Pairing floating solar with hydropower unlocks hundreds of GW opportunities globally. Designed to cope with large water-level variations, Tension Buoy removes one of the main barriers for deployment, providing safe, reliable, and efficient anchor mooring systems.
One of the main challenges for floating solar installations on sites with large water level variations is how to maintain consistent position and tension across shifting depths in water bodies. Water levels rise and fall, sometimes dramatically, leaving conventional mooring systems either too taut or too slack. The result is reduced efficiency, increased maintenance needs, and operational uncertainty.
By integrating a smart, automatic winch, the Tension Buoy designed by Fred. Olsen continuously adjusts the mooring line length in response to changing water levels.
Automatic adjustment
At the core of our Tension Buoy is a smartly integrated winch perched atop the structure, designed to deliver dynamic tension control with efficiency. As water levels change, this winch automatically adjusts the mooring chain length, consistently maintaining the optimal tension in the mooring line. It can be deployed temporarily for precise tensioning during installation, or installed permanently to adapt continuously throughout floating solar (FPV) operations.
The mooring chain is routed through the buoy’s centre: rising from below, gliding over the gypsy, and then descending again, while any surplus chain hangs freely, ready to adapt to shifting sea states.
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Hydro dams and reservoirs
Hydro dams are dynamic, with levels rising and falling by many metres in short periods of time. Where fixed mooring systems struggle with lines being either too short or too long when water levels change, the Tension Buoy adapts the lines to ideal lengths and tension without manual handling. This keeps floating solar arrays stable and secure through every cycle.
The system can unlock the latent potential of reservoirs behind hydropower dams. The self-adjusting anchoring system ensures floating solar and hybrid installations remain secure in all conditions. In doing so, it transforms challenging water bodies into productive assets, bringing clean energy to surfaces once considered impractical.
Pairing with existing infrastructure
When paired with existing hydro infrastructure, the Tension Buoy becomes a bridge to hybrid energy systems that offer greater stability and flexibility. Solar power can supplement hydropower during bright hours or dry periods, while dams continue supplying baseload where needed. Together, they forge a more resilient, efficient energy ecosystem.
Picture (top): Tension Buoy installed in Risør, Norway (photo by Fred. Olsen).
Also read: VIDEO: Next step in controlling vessel movements with ShoreTension mooring technology
