Drifters play a crucial role in monitoring surface ocean dynamics and informing weather, climate, and environmental models. However, their endurance is limited, as they traditionally rely on batteries or solar panels that are often ineffective in low-light or partially submerged conditions. The WECDA team addressed this challenge by developing a compact wave energy converter capable of capturing the slow, irregular movements typical of freely drifting buoys.
The Wave Energy Converter for Drifter Applications (WECDA) project, hosted at the EMSO Regional Facility OBSEA under the EMSO ERIC Physical Access Programme, explores innovative and environmentally responsible alternatives to enhance the autonomy and sustainability of oceanographic drifters. By validating a new kinetic energy harvesting technology in real marine conditions, the project contributes directly to the development of next-generation, low-impact observation platforms.
Picture 1: left) EH test on the Robot; right) WEC ready for deployment
Access to the EMSO-OBSEA cabled observatory, operated by the Universitat Politècnica de Catalunya (UPC), enabled a full evaluation of the device—from controlled laboratory characterisation to short-duration sea deployments and a dedicated long-term test. During field trials, the wave energy converter demonstrated stable and continuous energy harvesting, providing sufficient power to support low-duty-cycle sensing and some periodic wireless data transmission.
Picture 2: First week of long-term deployment results: left) Voltage and internal CPU Temperature; right) Position of the drifter
A long deployment near OBSEA further confirmed the system’s reliability. Powered exclusively by harvested wave energy, the device maintained a stable internal voltage and enabled hourly transmissions through an ultra-low-power communication module. Once retrieved, on-land measurements clearly illustrated the contrast between autonomous at-sea operation and passive discharge without wave forcing, underscoring the robustness of the energy harvesting approach.
Picture 3: Long-term evolution of a) battery voltage and b) internal temperature during the full one-month period. The orange line represents the moving average of the voltage. The first phase shows a nearly constant trend consistent with continuous energy contribution from the WEC, while the later phase displays the expected gradual decrease when the system operates without additional energy input.
The outcomes of WECDA highlight the potential of wave-powered drifters to improve the sustainability and endurance of ocean observing systems, particularly in scenarios where solar-based solutions are inadequate or intermittent. By enabling researchers to test emerging technologies in real marine environments, the EMSO Physical Access Programme continues to support innovation and expand Europe’s capacity for sustained ocean monitoring.
A scientific publication is currently being prepared, and future developments will focus on optimizing the harvester design and adapting it to a wider range of oceanographic platforms.
Authors: Ikram Bghiel and Matias Carandell – UPC / Zdenek Hadas, Miroslav Kvassay and Jakuv Moravek – BUT