Abstract: A wind turbine blade (40) for a wind turbine (10) includes an elongate body (42) defining a root end (44), a tip end (46), a leading edge (56), and a trailing edge (58). The elongate body (42) further defines a pitch axis (60) and a blade centre line axis (64) extending along a length of the blade (40). The blade centre line axis (64) defines a pre-bend in the blade (40), wherein the curve that defines the blade centre line axis (64) includes at least a first inflection point (I1) and a second inflection point (I2) between the root end (44) and the tip end (46) of the blade (40). A method of making a wind turbine blade (40) having a blade centre line axis (64) with multiple inflection points is disclosed and a moulding assembly (80) for making the pre-bent wind turbine blade (40) is also disclosed.

Abstract: In a first aspect of the invention there is provided a bondline structure for bonding a shear web to a wind turbine blade shell. The bondline structure comprises an elongate inner core made from a deformable material, and one or more outer layers comprising reinforcing fibres at least partially surrounding the inner core. The inner core and/or the one or more outer layers comprise an adhesive.

Abstract: A wind turbine blade includes first and second blade modules. The first module includes a first spar cap, and the second module includes a second spar cap. The first spar cap has a tapered end portion where the thickness decreases towards the end of the first spar cap. The blade further includes a connecting element having a first tapered end portion where the thickness decreases towards a first end of the connecting element. The first spar cap and the connecting element each include (i) an intermediate thickness band; (ii) an inner thickness band; (iii) an outer thickness band. A tapered end of the inner thickness band and/or a tapered end of the outer thickness band of the first spar cap has a lower rate of taper than a tapered end of the intermediate thickness band of the first spar cap.

Abstract: There is provided a wind turbine blade having a root end, a tip end, a blade shell, a lightning protection system and an integrated web-down conductor. The integrated web-down conductor comprises: a down conductor forming part of the lightning protection system: electrical insulation surrounding the down conductor; and a web that surrounds the electrical insulation so as to enclose the down conductor and electrical insulation and is coupled to the blade shell.

Abstract: A method of manufacturing a root ring for a wind turbine blade comprising winding metal sheet material onto a mandrel to form a metal section proximate a hub end of the root ring. Sheet fibre material is also wound onto the mandrel to form a fibre section of the root ring proximate a tipwards end of the root ring. The metal sheet material is interleaved with the sheet fibre material to form a transition section of the root ring between the metal section and the fibre section.

Abstract: A method of manufacturing a root ring for a wind turbine blade comprising winding metal sheet material onto a mandrel to form a metal section proximate a hub end of the root ring. Sheet fibre material is also wound onto the mandrel to form a fibre section of the root ring proximate a tipwards end of the root ring. The metal sheet material is interleaved with the sheet fibre material to form a transition section of the root ring between the metal section and the fibre section.

Abstract: According to the present invention there is provided a wind turbine blade extending in a spanwise direction between a root and a tip, and in a chordwise direction between a leading edge and a trailing edge. The wind turbine blade has a spar cap comprising a plurality of strips of fibrous composite material. Each strip extends in the spanwise direction between a first end and a second end to define a length of the strip, and each strip has a width and a thickness, the width being less than the length, and the thickness being less than the width. Each strip has upper and lower major surfaces defined by the length and width dimensions. Each strip has side surfaces defined by the length and thickness dimensions. The plurality of strips includes a first strip and a second strip. The first strip has a tapered end portion in which the thickness of the first strip decreases towards the first end of the first strip.

Abstract: A shear web for a wind turbine blade includes a lower flange, an upper flange and a web structure extending between the lower and upper flanges, wherein at least one of the lower flange, upper flange, and the web structure includes an open lattice structure having a plurality of elongate fibrous composite spindles intersecting each other at multiple nodes of the structure. A method of making the shear web using a continuous fiber-reinforced additive manufacturing method is also disclosed.

Abstract: A horizontal axis wind turbine comprising a rotor having a plurality of blades, the rotor having a radius of at least 80 meters, the blades comprising: a root end and a tip end; a leading edge and a trailing edge; a shoulder between the root end and the tip end where a chord length defined between the leading edge and the trailing edge is at a maximum; wherein: Solr is at least 0.0140 at 0.7R; Solr is at least 0.0116 at 0.8R; Solr is at least 0.0090 at 0.9R; Solr being the combined radius specific solidity of the blades.

Abstract: A bushing (42, 92) for connecting a wind turbine blade (20) to a rotor hub (18) of a wind turbine (10) including a main body (44, 94) defining a connecting end of the bushing (42, 92) for receiving a fastener (130) for securing the blade (20) to the rotor hub (18), a tubular extension (46, 96) extending distally from the main body (44, 94) and defining a tip end of the bushing (42, 92) and a central bore (52, 102) extending from the connecting end to the tip end of the bushing (42, 92) and defining a central axis (94, 104) of the bushing (42, 92). The tubular extension (46, 96) includes one or more tapered or cylindrical sections (74,124) and a tip section (76, 126) distal of the one or more tapered or cylindrical sections (74, 124) and adjacent the tip end. The tip section (76, 126) includes an outer surface and an inner surface that are substantially parallel to each other and substantially parallel to the central axis (94, 104) of the bushing (42, 92).

Abstract: According to the present invention there is provided a modular wind turbine blade comprising first and second blade modules connectable together to form at least part of the wind turbine blade, each blade module comprising an outer shell defining a pressure side and a suction side of the wind turbine blade. The first blade module comprises a first spar cap, and the second blade module comprising a second spar cap. The first spar cap has a tapered end portion in which the thickness of the first spar cap decreases towards the end of the first spar cap. The modular wind turbine blade further comprises an elongate connecting element for connecting the first and second blade modules together. The connecting element has a first tapered end portion in which the thickness of the connecting element decreases towards a first end of the connecting element. The first tapered end portion is configured for bonding to the tapered end portion of the first spar cap.

Abstract: A wind turbine blade comprising a leeward shell portion and a windward shell portion, each of the shell portions extending in a chordwise direction between a leading edge and a trailing edge of the wind turbine blade; a leading reinforcement arrangement comprising at least a leading leeward reinforcement structure engaging the leeward shell portion and a leading windward reinforcement structure engaging the windward shell portion; and a trailing reinforcement arrangement comprising at least a trailing leeward reinforcement structure engaging the leeward shell portion and a trailing windward reinforcement structure engaging the windward shell portion. The trailing windward reinforcement structure has a first stiffness in the lengthwise direction and the trailing leeward reinforcement structure has a second stiffness in the lengthwise direction, wherein the first stiffness is greater than the second stiffness at a chordwise plane of the wind turbine blade.

Abstract: According to the present invention there is provided a wind turbine blade extending in a spanwise direction between a root and a tip, and in a chordwise direction between a leading edge and a trailing edge. The wind turbine blade has a spar cap comprising a plurality of strips of fibrous composite material. Each strip extends in the spanwise direction between a first end and a second end to define a length of the strip, and each strip has a width and a thickness, the width being less than the length, and the thickness being less than the width. Each strip has upper and lower major surfaces defined by the length and width dimensions. Each strip has side surfaces defined by the length and thickness dimensions. The plurality of strips includes a first strip and a second strip. The first strip has a tapered end portion in which the thickness of the first strip decreases towards the first end of the first strip.

Abstract: There is provided a wind turbine blade having a root end, a tip end, a blade shell, a lightning protection system and an integrated web-down conductor. The integrated web-down conductor comprises: a down conductor forming part of the lightning protection system: electrical insulation surrounding the down conductor; and a web that surrounds the electrical insulation so as to enclose the down conductor and electrical insulation and is coupled to the blade shell.

Abstract: The invention provides a method for stabilising a wind turbine blade (106), the method comprising, attaching (S2) an air blowing arrangement (201) to the blade, detecting (S4) an oscillation of the blade, and operating (S5) the attached air blowing arrangement to provide a thrust to counteract the oscillation.

Abstract: In a first aspect of the invention there is provided a bondline structure for bonding a shear web to a wind turbine blade shell. The bondline structure comprises an elongate inner core made from a deformable material, and one or more outer layers comprising reinforcing fibres at least partially surrounding the inner core. The inner core and/or the one or more outer layers comprise an adhesive.

Abstract: A shear web for a wind turbine blade includes a lower flange, an upper flange and a web structure extending between the lower and upper flanges, wherein at least one of the lower flange, upper flange, and the web structure includes an open lattice structure having a plurality of elongate fibrous composite spindles intersecting each other at multiple nodes of the structure. A method of making the shear web using a continuous fiber-reinforced additive manufacturing method is also disclosed.

Abstract: A wind turbine blade comprising a leeward shell portion and a windward shell portion, each of the shell portions extending in a chordwise direction between a leading edge and a trailing edge of the wind turbine blade; a leading reinforcement arrangement comprising at least a leading leeward reinforcement structure engaging the leeward shell portion and a leading windward reinforcement structure engaging the windward shell portion; and a trailing reinforcement arrangement comprising at least a trailing leeward reinforcement structure engaging the leeward shell portion and a trailing windward reinforcement structure engaging the windward shell portion. The trailing windward reinforcement structure has a first stiffness in the lengthwise direction and the trailing leeward reinforcement structure has a second stiffness in the lengthwise direction, wherein the first stiffness is greater than the second stiffness at a chordwise plane of the wind turbine blade.

Abstract: A horizontal axis wind turbine comprising a rotor having a plurality of blades, the rotor having a radius R of at least 80 meters, the blades comprising: a root end and a tip end, the blades extending in a spanwise direction from the root end to the tip end; a leading edge and a trailing edge, the blades extending in a chordwise direction along a chord from the leading edge to the trailing edge; a shoulder between the root end and the tip end where a chord length defined between the leading edge and the trailing edge is at a maximum; the blades being twisted between the root end and the tip end and the twist is defined by a twist distribution curve along the spanwise direction of the blades, each blade further comprising: an inboard region between the root end of the blade and the shoulder of the blade; an outboard region between a rotor radius 0.

Abstract: A reinforcing structure for a wind turbine blade A reinforcing structure for a wind turbine blade (12) is described. The reinforcing structure comprises one or more pultruded strips (42C) having spanwise grooves (54). The grooves (54) impart transverse flexibility to the strips (42C), allowing the strips (42C) to conform to the curvature of a wind turbine blade mould (44). An associated method of making a reinforcing structure for a wind turbine blade (12) is described. The method comprises providing an elongate mould (44) extending in a longitudinal direction and defining a mould surface at least part of which is concave-curved in transverse cross section. One or more pultruded strips (42C) with spanwise grooves (54) are arranged in the mould (44) to form the reinforcing structure. The pultruded strip(s) are bent along the grooves (54) so that they substantially conform to the transverse curvature of the mould surface. In preferred embodiments the reinforcing structure is a spar cap (36).