The Wind Turbine Telltale
Its Interest :
Developed and improved for more than 15 years by Mer agitée, the E-Telltale® allow to make «electronic» the information normally only visual of the wool telltale. This system, developed, tested and proven by Michel DESJOYEAUX, has shown its efficiency and durability.
The E-Telltale® is a sensor that monitors in real time the state of the airflow (hooked/la minar or unhooked/turbulent) on an aerodynamic profile. It is a technology from offshore racing, which is very useful in the sailing merchant marine sector, the sport marine and in wind energy as well. Indeed, better tuning of the telltale allows you to optimize the performance of your wind turbine blade in order to take advantage of the wind’s potential.
Its Interest
The project participates in both the dynamics of Intelligent Objects and the Data Economy in order to provide operators and manufacturers of wind turbines with a solution that will enable them to improve the performance and optimize the maintenance costs of wind farms, which will ultimately contribute to the strengthening of the industry. The project, co-financed by ADEME within the framework of the “Programme Investissements d’Avenir” (PIA), has been conducted by “Mer Agitée” in partnership with the LHEEA lab (UMR6598), the CSTB of Nantes and EDF Renouvelables.
The E-Telltale® can be mounted on any existing wind turbine. With a worldwide installed capacity of 433 GW (141.7GW in Europe and 10.8 GW in France in 2016), the potential of E-Telltale® equipment is very important. An experimentation is conducted with EDF Renouvelables to test the E-Telltale® in real conditions on a 3MW wind turbine. The objective of this partnership is to test the product in endurance and to quantify the gains obtained in the context of an industrial use to prepare the connected blade.
At the present time, based on our experience, we will generate a gain in electrical production of about 3 to 5% thanks to the E-Telltale®. The stakes are therefore considerable with regard to the world wind power capacity of 433GW.

Its Use :
Wind turbines (off-shore and on-shore) must make the most of the available wind to produce electricity. The adjustment of the angle of incidence of the blades makes it possible to optimize their outpu
Its Use
By positioning the E-Telltales® directly on the blades, we obtain information on the actual airflow along the blades, much more precise than the one returned by a single anemometer, with non-optimal positioning. This real time diagnosis of the blade setting can then be used for several benefits:
- Diagnosis of the aerodynamic profile of the blades.
- Optimization of the aerodynamic efficiency: by continuously checking that the blade angle of incidence is correctly set and correcting it if necessary, lift is maximized and performance is increased.
- This function can be used both for start-up and during operation.
On the other hand, we have seen that the E-Telltale® also allows for advanced monitoring of wind turbine blades to ensure the structural integrity of the blades and to monitor their condition. This is all the more important as on some wind farms, serial defects of the blades are present and risk to worsen during the operation of the wind turbines.


The Technique :
With a small size (10 x 4 cm) and a weight of 65 g, the E-Telltale® is connected to an electronic system that will be able to interpret its movements at 360 degrees but also its elongation in order to refine the data.
The Technique
Wind turbines (off-shore and on-shore) must make the most of the available wind to produce electricity. The adjustment of the angle of incidence of the blades makes it possible to optimize their output by arranging our Telltales on an axis put in rotation so as to modify the angle of their tail following cycles.
Thus, it is possible to verify that they all have the same behavior (slopes) and the amplitude allows to calibrate the E-Telltale® in angle. Indeed, on one side, the minima correspond to the vertical position of the E-Telltale, i.e. with the tongue down and an angle of 0°. On the other hand, the maxima correspond to the horizontal position of the E-Telltale with an angle of 20°.
To date, only abacuses are used. This compares the incidence with the wind speed. The anemometer is often placed at the back of the wind turbine mast, a position where the airflow can be disturbed by the movement of the blades themselves. Another measurement technique is to place the anemometer at the top of a weather mast, and estimate the wind speed at the turbine, based on its relative position to the mast. The control of the blade position according to the measured speed is not done in real time, which suggests a potential for optimization.


History :
At TrimcontrolTM, the E-Telltale created with the help of Michel DESJOYEAUX is not new: indeed, many versions of the E-Telltale have been tested and then improved in order to be able to offer the product in its most efficient and best adapted version.
Notre Histoire
Depuis, la version finale a été déjà testée par des professionnels sur plusieurs courses de renom : Le trimaran MACIF avec François GABART, le monocoque SMA avec Paul MEILHAT, Michel DESJOYEAUX sur le fameux Vendée Globe, mais aussi sur d’autres sortes de bateaux comme les imocas, les bateaux de courses-croisières, super-yachts…

labelling & awards
Find here all the certifications and awards that the E-Telltale®️ from TrimControl has received since the beginning of its creation.

The press talks about it
Click below to access our press review and dive into the articles about us !
The TrimControl Documentation

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