Energy conservation is one of the most challenging issues throughout the world. As consumers demand alternatives to fossil fuel, the use of alternative energy sources including wind energy is increasing. With an increase in the use of wind energy a collateral issue of what to do with the large and voluminous wind turbine blades (WTB) has arisen. Currently, there are no economically viable recycling pathways for damaged or end-of-life WTBs, which are made primarily of glass fiber composites. This research evaluates an economically viable composite fabrication system using mechanically recycled WTB (rWTB) material as a feedstock for thermoplastic composites. The WTB material was first mechanically milled and classified through a range of varying screen sizes. We then blended this with high density polyethylene (HDPE) thermoplastic resin and extruded it to a profiled composite. We determined the influence of refined particle size, resin content and coupling agents [maleic anhydride polyethylene (MAPE) and methacryloxypropyltriethoxysilane (Silane)] on the properties of recycled composites. We also obtained static bending, coefficient of linear thermal expansion (CLTE) and water sorption properties for all composites. Overall improvement of mechanical and physical properties of composites achieved by using MAPE as a coupling agent. Findings show that mechanical recycling of wind turbine blades is a feasible and promising way to fabricate a high-performance second-generation composite.