Distributed manufacturing for distributed generation: 3-D printed solar photovoltaic module mounting mechanisms for wood racking

Solar photovoltaic (PV) wood-based rack designs support distributed manufacturing, have lifetimes equivalent to PV warranties, have lower embodied energy and carbon emissions and cost less than conventional racking. Unfortunately, wood racking does not enable the standard front surface attachments. To overcome this challenge this study introduces novel 3D printed clamps for front-surface PV mounting on wood racking. Four topologies (square spacer, H-shaped spacer, U-shaped clamp and T-shaped clamp) of 3D printed parts are designed, modelled and analyzed using finite element analysis for PETG, ASA and PC. The designs were fabricated, field tested and economically analyzed. The highest stress was observed in U-shaped spacer for spacer (4.53 MPa – PC material), bolt (32.01 MPa – PETG material) and frame (37.30 MPa) and for washer in the H-spacer (42.77 MPa). Mises stresses for all designs, however, are found within allowable limits qualifying the clamping technique to be adopted for future installations. Financial analysis of the clamps found up to 66% savings for the solutions. The T-shaped clamp is the recommended mounting technique with the lowest stresses while square spacer provides the least cost. The practical implications of the results indicate that 3D printing could provide an economic means of mounting PV modules and reducing solar energy costs.