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Home My WebLink AboutATT E BUS PLANCity of Atka, Electric Utility Business Plan Dispatchable Energy Project Introduction The City of Atka, Alaska is located 800 miles Southwest of Anchorage on the Aleutian Chain. Atka is incorporated as a second-class city within an unorganized borough. The current population is 59 year round residents, and a large seasonal population associated with the Atka Pride Seafood's plant in Atka. The current population of Atka is anticipated to grow. The existing Atka Pride Seafood's plant is in the planning stages of a major upgrade to add crab processing. This project will include the addition of a 65 person housing complex for workers. Recently the City of Atka constructed a new 300 kW hydroelectric power plant on Chuniisax Creek. The new hydroelectric power plant provides electric power to the existing distribution system and works in conjunction with the existing diesel power plant. The capacity of the new hydroelectric power plant is in excess of the current community electrical demand. The City of Atka is responsible for operation and maintenance of the electric utility. Project This project consists of installation of a Dispatchable Electric Energy system to supply electric space heat to public buildings in Atka including the Clinic/City Office; Community Rec Hall; Tribal Office; Post Office; City Shop; and Fire Station. Each building installation will include replacing existing single electric meters with duplex meter bases; new dispatchable electric energy panel and controller; electric boiler, unit heaters, or baseboard; associated wiring and hydronic heating connections; and reprogramming existing hydroelectric plant controls. Individual electric heating units were limited to 10 kW to reduce large variations in community electrical load. Existing space heating systems in buildings are left in place as this project offsets existing oil fired heating, but does not replace it. A future Clinic is proposed in the future for Atka that could be added to the dispatchable electric energy system. The existing Clinic/City Office would be repurposed to another community use leaving the requirement for dispatchable heat to the building. An analysis of the new hydroelectric plant capacity, community load and anticipated excess energy available for dispatchable heat was completed. The existing community electrical demand is about 470,000 kWh's per year. For this analysis, it was assumed that electric demand would double once lower -cost hydroelectricity is available and proposed future buildings are constructed. An average community electric demand of 107 kW was assumed requiring 939,320 kWh's annually to meet community electricity demand. Existing community electrical demand is fairly flat throughout the year, and the future increased community electrical demand is assumed to remain fairly flat year-round. The hydro plant governor load bank is assumed to have an average load of 37.5 kW to regulate electric frequency, requiring an additional 328,000 kWh of hydroelectric power. With an average rainfall year in Atka, it is estimated that the new hydroelectric plant can produce up to 1,677,471 kWh's of electricity a year. The available plant capacity is distributed over the year with highest available capacity during late summer and fall when increased rainfall is normal, and the lowest capacity during late winter and into the spring when cold weather and limited rainfall is normal. Page 1 City of Atka, Electric Utility Business Plan Dispatchable Energy Project Heat loss analysis was completed for each of the buildings to be served, and required heat loads were calculated based on average monthly heating degree days in Atka. Based on average air temperatures, it is estimated that up to 307,025 kWh's of excess capacity would be available at the hydroelectric plant to offset space heat in the public buildings. This is equivalent to 8,304 gallons of heating fuel displaced. Follows is a chart showing the estimated hydro plant capacity, the existing community electric load, assumed future community electric load (double the existing load), energy required for the load bank and the estimated excess energy available to be provided to public buildings. When the excess water is available in Chuniisax Creek, and excess capacity is available at the hydroelectric plant, the dispatchable controller in the switchgear will energize dispatchable energy panels in the public buildings. The electrical heaters in the public buildings will be controlled by the building thermostats. Existing space heat supplied by heating oil will be offset by the dispatchable energy system. Existing Infrastructure The City of Atka electrical utility generation system consists of a diesel electric power plant with two diesel fired 110 kW generators and one 37 kW generator, and an existing hydroelectric plant has a cross -flow turbine with a 300 kW generator. All generation is 480v Delta, three phase. Both plants have step up transformers to 7.2/12.47 kV Wye distribution voltage. The distribution system consists of underground single-phase and three phase jacketed concentric neutral. Transformers are located around the community to provide service voltage power to customers including 43 homes and 16 public and commercial facilities. A major portion of the distribution system was upgraded in 2012. The electric utility reads meters on a monthly basis for total kilowatt hours (kWh) and utility customers pay for kWh's consumed at the tariff rate. Page 2 City of Atka, Electric Utility Business Plan Dispatchable Energy Project Existing buildings to be served by this project are in various stages of maintenance. The proposed project provides a portion of the heating load required at all of these buildings so existing oil fired heating systems will need to be maintained. Weatherization upgrades to the buildings and modernization of the heating systems would further reduce the quantity of heating oil required to annually heat the public buildings. Utility Organization The City administration consists of a city administrator and admin staff, electric plant and water plant operators, and maintenance personnel. The public works department operates and maintains the electric utility and reads meters. The city administrator and staff handle billing and collection of fees. The city council oversees the city administrator and sets policy and approves budgets. This project will require amendment of the existing electric utility tariff to provide for a kWh cost for dispatchable electrical energy. Project Construction and Maintenance Costs Construction of the proposed dispatchable energy project is estimated to cost $123,390. Project life is estimated as 20 years. With a 5% interest rate and 20 year life the annual cost of a loan for construction would be $9,901.13 per year. After construction the operation and maintenance of equipment and system will be transferred to the owners of the public buildings. The annual maintenance cost of the installed system will increase the annual utility operational costs nominally as six additional electric meters have to be read, and additional bookkeeping required to invoice and collect fees. The additional annual labor cost is estimated at $500. Total annualized estimated cost for the project is $10,401.13. With an estimated annual supply of 307,000 kWh, the break even cost for dispatchable energy would be $0.04 per kWh. The annual maintenance cost to the individual building owners is estimated to be less than $100 per year in set aside funding for future replacement of meter bases, controller, and electric heating units. The supplied kWh of dispatchable energy is equivalent to 8,304 gallons of heating oil. With a conservative availability of 50% it is estimated that a minimum of 4,152 gallons of heating oil would be displaced annually. With the current cost of $6.00 per gallon the cost of the displaced fuel would be $24,912 per year for 4,152 gallons and up to $49,824 per year for 8,304 gallons. The energy cost for dispatchable energy would need to be set by the City Council, but for this analysis, assuming an energy cost of $0.05 per kWh the cost of dispatchable energy would be $7,675 for an annual savings of $17,237 for 50% availability. Full availability costs would be $15,350 for an annual savings of $34,474. With an estimated cost of construction of $123,390 savings will offset the cost in between 4 to 8 years. Appendix Project Construction Estimate Chuniisax Stream flow, Dispatchable energy estimate Page 3 Dispatchable Heat Polarconsult Alaska, Inc. 2/14/2013 Atka, Alaska Engineers Estimate Contract Labor 8hr days Labors M-Hrs Mob 2 3 48 Expediter 4 1 32 Plumber 6 1 54 Electrician 14 1 126 Electrician App 14 1 126 De mobe 1 3 24 Labor Hours 410 Labor Total $ 90.00 per hour $ 36,900 Equipment Days Rate Eq Total Pickup 20 22 $ 200.00 $ 4,400 Misc Sm Tools 22 $ 50.00 $ 1,100 Equipment Total $ 5,500 Materials units Rate Eq Total Duplex Meterbases 6 ea $1,000.00 $ 6,000 TTG 51 Installations 6 ea $ 400.00 $ 2,400 Disp Heat Panels 6 ea $ 250.00 $ 1,500 Electric Boilers 2 is $2,500.00 $ 5,000 Unit Heaters 4 ea $ 900.00 $ 3,600 Baseboard 76 ft $ 35.00 $ 2,660 Wire & Conduit 1 is $3,000.00 $ 3,000 Copper pipe, valves, ftgs 1 is $3,000.00 $ 3,000 Freight 1 is $4,000.00 $ 4,000 Materials Total $ 31,160 Travel & Perdiem Total RT Airfare 3 $1,568.00 $ 4,704 PerDiem 36 $75.00 $ 2,700 Housing 36 $100.00 $ 3,600 Travel & Perdiem Total $ 11,004 Const Contingencies 15% $ 12,685 Contractor OH & Profit 22% $ 21,395 Estimated Construction Cost $ 118,644 Inspection 10% $ 11,864 Admin Overhead 4% $ 4,746 (Waste Heat Project Estimated Cost $ 123,390 IP' i �., �: v, r. �3r,r 4r ,r r i� �, r � I I I I -__TTz- _ - _ �- �- - �ill!� �.l�l� i_I�I� NI_I_I �' INININ � iv.l< ICI- - -l-l- - ��I� N N��I�I�� I�I�I_ = - - 3 2 v'',, h = =_ _---- --�== -- tz -_ r v. a ; a ara a�a arS�a�a c - - - ,x In N �- K y M. 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