System integration of wind and conventional propulsion and its impact on the drive-line

In the framework of WP3, Optiwise partner, Wärtsilä, is responsible for evaluating the impact of wind propulsion on overall vessel operation and engine performance.

The system simulation model combines the well-known hydrodynamic performance estimate of the tanker vessel with the aerodynamic contribution from the sails. This wind propulsion contribution varies depending on the vessel's location along the route. Seasonal weather impacts are included in the simulations by averaging the performance over 365 days to determine the annual average performance. The vessel operation covers the laden trips to China and the ballast trips from China, and simulations have been conducted for three different vessel speeds: 9, 12, and 15 knots.

Given the variability of the wind propulsion contribution, three different vessel control logic approaches have been simulated: (1) constant vessel speed, (2) constant propeller speed, and (3) constant engine power. Clear energy savings have been observed under different vessel operating conditions.