Naples, Italy, based shipyard Cantieri Navali Megaride has commissioned Siemens to equip an ocean-going supply vessel for the Italian Coast Guard with the diesel-electric EcoProp hybrid propulsion system. This propulsion solution has been especially developed to meet the requirements of smaller ships. It includes two main gear units, electric propulsion motors and the hybrid propulsion control system. The standardized modules require very little space on board.
Siemens will be responsible for the project management, engineering and commissioning of the complete diesel-electric propulsion system. The ship design was planned by the Italian project office Errenavi in Rome, Italy.
When a ship is electrically powered in the lower load range, notes Siemens, efficiency of the propulsion system is increased, which in turn saves substantial amounts of energy and fuel. In fact, often only about 10 percent of the main propulsion power is required from the electric drive. As a result, hybrid propulsion systems offer substantial potential for increasing energy efficiency, particularly for ships with frequently changing drive modes and running speeds.
The correct propulsion mode for the particular task or purpose can be selected with a modern hybrid control system: In diesel mode the power comes from the diesel engines, which drive the electric machine as a generator for the on-board power supply system while the ship is at sea. In electric mode, the same machines that provide on-board power propel the ship, but at low speeds. This enables the main propulsion engines to run at optimum utilization in diesel mode, or to be switched off completely in the low operating profile when the ship is sailing at low speed.
Running the diesel engines continually within their optimum load range not only reduces fuel consumption and emissions but also lengthens service life. In addition, longer service intervals for the propulsion diesel engines also help save money. Using electric motors in combination with diesel engines substantially increases the availability of the overall system. Benefits include greater flexibility and safety in everyday operation as well as during difficult maneuvers in harbors and bays, and when anchoring.
June 6, 2011