Efficient wind turbine blades, wind turbine blade structures, and associated systems and methods of manufacture, assembly and use

A method for manufacturing a wind turbine blade, comprising:

• forming a radially inner region of a wind turbine blade to have a load-bearing truss structure, the blade having an overall length, the truss structure extending over approximately the radially inner two-thirds of the overall length;
• applying a skin to the truss structure;
• forming a radially outer region of the wind turbine blade to have a non-truss structure;
• and
• connecting the inner region of the wind turbine blade and the outer region of the wind turbine blade to each other.

A method for operating a wind turbine, comprising:

• rotating a wind turbine shaft carrying multiple wind turbine blades;
• transmitting loads from an individual wind turbine blade to the shaft via a radially inner region of the blade and a radially outer region of the blade, the radially inner region including an internal load-bearing truss structure that extends over approximately a radially inner two-thirds of an overall length of the individual wind turbine blade, the radially inner region further including an external skin carried by the internal truss structure, the radially outer region including a load-bearing skin positioned around a non-truss structure;
• and
• subjecting the individual wind turbine blade to cyclically varying gravitational loads by rotating the shaft about a generally horizontal axis.

A wind turbine system, comprising:

• a wind turbine blade having a leading edge and a trailing edge, the wind turbine blade including a truss structure with:
• a longitudinally extending first spar positioned toward the leading edge at a chordwise location;
• a longitudinally extending second spar positioned toward the leading edge and spaced apart from the first spar at approximately the chordwise location;
• a single, longitudinally extending third spar positioned toward the trailing edge;
• a plurality of spaced-apart ribs, with individual ribs connected to each of the first, second and third spars;
• a plurality of truss members connected among the first, second and third spars;
• and
• an external skin attached to and carried by the spars, the ribs, or both the spars and the ribs.

A method for manufacturing a wind turbine blade, comprising:

• forming a truss structure having only three longitudinally extending spars including a first spar toward a leading edge of the wind turbine blade at a chordwise location, a second spar toward the leading edge of the wind turbine blade at approximately the chordwise location, and a third spar positioned toward a trailing edge of the wind turbine blade;
• connecting truss members between the longitudinally extending spars;
• connecting ribs to the longitudinally extending spars;
• and
• connecting an external skin to the ribs, at least one of the spars, or both the ribs and at least one of the spars.

A wind turbine system, comprising:

• a wind turbine blade having a leading edge and a trailing edge, the wind turbine blade including a truss structure with:
• a longitudinally extending first spar positioned toward the leading edge, the first spar having a first rectangular cross-sectional shape with a first chordwise dimension that is greater than its thickness dimension;
• a longitudinally extending second spar positioned toward the leading edge and spaced apart from the first spar;
• a single, longitudinally extending third spar positioned toward the trailing edge, the third spar having a second rectangular cross-sectional shape with a second chordwise dimension that is less than its thickness dimension;
• a plurality of spaced-apart ribs, with individual ribs connected to each of the first, second and third spars;
• a plurality of truss members connected among the first, second and third spars;
• and
• an external skin attached to and carried by the spars, the ribs, or both the spars and the ribs.