Completion of Joint Development and Start of Sales for Overhang Permanent Magnet Shaft Generating System

MITSUI E&S Co., Ltd. (Head Office: Chuo-ku, Tokyo; President and CEO: Takeyuki Takahashi; hereinafter "MITSUI E&S") and Taiyo Electric Co., Ltd. (Head Office: Chiyoda-ku, Tokyo; President: Takuo Yamada; hereinafter “Taiyo Electric”) have completed the joint development of the “Overhang Permanent Magnet Shaft Generating System”  for large marine engines and commenced sales activities as of January 2026.

Unlike Taiyo Electric’s conventional shaft generators installed on intermediate shafts, this new system is mounted on the fore end of the main engine. This configuration minimizes the impact on engine room layout and stern hull design, contributing to improved fuel efficiency and enhanced energy-saving performance for vessels. In addition, the engine and generator can be ordered and delivered as further a single package, helping reduce the workload of shipyards during installation and outfitting.
The system adopts a permanent magnet generator, which offers higher efficiency and a more compact and lightweight design compared to conventional wound-rotor types. The reduced number of periodically replaced components also contributes to improved maintainability.
Furthermore, in addition to PTO*1 (power generation), the system supports engine-assist operation through PTI*2 (driving the generator as a motor) by providing supplemental propulsion power when required, the system supports stable vessel operation even under adverse weather conditions or in situations where additional acceleration is needed.

MITSUI E&S and Taiyo Electric will continue to expand the application of this system and enhance their service capabilities, thereby contributing to the reduction of GHG emissions and further  energy efficiency in vessel operations by responding to customer needs.

*1 PTO (Power Take-Off) : Generates electrical power from engine rotation to supply electricity 
onboard the vessel.
*2 PTI (Power Take-In) 　: Drives the generator as a motor to assist the engine output.

Contact details for this Press Release

For inquiries regarding products and technologies 

Planning & Administration Dept., Marine Propulsion Systems Div.
TEL : +81-3-3544-3077

For media inquiries

Internal Control Section, Corporate Planning Department
Tel: +81-3-3544-3147