Norwegian renewable energy company Fred. Olsen 1848 has announced that its Brizo floating PV (FPV) system design is undergoing testing and validation by Norwegian classification and certification body DNV.
DNV’s validation covers design methodologies, hydrodynamic load assessments based on physical scale-model testing, structural behavior and testing procedures, supporting the technology’s transition from pilot development to commercial deployment.
The system is designed to prevent structural loads from accumulating across the floating array, allowing individual modules to respond relatively independently to nearshore environmental conditions.
“The Brizo design was born out of the need for an FPV solution capable of withstanding environmental loads from wind and waves during tropical storm conditions, while remaining sufficiently cost-efficient for utility-scale projects,” Fred. Olsen 1848 CTO Geir Grimsrud told pv magazine.
“Most conventional FPV technologies consist of floating modules linked together in series,” he said. “However, extensive numerical simulations of such designs under wave conditions showed that compression forces and bending moments can build up, resulting in significant structural stresses. Consequently, we established the principle that the floating modules should not transfer loads between one another, but rather directly to the moorings. This became fundamental to the Brizo design.”
Grimsrud said that utility-scale floating PV plants comprise a large number of components with considerable combined weight, requiring a supporting structure capable of keeping the installation securely positioned and anchored to the seabed.
“Brizo addresses these requirements through a pretensioned fiber-rope mesh that forms the structural foundation of the floating island,” he said. “Fiber ropes combine high load-bearing capacity with low weight and competitive costs, while pretensioning the mesh provides the stiffness and hydrodynamic stability required to maintain the integrity of the installation under offshore environmental loads.”
According to the company, the rope-mesh architecture also enables a streamlined installation process. The mooring system can be deployed at the project site in advance, while the floating island is assembled and integrated onshore. The rope mesh, floating modules, walkways and electrical infrastructure can therefore be completed and tested before deployment. The fully assembled structure can then be towed to the project site as an integrated, seaworthy unit, reducing offshore assembly requirements and shortening commissioning times.
Grimsrud said the same structural concept also simplifies operations and maintenance (O&M). “Rather than relying on an extensive network of buoyant personnel walkways, as is common in many conventional FPV systems, Brizo is designed to be serviced using a dedicated O&M catamaran,” he said.
“The vessel provides safe access throughout the installation and supports routine inspection, repair and maintenance activities,” Grimsrud added. “These operations can also be supplemented by remotely operated vehicles (ROVs) and aerial drones where appropriate. Eliminating much of the dedicated floating access infrastructure while maintaining serviceability provides a clearer basis for estimating and controlling O&M costs over the project lifetime.”
In the proposed system configuration, the rope mesh serves as both the main structural element and part of the mooring system, providing four anchoring points for each floater. Through polyethylene (PE) pipes, bridles and surface buoys, the mesh is directly connected to the mooring lines.
“In other words, it provides a direct structural connection between the floaters and the anchors, allowing environmental loads acting on the floaters to be transferred directly to the anchors,” Grimsrud said. “As the mesh is made of rope, it must be installed with a certain level of pretension to maintain stiffness and preserve its geometry under load.”
The mesh provides four anchoring points for all the floaters.
Pretension is provided by the surface buoys during installation, provided that water-level variations at the site are limited. The mooring chain runs through the buoys and over a gypsy wheel. Once the anchors, mooring chains and floating rope mesh are installed, a tensioning tool is applied to each surface buoy to winch in the chain and pull the buoy deeper into the water.
“When the correct pretension is reached, the chain is locked in place, and the draft of the buoy maintains stable pretension across the rope-mesh system,” Grimsrud said.
According to the company, rope locks secure the intersecting rope members to create a stable grid. “Achieving a reliable clamp on a rope is challenging when expensive materials need to be avoided,” Grimsrud said. “The rope lock is manufactured entirely from high-density polyethylene (HDPE) to keep costs down. The challenge with plastic materials is creep, as even relatively small forces acting over time can reduce the clamping force.”
To address this issue, Fred. Olsen 1848 designed the rope lock so that clamping forces remain low under normal operating conditions and increase as loads rise. “During storm conditions, when the forces in the system are high, the clamping forces increase accordingly,” Grimsrud added.
Another key component of the Brizo platform is the floating walkway, which accommodates both DC and AC cabling as well as the string inverters. “The string inverters are located on the floating walkway to provide easy access for plant operators,” Grimsrud said. “At the end of the walkway, there is also a hang-off chute for routing the island’s AC export cable.”
Another key feature is the use of HDPE pipes to stabilize the rope mesh and maintain predefined spacing between the ropes. “The HDPE pipes also spread out the bridle lines, allowing us to reduce the number of mooring lines relative to the number of mesh ropes,” Grimsrud said. “Typically, eight to 10 bridle lines are connected to each mooring line. Spreading these bridle lines introduces compression forces that are absorbed by the pipes.”
According to Grimsrud, the pipes also help mitigate the effects of short-crested waves, which are typically generated by sea breezes. “These small but steep waves can cause mismatch losses on a daily basis,” he said. “The HDPE pipes effectively reflect such waves, reducing their impact and potentially increasing energy production compared with systems without HDPE pipes.”
Fred. Olsen 1848 has also developed a tension buoy that dynamically regulates mooring tension by adjusting the deployed line length as water depths change. The technology is intended for floating solar installations on hydropower reservoirs subject to substantial water-level variations. It combines a buoy-mounted winch with an automated control system to maintain stable station-keeping with limited manual intervention.
The concept has progressed from development and prototyping to field testing at EDP’s Alto Rabagão reservoir in Portugal. “The new design will be installed at the Ramskjær pilot in Norway and at the EDP pilot in the fall of 2026 for field trials during the winter months,” Grimsrud said. “The aim is to have the product qualified and ready for deployment in the first half of 2027.”
Image: Fred. Olsen 1948
Fred. Olsen 1848 tested the Brizo concept at a facility operated by Norwegian research institute Sintef under regular and irregular wave conditions, covering a range of wave heights and wavelengths. Based on the results, the company worked with DNV to develop a methodology for combining wave, wind and current loads to determine the resulting mooring and anchor forces.
DNV has been involved in the development and verification of Brizo since the early stages of the design process. A 3 MW Brizo island subsequently received a Statement of Conformity against DNV-RP-0584 for significant wave heights of up to 3.5 meters, wind gusts of up to 65 m/s and currents of 0.38 m/s. The assessment also accounted for an average of 10 cm of marine growth on the floats and ropes. According to Fred. Olsen 1848, the results support the deployment of the system in nearshore environments, as well as on large lakes and reservoirs.
Following the introduction of DNV-ST-C108 and DNV-ST-E309, two FPV-specific standards covering floating structures and mooring and station-keeping systems, respectively, Fred. Olsen 1848 is updating its technical documentation to demonstrate compliance with the new requirements.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: [email protected].
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: [email protected].
Comments
Please login to comment
Martedì, 22 Settembre 2026
11:00 – 12:00 CEST, Roma
Monday, October 26, 2026
10:30 am – 11:30 am CEST, Berlin, Paris, Madrid
Thursday, September 10, 2026
2:00 pm – 3:00 pm CEST, Berlin, Paris, Madrid
Tuesday, September 15, 2026
5:00 pm – 6:00 pm CEST, Berlin, Paris, Madrid
Our special edition for Intersolar South America 2026 is here!
Discover the latest insights into the Brazilian solar market – in Portuguese.
A two-day conference in Austin, Texas, bringing together leaders in US solar manufacturing, equipment specification, and factory execution.
Saudi Arabia is accelerating its clean energy transition—join the SunRise Arabia Clean Energy Conference 2026 in Riyadh to explore how solar PV and energy storage are powering its digital economy.
pv magazine USA hosts its multi-day virtual event on U.S. solar and energy storage, covering domestic manufacturing, distributed energy and the growing role of solar-plus-storage in meeting AI-driven power demand.
Thursday, October 7, 2026
11:00 am – 12:30 pm CEST, Berlin, Paris, Madrid
You have no items in your basket.
