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Home My WebLink AboutLarsen Bay Hydro Annual Inspection 1997\3-2 LARSEN BAY HYDROELECTRIC PROJECT ANNUAL INSPECTION FISCAL 1997 LARSEN BAY HYDROELECTRIC PROJECT ANNUAL MAINTENANCE INSPECTION July 28, 1997 The inspection participants were Stan Sieczkowski, Operations Manager, (Alaska Energy Authority) and Joe Katelnokoff, Plant Operator, (Larsen Bay). 1.0 PROJECT DESCRIPTION Facilities The Larsen Bay Hydroelectric Project is located on Humpy Creek about % mile from the City of Larsen Bay at Latitude 153 58’ 16” and Longitude 57 32’ 19”. The City of Larsen Bay is located on the Kodiak Island, about 60 air miles from the City of Kodiak. The community has approximately 110 permanent residents and seasonal influx of cannery employees. This run-of-river project has a 140-ft long, 14-ft. high dam, and a small reservoir with minimal water storage. The spillway at elevation 1676 ft., is 30 feet wide. The 6,062-ft. penstock (3,584 ft. 18 inch PVC and 2,416 ft. 16 inch steel) is buried in the road to the plant. A 4-inch line from the penstock feeds the domestic water treatment plant. The powerhouse has one generator rated at 475 KW. The turbine, at elevation 1006.25-ft., has two nozzles and deflectors and operates at 290 psi, with approximately 670 feet of head. There are two high voltage transformers and a set of high voltage disconnect switches in the hydro distribution system. There is a small maintenance shed and material storage yard near the power plant. The Alaska Energy Authority owns the Larsen Bay Hydroelectric Project. The project is operated and maintained by the City of Larsen Bay, for the state. The Project went into commercial operation on July 5, 1991. Operations The Fiscal Year 1997 (July 1, 1996 to June 30, 1997) operations summary is: Production: 387,897 KWH (431,174 KWH for calendar 1996) Utilization: Due to low water run off and turbine repairs needed the plant was shutdown in July and not operated until October 1997. Water use: The run of river operation diverts water from Humpy Creek, at the dam, and returns the diverted water, except for domestic water, back to the stream at the plant just above the old cannery dam. The water is not measured. Revenue: $169,567 O&M Expense: $ 71,279 Power Rate: $.40/KWH (Supplemented by PCE) HYDRO PROJECTS Larsen Bay Inspection ANNUAL INSPECTION July 28, 1997 Problems and Issues 1. The Office Staff needs help because of personnel turnover. 2. The City Utility operations staff has changed. 3. The Cannery appears to be operating with a shorter processing season and/or sharing with other canneries, resulting in less KWH sales from the Hydro. 4. There continues to be low water run off and the hydro plant cannot operate continuously, for the projected 10-month operating period. 5. The office staff requested the computer system be connected to the Internet system programs. 2.0 INSPECTION OF FACILITIES Dam and Reservoir The storage reservoir has silt building up and requires routine flushing. Alders need to be removed from around the reservoir. The spillway wire gabion baskets need to be monitored for sagging and loss of rock. The right side of the spillway lip is showing signs of erosion and needs to be monitored. No seepage has been detected around the dam. The water seeps from the hillside, appearing in the road at the rock notch (near station 06+00) and near the bottom of the hill (near station 44+90). Seepage appears normal and has not increased compared to past observations. Waterway An air valve needs to be replaced near the top on the penstock. The penstock was okay. The power plant tailrace left side, lower corner at the bend is showing signs of erosion and needs to be monitored and inspected annually. Powerhouse Equipment The Kato Generator was maintained. The Canyon Industry turbine runner has a casting flaw in bucket #6 that needs to be filled. There are small cracks in the root area in five other buckets that were located after the previous repair by Canyon Industry. The cracks are small and appear on the surface or where the weld was mated to the parent material. The runner is monitored and the cracks do not appear to be changing. Repairs are recommended when it is convenient to shut down and have the manufacturer on site. The Thompson and Howe control system is functional. The cooling water system continues to be a high maintenance item due to plugging from leaves, twigs, etc. The new strainer makes it more convenient to clean out the debris. The Main Unit Circuit breaker and the power plant transformer were okay. Transformer oil samples need to be taken and analyzed. The chipped grout needs to be cleaned from the ALASKA ENERGY AUTHORITY 2 HYDRO PROJECTS Larsen Bay Inspection ANNUAL INSPECTION July 28, 1997 spill containment area. The main penstock valve was okay. The protection relays appear functional. The Head Level meter needs to be repaired. Station service power system is okay. The equipment nameplate data is: Generator: KATO MEG. Model A246890000, 475KW @ .9 P.F., 480 Volt, 3 Phase, 900 RPM, Cat: 8P6-1500, Serial No. 96238, Type 24689 Circuit Breaker: Westinghouse Type SPB65, 800A., Ser. No. 21E3033 1A18506G68 Turbine: CANYON INDUSTRY, Custom Double Nozzle, 22”p.d., Maximum Flow: 11.00 CFS @ 475 KW, Minimum Flow 1.00 CFS @ 47 KW, Average Flow 3.20 CFS @ 150 KW, Pelton Wheel has 2 nozzles and 2 deflectors, Penstock Pressure 290 PSI. Controller: THOMPSON & HOWE ENERGY SYSTEMS INC. Prod. No. SG450KW480V, Ser. No. 91SG45, 60 HZ, 800 A., Load Tank: Solid state 120 KW resistor load controller Ser. No. 91M56 Computer Chip: S27C648-2317N02-9135RG Hydro Transformer: Jerry's Electric Type 1.0388-22, 500KVA, 12.47/7.2KV-480V, Grounded Star-Delta, 1.0 % Z, 65 degree Rise Cannery Transformer. ABB Style V73E5642RB, 500 KVA, 12.47/7.2 KV-480/277 V, 1.44 % Z, 95 KV BIL, Grd. Star-Star, 191 gal, 4890 Ibs, Ser. No. 91J924008, July 1991 Switch H1 (Diesel Plant): S&C Elec. Co., Pad Mount, Mod. 53152R1-E3F2G1G2H4J, Ser. No. 903274, June 1990, Manual PMS-9 Buildings/Facilities The paint is peeling on the facia on the powerhouse. The maintenance building is okay. The maintenance yard needs to be cleared of weeds and the materials properly stored and protected. Roads and Bridges The road to the project dam needs to be maintained. Equipment The Honda 4-wheeler needs the rear end repaired. ALASKA ENERGY AUTHORITY 3 HYDRO PROJECTS Larsen Bay Inspection ANNUAL INSPECTION July 28, 1997 3.0 OPERATIONS AND MAINTENANCE Safety Equipment clearance safety programs have been put into effect. The program requires that formal procedures are followed and all personnel need to be trained in the use of safety locks and tags. The project personnel need to maintain the power plant logbook and record the clearances placed. The log shall be maintained in a legible manner with no erasers. Water Availability Water runoff to the Project is low and is expected to remain that way until fall. General Maintenance and Housekeeping Housekeeping at the Power plant and maintenance building need to be improved. Security The plant fence needs to be repaired. The gate has been damaged and does not close properly. The facilities and gates were locked. Records The daily hydro plant records are available. The production records are incomplete but PCE records are available. 4.0 RECOMMENDATION 1. Take project transformers oil samples and analyze. Provide report to AEA and keep a copy on site for the permanent record. Repair project vehicles. Repair the Head Level meter. Repair the turbine runner buckets that are cracked and pitted. Replace the air vent release valve. Monitor the eroded area of the tailrace. Monitor the spillway gabions and lip area. Paint the power plant facia boards. Repair the project fence and gate. OMDNAAKRWN Attachment A - Maps. Attachment B - Operating diagram. Attachment C - Photographs ALASKA ENERGY AUTHORITY 4 ATTACHMENT A MAPS LARSEN BAY w a 2 3 cc aw Ww = 3 a | noe LARSEN BA HYD(2O 5 st Zz ATTACHMENT B OPERATING DIAGRAM LARSEN BAY city Oe 200 Kw CP) an 200 Kw 480V. 38 6OH2\\/ J *)sgov. 38 60Hz a TRANSF. =X 300 KVA AN wv Serene 480V-7.2/12.5KV a Je, 60 Hz INTERNALLY GROUNDED Hi-4° H2 12.SKV BUS —_ a ced —— ‘NOT . ie FUNCTIONAL 1-2 H2-4* §/H2-3 H1-3 Y TO SCHOOL & EAST CITY LOAD TO STORE & WEST CITY LOAD r 0 KVA ARR 205 2.2/12.5K0 3e, 60 Hz NOTES . 1. HI ANO H2 ARE S&C TYPE LOAD BREAK SWITCH PANELS. PAD MOUNT UNITS W/ FAULT INDICATORS. = 200A . *DANGER Crlonyorr) 00 NOT CLOSE SWITCH WHEN MORE THAN ONE GENERATOR IS RUNNING TRANSF. > 120/208v-480V o8v BUS ——— EXISTING CANNERY SYSTEM LEGEND — CONNECTION 80x H1-1— LOAD BREAK SWITCH @—cenerator W/ RATING 7 Ss KW 300 KW 210 KW 250 KW 300 KW (@) — wartwerer CANNERY POWER PLANT 1 52|— CIRCUIT BREAKER =n <<<K — TRANSFORMER PROJECT Alaska Energy Authority P.O. Box 190869 701 East Tudor Roos Anchorage, Agana 99519-0869 LARSEN BAY ELECTRICAL SYSTEM : 5; N State of Alaska TLE: ONE LINE DIAGRAM ATTACHMENT C PHOTOGRAPHS LARSEN BAY Larsen Bay Dam after completion June 1991 Larsen Bay Power House in June 1996 ae Generator and Turbine Larsen Bay Load Resistor Box Larsen Bay Control Board Larsen Bay Hydro Dam access road seepage at station 44+90 in Aug. 1995 Larsen Bay turbine runner repairs in June 1996 by Canyon Industries. Larsen Bay Tailrace — eroding in corner area on left S