Loading...
HomeMy WebLinkAboutCEA System disturbance Nov 14-1993Vile ey aley pitehoe CHUGACH ELECTRIC ASSOCIATION, INC. Anchorage, Alaska November 23, 1993 TO: File 1051 ee FROM: Daniel C. Rogers, Manager, Facilities nisin IO SUBJECT: System Disturbance of 11/14/93 - ML&P 34.5 kV PT Failure Oo VI OF EVENTS On November 14, at 19:32:15, AML&P experienced a 34.5 kV PT failure at Plant 1. ‘Primary protection reportedly was not in service, and the fault was cleared by second or third stage backup _ overcurrent, in approximately 2.5 seconds. Estimated fault current was 14,000 Amps. At approximately 19:32:17, Eklutna Unit 1, Beluga Unit 8, Teeland Breaker 538, 1310, and Douglas Bl tripped. Maximum frequency was 60.93 Hz; minimum was 59.24 Hz. None of the interconnected systems experienced first = loadshedding. ANALYSIS LE twhy not | System Operations: There were a number of items that could have contributed to a complete collapse of the Anchorage and Kenai systems. These are addressed in D. Burlingames memo of 11/17/93 (attached) . Teeland 538/Douglas Bl/Teeland SVC trips: The Teeland SVC and Teeland 538 tripped out on overvoltage. As can be seen from the Teeland DSM plots, the svc attempted to support the Voltage during the fault. At the time of clearing, the capacitively supported Voltage rose to 17.6 kV on the SVC (13.8 kV) bus, thus tripping the Svc and 538 on overvoltage. Future controls upgrades for the SVC can alleviate this problem by blocking capacitive reactive power during the fault interval. Beluga Unit 8 trip: Beluga Unit 8 tripped on loss of excitation. The loss of excitation relay is sensitive to power system swings. This sensitivity can be lessened by the installation of a supervisory timer. This protection improvement, along with a number of others, was identified to be installed in units 3 and 8 in 1994. Based on discussions with the plant, we will attempt to cut the timer in, hot, after generation schedules allow, approximately December 18. This will fix the loss of excitation tripping, but will leave the rest of the problems identified in the protection system until the 1994 project. Interconne.ted flows: As can be seen on the attached DSM plots from the AML&P 230 yard, P_ "leaned" on CEA based on the predisturbi e schedule, while attempting to restore lqad, its She system frequency was just at nominal, and the Kenai tie was 14 MW over the stability limit of the line. The flow out of Daves Creek reached a peak of 104 MW (143% of the recommended stability limit), which resulted in a calculated Girdwood voltage, at the station, of 92%. See D. Burlingames memo for details. Attachments dcr e:\outdata\931114\931114.out cc: Facilities Outage Book D. Burlingame M. Massin T. Newton 931114 19:32:13 teeland 230 KV bus voltage cycles 280.0 - ~ 229.9 kV @ 199 cy ng —— 262.4 kV @ 363 cy 240.0 [_ 229.1 kV @ 472 cy Z 200 - _* 203.6 KV @ 228 cy 200.0 - — 181.2kV @ 244 ¢ 193.6 kV @ 203 cy 0.0 500, 0 1000.0 1500.0 2000.0 + ~—«-2500.0 += 3000.0-«SS—t«800.0 93111 4 19:32:13 teeland SVC reactive power _ 20.0 fe 14.8 MVAr @ 199 cy -13.9 MVAr @ 252 cy 10.0 0 MVAr @ 367 cy 0.0 7 ea ee am Pat Par or e Sia aaa (as ed Koa 1 -10.0 - -20.0 - /, 30.3 MVAr @ 358-364 cy -30.0 - cs ~~ -48.7 MVAr @ 353 cy 49.0 | 15-4 MVAr @ 208 cy 0.0 | 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 18.0 - 16.0 + 14.0 - 12.0 - —.- 13.9 KV @ 199 cy Pe 17.6 KV @ 359 cy 13.9 k V @ 481 cy p+ 13.1 KV @ 228 cy —~12.3 KV @ 251 cy 12.1 kV @ 203 cy 0. T r 0 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 1931114 19:32:13 teeland 538 MW 6.0 - 4.0 - 2055 0.0 4 0.0 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 cycles 931114 19:32:13 amlp frequency Hertz 60.93 Hz @ 306 cy 61.0 / 931114 19:32:13 amlp frequency - Hz 60.5 | _, 60.00 Hz @ 3799 cy 59.92 Hz @ 950 cy ——— a 60.0 ~—— / ——| 59. 5 a a, 59.24 Hz @ 471 cy 59,98 Hz @ 197 cy 0.0 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 Cycles 931114 19:32:13 amlp auto power 16.1 MW @ 195 cy 27.0 SS “26.1 MW @ 375 cy _- 0.7 MW @ 1047 cy 0.0 ms = | ! il \ 14.4 MW @ 258 cy -27.0 -2.3 MW @ 3799 cy 931114 19:32:13 amlp auto power - Mil -§3.9 4 0.0 475.0 950. 0 1425.0 1900. 0 2375. 0 2850. 0 3325. 0 Cycles 9314 14 19:39:19 amlp frequency - Hz 59. 90 59.88 - 59. 86 il _/ 58.78 Hz @ 2648 cy Hertz 59. 82 59. 80 59.78 ~ 931114 19:39:19 amlp frequency - Hz. t T T T T T a 0.0 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 Cycles 931114 19:39:19 amlp auto power - MW —— 21.3 MW @ 3799 cy 2k 15.26 MW @ 0 cy 20. 3 ie 13.5 7 | 68 4 931114 19:39:19 amlp auto power - MW 0.0 475.0 950. 0 1425. 0 1900. 0 2375. 0 2850. 0 3325. 0 Cycles 931114 19:47:14 amlp frequency 59. 870 B59. 860 HTT I | Hl il { 1 AANA 59. 850 931114 19:47:14 amlp frequency - Hz 0.0 500. 0 1000. 0 1500. 0 2000. 0 2500. 0 3000. 0 3500. 0 Cycles CHUGACH ELECTRIC ASSOCIATION, INC. Anchorage, Alaska November 19, 1993 TO: Gene Bjornstad, Executive Manager, Operating Divisions FROM: David W. Burlingame, Manager, Power cxf SUBJECT: AML&P 34.5 kV Fault November 14, 1993 The following is a preliminary review of the events surrounding the above disturbance: 19:32:15 AML&P experiences a fault on their 34.5 kV system. Due to clearing problems, the fault is present for 2.5 seconds. Prior to fault, AML&P is receiving 18.8 MW from the CEA system on a scheduled interchange. 19:32:20 Eklutna unit 1 tripped, Teeland breaker 538 tripped (intertie breaker feeding Douglas), Teeland breaker 1310 tripped (Teeland SVC breaker), Douglas breaker B1 tripped (breaker feeding intertie), Beluga unit 8 tripped. AML&P contributes 19 MW of spin into the Chugach system. Interchange between the two utilities is 2.6 MW. (AML&P contribution is essentially their Bradley power) 19:32:48 Frequency restored to normal 19:32 - 19:36 unable to contact AML&P Dispatch 19:37 - Chugach Dispatch contacts AML&P Dispatch and asks if the Intertie 538 was the problem, AML&P states no the problem was in their 34.5 kV system. Chugach states they believe they have enough generation to cover loss of unit 8. (neither Chugach or AML&P the Eklutma operator were aware that Eklutna 1 had also tripped) AML&P has reduced their contribution to 9 MW. 19:38:55 Frequency dips below 59.90 and begins to fall. AML&P (the Eklutna operator) still has not voided the Eklutna schedules and is apparently not on flat frequency control (which would have in effect canceled Eklutna scheduled). AML&P contributing 15.5 MW to the Chugach system. Chugach begins attempts to contact AML&P Dispatch to request generation assistance (Due to the frequency decay, assistance should have been automatic) 19:39:47 AML&P appears to return to tie-line bias or takes some other action, begins to increase energy take from the Chugach system 19:41:03 AML&P appears to incorrectly return to the pre-disturbance schedule, taking 19.0 MW from the Chugach system. Frequency 60.0 Frequency excursions begin to occur. wn 19:44:22 IGT unit 2 start command given, Beluga unit 1 attempted to start 19:45:03 AML&P off original schedule, taking 21.8 MW from Chugach, frequency decay begins again. Daves Creek line to 86 MW. 19:46:03 AML&P taking 24 MW frum Chugach. Frequency decay to 59.96 Daves Creek tie loading 89.0 MW. 19:47:03 AML&P taking 27.7 MW from Chugach, frequency decay to 59.88. Daves Creek tie loading to 92.1 MW 19:47 Chugach contacts AML&P and asks for generation assistance, AML&P states they have 50 MW of spin and Chugach requests 30 MW. Chugach — to manually drop load in the Anchorage area to avoid overloading the Kenai tie-line. 19:48:03 AML&P taking 31.1 MW from Chugach system. Frequency 59.86. Daves Creek tie loading to 94.4 MW 19:49:03 AML&P taking 32 MW from Chugach system. Frequency 59.87. Daves Creek tie 96.3 MW. Tie peaks out at 104 MW. 19:50:03 AML&P begins reducing take from Chugach system to 26.7 MW. Frequency recovers to 60 Hz. Daves Creek loading decreases to 93 MW. 19:52:07 AML&P increases take from Chugach to 36.2 MW. Frequency 60 Hz. Daves Creek tie loading increases to 94 MW 19:53:03 AML&P increases take from Chugach system to 41 MW, frequency 60 Hz, Daves Creek tie loading 93 MW. 19:53 IGT start sequence failed, Beluga unit 1 starts aborted after three attempts, Chugach contacts AML&P and asks why no generation has been delivered 19:54 AML&P calls to say their generation is now beginning to pick up and notifies Chugach that they are beginning to pick up load. Chugach requests a delay as there is still 88 MW flowing north from Daves Creek. (AML&P closing into a fault at this level would most likely result in an unstable situation) ACE indicates AML&P begins restoring load, Kenai line loading increases to 93 MW. AML&P take from Chugach system 31.8 MW, Daves Creek tie 89.4 MW. 20:00:03 AML&P returns to pre-disturbance schedule, ie is not contributing to the Chugach system, but is no longer leaning on the system. 20:04 MEA Dispatch inquires as to the problem with the intertie since they cannot reach AML&P on the phones an 20:06 GVEA Dispatch inquires as to what is the status of the Intertie since AML&P won’t answer phones 20:08 AML&P (Eklutna Dispatcher) notifies Chugach of unit trip and asks what schedule to travel to, does not revise Eklutna schedule. Chugach requests not to return to schedule until 8 is loaded. 20:09 Chugach notifies AML&P to begin moving toward schedule 20:12:34 AML&P closes Teeland Breaker 538 without notifying Chugach or MEA, and without the SVC. 20:16:57 AML&P closes Teeland breaker 1310 without notifying Chugach or MEA 20:18:24 AML&P closes into a fault on the Intertie without notifying Chugach or MEA 20:19:41 AML&P closes into a fault on the Intertie without notifying Chugach or MEA 20:34 Chugach Dispatcher explains to AML&P dispatcher that we were close to losing the Kenai, AML&P responds that he was not watching the system, he was trying to get downtown back on. The events surrounding this outage are important, especially in light of the discussions involving the controller duties. It would appear the system was near collapse. At the time of the event the Soldotna SVC was operating with a failed capacitor. Total collapse of the Chugach system could have been instituted by several actions of the AML&P Dispatcher, if Teeland breaker 538 had been closed 10 minutes earlier, the Douglas load itself would have put the Kenai tie line into voltage collapse, resulting in separation and total collapse. AML&P Dispatcher could have closed into a fault on either the 138 kV Intertie or the SVC 5 minutes earlier and sent the system unstable. AML&P Dispatcher could have restored load in the AML&P system at the peak of the intertie loading and sent the system into voltage collapse. If we had been unable to contact ee ee eo erae paitzike toe decreasing generation would have collapsed the system. When airbanks Intertie for faults, collapse could occur anytime the Kenai is loaded above 75 MW. The Chugach system could have also collapsed due to the failure of one additional capacitor at the Soldotna SVC. It should be noted, that the AML&P dispatcher is probably the most qualified Dispatcher at AML&P and one of the most qualified dispatchers in the state, however, AML&P only operates with one dispatcher 24 hours per day. This dispatcher simply cannot perform all of the required duties of the Southern Controller and the Ekluta Dispatcher while also performing duties for AML&P. I would recommend we have an outage committee meeting as soon as possible to discuss these events. yy BOferbesdL POF Yser iris Py OUTAGE 11/10/93 1932 HOURS 31. 33.2384. 4 30 pAl 4432.45. 47. 49° SL 53255 57 591 3 5887 32 34 36 38 40 42 44 46 48 30 52 34 36 58 0 2 4 6 _»_ UNIT 7MW'S _4— NET INTERCHANGE CHUGACH cLECTRIC ASSOCIATION, INC. —— \a-24-43 4 DAVID L. HIGHERS General Manager Q December 27, 1993 Emmis Cay Jock EWUcUW se; |] William R. Snell | Executive Director DEC 30 i935 Alaska Industrial Development & Export Authority 480 West Tudor Road Anchorage, AK 99503-6690 Alaska Industrial Development and Export Authority Re: _ Existing Intertie Dear Riley: As you are aware, the Alaska Energy Authority is the owner of the existing intertie transmission line between Anchorage and Healy and is a party to the Alaska Intertie Agreement. The utility participants have asked me to propose to you that AEA consider transferring the ownership of this line to the utilities. We believe this makes sense for the State and would simplify a number of issues. First, the State's interest in this line is very limited, and is all risk. Unlike Bradley Lake (with outstanding bonds) or the Four Dam Pool (where the State collects debt service which can be reappropriated for other purposes), the existing intertie does not involve the payment of any funds to the State for bond or other State purposes. The utilities pay all of the operating costs and their responsibility for insurance, repairs, etc. The State's involvement does result in some risks and uncertainty for the State. As has been discussed at numerous meetings with the AEA, the correct reading of the contract actually results in the requirement to treat AEA as a "utility participant" which would owe a share of the utility expenses. This has been true since the date the AEA signed the Bradley Lake Power Sales Agreement and leaves the State with a financial exposure for the last three years, as well as one for future years. This result is possibly unintended, but is nonetheless the inescapable conclusion from application of contract provisions. AEA has not addressed how it intends to fulfill this obligation. In addition, because the State is the owner, it is almost certainly true that anyone asserting liability claims against the line would include the State as a defendant, thereby exposing the State to such risks. 5604 Minnesota Drive ¢ P.O. Box 196300 » Anchorage, Alaska 99519-6300 cc. E, Wowhrokr Phone 907-563-7494 ¢ FAX 907-562-0027 h. Beardscey William R. Snell December 27, 1993 Page Two After significant reflection on these issues, we believe they are most easily resolved by a transfer of the ownership of the line to the utilities and a release of the State from any of its obligations under the Alaska Intertie Agreement. We would like to discuss these issues with you at your earliest convenience. Please feel free to contact Ron Saxton for any explanation you may wish about the workings of the Alaska Intertie Agreement and the mechanics of how such a transfer might occur. Thank you for your cooperation. Sincerely, ACH, ELECTRIC ASSOCIATION, INC. David L. Higher: General Manager i ' J 01/19/94 07:53 S 27+ GVEA | @oo1/o04 ! | | CHUGACH ELECTRIC ASSOCIATION, INC. be Le | Anchorage, Alaska Ext BW vSrdho December 27, 1993 TO: Jim Hall, Matunuska Electric Association Brad Evans, Golden Valley Electric Association FROM: David W. Burlingame, Chugach Electric Associatio SUBJECT: Stevens - Douglas Losses Enclosed is a loss table which depicts the total line losses which occur between Stevens and Douglas Substation. The losses would have to be automatically applied via SCADA and would roll forward for every hour. The losses would be applied in the same ratio as the Stevens load was to the total line flow for the past hour. For instance, at a total line flow of 70 MW, with a Stevens load of 1.5 MW, Stevens losses would be (1.5/70) X 0.37 = .008 MW. Since the losses appear so small, we would probably not make economy energy adjustments until the adjustment for the end of the month meter correction is done. Chugach’s (and GVEA’s if desired) SCADA system would calculate the losses every hour and keep a rolling total. The total would be zeroed out the end of each month and added to the MEA energy metered at Douglas station. The transformer losses would need to be recorded by biasing the MEA mete: at Stevens Substation. Since the losses between Douglas and Stevens are so small and the use infrequ-ut, I would propose the existing loss tables be used for flows North to South until we have rea‘i:n to change them. Please advise if the proposed loss tables are acceptable. 01/19/94 07:55 io +++ GVEA {002/004 CHUGACH ELECTRIC ASSOCIATION, INC. Anchorage, Alaska December 27, 1993 TO: Dave Burlingame, Manager, Power Control FROM: Alice M. Mullins, Planning Engineer (42.2. YZ. Whe SUBJECT: Intertie Loss Table for Stevens Substation I have produced the attached loss table to document losses on the 138 kV line section from Douglas to MEA’s proposed Stevens Substation. Losses were calculated by running PSS/E for varying line flows from 0 to 70 MW south to north in 10 MW increments as measured at Douglas looking toward Stevens. The line impedance between Douglas and Stevens was calculated based on the impedance shown for the Douglas-Cantwell line in the Alaska Railbelt Data Book and on GVEA’s system one-line diagram and assumes that Stevens Substation will be located 26 miles from Douglas. A voltage schedule of 140 kV was modeled as you suggested. Losses were calculated at 1 MW intervals by a simple I?R calculation. For this calculation, a constant VAR flow of 12 MVAR north to south was assumed based on observation of PSS/E results. PSS/E tabular output for the cases is available upon request. 4379.AMM:BM Attachment cc: John Cooley, Tom Lovas, RF RECEIVED DEC 27 4993 Power Gaius Centor 01/19/94 ae 07:55 S 27% GVEA Douglas-Stevens Line Losses MW Losses MW Losses Stevens MW/| Calculated Flow by Excel by PSS i [0.0109 0.0153 9 0.0165 [00178] 0.031 = 2 ° ag id x 0.0371 20 t i BRR i 2 3S 2 > 003/004 01/19/94 07:56 Se 27+ GVEA 004/004 - Douglas-Stevens Line Losses Ny sie Municipal Light & Power 1200 East First Avenue Anchorage, Alaska 99501-1685 (907) 279-7671, Telecopiars: (907) 263-5204, 277-9272 DATE: December 6, 1993 TO: Brad Evans, GVEA Sam Matthews, HEA Dennis McCrohan, AIDEA/AEA Vince Mottola, FMUS Ken Richie, MEA TTA FROM: ML&P, Southern Operator, Alaska Intertie / yr w SUBJECT: CEA Ultimatum I am forwarding the attached ultimatum from CEA. 2G ean response to the letter I sent to each of you, "Proposal for Expediting the Stevens Substation", December 2, 1993. Mr. Burlingame's attached memo makes it obvious to me that the CEA agenda is removal of ML&P as Southern Operator of the Intertie, and not the betterment of MEA's ratepayers who would be well served by bringing the substation on line as soon as prudently possible and as ML&P proposes. Please keep in mind, the CEA ultimatum is delivered in the teeth of the Intertie Agreement, a contract they signed which clearly directs hourly Intertie accounting by each of the Operators for their respective Groups (Paragraphs &.4.3 and 8.4.4 among others). By issuing the attached ultimatum, CEA in fact is holding the Stevens Substation hostage to the outcome of a legal battle which if need be can occur quite apart from the Stevens on-line date. Over the years we have all been on the receiving end of such CEA ultimatums. This one appears to me to be particularly mean spirited in that they would defy a contract and deprive MEA ratepayers in an attempt, destined to be futile, to eliminate contractual Intertie oversight. I would submit that for the sake of the Stevens ratepayers, and of our future dealings with CEA (with or without contracts) their "ultimatum" modus operandi be quashed. I once again request your good office and support in ML&P's attempt to expedite the Stevens Substation. Attachment: CEA Letter, December 3, 1993 cet PR, Suere 5 Ss eczKouse] Putting Energy Into Anchorage ’. ee _ iC Whfez Frc” CHUGACH ELECTRIC ASSOCIATION, INC. Anchorage, Alaska December 3, 1993 TO: Tin McConnell, AML&P FROM: David W. Burlingame, Manager, Power conmaege™ : SUBJECT: — Stevens Substation - Your Proposal dated December 2, 1993 It would appear your proposal requires more work from Chugach than is required to operate the system. It would also appear that your proposal is based on the assumption that AML&P will continue to performs duties as it interprets the contract. We disagree with the continuation of those duties which serve no useful purpose and are not in the best interest of the operation of the Intertic. Should your insert Northern Controller in each place as opposed to Southern we wiil support it. We will not , however support any action which perpetuates the cost inefficiencics presently in place. We do not feel the recording of hourly loads serves any us¢ful purpose in the interim and are not required for reconciliation between the effected utilities. .. File CHUGACH E-ECTRIC ft ote ASSOCIATION, INC. 4c Own Oe 60° 19-24-43 DE NINE DAVID L. HIGHERS General Manager December 27, 1993 Well $e a SHAG yy D)fbliuzi i} William R. Snell Mae 4qah i J Executive Director DEG S.Y Hus Alaska Industrial Development & Export Authority ‘staid niostiid: Geudlanewen! 480 West Tudor Road ; : d Expert Autt Anchorage, AK 99503-6690 anal Expert Aothority Re: Existing Intertie Dear Riley: As you are aware, the Alaska Energy Authority is the owner of the existing intertie transmission line between Anchorage and Healy and is a party to the Alaska Intertie Agreement. The utility participants have asked me to propose to you that AEA consider transferring the ownership of this line to the utilities. We believe this makes sense for the State and would simplify a number of issues. First, the State's interest in this line is very limited, and is all risk. Unlike Bradley Lake (with outstanding bonds) or the Four Dam Pool (where the State collects debt service which can be reappropriated for other purposes), the existing intertie does not involve the payment of any funds to the State for bond or other State purposes. The utilities pay all of the operating costs and their responsibility for insurance, repairs, etc. The State's involvement does result in some risks and uncertainty for the State. As has been discussed at numerous meetings with the AEA, the correct reading of the contract actually results in the requirement to treat AEA as a “utility participant" which would owe a share of the utility expenses. This has been true since the date the AEA signed the Bradley Lake Power Sales Agreement and leaves the State with a financial exposure for the last three years, as well as one for future years. This result is possibly unintended, but is nonetheless the inescapable conclusion from application of contract provisions. AEA has not addressed how it intends to fulfill this obligation. In addition, because the State is the owner, it is almost certainly true that anyone asserting liability claims against the line would include the State as a defendant, thereby exposing the State to such risks. 5601 Minnesota Drive « P.O. Box 196300 « Anchorage, Alaska 99519-6300 Phone 907-563-7494 « FAX 907-562-0027 William R. Snell December 27, 1993 Page Two After significant reflection on these issues, we believe they are most easily resolved by a transfer of the ownership of the line to the utilities and a release of the State from any of its obligations under the Alaska Intertie Agreement. We would like to discuss these issues with you at your earliest convenience. Please feel free to contact Ron Saxton for any explanation you may wish about the workings of the Alaska Intertie Agreement and the mechanics of how such a transfer might occur. Thank you for your cooperation. Sincerely, ACH,ELEGTRIC ASSOCIATION, INC. David L. Higher General Manager TO: FROM: SUBJECT: FROM CHUGACH ELECTRIC T0 cc 998 PUU2/007 on a CHUGACH ELECTRIC ASSOCIATION, INC. Anchorage, Alaska November 17, 1993 , Riley snell, Executive Director \ AIDA ” David L. Highers, General Manager }. ML&P Southern Intertie Route Proposal The attached, for your information, is a new and different southern intertie route proposal faxed to me by ML&P. I don't know where this leaves us on the wheeling issue, but it confirms my views that routing decisions cannot be made intelligently at this time. 11-17-93 12:21PM FROM CHUGACH ELECTRIC TO 5618998 003/007 NOV-17-93 WED 10:50 MLQP GEhenm MANAGER FAX NO, 907263620¢ P.O WW ~ AW ey Municipality of Anchora: Municipal Light & Power Tom Fink, Mayor 1200 East First Avenue Anchorage, Alaska 99501-1685 1907) 279-7671, Telacopiers: (90?) 276-296 1. 277-9272 TRANSMITTAL SWEET VUNICIPAL LIGHT & POWER ADMINISTRATIVE OFFICES PAX #: (907) 263-5204 DATE: 11/17/93 TO: SEE DISTRIBUTION BELOW PROM: TOM STAHR, GENERAL fANAGER, ML&P SUBJECT: LEAST COST TESORO/FIRE ISLAND INTERTIE ROUTE THIS OOCUMENT CONTAINS 5 SHERTS (INCLIIRING THR COVFR SHRRT). TF YOU WISI TO VERIFY RECEIPT OF THIS DOCUMENT OR YOU 01D NOT RACEIVE ALL SREETS INDICATED PLEASE CALL __ Anne AT (907) 279-7671, ext. __520]_. MANY THANKS! ERIC REDMANN/HELLER EHRMAN/206-447-0849 RON SAXTON/ATER WYNNE/503=226=0079 GVEA/KELLY/ 451-5633 CEA/HIGHERS/562-0027 Putting Energy Into Anchorage R=-93% 9072635204 Li-17-93 10:56AM POOL #20 12.21TM PRUM UlUVAUD CLEVIRIY iV NOV-17-93 WED 10351 ML&P Gris MANAGER FAX NO. 907263520. P, 02 R“93% LEAST COST TESORO-FIRE ISLAND-ML&P ROUTE The Enstar ML&P route | previously sent intormation on was developed afler Rick Redman had indicated there were serious probloms with tho Fire Island route. Now that the Fire Island rota has bean rehabilitated we have developed a ML&P Fire Island route. This is based on one of the alternatives Power Engineers had developed in 1987. Fortunately this route is less expensive than the Fire Island -voronzof route wnicn previously appeared least costly, This route starts at the HEA 118kV line near Bernice Station and then generally follows the Tesoro pipeline route to Point Possession and then crosses Tummaguin Anm to the south end of Fire island, It then goes north on Fire Island Untill It reaches the place clusesl lo Point Campbell and then crosses to the mainland a littlo north of Point Campbell. Then it follows, more or less, the south Intamational Airport boundary till It goes underground for the North-South runways. It then follows Raspbery Road to Arctic Blvd, extended to tle Into the ML&P line at International Airport Read. Tha HFA line from Soldotna Station to Bemice is one of the HEA lines leased lo CEA on a long term lease. Fortunately the lease is very explicit as to the cost elements so the cost of this line segment can be easily determined. Since regulatory practice fs to allow 8 relurn on invesiment but not a mark-up on expenses, and the appropriate TIER te alroady In the base jease rate CEA pays it is extremely unilkely CEA would be allowed ta racover more than it's expenses on this line segment. Preferably the IPG should acquire this line segment for incorporation in to the Southem Intertie. Redman in nis tour proposals has Indicated this possibilily. | have not attempted to quantify the cast of acquiring or the annual lease costs of this link because only HFA has the necessary data. Nor have | tried to allocate usage between CEA and the intertie. At the ML&P end of the line | did not snow the auto-transformer station nor did | hiclude it’s cost in the cost estimate, There aro sovoral reasons for this . One Is that the line segment immediately north of Intemational Airport Raad is to a considerable extent over insulated for 1415KV so with little or no work can be used for 138kV. Anather reason Is that it would be preferable but not essential to the MLAP system to have separate breakers for each fine direction leaving 36th and Arctio Blvd which would require a station closer to that location. As for enst sharing between MLA&P and the Intertie Doug Rosenber is presenting fo the Attarneys a proposal which would essentially hold other IPG participants harmless from any costs in excess of the lowest cost route. Clearty this route could just as easily terminate at CEA’s international Station and there would also be unquantified termination costs there because they would need one more breaker and a haif section and a complete additional 136kV Station bay. But again the principal applies there is n0 Justification for a CEA whooling charge because an altemative exists which requires no wheeling payments to CEA and It's cost is not higher. Emo with a new intertie the value of CEA wheeling to Anchorage Is zero. Wheeling on to the north from Anchorage as previously detailed shduid not exceed 2.8 mitis/kWh. 9072635204 Li-t7-93 10:56AM FoO2 #20 ! ‘ Tote da-1c: Cre NOV-17-93 WED 10:52 R=93% he iG H KI rRI{ FRUM CHUGAUH ELECTRIC ML&P GENkkAL MANAGER TO 9618998 005/007 FAX NO. 907263520, Preliminary Cost Estimate For Tesoro/Fire Island Route to ML&P Ststem at Arctice & International Link Miles 3.2A 11.50 343 24.75 3.22 4.7 3.6 2.8 3.0 3.90 Bernice Lake 3.7 1.0 3.25 4.0 3.41 6.8 3.42 3.2 Bescription Steel Single Pole Steel X Structure Steel X Structure Fire Island Steel Single Pole Steel slngle role Substation Subtotal R/W & Acquistion Design 44% eM 4% Subtotal 1 Underground Cable Underground cable Submarine Cable & 2 Tern Submarine Cable & 2 Term Subtotal 2 Utility Admin 1% (Sub 1 & 2) AEA Admin Contingency 10% (Sup 12 & 2) Estimated Total 9072635204 gost 3,392,736. 9,210,447. 2,350,000. 826,056. 365,U6U. 2,300,000. 16,964,299, 2,750 000. 758,572 758,572. 23,231,443, 2,209,038. 8,073,954. 23,056,800. 13,141,995. 46,491,787. 697,132. 250,000. 6,971,323. 77,631,685. 11-17-93 10:56AM P, 03 POO3 #20 - NOV-17-93 WED 10:52 - MLAP GEnsxAL MANAGER FAX NO, 90728352. P, 04 Anchorage-Kanai New 138 KV Intertie Tesoro/Fire Island Route Loa Reference ML&P Link System No. PEI/MLAP =. 4987/1993 3.8 PEI 1987 a7 PEI/ML&P 1987/1993 DG D&L/ML&P 1993 3.42 D&L/ML&P 1993 3641 DEL 1993 3.41 D&L 1993 a3 D&L 1993 3.2B D&L 1993 3.2A 138KV R=94% atin Description 3.0 Miles O/H Single pola steel 1,0 Mile use 2.8 Miles O/H single pole steel 3.2 Miles submarine +2 terminals 4.7 Miles (Fire Island) steel X structure 6.8 Miles submarine + 2 tearminale 24.75 Miles Steel *X Structure 4.0 Miles U/G 11.5 Miles Single steel pole Bernice Substation Existing 115KV 0/H Soldotna Substation 9072635204 $1-37-93 10:56AM vooa #20 Oc 900d Wyo Fiat: IAT Ep 5 sled nel n 2 | »N@GE9CL06 ‘ON X¥d SIOVNVH TWYANAD d BIH ES'01 aM €6-L1-AQN. :