Written on
May 24, 2020

Green Ship of the Future retrofit project

Green Ship of the Future retrofit project

Optimum Voyage delivers an algorithm driven route and speed optimization service directly applicable for all commercial vessels. A fuel consumption model is customized individually for each ship, and accounts for the influence of weather on voyages. In order to utilize the full voyage potential an optimization is run daily based on latest position and available weather forecast.

Description of action and technology

In order to uncover the savings potential for Hafnia Lise an extensive optimization study has been carried out. A fuel consumption model has been customized for the ship based on information made available by Hafnia. This energy model has continually been updated and improved based on noon reports to constantly have a clear picture of the state of the ship.

The optimization study has been carried out based on executed voyages for the past one and a half years, where Optimum Voyage has simulated advising the vessel. Upon departure an initial voyage suggestion has been given. Every 24 hours the suggestion has been updated based on the vessel position had it followed the previous suggested best route. Every optimization has been carried out using only the weather forecast available at that point in time. Upon arrival, the executed voyage has been compared with the optimized to show any potential fuel saving.

Of all the executed voyages disclosed by Hafnia a total of 32 have been optimized. Executed voyages have been discarded in cases where destination port has been altered mid-voyage, when there have been periods of very slow steaming, assumed awaiting external factors, or when there have been assumed ice restrictions not expressly specified.

Energy savings based on baseline of calculations

The total average fuel saving 14.1% for all optimized voyages. HFO consumption has been reduced by 26.7% and LSFO consumption has been increased by 14.5%.

The voyage optimization affects ME consumption for days en-route for both laden and ballast days, resulting in a yearly baseline consumption of 2,875 mt HFO and 1,234 mt LSMGO.

Applying average reduction and increase, the yearly reduction is:

  • 768 mt HFO
  • -179 LSMGO
  • 589 mt total fuel savings which equals 1.815 mt CO2


The Optimum Voyage route optimization service works on a prorated subscription basis with a yearly fee for each vessel. The yearly cost is 6,500 USD.


The yearly cost should therefore be covered within 12 days on average, thus disregarding whether the ship is idle, in port or enroute. The study has been carried out assuming fixed arrival times for all voyages. Optimum Voyage also provides arrival time optimization in the yearly service fee and the payback period is therefore expected to be shorter.

Does it make sense to implement in this particular case?

Hafnia Lise is listed in Hafnia Management’s MR Pool and operated from there. When receiving a charter, it is stated where and when the vessel has to be upon finalization of the voyage. In the charterparty, the planned average speed the vessel has to sail is also specified. If the agreed arrival time is not met, the vessel receives a penalty. Optimum Voyage arrival time optimization is not applicable as a fuel saving means in this particular case. Given consent from the client for the vessel to comply with minimum average speed and specified arrival time, but at a variable speed for the single legs of the voyage the Optimum Voyages fixed ETA optimization is fully applicable and expected to deliver the savings seen in this study.

Further Comments:

The Optimum Voyage optimization service is one of the most directly applicable technologies for fuel consumption reduction as it does not require investments in either hard- nor software and is relevant for all ships in a fleet, no matter the age or state.

Read more and the full report HERE