E-OP Optimized Fuel Consumption

The tool for significant fuel savings in the E-PP system

E-MS avoids the operation of diesel generator sets at inefficient speeds and unacceptably low efficiency of the combustion engines by using E-OP, the E-MS control system for optimized fuel consumption based on different loads and speeds.

This tool implements an innovative start-stop system for the diesel generator sets and enables significant fuel savings at partial or low loads.

The advantages at a glance

  • Significant fuel savings
  • Reduced emissions
  • Reduced generator operating hours
  • Extended maintenance intervals
  • Falling operating costs
  • Fast response on varying load requirements


For optimal efficiency in a traditional diesel-mechanical system, the diesel engines are ideally driven along the propeller curve, which runs across the engine map – between points (3) and (1) in the diagram.

In a traditional diesel-electric system, all generators are synchronized at a common speed, so that this speed is defined as the nominal speed. This operating state is very efficient under full load (1), but very inefficient in partial load operation (2). Yet special or passenger ships in particular often only operate in partial load operation.

The E-PP System decouples the diesel generator sets so that they can be operated independently of each other at variable speeds. As the entire engine map for the diesel engine is available for operation, the E-OP system can control the optimum speed for every power requirement. In the partial load range, generator operation is therefore not only possible at (2), but also at (3).


In addition, if allowed by the rating, further reserves of the diesel generator sets can be used. For example, if there is an increased power requirement, the speed can be increased above the nominal speed (area hatched in red in the diagram/speed reserve). A higher power reserve (blue hatched area) is therefore available for a short time. This means that it is no longer necessary to start an additional generator for short-term peak loads (e.g. when accelerating the ship after a lock or docking manoeuvre, with additional short-term loads due to the bow thruster, etc.).


The E-OP system has already proven its worth extraordinarily well on board of mega yachts and passenger ships. Here, as the power requirement increases, the running diesel gensets are initially continuously brought to a higher speed. In many maneuvering or operating situations, it is therefore
no longer necessary to start additional generators, unlike with conventional systems.