Method and apparatus for turbine blade protection

Abstract

There is provided herein method and apparatus for turbine blade protection. In particular, there is provided a method for protecting a wind turbine blade or part thereof by an erosion shield comprising a polymer composition, the method comprising the steps of: receiving geometric data of at least a portion of a wind turbine blade to be protected; selecting an erosion shield based at least in part on an offset of the received geometric data; and optionally applying the erosion shield to the portion of the wind turbine blade to be protected using an adhesive, the adhesive being arranged between the erosion shield and the portion of the wind turbine blade to be protected.

Description

METHOD AND APPARATUS FOR TURBINE BLADE PROTECTIONBackground

[0001] Wind turbines are designed to function in various weather conditions, allowing them to harness wind energy and produce electricity. However, their exposure to different elements poses risks to their performance and structural integrity. Damage to the wind turbine blades can be caused by the collision with the blade of airborne particles or by other severe weather events or collisions with birds. Such damage can significantly reduce the turbines' efficiency and power generation capacity.

[0002] As a result, the aerodynamic performance of the wind turbine blades can be adversely affected leading to a loss in annual energy production. In addition wind farms may experience periods of non-operation to address and repair the damages, leading to substantial financial losses and decreased annual energy production. To ensure optimal efficiency and costeffectiveness, wind farm operators have to prevent damage from occurring, or implement robust maintenance and inspection protocols to detect and repair blade damage promptly.Summary

[0003] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0004] A first aspect provides a method for protecting a wind turbine blade or part thereof by an erosion shield comprising a polymer composition, optionally an amorphous polymer composition, the method comprising the steps of: receiving geometric data of at least a portion of a wind turbine blade to be protected; selecting an erosion shield based at least in part on an offset of the received geometric data; and optionally applying the erosion shield to the portion of the wind turbine blade to be protected using an adhesive, the adhesive being arranged between the erosion shield and the portion of the wind turbine blade to be protected. Another aspect provides an erosion shield for protecting a wind turbine blade or part thereof suitable for use in the method identified above. Yet another aspect provides a wind turbine blade or part thereof protected by an erosion shield using the method identified above.

[0005] The preferred features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the invention.Brief Description of the Drawings

[0006] Embodiments of the invention will be described, by way of example, with reference to the following drawings, in which:

[0007] Figure 1 illustrates a wind turbine during operation, which has sustained damage to one of the blades;

[0008] Figure 2 illustrates a wind turbine blade fitted with a protective erosion shield;

[0009] Figure 3 illustrates the application of adhesive to a wind turbine blade;

[0010] Figure 4 illustrates the application of adhesive to the erosion shield;

[0011] Figure 5 illustrates the application of the erosion shield to the wind turbine blade; and

[0012] Figure 6 illustrates the removal of a protective film from the erosion shield.

[0013] Common reference numerals are used throughout the figures to indicate similar features. The figures are for reference purposes only, and the drawings therein are not intended to be to scale.Detailed Description

[0014] Wind turbine blades can be damaged due to various factors. Examples of such damage include erosion caused by airborne particles, birds, UV rays, and weather elements like rain and hail, leading to a reduction in blade thickness and aerodynamic efficiency over time.

[0015] Manufacturing defects or material imperfections can also make the blades susceptible to early wear and tear. As a result of these issues, wind turbine efficiency can decrease, maintenance costs can escalate, and, in extreme cases, blade failure can occur, necessitating timely inspection, repair, and enhancement of blade designs. As shown in Figure 1 , there is represented a wind turbine in action, designed to harness the power of wind and convert it into renewable energy. The wind turbine 105 comprises three main components: the tower 115, the nacelle 120, and one or more blades 100. The tower 115 is a tall structure that provides support and stability to the entire system, and raises the blades 100 to a necessary height. At the top of the tower 115, the nacelle 120 is positioned, housing the machinery responsible for power generation.

[0016] The blades 100 are used to capture the kinetic energy of the wind. The number of blades 100 can vary depending on the specific design of the wind turbine 105, but the most common configurations include two or three blades 100.

[0017] The particular wind turbine 105 represented in Figure 1 has encountered an issue during its operation, and the leading edge of one of its blades 100 has sustained noticeable damage 110. The leading edge generally experiences the most direct impact from wind and other environmental factors. Often leading edge erosion will appear as a rough eroded surface and / or the exposure of substrate laminate. If structural damage occurs, the nature and extent of the damage might vary; there could be a visible crack, a significant break, or a bend that alters the aerodynamic profile of the blade 100.

[0018] The damage to the blade can have several consequences on the wind turbine's performance and overall efficiency. The unbalanced load caused by the damaged blade can generate vibrations, leading to increased stress on the entire structure. This increased stress may accelerate the wear on other components and jeopardize the stability and structural integrity of the entire wind turbine. Further, the damaged blade's altered aerodynamics can disturb the optimal airflow across the rotor, reducing the wind turbine's overall energy capture efficiency. This diminished efficiency translates into lower power generation and, subsequently, decreased output of renewable electricity.

[0019] Figure 2 illustrates a wind turbine blade 100 equipped with a protective erosion shield 200, designed to safeguard the surface of the leading edge of the blade 100 from external damage. The erosion shield 200 serves as a proactive measure to prevent, minimize, or repair the impact of wear and tear, particularly due to the forces of wind, rain, sand, UV rays, temperature variation, and / or other abrasive elements that blades encounter during their operational lifetime. There should be no delamination of substrate (wind turbine blade material) and leading-edge erosion shield 200, irrespective of chemical structure of the substrate or preapplication physical condition of substrate. Application of the erosion shield 200 may be to both virgin and eroded substrate with no requirement for substrate repair except where structural repair is required.

[0020] The erosion shield 200 may be formed from a plurality of smaller pieces applied in series, for example the pieces 200’, 200”, 200”’, 200”” shown in Figure 2, and cover a portion of the blade 100 or substantially the entire blade 100. It is appreciated that the erosion shield 200 may be formed from more or fewer pieces depending on the specific model used. The erosion shield 200 may further comprise a “boot” piece 205, which covers at least a portion of one end of the blade 100, for example the end remote from the nacelle 120. For example, the boot length may be between 100mm and 600mm, for example between 200 mm to 400 mm, such as 300 mm. The erosion shield 200 may also be formed from a single piece, depending on the specific model used.

[0021] The plurality of smaller pieces 200’, 200”, 200”’, 200””, and / or the boot 205 of the erosion shield 200, may comprise one or more locator reference points 210. Locator reference points are specific points or features designed into the parts of the erosion shield 200 to facilitate proper alignment and connection when assembling the erosion shield 200. These points serve as guides to ensure that the different parts of the erosion shield 200 fit together securely and accurately, creating a cohesive and effective erosion protection system.

[0022] The locator reference points typically consist of corresponding notches, grooves, or cutouts, for example substantially U-shaped cutouts, strategically placed on the edges or surfaces of the smaller pieces 200’, 200”, 200’”, 200””, and / or the boot 205 of the erosion shield 200. When connecting two pieces, these reference points interlock or fit into each other precisely, leaving little to no room for misalignment or gaps.

[0023] Male or female locator reference points 210 help ensure the next shield piece in sequence locates precisely and therefore each shield piece in sequence will locate precisely to the section of blade it is designed and formed to fit. They also minimize human error, which is a common feature of poor installation and cost in the industry. This promotes a tight fit for each shield piece in sequence. The shape of each shield piece may allow a flush joint with the next shield piece over the leading edge and flared towards the trailing edge. Each of the smaller pieces 200’, 200”, 200’”, 200”” of the overall erosion shield 200 in sequence may be designed to have an end-to-end flush joint of the leading edge with the join flared, for example 1 mm to 3mm, for example 2mm, to cater for wind turbine blade flex during operation. The length of each of the smaller pieces 200’, 200”, 200’”, 200”” of the overall erosion shield 200 along the length of the cord (leading edge) of the blade may be, e.g., between 750mm and 930mm, typically 850mm, which may be considered as a useful length range to allow for ease of handling by installers while maximizing the length covered by each shield and therefore the optimally efficient use of time and materials. The thickness of the erosion shield 200 or any or each of the smaller pieces 200’, 200”, 200’”, 200”” of the erosion shield 200 may be, e.g., between 1 mm and 5mm, such as between 2mm and 3mm.

[0024] The use of locator reference points 210 in erosion shield 200 assembly helps align the different components precisely, ensuring that they are positioned correctly relative to each other. This alignment may be important to maintaining the structural integrity of the erosion shield during installation and use. By tightly connecting the components, the locator reference points 210 also enhance the stability of the erosion shield. This may reduce or even prevent any shifting or separation between the parts, which could compromise the effectiveness of the erosion control measures.

[0025] Further, the locator reference points 210 simplify the assembly process, making it easier for workers or contractors to put the erosion shield 200 together correctly and efficiently. By using locator reference points 210, consistency in the installation process may be improved, reducing the risk of human error and producing a more uniform erosion protection system. A properly assembled erosion shield with well-matched locator reference points 210 is likely to function more effectively to protect the blade 100.

[0026] The erosion shield 200 or any (preferably each) part 200’, 200”, 200”’, 200”” of the erosion shield 200 may have a substantially semi-tubular shape, with a substantially U-shaped cross section. This substantially U-shaped cross-section may be configured to match the contour of the portion of the blade to be protected, preferably the blade's leading edge, ensuring a precise and close fit. The or each part 200’, 200”, 200’”, 200”” of the erosion shield 200 may alternatively be of different cross-sectional shapes, for example a substantially “J-shaped” cross section, A snug fit minimizes the risk of any gaps or crevices between the erosion shield 200 and the surface of the blade 100, effectively sealing the blade from the external environment. The erosion shield 200 or any (preferably each) part 200’, 200”, 200’”, 200””, 205 of the erosion shield 200 may be considered to have an “inside” part which, in use, is adjacent the surface of the blade 100, and an “outside” part which, in use, is remote from the surface of the blade 100.

[0027] The length of the erosion shield 200 or any (preferably each) part 200’, 200”, 200’”, 200””, 205 of the erosion shield 200 on the pressure and suction sides of the blade, from the leading edge towards the trailing edge of the blade, may be designed to maximize the efficiency of use of material balanced against aerodynamic performance of the wind turbine blade 100 and the requirement to cover blade areas most prone to erosion. Optionally, the length from the cord to the trailing edge on both sides is typically equal or nearly equal, but an asymmetry of these lengths may also beneficial to aerodynamic performance in some circumstances.

[0028] The semi-tubular shape may be designed to minimize disruptions to the airflow around the blade 100. By following the curvature of the portion of the blade to be protected, such as the leading edge of the blade 100, the erosion shield 200 maintains the blade's aerodynamic profile, allowing it to continue capturing wind efficiently and generating renewable energy.

[0029] When choosing an erosion shield 200 for a particular wind turbine 105, the selection process involves obtaining geometric data related to the specific portion 110 of the wind turbine blade 100 that requires protection. This geometric data typically includes measurements and dimensions that describe the shape, size, and curvature of the blade or of the blade's leading edge, which is the primary area susceptible to erosion and hence requires protection. This data may be gathered and / or acquired through various means, such as technical specifications,laser scanning, 3D scanning, Computer Aided Design (CAD) modelling, 3D modelling, or other measurement techniques, ensuring accuracy and precision. Optionally, the method of gathering data includes capturing blade geometry and creating a digital mesh which can then be converted into a surface model, and then used to effect CAD designs for the production of the vacuum forming tools and the blade protection shields, in particular the leading edge protection shields. Features of the blade 100 itself, like lightning protections or drainage holes, may be captured in geometry and incorporated in design. If there is variance on a blade 100, such that features are in a different position from the position indicated on geometry, the erosion shield 200 may be manually altered by a technician in the field who can cut, grind, drill, and / or modify the shield accordingly.

[0030] The received geometric data is then carefully analyzed and processed to determine the specific requirements for the erosion shield 200. This analysis may include studying the blade's contour, the curvature of the leading edge, and any unique features or challenges presented by the turbine's design. Based on the analyzed geometric data, the appropriate erosion shield 200 is selected. The erosion shield 200 typically matches the dimensions, shape, and curvature of the wind turbine blade's leading edge to ensure a proper and secure fit.

[0031] One criterion for selecting a particular model or shape of erosion shield 200 may be the offset of the received geometric data. The offset refers to the deviation or difference between the actual geometric measurements of the blade 100 and the erosion shield's design. The offset addresses manufacturing tolerances and variations in individual turbine blades. Further, the erosion shield 200 selected may have an offset that accommodates these variations while still providing effective protection. The offset is positive, as the erosion shield 200 needs to be slightly larger than the blade's actual dimensions to allow for blade variations and the application of adhesive. By taking the offset into account during the selection process, the erosion shield will both align precisely with the portion of the blade to be protected, such as the blade's leading edge, and cater for blade variations and the adhesive layer, providing the best possible protection against erosive forces.

[0032] If a particular model or shape of erosion shield 200 is required, it may be formed using a vacuum forming process. Extruded sheet material, optionally 2 mm to 3 mm thick, may be vacuum formed into erosion shield shapes and trimmed where necessary. Other means of manufacture may be used to form the erosion shield 200.

[0033] The erosion shield 200 may be further adapted to enhance its performance and functionality based on the specific requirements of the wind turbine blade 100. Modifications to the geometric profile of the shield may be made to improve the aerodynamics of the blade. The shield can therefore include the addition of one or more notches, grooves, bulb profiles, orwave-like patterns, suitably arranged to reduce drag and enhance the overall efficiency of the wind turbine. The shield 200 may incorporate one or more strain gauges, allowing for real-time monitoring of the blade's stress and strain during operation. The shield 200 may comprise one or more lightning protection features, suitably providing a dual function of erosion protection and lightning strike mitigation. The shield 200 may comprise materials or adhesives to better suit specific environmental conditions or performance requirements, such as providing enhanced durability, flexibility, or resistance to environmental factors. The inclusion of one or more of these modifications ensures that the erosion shield 200 is not only tailored to fit the geometric profile of the blade but also may be further optimised for improved performance and extended operational life of the turbine.

[0034] The erosion shield 200 or any (preferably each) part of the erosion shield 200 may be formed from a durable and resilient material, that has sufficient rigidity to enable ease of handling, application and minimize air pocket potential while maintaining sufficient flexibility to allow for a tight fit on application. Optionally, the erosion shield 200 is at least partially formed from a polymer composition which comprises:(I) a thermoplastic component comprising a thermoplastic copolymer matrix A including optionally substituted styrene and acrylonitrile, and a graft copolymer B containing a graft base comprising C1-C8-alkyl(meth)acrylate and a graft shell;(II) optionally one or more fibers that may optionally react with the copolymer matrix A; and / or(III) optionally one or more polycarbonates.

[0035] Alternatively or additionally, the polymer composition of the erosion shield 200 may comprise:(I) 20 to 100 wt.-% of a thermoplastic component T comprising (or consisting of):(A) 10 to 90 wt.-%, related to the thermoplastic component T, of at least one thermoplastic copolymer matrix A comprising:• (A1) 50 to 95 wt.-%, related to the thermoplastic copolymer matrix A, of at least one monomer selected from styrene and alphamethylstyrene; and• (A2) 5 to 50 wt.-%, related to the thermoplastic copolymer matrix A, of at least one monomer selected from acrylonitrile and monomers bearing a functional group M-l; and(B) 10 to 90 wt.-%, related to the thermoplastic component T, of at least one graft copolymer B comprising (or consisting of):• (B1) at least one graft base B1 having a glass transition temperature Tg below - 20°C, wherein the graft base B1 comprises at least one C1-C8-alkyl(meth)acrylate as monomer B11 ; and optionally one or more poly-functional cross-linking monomers B12; and• (B2) at least one graft shell B2 comprising (or consisting of) at least one monomer B21 selected from the group consisting of styrene, alpha-methylstyrene, C1-C8-alkyl(meth)acrylate, and mixtures of styrene and at least one further monomer selected from the group consisting of alpha-methylstyrene, p-methylstyrene and C1-C8- alkyl(meth)acrylate; and optionally one or more further monomers B22 selected from the group consisting of acrylonitrile and mixtures of acrylonitrile and at least one further monomer selected from the group consisting of: methacrylonitrile, acrylamide, methyl vinyl ether, anhydrides of unsaturated carboxylic acids and imides of unsaturated carboxylic acids;(II) 0 to 80 wt.-%, related to the thermoplastic component T, of one or more fibers F, optionally comprising at their surface, a functional group G-l forming a covalent bond with the functional group M-l of a monomer A2;(III) 0 to 80 wt.-%, related to the thermoplastic component T, of one or more polycarbonates;(IV) 0 to 50 wt.-%, related to the thermoplastic component T, of one or more further (co)polymers; and(V) 0 to 10 wt.-%, related to the thermoplastic component T, of one or more polymer additives.

[0036] The materials in the erosion shield 200 may be carefully chosen to withstand the harsh environmental conditions that wind turbine blades commonly endure, without compromising the blade's aerodynamic efficiency and overall performance.

[0037] There are two primary scenarios in which the erosion shield 200 may be applied:

[0038] Post-damage application: As shown in Figure 2, the erosion shield can be employed after the wind turbine blade 100 has experienced damage, similar to the damage portrayed in Figure 1. Once the damage is detected, the severity and extent of the impairment can be assessed. If the blade's structural integrity is intact and the damage is limited to the surface, the application of the erosion shield 200 can help protect the blade 100 from further deterioration and restore its aerodynamic shape. When used for post-damage application, erosion shields 200 may optionally also be applied to the non-damaged blades of a wind turbine 105, in order to balance the load and reduce vibrations. In cases where several blades 100 of a wind turbine 105 have experienced damage at different positions along the length of the blades 100, the composition of the individual erosion shields 200 or pieces 200’, 200”, 200”’, 200”” of the erosion shields 200 may optionally vary (e.g. by inclusion of density modifying fillers), in order to balance the load and reduce vibrations.

[0039] Factory-fitted standard item: In some cases, wind turbine 105 manufacturers may opt to fit the erosion shield 200 as a standard feature during the production of the blade 100 in a factory. By doing so, the blade 100 is equipped with an extra layer of protection right from the outset, enhancing its resistance to environmental challenges and extending its lifespan.

[0040] The erosion shield 200 acts as a barrier against the erosive forces described herein that can gradually wear down the blade's surface. Further, the erosion shield 200 mitigates the potential formation and spread of small cracks and surface imperfections that can lead to more severe damage over time.

[0041] By incorporating erosion shields into wind turbine blade design and maintenance practices, operators and manufacturers can enhance the turbines' reliability, extend their operational lifespan, and reduce maintenance costs. This approach may align with the broader goal of wind turbine use regarding maximizing the efficiency and sustainability of wind energy, contributing to a cleaner and more environmentally friendly power generation landscape.

[0042] Applying the erosion shield 200 may require care, and involve precise installation techniques to ensure it adheres securely to the surface of the blade 100.

[0043] Before applying adhesive 305 as shown in Figure 3, the designated area 110 of the wind turbine blade 100 that requires protection is thoroughly cleaned using a specialized cleaning agent. This cleaning agent is chosen for its ability to remove any dirt, debris, contaminants, and / or remnants of a previous protective layer (if applicable). Additionally or alternatively, a grinder and / or wire brush may be used to remove loose or flaking material within the designated area 110. Ensuring a clean surface can help to achieve a strong bond betweenthe adhesive 305 and the blade 100. If there are any deteriorated or damaged sections on the wind turbine blade's application area 110, these areas may be carefully removed or repaired to create a ready surface for the adhesive application. The cleaning agent may comprise any suitable agent, such as alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, water and mixtures thereof, and may further contain additives, such as detergents. For example, Isopropyl Alcohol (IPA) may be used, optionally with a maximum 70% alcohol by volume, a solvent known for its effective cleaning properties and ability to remove contaminants from surfaces.

[0044] After removing any deteriorated portions or repairing structurally damaged areas, the cleaning agent may need to be reapplied to ensure that the entire application area 110 is clean and free from contaminants. Once any cleaning agent is applied to the application area 110, a sufficient amount of time may be allowed for at least a portion of the cleaning agent to evaporate. In some cases, most or all of the cleaning agent must evaporate or be removed before any adhesive is applied. This allows for the surface of the application area 110 to be dry and ready for the adhesive 305 to adhere effectively.

[0045] Following the necessary preparations, the adhesive 305 is applied, e.g. as shown in Figure 3, along at least part of the portion 110 of the wind turbine blade 100 that requires protection. Tape 310, such as masking tape, may be used to avoid the adhesive 305 from being applied to areas of the blade 100 it is not meant to be applied to. The tape 310 may be removed once the adhesive 305 is applied. A spreading means, such as a flexible plastic comb may be used to spread and distribute the adhesive 305 along the blade 100, which assists the worker in applying equal pressure on both sides on the blade 100 during a consistent movement along the blade 100.

[0046] As shown in Figure 4, the adhesive 305 may also be applied along at least part of the inside surface of the erosion shield. In this example, beads of adhesive 305 are applied to an inside portion of the boot 205. Other pieces 200’, 200”, 200”’, 200”” of the erosion shield 200 may have adhesive 305 applied in a similar manner.

[0047] The adhesive 305 may be any type of adhesive suitable for obtaining a sufficiently strong bond between a turbine blade 100 and the erosion shield 200. For example, the adhesive 305 may be a pressure-sensitive adhesive, a curable resin or a hot-melt adhesive. For example, the adhesive 305 may comprise a monomer or monomer mixture that polymerizes (e.g. through addition of a catalyst or initiator) to bond the erosion shield 200 to the wind turbine blade 100, or the adhesive 305 may be a polymer composition, which is applied as a polymer melt and bonds the erosion shield 200 to the wind turbine blade 100 when cooled. For example, the adhesive may comprise Methyl Methacrylate (MMA), which is a type of structural adhesive known for its bonding properties and comparatively high strength. The target tensile strength ofthe bond between the erosion shield 200 and the wind turbine blade 100 may be greater than 15 megapascals (MPa) at 23 °C. The tensile modulus requirement for the adhesive used in the erosion shield application process may be specified to be greater than 600 MPa at 23 °C. The tensile modulus measures the stiffness or rigidity of a material and its ability to resist deformation under tensile stress. A tensile modulus >600 MPa at 23 °C indicates that the adhesive possesses high stiffness and will maintain its structural integrity under significant loads and stresses, such as those experienced during wind turbine operation.

[0048] A specified elongation at break requirement of >100% at 23 °C may be mandated for the adhesive 305, and refers to the adhesive's ability to stretch or elongate before it reaches its breaking point. Elongation at break measures the percentage increase in the adhesive's length before it fractures when subjected to tensile stress. An elongation at break >100% means that the adhesive can stretch to at least twice its original length before failure, indicating good flexibility and resistance to brittleness.

[0049] A requirement for the average lap shear strength of the adhesive 305 may be required to match or exceed 2 MPa at 23°C (room temperature). Lap shear strength is a measure of the adhesive's ability to resist the applied shear force when two substrates (in this case, the erosion shield 200 and the wind turbine blade 100) are bonded together with an overlap between them.

[0050] The viscosity of the adhesive used in the erosion shield application may be less than 160 centipoise (cP) at a shear rate of 100 s1under the conditions at which the adhesive is applied. For example, where the adhesive is a hot-melt adhesive, the viscosity may be less than 160 cP at a shear rate of 100 s1at a temperature above the melting point of the adhesive, e.g. at 200 °C. Alternatively, where the adhesive is a curable resin, such as a monomer or monomer mixture, which polymerizes by addition of a curing catalyst or initiator, the viscosity may be less than 160 cP at a shear rate of 100 s-1at 23 °C. Viscosity is a measure of a fluid's resistance to flow, and a viscosity of less than 160 cP at a shear rate of 100 s-1at 23 °C. indicates that the adhesive has a relatively low thickness or fluidity. It flows easily and smoothly, making it easier to apply and work with during the erosion shield installation process. Adhesives with lower viscosities tend to spread more evenly and penetrate into any surface irregularities, creating a strong and uniform bond between the erosion shield 200 and the wind turbine blade 100.

[0051] The adhesive may be selected to as to not be significantly affected by changes in the dew point temperature, also referred to as “dew point indifferent”. The dew point is the temperature at which air becomes saturated with water vapor, leading to the formation of dew or condensation on surfaces. In certain environments, such as coastal or humid regions, wind turbines may experience dew formation due to temperature fluctuations. An adhesive may beselected which does not undergo significant changes in its performance, properties, or bonding characteristics when exposed to varying dew point temperatures. This quality is advantageous for wind turbines, as it ensures the erosion shield's reliability and effectiveness under different climatic conditions. An erosion shield or adhesive that is dew point indifferent is more likely to maintain its integrity, bond strength, and protection capabilities regardless of the environmental conditions.

[0052] Figure 5 shows the application process of the erosion shield 200 onto the wind turbine blade 100. After following the preparatory steps described herein, the erosion shield 200 is firmly secured onto the portion 110 of the wind turbine blade 100 that requires protection. In this step, the erosion shield 200 is carefully positioned over the portion 110 requiring protection, e.g. the leading edge of the wind turbine blade. The erosion shield 200 is selected so as to fit according to one or more predetermined criteria over the specific portion 110 of the wind turbine blade 100 that requires protection. The semi-tubular shape and substantially U-shaped crosssection of the erosion shield 200 allow it to conform precisely to the blade's leading edge. Once in place, the erosion shield 200 is firmly pressed onto the surface of the blade 100 to create a strong and secure bond between the previously applied adhesive (not shown) and the inside surface of the erosion shield 200 and / or the outside surface of the blade 100.

[0053] The pressing process is done, optionally by a worker, with precision and care to ensure that the erosion shield 200 adheres uniformly to the blade 100, preferably along the leading edge of the blade 100. The pressure applied during this step ensures that the adhesive effectively sticks to both the blade 100 and the erosion shield 200, creating a seamless and durable protective layer. Depending on the adhesive used, the pressure applied can activate the adhesive, promoting better bonding and increasing the bond strength between the erosion shield 200 and the blade 100. This ensures that the erosion shield 100 stays securely in place even under the stresses and forces experienced during wind turbine 105 operation. Pressing the erosion shield 200 firmly onto the blade's surface may also help eliminate any air pockets or voids that could potentially weaken the adhesive bond or compromise the erosion shield's protective capabilities. Tape may be applied laterally to hold the erosion shield 200 in position until the adhesive has set.

[0054] Figure 6 shows the process of removing a protective film 605 from the erosion shield 200 after it has been securely applied to the wind turbine blade 100. Once the erosion shield 200 is successfully pressed onto the wind turbine blade 100 and the adhesive has set, the protective film 605 that optionally has been covering the erosion shield's exterior surface can be removed. The protective film 605 serves as a temporary covering over the erosion shield 200, safeguarding it from dirt, dust, and potential damage during transportation, installation, or storage. Once installation is finished, the new leading edge of the blade 100, now formed fromone or more erosion shields 200, may be smooth with no steps between the shields, and a gap of approximately 2 mm between each individual piece of the erosion shield 200 on the trailing edge.

[0055] Any examples or embodiments described herein represent suitable ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.

[0056] Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person.

[0057] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0058] Any reference to 'an' item refers to one or more of those items. The term 'comprising' is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

[0059] The term “(meth)acrylate” as used herein includes acrylate, methacrylate and mixtures thereof. The term “(co)polymer” includes both homopolymers and copolymers. The term “copolymer” includes any polymer obtained from at least two different monomers.

[0060] Unless specified otherwise, numerical values provided for properties are as measured under ambient conditions, i.e. at 23 °C and 1013 mbar.

[0061] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

[0062] It will be understood that the above description of a preferred embodiment is given by way of example only and that various modifications may be made by those skilled in the art. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the artcould make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention.

Claims

CLAIMS1 . A method for protecting a wind turbine blade or part thereof by an erosion shield comprising a polymer composition, the method comprising the steps of: receiving geometric data of at least a portion of a wind turbine blade to be protected; selecting an erosion shield based at least in part on an offset of the received geometric data; and optionally applying the erosion shield to the portion of the wind turbine blade to be protected using an adhesive, the adhesive being arranged between the erosion shield and the portion of the wind turbine blade to be protected.

2. The method of claim 1 , wherein the step of receiving geometric data comprises generating a 3D scan.

3. The method of any preceding claim, wherein the portion of a wind turbine to be protected is a leading edge of a blade of the wind turbine.

4. The method of any preceding claim, wherein the adhesive is a Methyl Methacrylate Adhesive (MMA).

5. The method of claim 4, wherein the MMA is operable to provide one or more of: a bond tensile strength between the portion of the wind turbine blade to be protected and the erosion shield of >15MPa; a bond tensile modulus between the portion of the wind turbine blade to be protected and the erosion shield of >600MPa; and / or an elongation at break of >100%.

6. The method of any preceding claim, further comprising the step of: preparing the surface of the portion of the wind turbine blade to be protected before applying the erosion shield.

7. The method of claim 6, wherein preparing the surface comprises one or more of: abrading, grinding, polishing, and / or removing loose material.

8. The method of any preceding claim, wherein the selection of the erosion shield includes the step of: designing the erosion shield on a computer-aided design (CAD) program.

9. The method of any preceding claim, wherein the erosion shield is fabricated from a vacuum-formed extruded sheet.

10. The method of any preceding claim, wherein the erosion shield has a semi-tubular shape comprising a substantially U-shaped cross section.11 . The method of any preceding claim, wherein the erosion shield is between 1 mm and 5mm thick, optionally between 2mm and 3mm thick.

12. The method of any preceding claim, wherein the erosion shield is between 750mm and 930mm long, and / or 850mm long.

13. The method of any of claims 1 to 10, wherein the erosion shield corresponds to the shape of an external surface of a tip of a wind turbine blade.

14. The method of claim 13, wherein the erosion shield is between 100mm and 600mm long, and / or between 200mm and 400mm long, and / or 300mm long.

15. The method of any preceding claim, wherein the erosion shield comprises one or more locator reference points.

16. The method of claim 15, wherein the one or more locator reference points comprise grooves and / or notches, optionally arranged to tessellate in one orientation only.

17. The method of any preceding claim, wherein the step of applying the erosion shield to the portion of the wind turbine blade to be protected further comprises the steps of: cleaning an application area of the portion of the wind turbine blade to be protected using a cleaning agent; waiting for at least a portion of the cleaning agent to evaporate from the application area; applying the adhesive along the leading edge of the portion of the wind turbine blade to be protected and / or applying the adhesive along the inside of the leading edge of the erosion shield; and orientating the erosion shield onto the application area using the one or more locator reference points; pressing the erosion shield onto the portion of the wind turbine blade to be protected.

18. The method of claim 17, wherein the step of cleaning the application area is followed by at least one of the steps of: removing a deteriorated portion of the application area; and / or reapplying the cleaning agent to the application area;19. The method of claim 18, wherein the step of removing deteriorated areas of the application area is performed using a grinder and / or a wire brush.

20. The method of any of claims 17 to 19, wherein the step of pressing the erosion shield onto the portion of the wind turbine blade to be protected is followed by the step of: removing a protective film from the erosion shield.21 . The method of any of claims 17 to 20, wherein the cleaning agent is Isopropyl Alcohol (I PA) solvent.

22. The method of any of claims 1 to 21 , wherein the erosion shield is at least partially formed from a polymer composition which comprises: a thermoplastic component comprising a thermoplastic copolymer matrix A including optionally substituted styrene and acrylonitrile, and a graft copolymer B containing a graft base comprising C1-C8-alkyl(meth)acrylate and a graft shell; optionally one or more fibers that may optionally react with the copolymer matrix A; and / or optionally one or more polycarbonates.

23. An erosion shield for protecting a wind turbine blade or part thereof suitable for use in the method of any preceding claim.

24. A wind turbine blade or part thereof protected with an erosion shield using the method of any of claims 1 to 22.

25. A wind turbine comprising a blade or part thereof protected with an erosion shield using the method of any of claims 1 to 22.

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