According to the recent comments of a senior engineer from Siemens Marine & Shipbuilding, Kay Tigges, in Tradewinds, waste heat recovery (WHR) systems can result to big fuel economies and thus reduce the fuel costs in the shipping sector. The current marine power plants normally extract only 50% of the available potential energy from the fuel, and then emit hot exhaust gases in the atmosphere. The WHR systems use the hot exhaust from the ship diesel engines in order to drive turbo generators to produce electric power for the needs of the ship. In this way, the overall efficiency of the engine of the vessel in terms of shaft power can be increased by about 55% and the fuel consumption can be decreased by approximately 12 percent. Apart from the energy and cost savings for ship owners, the use of WHR systems in ships can have a great impact in reducing environmental pollution. Most vessels consume heavy fuel oil which has a relevant low cost but contains numerous pollutants like CO2, sulfur oxides and nitrogen. WHR systems can reduce the emission of these pollutants in the environment. These innovative systems are among the priorities for engine manufacturers despite the trending focus on cleaner fuels like LNG and low-sulphur bankers which can counter greenhouse gas emissions. After all, according to Tigges, heavy fuel oil will continue to be the primary energy source for lots of vessels, so it is wise to address the energy lost from burning it.

By Christi Psara,
iMBA, PT14