Offshore wind energy represents a significant advance in sustainable electricity generation. Using wind turbines installed offshore, these installations take advantage of the strongest and most constant winds in the ocean, increasing efficiency and power generation capacity. With more than 70% of the Earth's surface covered by seas and oceans, offshore wind energy transforms vast ocean areas, which have productive potential and were not being used, into valuable energy assets, even though many installations are still relatively close to the coast.
Operation of an Offshore Wind Farm
Offshore wind farms can be divided into two main categories, based on the turbine installation technique:
Turbines Fixed on the Seabed: Used in areas close to the coast or in shallow waters.
Turbines on Floating Platforms: Suitable for the open sea, where the depth is greater and the sea floor is more complex.
The operation of these turbines is similar to onshore ones: the wind drives the rotating blades, which in turn drive an electrical generator, converting mechanical energy into electrical energy. The crucial difference is the location, as the wind speed in the ocean is higher and more uniform, enhancing energy generation.
Types of Floating Platforms
Floating offshore wind energy is made possible by several floating platforms, chosen according to the oceanographic conditions of the location and the specific project:
Barge: Large surface area in contact with the water, providing stability, similar to a boat.
Semi-submersible: Minimize exposed surface area, maximizing volume moved for stability.
Spar: Cylinders with weight at the base to guarantee vertical stability, ideal for larger turbines.
TLP (Tensioned Legs Platform): Stellar structure with minimal arms, anchored by tensioned cables.
Challenges and Advantages
Challenges: Designing platforms to withstand the variability of wave movement and intensity so as not to compromise operation and structure, construction at greater depths, transport and installation of large structures and the complexity of sea floors.
Advantages: Use of vast maritime areas, without the presence of relief or stronger winds, contributing significantly to renewable energy and sustainability.
Case Study: CFD Design of Floats for Offshore Wind Turbines
To support and accelerate the development of floating platforms for offshore wind turbines, a detailed study was carried out using computer simulation on the operation of the Extended Response of Oscillation (RAO). Tests conducted in the laboratory measured the response of the floats, and these experiments were faithfully reproduced with CFD simulation by Simcenter Star-CCM+. The precision present in this tool is crucial to reducing development time and costs, allowing fast and efficient optimizations of floating platform designs and other wind turbine components.
RAO Motion Validation: Star-CCM+ enabled accurate validation of RAO (Amplified Oscillation Response) motion using model-tested wave signals. This process is essential to accurately represent the physical behavior of the different fluid and solid phases, ensuring that simulations accurately reflect the real conditions faced by floating structures. RAO validation is critical to ensuring that float designs can operate stably and efficiently in marine environments, minimizing the risks of structural failure and maximizing power generation efficiency. In the graph below, the experimental (Test Model) and numerical (CFD) curves are compared, demonstrating the great accuracy of Star-CCM+ in reproducing the tests. This precision is crucial to reducing development time and costs, enabling fast and efficient design optimizations of floating platforms and other wind turbine components.
Lift response comparison (Blue: Test Model, Red: CFD )
Pool Wave Testing (OTRC 2013): Pool wave testing uses scale models to validate the performance of floats in simulated marine conditions. The pool generates controlled waves to replicate the sea, and sensors measure forces and movements of the models. These tests identify and correct design issues before actual construction, saving resources and ensuring the efficiency and safety of offshore operations.
Design Tree Optimization: Development of efficient floats for applications in wet and dry conditions, ensuring optimized performance and adaptability to different operating environments. This process involves the analysis and modification of several design parameters to maximize the efficiency, durability and cost-benefit of the floats, taking into account factors such as corrosion resistance, stability in different sea conditions and ease of maintenance.
Offshore wind energy, especially with the use of floating platforms, represents one of the most promising solutions for generating renewable energy.
With the support of computer simulation and advanced Siemens software, technical challenges can be overcome and the development of solutions is accelerated, allowing the implementation of efficient and sustainable projects quickly.
Advances like these not only contribute to a greener planet, but also drive innovation in the renewable energy sector, promoting a more sustainable future for everyone.
Schedule a meeting with CAEXPERTS to find out how we can help make your offshore wind energy projects a reality. Let's drive innovation and sustainability in the energy sector together!