A system for manufacturing a rotor blade comprises a first tooling, positioned at a factory location and configured to assemble a first blade module, comprising a first-module skin and a first-module spar, each comprising a first thermoplastic polymer and a first reinforcement material. The system also comprises a second tooling, configured to assemble a second blade module, comprising a second-module skin and a second-module spar, each comprising a second thermoplastic polymer and a second reinforcement material. The system further comprises a first support, positioned at a field location and configured to receive the first blade module, and a second support, positioned at the field location and configured to receive the second blade module. The system also comprises a spar welding assembly, positioned at the field location and configured to join the first-module spar with the second-module spar.