Abstract

Gravity-based wave energy converters present mechanically simple and maintainable solutions for coastal and island environments; however, their operability under irregular, low-to-moderate wave conditions is not well documented. This research introduces a compact operability assessment framework and applies it in an initial full-scale on-site demonstration. Following construction and installation, gearbox-output flywheel rotational speed and generator terminal voltage were measured during separate, non-synchronised operational runs. The gearbox-output flywheel rotational speed ranged from 63 to 359 revolutions per minute, while a separate open-circuit, no-load run yielded terminal voltages between 11.23 and 20.36 V. Due to the lack of simultaneous acquisition of environmental and operational records, a quantitative wave-to-response relationship could not be established. The results confirm short-term mechanical and electromechanical operability but do not address load-deliverable power, power take-off efficiency, grid-integration compatibility, or deployment readiness. The primary contribution is a field-informed framework for assessing functional operability, rather than predicting regulated electrical output. The compact engineering proxy does not account for added mass, viscous drag, wave slamming, or multidirectional wave-group mechanics. Seasonal variability, long-term degradation, corrosion, and structural wear remain unexamined; therefore, synchronised load-connected measurements, multi-season monitoring, and extended marine durability testing are recommended.