Contributed by Will Hodshon, Vysus Group

We may only be a quarter of the way through 2022 but significant strides have been taken already in the renewable energy world, not least within the offshore wind sector. The record-breaking New York Bight auction and the Scotwind leasing round in the North Sea are prime examples of why wind power is the jewel in the crown when it comes to clean energy.

However, while such high-value auctions have shown the appetite and enthusiasm for wind power implementation, the time to develop a site is still surprisingly slow. Vysus Group’s Will Hodshon explores where the process could be sped up, in his field of site assessment.

In the last decade, wind power has experienced a significant identity change. From being one of the more expensive and impractical means of energy generation, caught in a tangled web of red tape and legislation, to now what is one of the cheapest and cleanest forms of energy production at the heart of many countries’ clean power aspirations. Though it is agreed that the transition needs to gather pace, the current development process could be significantly streamlined.

Being awarded the lease for a wind farm is, as many of us know, the first step in a journey that at the moment takes, on average, around 10 years to begin generating power. It is akin to buying a block of land to build a house – once all the contracts are exchanged, comes the sizeable and expensive job of building the house. To continue this parallel further, you wouldn’t build a house without knowing all the potential costs associated with it and just like offshore wind, one of the biggest variables is the cost of the foundations.

While specific ground conditions vary considerably between any potential site, the techniques for understanding those ground conditions, broadly speaking, have remained consistent for several decades. It is perhaps here where we can start to explore different techniques and a general ethos change to the methodology to speed up the process while also improving our understanding of the ground conditions and further reducing risk.   

One example of this would be to conduct a single 3D seismic survey that covers the entire site at the beginning of the project, as opposed to the common practice of conducting multiple 2D seismic surveys over a number of years.  Although the cost of a 3D seismic survey is far more than the reconnaissance level 2D survey traditionally conducted at that stage of the project; the cost of a 3D survey is now comparable to the total amount spent on foundation zone geophysical surveys over the life span of the project, but with huge advantages in terms of data volume, quality and the ability to interpret and model the ground conditions of the site. 

Scale has often been seen as a stumbling block for renewable energy. Advancements such as wider turbine blades are hindered by the fact that infrastructure and installation vessels are lagging behind. Modern wind turbines have increased in size – it is estimated the average hub height will be around 500 feet (152.4m) with the length of the blades surpassing 378 feet (115.5m) by 2035 – which will have tremendous generation benefits in the mid-to-long-term, but before that, the issue of looking too far ahead remains.

As the size of the turbines increases, so do the logistical challenges of getting each part assembled and to the wind farm site. Even though a vessel may well have the deck space to transport the blades for a small installation, windfarms with 50, 100, or 150-plus structures with three blades will be delayed because of a lack of vessels capable of carrying such high numbers. There is the added cost of upgrading existing fleets, compounded by restrictive legislation and hesitancy about whether investing in new ships is even commercially viable.

Routes are being explored to overcome these challenges, from multiport assembly to utilizing smaller vessels to bring the necessary construction equipment out to sea and assemble the turbine off the coast. And unpicking this conundrum will need to be completed sooner rather than later, given how much global investment governments are making for offshore wind to be a viable component of a clean energy future.

The good news is that innovation to combat these issues is gathering pace. Floating offshore wind farm technology (FOWs) not only opens up new areas of seabed real estate but also arguably lends itself better to being locally constructed.   

3D ground modeling and repurposing of existing and newly discovered seismic data could also reduce the time and cost of understanding the ground conditions of a site. While this technology and techniques may incur a higher cost in the first instance, this is mitigated by the potential removal of initial expensive surveys or site investigations, as was the case in the Scotwind feasibility studies. In the case of the Scotwind development, seismic exploration data from as far back as the 1960s was repurposed and then modeled to help understand the ground conditions of the sites pre-auction.

Generally, surveying accounts for approximately 1-2% of the entire wind farm development cost; relatively small in comparison to say decommissioning. Yet without it, plans simply cannot move forward as the results determine the foundation and cable design not to mention whether it is even worth pursuing a wind farm in that particular location in the first place.

As well as the ground conditions there are many other sizeable obstacles to developing an offshore wind farm. One example of this is that the state of California, at the time of writing, does not have a port suitable for the construction of offshore wind turbines. Though it is possible to develop an offshore windfarm minus the port, logistical challenges will pose complications.

If feasibility studies can reveal the potential for power generation, similar processes can be used in contingency planning, especially within the wind sector. Solving the complex problem of an alternative energy source for when the wind drops has long remained a challenging area for it to overcome; hydrogen may hold the answer, given its capacity to be stored underground, however, there will still be a need for surveys to be conducted in order to connect the tanks to pipelines, and then connect the pipelines to fuelling stations or other generation facilities.

Throughout recent years, the language used within energy transition debates has been all about speed and acceleration. Important, yes, and time is very much of the essence, but there we can still achieve the same targets by working smarter and efficiently, as opposed to keeping the throttle pushed to the floor.

About the author

William Hodshon – Head of Offshore Wind Site Assessment

As the head of Vysus Group’s offshore wind site assessment team, Will acts not only as a senior consultant and project manager but is also responsible for product and services development, mentoring and quality control, and business development.

In his consultant capacity Will frequently takes responsibility for a project from conception to completion, undertaking the initial desk studies through to survey design/specification, data quality control, interpretation, and finally the 3D ground model development