Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48JANUARY/FEBRUARY 2017 • FOGHORN 27 and have a required battery bank capacity of approximately half the size required for a single overnight charge scenario. This saves money in the cost of the battery AND the demand cost of the electricity being used. SUMMARY OF CHARGING OPTIONS Obviously, the operating and charging scenario can vary tremendously, but keep in mind that this will determine a large part of the total system rating (batteries and equipment), as well as the electrical power costs for the vessel. In any scenario, partial charging during the day will reduce the size of the system and the vessel operating costs. COST COMPARISON ANNUAL ENERGY COSTS Based on 18 trips per day, 365 days/year, the estimated annual energy usage and cost is shown (Figure 1) for the two charging scenarios using rates from Puget Sound Energy ((PSE). ANNUAL BATTERY COSTS The recommended battery type is generally dependent upon the operating and charging scenario. This article is NOT intended to be a reference for battery selection. For an excellent review of the options, I would highly recommend reading “Advantages & Applications of Various Lithium-Ion Chemistries” by Gordon Fry, Senior Applications Engineer at Spear Power Systems (www.spearpowersystems.com). NEXT GENERATION NEXT GENERATION TAKINGPASSENGER VESSELSTOTHE TAKINGPASSENGER Starship Express refit and repower | Winter 2016-17 Marine Group Boat Works is the finest California boatbuilder and repairer of steel and aluminum high-speed ferries, catamarans and passenger vessels up to 220 feet-long.Operating two shifts, six days per week for fast turnarounds and minimized vessel time out-of-service. marinegroupbw.com | [619] 621-2220 Contact Leah Yam to quote or schedule your next haul out. Complete control and steering systems for vessels of all types and sizes. +1 (604)572-3935 • Surrey, BC, Canada sales@kobelt.com • www.kobelt.com KOBELT MANUFACTURING CO.LTD. TECHNOLOGY Single Overnight Charge Partial Charges Charge after each trip Energy per round trip (kWh): 284.2 284.2 284.2 Number of round trips/ day: 18 18 18 KWh/day 5116 5116 5116 System Efficiency: 90% 90% 90% Utility Power (kWh/day): 5684 5684 5684 Power Cost ($/kWh): 0.0598 0.0598 0.0598 Cost/day: $340 $340 $340 Total energy cost/year: $124,100 $124,100 $124,100 Utility Demand Cost (per max kW): $10.90 $10.90 $10.90 Charging Power (kW): 1000 417 1000 kW Cost/month: $10,900 $4,545 $10,900 Total demand cost/year: $130,800 $54,540 $130,800 Billing Cost/year: $1,260 $1,260 $1,260 Total Utility Cost/year: $256,160 $179,900 $256,160 Figure 1.