Here is helpful guidance on considerations and operational practices when selecting energy efficiency technologies for ships published by the Global Industry Alliance to Support Low Carbon Shipping (Low Carbon GIA) under the IMO-Norway GreenVoyage2050 Project.
General recommendations include:
- The Ship Energy Efficiency Management Plan (SEEMP) should be updated and revised to reflect the ship’s current operational profile.
- Higher-frequency auto-logged data from sensors give the vessel’s efficiency better understanding. However, sophisticated analysis and proper calibration of the sensor are required.
- For manual systems, the possibility of data entry errors increases (e.g., by transferring the data from a noon report into a performance monitoring spreadsheet).
- Validation of the data and relevant cross-checks might ensure the proper monitoring of the parameters.
- Extra records of weather and loading conditions can support a possible like-for-like comparison.
Before the selection of an energy efficiency technology there are several basic operational measures to encounter.
1 Hull and propeller cleaning
Based on the subject study fouling may increase fuel consumption by 10% to 20%, and more.
Specifically, «a layer of slime as thin as 0.5 mm covering up to 50% of a hull surface can trigger an increase of GHG emissions in the range of 20 to 25%».
2 Seed optimization
3 Weather routing
4 Trim optimization
5 Generator rationalization
The average energy saving ratio and standard deviation for a range of energy efficiency technologies (data and analysis by GRIP project) is presented in the following figure.
Also, you can find below the high-level assessment excel tool based on a “traffic light” scorecard to provide an overview of the relative benefits of different energy efficiency technologies as published by the Global Industry Alliance, and the IMO.