ELLE™ Leading Edge Protection
ELLE™ Leading Edge Protection

ELLE™ puts an end to leading edge erosion, downtime and costly repairs to your blades

Bigger wind turbines mean longer blades, faster tip speeds and growing challenges linked to eroded leading edges on account of the merciless onslaught from rain, hail, sand and airborne particles. Everlasting Leading Edge Protection (ELLE™) from PolyTech eliminates the problem. Simply. Efficiently. And no matter where in the world your turbines are located.

How much money have you spent on repairing or replacing your wind turbine blades?
Regardless of whether your business is OEM manufacturing, developing and building blades, or owning and running wind farms, one of the items likely to be found high on your business agenda is:

How do we tackle the challenge of leading edge erosion?

As wind turbines are getting still taller, and as they are being erected in ever-tougher and more remote locations – including offshore sites – leading edge erosion has become a particularly tangible challenge. And one that makes its financial mark in several contexts:

  • Reduced AEP (= diminished energy generation)
  • Frequent leading edge repairs (= downtime and service expenses)
  • Reduced service life of the blades (= replacement)

Added to these problems is the issue of wear and warranty cover, with the potential legal wrangling this may lead to.

Leading edge erosion is a significant issue, especially in remote areas such as offshore, desert and mountain sites where weather conditions are tough. Not only because heavy downpours and large volumes of airborne particles cause faster and more drastic erosion, but also because it is costly and difficult to reach the wind turbines and do blade repair; or, in the worst case scenario, to replace them.

A permanent solution. Finally
In recent years, manufacturers, Independent Service Providers and wind farm owners and operators have all been searching for a permanent solution to the erosion issue. A common trait of the Leading Edge Protection (LEP) solutions to date is that their protective effect has been only temporary. It has therefore been necessary to replace or repair the products at frequent intervals.

It was thus something of a game-changer when in 2017 – following months of intense product development and two years of thorough field and lab tests – PolyTech unveiled a completely new type of protection: ELLE™ – Everlasting Leading Edge.

Blade-specific polyurethane shells
The ELLE™ solution comprises pre-cast sections made of robust, yet soft and flexible, polyurethane shells.

Each section measures approx. 100 cm in length and is customised to match the geometry of the blade model in question, making it possible to protect the desired section of the blade’s leading edge (typically the outermost 15–20 m) against erosion.

Protect and absorb
The unique softshells have been developed on the basis of PolyTech’s deep insight into wind turbine technology, backed by our comprehensive knowledge of polyurethane and manufacturing processes. The shells are strong enough to protect the blade throughout its service life, and the PUR surface is designed and dimensioned to absorb the kinetic energy from drops of water, hail and airborne particles. As such, the shells provide optimal protection for the rigid and fragile fibreglass surface of the blade.

Easy to fit
ELLE™ is supplied as complete sets of shells, ready to fit to leading blade edges. The installation process itself is quick and simple thanks to the specially developed adhesive. The ELLE™ shells can be applied in a wide weather window, and up-tower installation using either rope or basket is no problem at all.

In this regard, PolyTech also offers to provide training for your own service teams in how to apply ELLE™ correctly. Training courses can be held at our own factory facilities in Denmark or on-site – anywhere in the world.

Production and logistics
LEP softshells are manufactured at PolyTech’s state-of-the-art production facilities in Denmark. Here, the PUR shells are cast and CNC-laser cut under continuous quality management through the use of SCADA and in accordance with both APQP4Wind and ISO 9001.

A QR code and a unique serial number are then laser-printed on each section (softshell) to allow tracking of each and every sub-process from raw material batch to finished product. 

Why choose ELLE™ for erosion protection?

  • Reduces Cost of Energy (COE)
  • Optimises Annual Energy Production (AEP)
  • Prevents leading edge erosion
  • Absorbs kinetic energy from rain, etc.
  • Wide weather window for application (5°C to 35°C, 30–90% RH)
  • Quick, solid application (3 hours per blade fitted to WTG)
  • Can be applied on the ground or from basket/rope
  • Fully traceable via QR code and unique serial number
  • No HSE risks

Test results

  • Rain erosion in accordance with ASTM G73-10, 160 m/s
  • New test objects: 100 hours RET without damage
  • Objects after 6,000 hours’ UV impact: 130 hours RET
  • Objects after periodical impact of UV/salt mist/-20 °C in accordance with ISO 20340: 40 hours without damage
  • Adhesion to different sub-surfaces in accordance with ASTM 3330
  • Fitted track record


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