Tetraspar full scale demonstration

Project Overview

• The TetraSpar Demonstration Project is the world's first full-scale demonstration of an industrialized offshore foundation for floating wind turbines.
• It is a collaborative effort between Stiesdal Offshore, Shell, RWE, and TEPCO Renewable Power.

Location and Deployment

• The project is located 10 kilometers offshore from the coast of Norway, at the Marine Energy Test Centre near Stavanger, in water depths of 200 meters.

Design and Structure

• The TetraSpar platform features a unique design consisting of a tubular steel structure with a suspended keel. This design provides spar-like stability with a very low center of gravity, which is achieved by a hull at the water’s surface supporting the wind turbine tower and a high-density keel suspended below the main body.
• The platform is made of readily manufacturable tubular steel members that require limited to no welding during assembly, allowing for the use of many potential ports without the need for deep-water facilities.

Wind Turbine

• The platform supports a 3.6 MW Siemens Gamesa Renewable Energy wind turbine with a rotor diameter of 130 meters.

Assembly and Installation

• The platform, including the turbine, was assembled in the port of Grenaa in Denmark and then towed to the installation site in Norway.
• The installation was completed and the project was commissioned in November 2021.

Mooring System

• The TetraSpar platform is moored to the seabed by three anchor lines, ensuring stability in deep waters.

Technical and Operational Aspects

• The project includes advanced monitoring and sensing technologies. It is equipped with various sensors, including power, pitch, rotor speed, tower acceleration, inclinometers, and GPS sensors, which are used to validate digital twin models and estimate structural loads and fatigue lifetime.
• The digital twin solution integrates a Kalman filter, an aerodynamic estimator, and physics-based virtual sensing procedures to monitor and predict the performance and structural integrity of the platform and turbine.

Partners and Funding

• The project is funded by an €18 million investment, with Shell holding a 66% stake, Innogy maintaining a 33% commitment, and Stiesdal Offshore Technologies holding a 1% share.

Objectives and Impact

• The project aims to demonstrate the feasibility and efficiency of the TetraSpar design for floating offshore wind farms, with a focus on reducing costs and accelerating the commercialization of floating wind technologies.
• It also provides valuable technical insights and data for improving the design and operation of future floating wind projects.

This demonstration project marks a significant step forward in the development of floating offshore wind energy, showcasing innovative design, efficient assembly, and advanced monitoring technologies.