Epsiline WindEagle

The unique All-in-one solution for independent

Wind Turbine Monitoring and Optimization


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The nacelle-mounted wind LiDAR WINDEAGLE provides valuable information that enables multiple types of analysis of wind turbine performance and optimization:


1. Static yaw misalignment detection :


60% of wind turbines are misaligned, some with a yaw up to 15°. 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 10% gain in performance.

A case study is available here


2. Turbulence Intensity in different wind sectors


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

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


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

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


3. Aerodynamic and mass 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 4% gain in performance.


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.


6. Gust detection

Thanks to its 2s wind speed measurements, the lidar-based sensor suite is able to detect rapid changes in wind speed or gusts.




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’ technologic 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 develops Iot wind measurement solutions based on laser systems (LIDAR) and serves the wind energy industry. The company is located in Toulouse, France.

Board :
André ANTOLINI, Chairman of the board

Management :
Christophe LEPAYSAN, Chief Executive Officer

epsiline windeagle 3

They have trusted us…

  • Total Eren, Greece
  • Valemo, France
  • Eurus Energy, Japan
  • Ningxia Jiaze New Energy, China
  • Innergex, France
  • Boralex, France
  • Renew Power, India
  • ERG, Italy
  • EDF Renewable, France
  • Engie Green, France
  • Iberwind, Portugal


EPSILINE WindEagle deployments

… and have deployed the solution on 120 wind turbines


epsiline windeagle 2



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.



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

Canada Distributor

X Wind Services Inc.
Adress: 1020 rue Bouvier, 4ième étage, Québec, QC, Canada, G2K 0K9
Phone : +1 418 558 6977

China Distributor

Shanghai ShangYi Industrial Trading
Phone : +86 13917819317

Korea Distributor

Antevista Korea Co, Ltd.
Adress: Hangang POS Ville 1117, Yangpyung-ro 67, Yeongdeungpogu, Seoul, Korea
Phone : +82 2 2298 2628


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