Page 31: of Marine News Magazine (September 2014)

BOAT OF THE MONTH Elco says that gathering this informa- tion is what this project is all about and it will take a year or two to unfold. For example, the difference in cost between the each power charge and conventional diesel bunkers will be an interesting comparison, when it is all said and done. And, while typical power genera- tion in New York is arguably cleaner than that produced in other states, the question of whether an electric connection merely moved the carbon ?burn? further downstream remains to be answered. Early indicators point to combined savings from reduced energy costs, maintenance costs, envi-ronmental impact, and other variables will eventually yield a breakeven ROI in two to three years, after which there are (signi cant) annual cost savings to be experienced. Real World Performance, LogisticsOutlets for recharging the boat?s batteries are positioned at key spots on the canal, but the ?Tender 4? can also charge from barge or dredge gensets that it is pushing. On board the Ten- der, batteries are located port and star- board, readily accessible and charging is a convenient event. The workboat consumes about 55kw of energy on average, so the batteries were designed to provide 66kw ? a safety factor of 20 percent, just to make sure any and all anticipated energy needs are met. About 10 hours of battery power in one charge ? 6 to 8 hours ? is achieved utilizing a standard shore connection, single phase 208v ? 240v input. That said; in reality, the tug can go and ?bunker? at any marina and plug in. Hence, what might seem as a geo- graphically limited workboat is, in reality, anything but. In the water, an electric engine pro- vides instant response time and full torque immediately. In comparison to a similar powered diesel engine, the electric engine is smaller, lighter, and does the same work. Bollard pull, in this case, is rated at 3,500 pounds. And the old fuel tank? Fully washed and cleaned ? it is still on board. The tug can use that as necessary, for bal- last purposes.www.marinelink.com MN 31MN Sept14 Layout 18-31.indd 31MN Sept14 Layout 18-31.indd 318/20/2014 11:44:41 AM8/20/2014 11:44:41 AM