Marine current turbines offer a potential source of renewable energy, but the accumulation of organisms such as barnacles and algae on underwater surfaces, known as biofouling, degrades turbine performance and lifetimes. Biofouling on cross-flow turbines specifically hasn’t been experimentally studied and has extra motivation due to the upcoming installation of cross-flow turbines at Pacific Northwest National Laboratory’s Marine Sciences Laboratory.
The team set out to evaluate changes in turbine power output and structural loads at various stages of barnacle colonization on turbine blades. A real barnacle, taken from the shores of Puget Sound, was 3-D scanned, modeled, and patterned on the surface of turbine blades at three different sizes and densities using 3-D printing techniques.
The impact of barnacles on turbine power output was found to be substantial and, for the most severe cases of fouling, the turbine does not produce power at any rotation rate. Conversely, barnacle fouling was found to have minimal impact on structural loading. To maintain generation capacity over extended periods, these results highlight the importance of antifouling coatings and proactive blade cleaning.