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Home My WebLink About130800-False Pass Power System 1 | Page False Pass Power System August 2013 Marsh Creek, LLC 2000 E. 88th Ave. Anchorage, Alaska 99507 2 | Page Contents Existing Power Plant Infrastructure .............................................................................................................. 3 Power Plant ............................................................................................................................................... 3 Diesel Generator Sets ............................................................................................................................... 5 Day Tank .................................................................................................................................................... 5 Cooling System .......................................................................................................................................... 5 Controls and Switch Gear.......................................................................................................................... 7 Heat Recovery ........................................................................................................................................... 8 Tank Farm ................................................................................................................................................. 9 Distribution System ................................................................................................................................... 9 Operating Schedule ............................................................................................................................... 9 Electrical Distribution System ............................................................................................................... 9 New Loads ............................................................................................................................................. 9 3 | Page Existing Power Plant Infrastructure False Pass depends on diesel powered generators to provide their homes and businesses with electricity, and fuel oil to generate heat. Fuel is purchased once a year and is brought into False Pass by barge in the spring. Diesel is stored in a city‐owned and operated tank farm with a capacity of 60,000 gallons. Once a week, fuel is transferred from the tank farm to another city‐owned 5,000 gallon tank located at the city power plant via an 850 gallon fuel truck. The City of False Pass owns and operates the community’s power utility, generating all electricity with three diesel generating sets (gen‐sets) located in the False Pass Generator Building. The following map and pictures provide a general location and condition: Power Plant The module power plant includes a distribution feeder switch arrangement that is operated through a secondary breaker at the old power plant that sits adjacent to the new modular plant. The secondary main breaker at the old plant is tied to the existing bus bar in the old plant switch gear. There is an arrangement of manually operated circuit breakers that feed to the distribution transformers. A transformer is switched out of the circuit by opening its primary main breaker or by opening a secondary breaker to de‐energize the transformer and isolate the transformer from its is electrical supply source. It is unclear that the rating of the breakers is adequate to protect feeder conductors and transformers. Further it is unclear if the breakers will properly open on a fault current condition. An interim electrical or key interlock scheme should be added to enforce the proper operating modes of this type of system, especially in light of the fact that the switching is carried out over several pieces of equipment that are in different locations from one another. This is of particular importance because of the potential safety concerns to plant operators and other personnel as it pertains to arc fault current. Unless circuit breakers and other protective devices have been selected and installed to handle the arc fault condition, they will not trip and the full force of an arc flash will occur. Transition from arc fault to arc flash takes a finite time, increasing in intensity as the pressure wave develops increasing the chances of a serious injury to the worker. An application review with corrective recommendations should be conducted to remedy the switching arrangement of the distraction feeder circuit. 4 | Page Old Power Plant – distribution service from Old Power Plant – Village Feeder Switch new power plant Old Power Plant – Village feeder and metering Distribution Transformers – Three phase from Old Power Plant feeders False Pass Power Plant with 5,000 gal. fuel tank. 5 | Page Diesel Generator Sets The power plant is operated and maintained by Monty Chitty . The power plant is very clean and well maintained. The power plant has three diesel Gen‐Sets consisting of one John Deere 6068TF generator set rated at 75kW, a 6081TF generator set rated at 125kW and a 6081AF generator set rated at 175kW. Power Plant – Layout overview Day Tank The day tank controls have proved to be difficult in the past and will need to be repaired. The motor operated vale for the bulk tank was not working properly and caused intermittent fill issues. The fuel fill safeties are believed to be bypassed. The tank is a standard 100 gallon day tank. Power Plant Day Tank and Controls Cooling System The cooling system is comprised of 3” copper piping and 2 remote radiators. The cooling system glycol is piped into the lower coolant manifold on the engines and the hot coolant is routed out through the upper coolant manifold through the heat exchanger, transferring heat to the city shop heat recovery loop. The glycol loop continues on through a thermostatically controlled mixing valve that automatically mixes cool and warm coolant to keep the loop temperature stable. At this juncture, the glycol is either piped back to the engines or continues on to the radiators. The radiators blow away excess heat outside 6 | Page and the loop continues back to the generator sets. Prior to the generator sets, the loop intersects the return from the thermostatic mixing valve. Note – reported in the full AEA assessment, it was stated that the switchgear was manually paralleling. This is not correct; the switch gear is semi automatic. 7 | Page Controls and Switch Gear The controls were provided by Thompson Tech and consist of woodward loadsharing and synchronizing modules with Thompson Tech MEC20 controllers on the doors. Gen‐Set Controls with Load Share Power Plant Gen‐Set Switch Gear – Close up Power Plant Switch Gear ‐ Overview 8 | Page Heat Recovery A tube and shell heat exchanger located in the generator building transfers heat from the generators via a buried glycol piping loop to two Modine unit heaters in the City Shop. Any heat that cannot be utilized by the City Shop is dumped from the generator building by two radiators. The radiators are not run by a Variable Frequency Drive (VFD) and consequently when actuating place an instantaneous load on the system. Remote Radiators Radiator controls An old heat recovery system exists that runs from the Old Generator Building to False Pass School via a 3in HPDE piping loop nested in a 2ft deep trench. The pipe runs through the school’s crawlspace, but is no longer connected to the heating system. Residents claim that the system never sent an adequate amount of heat to the school, likely due to the length of the piping run and the lack of proper piping insulation. YCE’s renewable resources assessment determined that there is sufficient waste heat from the power plant to heat a large percentage, or even all, of False Pass School. Proper insulating and jacketing of the heat distribution pipe would be critical for success in this endeavor. An economic evaluation was completed at the time of the assessment, with the assumption that the waste heat system would displace all of the heating oil consumed by the school. That assessment is reflected in the following table: False Pass Heat Recovery Building receiving heat False Pass School Distance from Power Plant 600 ft Estimated project cost $300,190 Annual heating oil savings (gal) 5,162 Annual heating oil savings @ $3.45/gal $17,809 Annual O&M costs $1,500 30 yr net present worth $775,223 Payback (yrs) 14 9 | Page Tank Farm With the impending shutdown of the Peter Pan Seafood’s tank farm, there is currently only one bulk fuel storage facility in False Pass. The City of False Pass owns and operates the facility outlined in the following table: From AEA Bulk Fuel Facility Monitoring Plan ‐ 2008 Distribution System Operating Schedule Electrical Distribution System The utility’s power distribution system is all underground 3‐phase wire operating at 12,470 volts grounded Y. False Pass Power Plant is maintained by Monty Chitty for City of False Pass Electric (CFPE). CFPE also maintains the village distribution system. There is currently a plan to upgrade Genset #1 with a bigger unit. The Process Plant is planning a new addition which will increase the electrical load on the distribution system. The biggest electricity users are currently: GCI, the school, the fish plant, the bunkhouse, and the Peter Pan facility. Seasonal load increases come from Peter Pan and the BPS Plant. Currently the distribution system phases are balanced as such: 1) 130 AMPS 2) 120 AMPS 3) 150 AMPS There is a heat recovery system already in place that feeds one location in False Pass: the City Shop. The system currently uses jacket water heat recovery only, and loses 38 degrees into the system. New Loads