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 25 the calculation. If this is not feasible or you are looking to get a quick energy cost estimate, using the actual vessel fuel usage over a specific time period is also a useful methodology. For vessels equipped with a fuel moni- toring system this is very easy and can allow you estimate the energy usage for specific operations (transit, docking, idling, etc.). If no fuel monitoring system is installed, we can also use the total amount of fuel utilized during the year to estimate energy usage. Estimate the average energy per round-trip and then modify this number to account for the atypical day that would require the highest energy usage and, therefore, dictate the worst case energy require- ments for a single day or period of operation. These requirements could then be used to determine the battery capacity and the required ratings of the power electronics. ENERGY FROM DIESEL FUEL Diesel fuel (ULSD; ulta-low sulfur diesel) contains 137,500 BTU per US gallon (US Energy Information Administration; http://www.eia.gov/todayinenergy/ detail.cfm?id=20092 ). Converting this to energy required per trip: Gallons/trip x 137,500 BTU/gal x Engine Efficiency x 1 kWh/3412 BTU = kWh/trip Typical diesel engine efficiency is 30-40% and can vary significantly between low and high power operations. A simple spreadsheet can estimate the required power. Below is an example for a small vehicle ferry on a short run, utilizing twin 600HP drives: Mode of Time Power Fuel Used Engine Energy Used Operation (min) Level (gallons) Efficiency (kWh) Idling at Dock 20 10% 2 0.25 20.2 Outbound Transit 15 80% 9 0.35 127.0 Idling at Dock 10 10% 1 0.25 10.1 Return Transit 15 80% 9 0.35 127.0 So a 60 minute round-trip uses a total of 284.3 KWh of energy. If the vessel makes 18 round-trips per day, the total energy required is 5117 KWh. SIZING THE BATTERY Now that we know the energy needed for each trip (and this may vary significantly due to tidal currents or other factors), we can look at the options for charging the battery and then sizing the battery. TECHNOLOGY +1 920.686.5117 sales@burgerboat.com burgerboat.com/commercial Proudly built in the USA Burger is recognized worldwide for quality custom vessels that provide years of dependable service. Quality Commercial Vessels... Built by Burger to Your Requirements • Aluminum and Steel Fabrication • Passenger Vessels • Research Vessels • Fast Crew Boats • Fast Supply Boats • Wind Farm Support Vessels • Fishing Vessels • Other Vessels to 260' (80m) See us at M ariTrends 2017 Jan 29 - Feb 1, Booth 53 Under Construction 103’ (31m) Steel Explorer Vessel