A spoiler for a rotor blade includes a base member, which base member has a mounting face for mounting onto a surface of the rotor blade, and an aerodynamic member for detachably connecting onto the base member. Further, a wind turbine includes a number of rotor blades attached to a hub, wherein at least one rotor blade has such a spoiler mounted on a surface strip of the rotor blade. Also, a method of constructing a wind turbine is provided. A rotor blade is manufactured. A base member of the spoiler is mounted onto the rotor blade. The rotor blade is connected to a hub of the wind turbine. An aerodynamic member of the spoiler is attached onto the base member, wherein at least the mounting of the base member onto the rotor blade is performed prior to the connecting of the rotor blade to the hub.

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).

A self-supporting wind turbine tower with walls comprising an upper portion (12) and a lower portion (14). Substantially all of the upper portion (12) is formed from a composite plastic. Substantially all of the lower portion (14) is formed from mild steel.

A wind turbine blade bushing system for arrangement in a root end of a wind turbine blade is described. The wind turbine blade bushing system comprises a threaded element for retaining a mounting bolt for a wind turbine blade, the threaded element being formed from a first material; and an anchor element for arrangement at the root end of the wind turbine, wherein the anchor element acts to at least partly retain the threaded element in the wind turbine blade, the anchor element being formed from a second material. The first material has a higher strength and higher fracture toughness than the second material.