WT on Wind Europe’s Technology Workshop: Is offshore finally part of the agenda?

This month marks the one year anniversary of Wood Thilsted’s Energy & Climate Analytics Department (ECA), a team dedicated to the understanding of the atmospheric and oceanographic conditions of offshore wind farm sites, including wind resource and site assessment. The ECA group, who will continue to grow and will soon be made up of 6 world renowned experts, have been tackling the technical challenges associated with the understanding of these conditions. They recently presented some of their findings at the Wind Europe Technology Workshop in early September. They also participated in the offshore CREYAP 2021 (Comparison of Resource and Energy Yield Assessment Procedures), an industry exercise organized by the same entity in partnership with Ørsted and DTU Wind Energy.

Wind Europe’s Technology Workshop has, over the years, become the main European forum of technical discussion around topics related to wind resource assessment and operational analysis of onshore wind projects. Although many of the challenges and methodologies are common to both the onshore and offshore environments, the former had always been the preferred of the two, to the point that metocean related site conditions issues had always been greatly ignored by these wind focused conferences, and addressed at altogether separate events.

With offshore wind predicted to get a bigger slice of the wind pie and the similarity between the atmospheric and oceanographic disciplines, it makes sense to finally bring the offshore focused subjects to the technical wind table and, what better place than Wind Europe’s Technology Workshop? Wood Thilsted did exactly that with presentations covering the validation of the New European Wind Atlas (NEWA) for offshore wind resource assessment application, and also summarizing the most recent research into the impact of Climate Change on the metocean conditions to be expected in the North Sea.

Modelled datasets, such as NEWA, are publicly available and have become a key tool in supporting early site scoping and development activities to inform estimates of the likely wind regime, especially in regions where public offshore wind measurements are scarce. However, due to their nature, they carry elevated uncertainty. Wood Thilsted set out to validate the NEWA model against several high-quality offshore measurements, with the aim to understand any potential limitations of this publicly available wind atlas. The authors have looked at not only the mean wind speed, but also other metrics relevant for early-stage site development such as the wind shear profile and wind frequency distributions, hoping to provide useful insights to proposed offshore developments in European waters.

Whilst the NEWA validation highlighted a few shortcomings of this product, it has also allowed for the potential quantification of an existing bias and its consideration in areas where robust measurements are not available. Although modelled data will not replace the need for high quality on-site wind measurements, this work demonstrates that these types of datasets do provide a useful first estimate and a valuable baseline for offshore wind resource and energy yield estimates, where their limitations are known.

Despite all the attention and focus that Climate Change has been having from the scientific community, the media, politicians, policy makers, as well as the public at large, research into its impacts on wind energy production in general, and metocean conditions in particular, are scarce and findings are highly uncertain.

Take the example of extreme events, hailed by many to expect an increase in frequency and strength (thus potentially greatly impacting the life or even the survivability of offshore structures), yet the uncertainty surrounding these claims is compounded not only by the uncertainty of the climate models themselves, but principally by the one related to the statistical treatment of extremes. The total uncertainty of these two components confers a spread of possible outcomes even greater than that associated with the different emission scenarios one would typically model.

During the course of this work, it has become apparent that, in order for the industry to be able to include the impacts of climate change into the design of structures and operating plans, further and better research is needed, and one focused in understanding the changes in industry relevant metrics, such as the ones depicted below.

An appeal has, therefore, been made: the wind industry needs targeted and specific research into these metrics and their probable modification due to Climate Change. This should be targeted at institutions capable of running the most up-to-date climate models, but also at industry players in possession of measured datasets which can be used to calibrate and validate such models for these atmospheric and oceanographic metrics.

We also saw some other industry players addressing offshore related topics at the Wind Europe Technology Workshop, namely on the subject of floating wind, given the anticipated need to estimate energy production for floating offshore wind farms, and the absence of track record to base any performance losses that might be associated with turbine motion. This, however, remains an open discussion and matter of further research.

Validation had the usual focus one would expect at an event of this level, as well as timeseries modelling approaches. Remote sensing, particularly what concerns LiDAR devices – both vertical profiling and scanning – have probably been, the most talked about subject of the whole conference. Open-source tools to help plan measurement campaigns have been presented and a few validated solutions to correct for LiDAR measurements in complex terrain have also been discussed.

Wood Thilsted welcomes the inclusion of both the offshore and the Climate Change topics in Wind Europe’s Technology Workshop agenda and is very happy to be a part of this discussion. Please get in touch with our Head of the Energy & Climate Analytics team, Carla Ribeiro – clr@woodthilsted.com, to request a copy of our presentations, find out about our CREYAP exercise results, or just find out more in general.