Farwind: an energising design concept

Farwind has led to the development of a multihull that is fully propelled by the wind. And as it sails, water turbines underneath are powered to generate electricity. The harvested energy is stored on board and brought to shore.

However, with a sailing craft, increasing the power coefficient also brings down the ship speed, thereby decreasing the apparent wind over the Flettner rotors and generally lowering the flow speed over the turbine. The optimum working point is thus at a much lower loading, which is completely different compared to existing tidal turbines.”

Farwind design concept

Similar challenges are relevant for the sailing performance. Interaction effects (with multiple devices both above and below the water) can have a significant impact on overall performance.

At societal level, such a project could make a big impact and help to deliver zero emission fuels, improving problematic availability in areas with little infrastructure. On the technical level, the project is interesting because it integrates automated wind propulsors with a tidal turbine.

MARIN was given the chance to contribute within the broader frame of the Marine Energy Alliance Interreg project. Farwind had been doing its own modelling1


concept development and was now in need of some review work and consultancy regarding various design options. MARIN’s review showed that Farwind had been comprehensively covering the entire performance but there were some points needing attention.

Rogier Eggers, 26 report

Farwind’s CTO Aurélien Babarit commented: “A key challenge in the energy ship concept is to develop an appropriate design for the water turbine. Indeed, the common designs for tidal turbines maximises the power coefficient without paying attention to thrust.

References [1] A. Babarit, G. Clodic, S. Delvoye, J-C. Gilloteaux (2020) Exploitation of the far-offshore wind energy resource by fleets of energy ships – Part 1: Energy ship design and performance. Wind energy science, Vol. 5, 839-853

MARIN’s contribution indicated ideas for design improvements, as well as methods to improve performance predictions. Our contribution may be modest, but such early involvement can sometimes have the largest impact down the road. We wish Farwind every success with their concept!

The Marine Energy Alliance project is funded by Interreg North-West Europe.

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28