According to DNV’s latest report, action needs to be taken to reduce emissions today and energy efficiency measures can deliver short-term emissions reductions, while also reducing costs to shipowners.
As explained in the “Energy Efficiency Measures and Technologies” report, there is significant potential for improving the energy efficiency of vessels. For example, prime-mover efficiency can be enhanced by recovering waste heat from the engine exhaust and cooling water. Meanwhile, propeller efficiency can be improved by installing propulsion-improving devices, reducing propeller losses.
As shown in the report, the uptake of these measures is still low. Our research shows that a major factor behind this is the lack of trust in the efficacy of many energy-efficiency measures and whether they actually present a strong business case to shipowners.
… said Knut Ørbeck-Nilssen, CEO Maritime, DNV, adding that much work has already been done, but it is important that more data is collected and more verification processes carried out so that the true value of each energy-efficiency measure is demonstrated and shipowners can make crucial investment decisions with confidence.
Hull efficiency can be increased by using hull cleaning technologies, reducing hull fouling. Beyond energy efficiency, energy use can also be reduced by harvesting energy from the surroundings, mainly sails and potentially solar panels to a much smaller degree. Energy-efficiency measures may be categorized as follows:
- Operational: measures that relate to the way in which the vessel is maintained and operated and the cargo is handled.
- Propulsion and hull: measures that improve the hydrodynamical performance of the vessel.
- Machinery: measures that relate to the machinery on board the vessel, including main engines, auxiliary engines, and related systems.
- Energy consumers: improvement in energy efficiency of onboard consumers such as lighting equipment and cargo handling systems.
- Energy harvesting: measures that capture energy from the surroundings, converting it to propulsion power or electricity (e.g. sails and solar panels).
Shipowners should prioritize measures based on cost efficiency and other aspects such as technical maturity, complexity, safety and reliability, lack of experience, and crew training needs. Survey results indicate that operational measures have lower barriers than technical measures.
It is critical for shipping companies to have an energy management strategy and system (e.g. ISO 50001) well-anchored in the organization to manage, contain, and reduce energy use on a vessel in a systematic way. This will include setting energy-saving targets and developing specific key performance indicators (KPIs) for assessing vessel performance. Vessel performance should be continuously monitored and benchmarked per KPI.
With a range of singular solutions on the table, each shipowner needs to devise an energy-efficiency plan which suits them and their fleet best. This report shows that a strategic plan is needed on how to implement changes and improvements over time, but also across the owner’s fleet.
… Jason Stefanatos, Global Decarbonization Director, DNV, explained.
