Energy consumption is a major issue at sea as each vessel has its limits in terms of energy efficiency which, if violated will result in a failure of systems and therefore take toll on the crew. We have seen ship systems fail during a voyage and now, with newer builds aiming to reduce impact on environment the effect would maximise since electricity and natural gas is the main driving force. Along with that, fuel is also spent at a faster rate thus increasing a chance for a vessel to become stranded during a voyage due to expiration of fuel.
Firstly, a ship’s generator can have varied minimum and maximum load criteria where a sudden spike in load can result in a ship-wide blackout. An efficient operating pattern may be a single generator running at 30% load than 2x at 15% whereas one running at 70% consumes more fuel than 2x running 35% each.
Managing power aboard a ship can start from changes to existing power-consuming structure starting from simple yet essential and prominent aspect; lighting. Conventional lamps consume more power where a globe/ incandescent bulb (lifespan of 1000 hrs) and a fluorescent lamp (7500 hrs lifespan) require to be replaced by LED lights. LED lights have a lifespan of 50,000 hours and consume 60% less energy than conventional lighting therefore more efficient at power management alongside reduction of maintenance hours and operating costs. (Generator fuel and light maintenance)
Going onto the generators themselves it is worth mentioning that less efficient, conventional generators experience more loss during start (iron loss, stator and rotor loss, friction loss etc) Energy-saving motors not only reduce maintenance effort and costs but also improves efficiency even on lower temperatures. Soft-starter technology is another way which can improve operation and lifespans of motors in ways of smoothing their acceleration and deceleration.
When talking about power it is also important to consider transformers; a device transferring electrical energy between circuits. Energy-efficient transformers reduce energy loss by 70% as compared to a conventional transformer; the other difference is that this transformer uses amorphous material, metallic glass alloy, for the core. This type of transformer is also capable of maximum efficiency at a lower load; e.g.t 35% load, approximately 98% efficiency is achieved.
Finally, the way to manage a ship’s power can also lie in electronic ballast which also improves efficiency of fluorescent lamps. Electronic ballast works on gas discharge principle which controls the starting voltage and operating current of lighting devices; eliminating flickering and buzzing of lamps. The system operates at 40-50 Khz instead of 60 Hz; increasing efficiency and service life of lamps.
