Madrid Substation... 6 4. SCOPE DETAILS...6 5. COSTS...7 6. SCHEDULE...7 7. ATTACHMENTS...7 A. Location Drawings... 7 B. One Line Drawings... 7 Entergy Transmission Business Page 3 of 8
1. EXECUTIVE SUMMARY Mid American Energy (Customer) submitted a transmission service request for long term firm point to point service for 103 MW from Ameren Control Area (AMRN) to Southern Company Control Area (SOCO). The time period for this transfer is from 1/1/2008 until 1/1/2009. The direction of the transaction is AMRN to SOCO. This facility study identifies substations that must be upgraded in order to mitigate undesirable system conditions. This facility study is a unique study in that it impacts not only Entergy, but also Ameren and AECI. Entergy cannot determine the final list of upgrades until a solution for increasing the AMRN-AECI-EES contract path is finalized between the three parties. No additional studies were performed to determine any other facilities required for this Transmission Service Request to be available. Entergy is willing to jointly work with the affected systems to determine the final solutions for granting this service, but any additional studies Entergy performs at this time would not provide much in the way of useful results. Under Entergy s Independent Coordinator of Transmission which became effective on November 17, 2006, Entergy will recover these costs based on the Attachment T to our OATT. The ICT has not classified any upgrades, but will evaluate any future solutions. Pending the results of AECI s Affected System Study and coordination between AMRN-AECI-EES, any changes will need to be reviewed by the AMRN- AECI-EES contract path parties. The single connection between Entergy and AMEREM is the 500 kv line connecting Entergy s Dell Substation and AECI s New Madrid Substation. The limiting element for power flow on this line is the transformation capability at the New Madrid substation. The transformation limit is 1500 MVA. This interface capability has been split on an equal basis with 500 MVA to AMEREN, 500 MVA to AECI and 500 MVA to Entergy. Since the original TSR was queued, the methodology for allocating the Ameren/Entergy, & the AECI/Entergy contract path limits was modified. (See OASIS posting at: http://oasis.e-terrasolutions.com/documents/ees/amrnaeciinterfaces.pdf). Entergy allocates its 500 MVA share to transmission service customers on a first come first served basis. This allows AMEREN to have a possible contract limit on this interface of 500 MVA to 1000 MVA depending on the timing of the requests received. The exact amount available to AMEREN is a dynamic amount that can only be provide by the ICT due to competing requests and rollover rights that may or may not be confirmed. Entergy Transmission Business Page 4 of 8
2. SAFETY AWARENESS Safety is a priority with Entergy. Safety will be designed into substations and lines. The designs will be done with the utmost safety for personnel in mind for construction, operation and maintenance of the equipment. Should the work contained within this Facility Study be approved, a detailed Safety Plan will be formulated and incorporated within the project plan. All employees working directly or indirectly for Entergy shall adhere to all rules and regulations outlined within the Entergy Safety manual. Entergy requires safety to be the highest priority for all projects. All Entergy and Contract employees must follow all applicable safe work procedures. 3. SCOPE SUMMARY I. Contract Path Allocation Modification The existing 500 kv transformers at the New Madrid substation limit the interface capability to 1500 MW. Each of the parties connected to this interface split capacity on an equal basis with 500 MW allocated to Ameren, 500 MW allocated to AECI and 500 MW allocated to Entergy. Previous Allocation Summary One third of the 1500 MW thermal capability of the New Madrid interface is allocated to each party (500+500+500) One half of the resulting 500 MW Entergy portion is made available to the AMRN path and the other half to AECI path The New Madrid interface is the only tie to AMRN so the AMRN interface limit = 1/3(New Madrid thermal limit) + ½(Entergy s third) = 500 MW+ ½(500) MW = 750 MW AECI has additional ties to Entergy. The thermal limit of those ties is 805 MW. The AECI interface limit = 805 MW + 750 MW= 1555 MW Total Interface Limit on AECI path and Ameren Path = 750 + 1555 = 2305 Beginning September 2007, Entergy modified the split allocation and allocated its 500 MW share on a first come first served basis. This will allow Ameren path to have a contract limit on this interface of up to 1000 MW and the AECI path up to 1805 MW, depending on the timing of the requests received. This change of the contract interface will allow more efficient use of available transmission service. Revised Allocation Summary The 500MW Entergy portion will be made available on a first come first serve basis New AMRN interface limit = 500 MW + 500 MW (if available) Entergy Transmission Business Page 5 of 8
AMRN s 1/3(New Madrid interface) + Entergy s 1/3(New Madrid interface) New TTC = 1000 MW New AECI interface limit = 805 MW+ 500 MW+ 500 MW (if available) AECI tie lines + AECI s 1/3(NM-Dell) + Entergy s 1/3(NM-Dell) New TTC = 1805 MW A new North Interface Limit Flowgate (NIFL_TieCap) will ensure that the total simultaneous transfers across the AMRN and AECI interfaces do not exceed the existing limit. The total North Interface Limit will remain unchanged at 2305 MW, and the total transactions across both paths will be limited to 2305 MW. The Facility Study has identified one transmission constraint, but cannot determine the final list of upgrades until a solution for increasing the AMRN-AECI-EES contract path is finalized between the contract path participants. The constraint can be addressed in the following manner: II. New Madrid Substation An increase in the contract limit on this interface will require the installation of additional transformer capacity at the AECI New Madrid Substation. To grant the transmission service, the EHV auto-transformers at New Madrid must either be upgraded to allow the full 3000 amp capacity across the Ameren contract path or additional EHV transformer capacity must be installed. Feedback from Siemens has indicated that the current delivery time for large EHV auto-transformers is 26 months if ordered from Brazil and 48 months if ordered from Germany. These lead times are consistent with recent Entergy experience. It will be necessary to coordinate with AECI for the Affected System Study. 4. SCOPE DETAILS Required Transmission Upgrades I. New Madrid Substation This substation is owned by AECI. The ICT has notified AECI that they are an affected system from this facility study. AECI will determine the required transmission upgrades needed to accommodate this request from an Affected System study. This information is included to provide a complete scope of work; however, this work will be done by other entities. Upgrade to allow the full 3000 amp capacity across the Ameren contract path or additional EHV transformer capacity must be installed. Yet any changes on the affected party s side will need to be reviewed by the AMRN-AECI- EES contract path parties. Entergy Transmission Business Page 6 of 8
5. COSTS The ICT has no upgrades to review since Entergy cannot determine the final list of upgrades until a solution for increasing the contract path is finalized. The cost estimate for work at the New Madrid substation should be provided by AECI. Should upgrades be needed on the Entergy system resulting from AECI s completed Affected System Study, the ICT will then make a determination of the upgrades. For more information on cost responsibility for Base Plan and Supplemental Upgrades, see Attachment T to Entergy s OATT. 6. SCHEDULE Software changes have been implemented to make Entergy s 500 MW portion of the contract path capacity of the New Madrid Dell 500 kv line available to the market on a first come, first served basis. A detailed schedule will be prepared subsequent to customer approval. The line upgrades are dependent on obtaining outages for the line work. If outages cannot be obtained or must be sequenced due to seasonal requirements, additional time will be required to complete the upgrades. 7. ATTACHMENTS Description A. Location Drawings Page Dell New Madrid Area A-1 B. One Line Drawings Description Page Dell Substation Sheet 1 B-1 Dell Substation Sheet 2 B-2 Entergy Transmission Business Page 7 of 8
Dell New Madrid 500 kv Line Segment Line #866 A-1 Arkansas Missouri Border 9.4 Miles 3/B 954 MCM ACSR Entergy Transmission Business Page 8 of 8