InsightsIs Your Ship the Next Prius?Reducing operating costs by saving energy is a concept By Robert Kunkelthat has moved from discussion to action in shipping. he debate has been fueled by pending emission reg-ulations and options that may be an alternative to the use of high cost low sulfur distillates when op-T erating in the emission control areas or in restricted ports. This quest for energy ef? ciency has gone beyond “ECO” main engine performance, slow steaming or variable frequen-cies of motor and pump operations to reduce electrical load. Shipping is now diving deeper into ef? ciency details with the use of LED lighting, computerized modeling of hull optimi-zation and further introductions of sophisticated hull coatings to assist those new optimized hulls through the water without burning fuel. Moving from sail, to steam and ? nally to internal combustion engine, shipping is now following the lead of the automotive industry and talking Hybrid marine power. At a recent industry conference, owners asked the major engine manufacturers how they could reduce their fuel con-sumption. There answer: “Don’t run your engine.” The argu-ably sarcastic reply, however, was right on the money. And, that is exactly what many Hybrid power systems are designed to accomplish. The de? nitions of hybrid marine power or hybrid marine propulsion describe main and auxiliary systems where power BAE Hybrid Drive traction motor during Factory is supplied from more than one source. Diesel-electric pro- tests in Seattle.pulsion lends itself best to the hybrid power application and we are seeing future ship designs moving away from stan-dard direct drive applications and more towards this style of Hybrid Applications De? nedA hybrid application can demand a higher load from the propulsion system. And, here’s why: Diesel/Electric systems have mechanically disconnected the combustion engine from combustion engine than required by propulsion to maintain the propeller creating the ability to ? x the engine speed at an an ef? cient fuel burn. The additional energy supplied is buff-optimum load, match the power required by the ship and then ered in a battery bank and utilized as the second power source. convert the power to electric energy required by the motor to Once the batteries are fully charged, the engine can be secured and propulsion power is provided directly from the batteries. drive the azimuth or propeller.The combustion engine(s) operate at an ef? cient constant When the batteries become depleted, the engine is reengaged and the cycle is repeated. speed and load. For internal combustion engines driving di-The Hybrid systems are best suited to applications where the rect shafts at speeds below normal continuous ratings (NCR), energy ef? ciencies are decreased and emissions increased at power variations are high. The operating pro? les for tugboats, offshore supply vessels, research vessels and small ferries ? t these low loads. This is especially true with shipping’s accep-tance of “slow steaming.” To meet “ECO” fuel consumption well. Foss was the ? rst to commission a hybrid tug in 2009. The ? rst hybrid offshore supply vessel, Viking Lady, was also demands in ship design, smaller direct drive engines have been installed to meet these new slow steaming loads sparking a commissioned in 2013. Amtech’s Hybrid example is a sixty-? ve foot catamaran research vessel under our construction su-heated safety debate between builders, owners and managers. 12 Maritime Professional 1Q 2014I I MP Q1 2014 1-17.indd 12 MP Q1 2014 1-17.indd 12 2/27/2014 11:46:36 AM2/27/2014 11:46:36 AM