SeaGreen PTO/PTI
The SeaGreen™ PTO/PTI system is an effective, simple way of creating an electric hybrid on a ship, and helps ship owners improve fuel efficiency, reduce emissions and meet environmental regulations.
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Supporting decarbonization and fuel efficiency
GE’s PTO technology works with the mechanical energy of the vessel’s drive shaft to convert it into electrical energy. In PTO (power take-off) shaft generator mode, excess energy from the ship’s main propulsion engines can be directed to provide electric power for onboard systems, which diminishes the need to burn extra fuel to power these systems through separate diesel gensets. The result in fuel savings is significant, especially when coupled with improved operational flexibility. The system can also drastically decrease the operating hours of auxiliary generators - and their need for maintenance - for additional operational cost savings, and help main engines run at a more efficient operating point.
With GE’s technology, we are helping our customers meet sustainability targets with cleaner and innovative energy solutions.
The technology advantages
SeaGreen PTO/PTI system incorporates GE’s medium voltage, compact Advanced Permanent Magnet Machine (APMM) for marine applications. Unlike its competitors, the electric machine is equipped with induction motors instead of synchronous motors. By removing transformers, it offers a simpler design and therefore reduces the complexity of the system, making it more reliable and requiring less CAPEX. The arrangement of induction motors reduces the frequency and extent of maintenance, and combined with the system’s fuel saving characteristics, brings down operational expenditure for customers.
Other advantages of GE’s technology include unrestricted operation in the main engine’s operating speed range, reduced noise levels associated with on-board power generation from auxiliary engines, a Power Take In (PTI) ready system, and its in-house machine and drive single-source integrator product. In PTI mode, the machine is used as a motor to provide propulsion power.
Functionality
PTO: in PTO mode, the ship’s conventional gensets are stopped. The electrical power is supplied by the main engine through the waste heat recovery (WHR) system and the SeaGreen PTO shaft generator. The main engine fuel is much cheaper than the Diesel Oil.
PTI: In PTI mode, the ship’s fitted gensets are operated if required. An additional mechanical propulsion power is supplied by the SeaGreen PTI shaft motor through the variable frequency drive (VFD), enabling a speed boost.
Benefits
- Reduced emissions
- Reduced complexity and footprint of the system
- Higher reliability
- Reduced CAPEX and OPEX
- Increased flexibility