Technology Readiness Level assessment of hydrokinetic energy converters

Oceanic, tidal and riverine currents contain vast reserves of renewable hydrokinetic energy. Over the years, numerous innovative hydrokinetic energy converter (HEC) designs have been developed to extract this energy. This paper provides a comprehensive review of HEC designs. Using the U.S. Department of Energy’s Technology Readiness Level (TRL) scale, each HEC is assessed to determine its technical maturity and functional readiness, with a corresponding rating assigned. Results indicate that there are fourteen HECs, categorized into riverine, tidal, and oceanic types, distributed across different stages of technological development and corresponding TRL ratings. Among these HECs, two are designed to harness energy from riverine currents, eight from tidal currents, and four from oceanic currents. This distribution suggests a lack of convergence towards a single HEC design capable of harnessing hydrokinetic energy from multiple current sources. • This study shows fourteen existing hydrokinetic energy converters. • Each converter is at different level in the technology development & maturation process. • A Technology Readiness Level rating is provided for each converter. • Eight hydrokinetic energy converters are at a full-scale system demonstration level.