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 4828 JANUARY/FEBRUARY 2017 • FOGHORN For the example above, the below table illustrates how the charging scenario can impact the battery type, size, and costs. Given the rapid advancement in battery production tech- niques, battery replacement costs will probably be 30-50% lower in 10 years. So, the actual replacement costs is lower, which should be reflected in significantly reduced operating costs. SUMMARY The above example is a simplified version of the analysis that should be conducted when considering the cost benefit of any propulsion system, and battery systems are no different. There are many variables that must be worked through and the vessel specific operating scenarios will determine the size and type of battery best suited for your vessel. Your bottom line for these systems is very straight forward. The initial cost of these vessels should be the same as the diesel-driven option, and the annual operating costs will definitely be less. The cost of an engine driven system is increasing significantly with new emission restrictions, while the cost of batteries is coming down every year. High- power battery systems provide a zero emission solution combined with low maintenance requirements and warrant a thorough evaluation for any new-build or propulsion upgrade project. n TECHNOLOGY Single Overnight Charge Partial Charges Charge after each trip Recommended Battery Type*: NMC NMC LTO Maximum Recommended Depth of Discharge: 75% 75% 48% Required Battery Size (kWh): 6823 kWh 3315 kWh 596 kWh Estimated Cost/KWH: $650 $650 $1350 Battery Cost: $4,434,700 $2,154,800 $804,600 Estimated Battery Life (years): 10 10 10 Annual Battery Cost: $443,470 $215,500 $80,460 Single Overnight Charge Partial Charges Charge after each trip Annual Utility Costs: $256,100 $179,900 $256,100 Annual Battery Costs: $443,470 $215,500 $80,460 Total Annual Costs: $699,570 $395,400 $336,560 *NMC: Nickel Manganese Cobalt, LTO: Lithium Titanium Oxide Figure 2. Courtesy of Spear Power Systems. Figure 3.Total Annual Cost for Battery/Energy Fuel.