Supplementary file 1_Architecture-informed O&M modelling of modular X-Rotor configurations for offshore wind: a two- and three-module comparison.pdf

The three-module configuration gives a model-reported availability of 92.28% and a total O&M cost of £10.70/MWh, compared with £8.00/MWh for the established two-module X-Rotor and £13.76/MWh for the conventional 3-stage geared HAWT. Sensitivity analyses show that the three-module result is conditional on the assumed reliability mapping, reduced-capacity operation, repair-cost scaling, and cross-member/main-shaft bearing replacement uncertainty.

Higher failure-rate assumptions, more conservative production-impact assumptions, and upper-bound bearing replacement scenarios reduce or remove the cost margin relative to the conventional geared HAWT. These findings indicate that the three-module architecture can retain an O&M cost advantage in the base-case 100 km offshore scenario, but this advantage depends on component reliability, modular replacement access, reduced-capacity operation, and bearing design maturity.

The results should therefore be interpreted as an architecture-informed comparative O&M assessment based on adapted reliability data and engineering assumptions, rather than as a direct prediction of field performance.</p>