A proven setup where combustion engines drive generators and electric motors power the propeller.
Decarbonisation targets require more than one propulsion pathway. Mechanical propulsion can lose efficiency at variable loads, while battery-electric solutions are often limited by range. A fuel electric propulsion system bridges that gap by using genset-driven electricity to power propulsion motors and onboard loads, giving operators high efficiency and strong redundancy across changing duty cycles.
This architecture is especially valuable when vessels operate with large variations in power demand, where optimised genset loading can reduce fuel use without compromising reliability.
A diesel electric propulsion system decouples combustion engines from the propeller shaft. Engines run as gensets, producing electricity that feeds propulsion motors and hotel loads through an integrated power management system. By running only the number of gensets needed at any time, engines stay closer to their optimal efficiency window.
This approach enables stable performance for vessels that shift frequently between manoeuvring, transit, DP work, or low-load operation. These are typical conditions where diesel electric marine propulsion outperforms fixed mechanical loading strategies.
A reliable marine genset propulsion system brings power generation, distribution, and propulsion control into one coordinated setup. Instead of linking engines mechanically to the shaft, the system manages energy flow electrically to keep propulsion efficient and predictable.
Key elements include:
Combustion engines operating as gensets to generate electric power
Electric propulsion motors as prime movers for Controllable or Fixed Pitch Propellers, Azimuth Thrusters, or Tunnel Thrusters units
Power management that optimises which gensets run and at what load
Frequency converters and drives (or DC hubs) for precise motor control
A bridge interface that supports clear, intuitive propulsion operation
Fuel-electric propulsion makes it easier to design the machinery layout freely and keep engines running in their most efficient load range.
Typical benefits include:
For crews, this delivers stable propulsion response and clearer day-to-day operation, even when load demands shift quickly.
By keeping gensets at efficient load points and powering propulsion through electric motors, fuel-electric systems reduce CO₂ and pollutant emissions (NOₓ and SOₓ) compared to conventional mechanical drive. Electric drive operation also reduces noise and vibration, including underwater radiated noise, improving comfort and environmental performance in sensitive areas.
A fuel-electric setup is built around modular genset packages as prime movers. These generators can be driven by diesel, LNG, methanol, or other combustion engines, depending on the vessel’s fuel strategy. Propulsion motor power and type are configured per vessel, with options for inline or geared arrangements using permanent-magnet or induction technology. Drives and motors can be designed with air-cooled or water-cooled solutions.
Electric power is distributed through an onboard grid that can be AC or DC, enabling an AC/DC grid propulsion system tailored to operational needs. Where relevant, the system can also be integrated with batteries or alternative energy storage to support hybridisation.
Fuel-electric solutions are used where power demand shifts frequently, reliability must be built in, or comfort and low noise are important. Typical vessel segments include tankers, ferries, yachts, offshore supply and support vessels, ice-class ships, naval vessels, research vessels, and cargo vessels.
They are especially well suited to operations with:
In these profiles, a fuel electric propulsion system delivers efficient electric drive with strong endurance and operational flexibility.
Combustion engines operate as gensets to generate electric power onboard. This electricity is distributed through an AC or DC grid to the propulsion drives. Frequency converters (or DC hubs) then deliver controlled power to the electric propulsion motor system, and the electric motors drive the propeller.
At the same time, the power and energy management system continuously determines how many gensets should run and at what load, keeping them in their most efficient operating range. The result is a stable marine electric drive propulsion loop that reacts quickly to changing power demands without sacrificing efficiency.
Fuel-electric projects deliver the strongest value when genset sizing, grid architecture, and propulsion motor configuration are tailored to real duty cycles. For vessels facing variable loads, high redundancy requirements, or comfort-class demands, a fuel electric propulsion system can provide efficient endurance with low emissions and stable performance.
Contact a propulsion and electrical integration expert to discuss your vessel profile and the right fuel-electric setup.
Fuel-electric propulsion is often chosen when uptime and safety margins are non-negotiable. With multiple gensets and flexible power distribution, propulsion can be maintained even if one power source is offline. Where multi-motor layouts are used, this creates a redundant electric propulsion system that fits offshore, naval, and other high-consequence operations.
This built-in redundancy also strengthens operational resilience for long voyages, harsh environments, and demanding manoeuvring profiles.
Fuel-electric systems are tailored to vessel realities early in design. Configuration choices include prime-mover fuel selection, AC vs DC grids, and single or twin-shaft motor arrangements. Optional integration with batteries supports peak-shaving or hybrid operation.
The solution is also ready for future fuel engines and supports gradual transitions toward lower-carbon operations as fleet strategies evolve.
Fuel-electric propulsion integrates with Controllable or Fixed Pitch Propellers, Azimuth Thrusters, or Tunnel Thrusters setups for both fixed-pitch and controllable-pitch configurations. Power and propulsion are controlled through MPC in cooperation with EMS and PMS architectures.
For system definition, integration scope, and operational profile studies, regional support and electrical system integration specialists can support project planning.
Berg Propulsion Tunnel Thrusters are in service on vessels operating in demanding maritime environments worldwide. Our customer success stories demonstrate how reliable lateral thrust, robust design, and seamless system integration contribute to safe docking, efficient operations, and reduced lifecycle costs.
Frequently Asked Questions. Don’t find what you are looking for? Contact us directly.
A power management system ensures only the necessary gensets run at a time and at efficient loads. This maintains fuel efficiency even during DP work, manoeuvring, or frequent speed changes.
Yes. Power can be distributed through either an AC or DC onboard grid depending on vessel requirements, supporting AC DC grid marine propulsion system configurations.
Yes. Multiple gensets and intelligent distribution create a redundant electric propulsion system marine, maintaining propulsion capability even if one power source is unavailable.
We are looking forward to hearingfrom you and discussing how we can be of assistance in making sure that your fleet is fully covered.
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