Epsiline WindEagle

The unique All-in-one solution for independent

Wind Turbine Monitoring and Optimization


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The WINDEAGLE SaaS solution, backed by nacelle-mounted laser-based IoT sensors provides valuable information and analysis for wind turbine performance diagnostics and optimization:

1. Static & dynamic yaw misalignment correction :


60% of wind turbines are misaligned, frequently with a yaw misalignment between 5 and 10° . This leads to a sharp drop in performance. EPSILINE WindEagle provides accurate and reliable measures of wind direction directly in front of the blades where it is relevant.

With EPSILINE WindEagle, wind farms operators can accurately correct the yaw and can lead to typically 1-3% AEP gain. In some specific cases, the improvement is up to 10%.

A case study is available here


Poster: Variation of loss coefficient as a function of yaw misalignment, considering the impact of aerodynamic power coefficient



2. Aerodynamic and mass rotor imbalance


25% of wind turbines suffer from rotor imbalance, up to 2°. Rotor imbalance reduces the aerodynamic efficiency of the wind turbine and can lead to reduced asset life due to excessive loads. EPSILINE WindEagle detects aerodynamic and mass imbalance.

Correcting rotor imbalance improves the lifespan of major wind turbine components and can lead to 1% gain in performance.

A case study is available here


3. Turbulence Intensity in different wind sectors


Thanks to its short range measurement in front of the wind turbine blades, the unique laser included in EPSILINE WindEagle is able to measure precisely Turbulence Intensity for each wind turbine.

You can find more precise information on Turbulence Intensity herePDF-LOGO


Poster: Turbulence Intensity within a windfarm



The wind farm operator can thus check and optimize its curtailment strategy.

In addition, Wake steering control strategy brings 3-5% AEP gain.

Finally, Turbulence Intensity data are the most important data in Wind turbine life extension estimations by reducing uncertainty in these estimations.


4. Performance analysis using Relative Power Curves


  • Power Curve analysis to compare performance before and after improvements on the wind turbine e.g. yaw or pitch modifications, blade extensions, upgrades, retrofitting, etc
  • Power Curve for Long term monitoring of performance and evolution over time.

Discover here why using SCADA Data for optimization is not enough


5. Free-stream equivalent Power Curve. Comparable with site assessment data or power curve verification.


Get here a presentation on how to compare the windeagle data with your current SCADA Power Curve



The traditional measuring instruments on a wind turbine (anemometer and wind vain) are used to control the wind turbine. In particular, the wind vain allows the wind turbines to rotate and follow the wind direction. 

However these measurements, down wind from the blades are subjected to turbulence and will be inherently erroneous, despite sophisticated software to correct them. Consequently wind turbines will not be perfectly aligned with the oncoming wind direction, causing Yaw misalignment, lost performance and additional stress loads on the wind turbine.

The solution is to install on the top of the nacelle roof a LiDAR (laser anemometer) and measure in front of the blades. Consequently the Lidar provides precise and continuous measurements of wind speed and direction.


The complete brochure of the WindEagle is available here


About Us

epsiline windeagle 1

Who We Are

EPSILINE is an innovative company offering ‘state-of-the-art’ solutions to the global wind industry, keeping a fine balance between high-end technology and the economic reality of wind farms.

EPSILINE is a SME company which sells SaaS solutions backed by nacelle-mounted IoT. The company is located in Toulouse, France.

Board :
André ANTOLINI, Chairman of the board

Management :
Christophe LEPAYSAN, Chief Executive Officer

epsiline windeagle 3

The windeagle has been deployed in…

  • EMEA : Ireland, Portugal, France, Germany, Italy, Poland, Greece, Turkey
  • North America : Canada
  • Latin America : Argentina & Brazil
  • Asia : India, China, Japan
EPSILINE WindEagle deployments

… and on 250 wind farms with all major turbine models



turbulence intensity
oct 20th, 2021 Turbulence Intensity: unlocking the mystery

Turbulence is one of the most elusive factors of wind production, impacting both on-shore and off-shore wind turbines.

Turbulence, expressed as Turbulence Intensity or the standard variation from an average wind speed , most often 10 minutes, is not only difficult to understand, but its impact and importance also vary with wind speed. At medium speeds though, productivity will decrease due to turbulence ; but this impact will diminish as speed increases towards cut-out.

The impact of Turbulence Intensity is most certainly inversely proportional to our efforts, and up to now, our ability to measure it.


mass and aerodynamic imbalance
oct 20th, 2021 Wobbling giants: why is rotor imbalance an issue?

The tip of a wind turbine blade can rotate as fast as 80 m/s. That is like driving at 300 km/h. When you are going that fast, you want stability. Rotor imbalance is a concern that increases with speed. With ever longer blades, this is a key issue. Whether the cause is aerodynamic or mass, any impact on its stability can be detrimental to both productivity and wind turbine life expectancy.


wind turbine, yaw impact, lidar, wind speed, wind turbulence
août 25th, 2021 Impact of Yaw on Productivity and Wind Turbine life extension

More than 60% of wind turbines show the presence of Static Yaw leading to performance loss and in half of these cases, the AEP loss is greater than 3%. Yet the importance of managing Static Yaw has not always been among the wind industry’s top priorities, especially with high subsidised wind energy prices.


juil 15th, 2021 3 reasons a wind farm from Northern France has choosen WindEagle solution

A French IPP has identified a rotor imbalance on its wind turbines. Discover how Epsiline collected high data quality and helped the IPP to implement an effective monitoring method to increase its productivity and extend wind turbines life time’s.

Click here to download our case study 

juil 13th, 2021 WindEagle orders in 4 countries

Great day for Epsiline as we continue expanding our global presence! This month we get orders for Windeagle solution in 4 different new countries : Epsiline reinforces its presence in Brazil, Argentina, Turkey and the Republic of Ireland and contributes to customer success with increased AEP through turbine optimization!


nov 17th, 2020 EPSILINE will equip a number of TOTAL EREN onshore wind farms in Europe

Toulouse (France), November 17th 2020


After more than two years of testing TOTAL EREN has selected the latest version of WindEagle, a comprehensive hardware/software solution designed and produced by the French company EPSILINE, to be implemented in a number of wind farms in France, Greece, Portugal and Italy.




118, Route d’Espagne, F-31100 Toulouse, France
Tel : +33 5 32 10 83 50

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