A wind turbine (20) includes a turbine wheel (22). Radially extending sailwing assemblies (30) are supported between the axle structure (28) and the perimeter rail (26) of the turbine wheel. The sailwing assemblies include sail end supports (52, 53), sail support cables (54, 55) extending between the sail end supports, and sailwings (58) that are supported by the sail support cables and extend between the axle structure (28) and the perimeter rail (26) of the turbine wheel. The sail end supports (52, 53) may be pivoted to form a pitch in the sailwings (58) and pivoted with respect to each other to form a twist in the sailwings, and sail spreader bars (70) may be mounted in the sailwings and connected to the sail support cables (54, 55) to adjust the effective width and loft of the sailwings.