Engineers sent a solar raft into the Yellow Sea to see how badly waves would shake it, and the seaweed that moved in quietly became a set of free shock absorbers

The heavy waves of the Yellow Sea are putting experimental solar platforms under pressure. This ocean action weakens metal frames and can even tear floating rafts apart completely.

Engineers recently installed a test solar platform to measure wave forces in open waters. Before long, seaweed started being caught on the support structures under the water. The raft started moving differently in the rough seas.

This biological shift raises a question about hydrodynamics: Why did the seaweed act like shock absorbers?

How floating solar platforms are undergoing structural monitoring at sea

Floating solar platforms in open ocean waters face continuous strain from heavy wave action on the surface. Research teams anchored an experimental raft in the Yellow Sea and fitted it with motion sensors, strain gauges, and accelerometers to track the motion.

The instruments collected data about the continuous lifting, tilting, and rolling that the structure undergoes under different wave heights. The trial aimed to figure out utility-scale marine solar equipment limits.

During initial field tests, ocean currents carried native macroalgae spores that attached to the frames of the raft. Seaweed also got attached to the mooring lines, undersides of the pontoon, and structural joints.

Standard engineering models usually assume marine growth adds useless dead weight, increases surface roughness, and speeds up hardware corrosion.

Yet sensor logs indicated that the movement of the platform dropped noticeably when waves were at their peak height and force.

Scale of offshore aquavoltaic expansion and biofouling challenges

Moving solar power out onto open water is a relatively new move in the clean energy sector. Developers in Asia have begun planning offshore facilities that take up thousands of acres to avoid using land onshore, which is running out.

Operating floating platforms miles off the coast means the equipment is exposed to waves, salt spray, and constant mechanical stress and wear. To keep the systems intact, heavy anchor lines and reinforced frames must be built to endure millions of continuous wave impacts each year.

Submerged marine growth is a constant problem for offshore energy site managers. Algae, barnacles, and shellfish are quick to cover underwater surfaces. They build up into thick layers of biomass within weeks of the start of operations.

Offshore operators usually view marine growth as a costly hazard requiring constant manual scraping or toxic coatings.

Yet measuring how natural biological accumulation alters raft movement provides critical physical data for building tough ocean platforms.

Hydrodynamic damping mechanisms and engineering conclusions

The seaweed acted as shock absorbers because its dense, flexible blades created hydrodynamic drag and trapped fluid mass that absorbed incoming wave energy.

As waves lifted the solar raft, trailing seaweed stems pulled against surrounding seawater. This viscous friction resisted sudden upward jerks.

When waves dropped, water trapped within the thick algal mat added temporary weight that slowed the downward drop.

This constant viscous drag shifted the platform’s motion away from dominant wave rhythms, smoothing out sharp pitching and rolling without needing mechanical dampers.

There are limits to the weight that can be added to the infrastructure

Despite these dampening benefits, researchers point out real physical limits. Dense algal growth adds dead weight to floating pontoons, slightly lowering platform freeboard above the waterline.

Heavy growth on mooring lines can also speed up mechanical wear or alter cable tension, especially during the regular major storms over offshore waters. Biological damping also changes with the seasons as algae grows and sheds foliage.

The study authors came to the conclusion that natural bio-damping is a practical physical mechanism for cutting structural fatigue on floating solar arrays.

Being able to factor passive biological damping into their platform models means engineers can refine mooring designs and extend equipment lifespans. Maintenance schedules can also be better optimized under complex ocean conditions.

All the details of the study can be found here: Zhang, P., Qi, X., Cheng, Z., Zhao, Y., Li, J., Zhang, L., … & Ding, H. (2025). Field trial research of a semisubmersible floating photovoltaic platform. Solar Energy, 301, 113982.