Coordinateurs du projet
Context
The exploitation of offshore wind resources is a highly innovative concept that has been the subject of very few scientific and technical studies. In total, there are only six research groups worldwide working on this topic.
The development of wind power, autonomous ships, and energy storage systems that convert electricity into gas or liquid are the key elements that make this concept possible today. However, a great deal of research is needed to determine the most effective technical solutions.
Scientific breakthroughs and innovation
- Development of a velocity and power prediction tool (Velocity and Power Prediction Program—VPPP) for floating wind turbines.
- Optimization of anti-drift characteristics and propeller design.
- Evaluation of load factors.
Expected technical and economic impact
Since 2016, the EMO team at the LHEEA laboratory has been working on recovering wind energy from the high seas. This resource, which is currently completely untapped, represents a considerable potential for renewable energy, equivalent to several times the world’s energy consumption.
One concept for exploiting this resource is the floating wind turbine, which is neither connected nor anchored and would be supported by a barge-type float. This concept is promising because it would eliminate the need for electrical connections, anchoring, and associated installation work, which would reduce the investment required to deploy offshore wind turbines by about half. In addition, since the wind turbines are mobile, their energy production could be optimized by weather routing.
The EOLNAV project aims to study the potential of this concept through digital simulation.
Results
Using a digital model of a floating wind turbine developed as part of the project, speed and energy production curves were obtained for a realistic floating wind turbine design. These curves show that it is possible to achieve significant net energy production under realistic environmental conditions. The floating wind turbine concept therefore appears to be potentially viable.
One initial operating mode is that of a drifting wind turbine. In this mode, the wind turbine drifts with the wind, but at a significantly lower speed than the wind. There is therefore a significant apparent wind speed that allows energy to be produced. The disadvantage of this mode is that, by definition, the position of the wind turbine drifts over time, making it necessary to provide an additional means of returning it to its starting point.
A second mode of operation is that of the sailing wind turbine. In this mode, net energy production can be achieved in conditions of tailwind, but also, counterintuitively, in headwind conditions. This mode of operation is interesting because it allows the position of the wind turbine to be controlled over time (no additional means are required to return the wind turbine to its initial position). However, energy production is reduced in headwind conditions compared to the drifting wind turbine configuration.
Figure 1: Diagram of a 2 MW floating wind turbine installed on a square barge measuring 40 m on each side, equipped with a 150 m² keel and two propellers measuring 6 m in diameter. Below, polar curve for the net energy production of this floating wind turbine.