In this study, the concept of sailing wind turbines is investigated. The considered study case is a 40m x 40m barge with a height of 10m and a draft of 7.5m. It is equipped with a wind turbine, a keel, and two propellers. The propellers are used to propel the barge. Because of the thrust of the wind turbine and due to the fact that it is directed along the apparent wind velocity vector, the platform experiences drift. The flow around the keel creates a lift force and a drag force that counteract the thrust of the turbine. Moreover, as sailing wind turbines are not grid connected, they must include energy storage (e.g. batteries, hydrogen, ...)

In this preliminary study, a VPPP (Velocity Power Prediction Program) has been developed in order to estimate the platform velocity, the power generated by the wind turbine, and the power consumed by the propellers as function of the wind conditions, rotational velocity of the propellers, and design parameters (e.g. propellers' diameter, Turbine's diameter, ...).

Results show that there are two operating regimes that can culminate in positive net energy production. They are the drifting regime, where drifting motion dominates, and the sailing regime, where sailing motion dominates. It is shown that the drifting regime is highly affected by the keel's size, whereas the sailing regime is affected by the propellers' size. In addition, increasing the size of the wind turbine reduces the net power for the sailing regime whilst it increases it for the drifting regime, and vice versa.