In 10 years, the Offshore Wind Accelerator (OWA) has run over 150 projects supporting innovations that have led to both a significant reduction in the cost of energy and risk, whilst making offshore operations safer. To mark this milestone in R&D collaboration, we have selected 10 high impact innovations to showcase the breadth and depth of the programme.
Laying foundations for any structure on the seabed is costly and complicated. The number of variables that impact the design and cost of foundations are significant: the depth of the water, seabed conditions, the distance from land, whether individual windfarms have similar conditions which might enable mass manufacturing, or whether a bespoke design is necessary for different turbine locations.
In 2009 the OWA launched an international search for novel designs through the Foundation Design Competition, to generate innovative, cost-competitive designs for the next generation of offshore wind farms. We hoped to gather knowledge about which solutions do and do not work to enable the industry to focus its efforts and investment more effectively.
The key requirement of the competition was that the proposed foundation designs had the potential to be cheaper than conventional designs in water depths of 30 to 60 metres. This could be through improvements leading to reduced cost of manufacturing, installation, maintenance and/or decommissioning.
We received over 100 applications from all around the world, and narrowed the field down to a few promising applications. Each of these finalists presented a different foundation design, many proposing innovative ways of installing the steel structure into the seabed.
One example is the Universal Foundation’s Monobucket, based on an inventive premise: using suction instead of traditional piling. This principle can be applied to secure structures to the seabed. By placing a bucket at the bottom and pumping out the seawater, the bucket is pushed into the seabed due to hydrostatic pressure. It effectively installs itself, without the need for hammering.
Another innovative design, the SPT Offshore’s Suction Bucket Jacket, uses the same idea as the above, but uses three legs instead of one. The suction bucket jacket was taken on by Ørsted and is now part of a demonstration project at Borkum Riffgrund.
Keystone Engineering’s Inward Battered Guide Structure (IGBS) is another design supported by the OWA. This uses a new idea entirely: a structure with potential to reduce fabrication and installation costs with less complex welding and a modular design for installation.
The OWA also supported the ‘PISA’ (Pile Soil Analysis) discretionary project. This project focused on addressing older, more conservative design standards used for piles for offshore oil and gas structures. These design standards were clearly inappropriate for the type of larger diameter, shorter piles that were being used for monopile design in offshore wind. The project brought together the best of academia, industry, testing houses and certification bodies to produce, validate and implement a new design methodology. The methodology was validated at scale with real life pile installations onshore, and now has the potential to reduce the embedded length of monopiles (the amount of steel in the ground) by up to 1/3. It was so successful, a second follow-on project was kicked off to apply the methodology to a wider variety of soil conditions such that it can be more widely used and applied by the industry.
Through these innovative designs, offshore foundation structures can be further refined and optimised, allowing new sites to be accessed and costs to be further reduced.
This article is part of 10 years, 10 innovations: A summary of the impact of the Offshore Wind Accelerator