Monopile Foundations for the Next Generation of Offshore Wind Farms

The offshore wind sector is thriving worldwide, with a steady trend towards installations in deeper waters and more challenging conditions. In the North Sea, countries are preparing unprecedented expansions. The Netherlands aims to achieve around 21 GW of offshore wind capacity by the end of 2032, while the North Sea countries together target 193 GW by 2040. This growth goes hand in hand with turbines that are becoming increasingly larger, presenting new challenges for foundation engineering.

Monopile foundations, steel tubular piles, form the backbone of these developments. They are relatively simple, cost-efficient, and remain the standard foundation type for fixed offshore wind turbines, alongside emerging floating concepts for the deepest waters. To support the latest 12 to 20 MW turbines in open seas, these monopiles are also increasing in size and complexity. For technical professionals, staying up to date in this niche is crucial to ensure safe and sustainable wind farms.

Larger Turbines Require Larger Foundations

In recently launched wind farms, we are seeing monopiles of unprecedented dimensions. For a recent UK project, a monopile measuring 83.9 meters in length, 10.6 meters in diameter, and weighing 1,800 tons was installed, setting a European offshore wind record. This foundation supports a 14.7 MW turbine. Installing such large piles required the installation vessel to be specially equipped. This illustrates the new scale the sector is reaching.

As Dutch waters are also hosting increasingly larger wind farms, the industry is investing heavily in scaling up. In May 2025, Sif opened an extensive monopile factory at the Maasvlakte. This state-of-the-art production line can manufacture piles up to 11 meters in diameter and 120 meters in length, with a capacity of 200 monopiles per year. The first projects are already underway, including the supply of 54 monopiles for the US Empire Wind 1 project and 52 for the Dutch Ecowende wind farm. This expansion underscores the Netherlands’ leading role in the offshore wind supply chain.

Innovation in Installation and Design

Not only the scale but also the installation methods are evolving. Traditionally, monopiles are driven into the seabed with a pile hammer, which is effective but noisy and potentially harmful to marine life. In 2024, Ørsted tested a revolutionary silent technique at the Gode Wind 3 wind farm: a patented jet system that loosens the sandy soil around the pile, allowing the monopile to be installed without hammering. The result was a drastic reduction in underwater noise, and the method promises faster, more cost-effective installation, while also enabling lighter foundation designs because piles no longer need to be over-dimensioned for heavy impacts.

Innovations are also occurring in monopile design. For years, traditional p-y curves have been used to predict lateral pile deflection. However, for the new large piles, more accurate modelling is required. In recent years, the PISA method has been developed, translating advanced 3D soil analyses into efficient 1D calculations, providing a more reliable prediction of pile behavior. This approach offers better insight into both deformations and bearing capacity, and can also lead to significant steel savings.

A remaining challenge is the effect of cyclic loading from wind and waves over the structure’s lifetime. Current designs typically account for this through simple correction factors on monotonic bearing capacity, which does not capture all complex effects. Research initiatives such as the international PICASO project focus on modelling fatigue and long-term deformations more accurately, ensuring that monopiles remain stable after thousands of load cycles without unnecessary over-dimensioning. This knowledge advancement helps guarantee safe foundations over the long term.

Bridging Current Insights with Practice

For professionals involved in these developments, PAOTM offers the two-day course Monopile Foundations for Offshore Wind Turbines. This course bridges geotechnical theory and practical application, enabling both specialists and engineers without a geotechnical background to understand fundamental principles and the latest trends. Under the guidance of experienced instructors, including experts from TU Delft, participants will cover topics such as:

• Different foundation types for offshore wind turbines and their areas of application
• Soil investigation and characterization techniques for offshore sites
• Methods for monopile installation and design, including advanced calculation methods such as PISA
• Monopile-soil-environment interaction, including lateral capacity, stiffness, cyclic behavior, seabed cracking, and scour protection
• Challenges and lessons learned from offshore construction projects, as well as the latest R&D developments both domestically and internationally

The course is conducted in English, allowing a broad group of professionals to participate. The content is relevant for designers, builders, and operators of offshore wind farms, even if geotechnics is not their specialization. Thanks to a mix of lectures, lab sessions, and case discussions, the learning experience is practice-oriented and directly applicable to projects.

Experiences from Previous Participants

Previous participants have expressed their enthusiasm for the course:

• "A very interesting course with insightful lectures, enjoyable practical sessions, and excellent networking opportunities. Presentations of laboratory analyses and research projects were very engaging."

• "The course was great for learning and experiencing the fundamentals and the offshore wind world. It was a good way to combine technical knowledge with practical information."

• "Without exception, all speakers seemed highly motivated to deliver interesting presentations. The two laboratory tests were entertaining while also being very educational, a great addition."

This feedback highlights that the course not only provides theoretical insight but also practical knowledge that can be directly applied to projects.

For more information about this course, click below.