Offshore wind projects are built on decisions made long before the first foundation is installed. Where to position a structure, how to design it, when to send a vessel offshore and how to manage an asset over decades all depend on understanding one main thing – the operational environment.
Metocean data provides that understanding. By measuring wind, waves, currents and other environmental parameters, it turns an uncertain marine environment into something that can be characterised, forecast and acted upon.
The influence of meteorology and oceanography impact every decision offshore and should be monitored throughout the project lifecycle. At the outset, a wind resource assessment underpins the final investment decision, without it, no development gets the green light.
From there, waves, currents and the physical characteristics of the marine environment shape every aspect of structural design. Defining the physical environment early means a platform can be positioned sufficiently high above the sea surface, beyond the reach of the most extreme wave heights you would expect during the life of the asset.
The same data determines how much steel is needed to withstand 30 years of operational life, how mobile sediments will affect cable routing, and where foundations can safely be placed. Site-specific forecasts and real-time onsite data inform vessel scheduling, lifting operations and the safe movement of personnel. For floating offshore wind, every one of those considerations is amplified.
Accuracy matters, but so does clarity. The same data needs to serve metocean specialists, design engineers, marine controllers and vessel masters, therefore the presentation of metocean data in a meaningful form to end user is critical.
Deploying and maintaining instruments in the open ocean is not straightforward. Collisions with vessels happen far more often than many would expect, and the environment itself is no less punishing.
At Dogger Bank two days after the deployment of the first metocean buoys in October 2010, there was a significant storm with waves exceeding 12 metres, highlighting immediately the importance of observed data from site as the forecast at that time was wildly underestimating the waves.
Mobile sediments can bury instruments, biofouling can block acoustic sensors and corrosion can degrade equipment over time. Reliable metocean data therefore depends not just on sensor selection and mooring design, but on robust communications, active maintenance and safe offshore operations. The technical challenges are significant, but so is the need to keep people safe. Safety cannot live in a document onshore; it has to be embedded in the way metocean operations are planned and carried out.
For most offshore wind projects, measurement campaigns start with moored systems. OEG designs and deploys multi-parameter mooring spreads combining floating Light Detection and Ranging (LiDAR) buoys, directional wave rider buoys, current profilers and water quality sondes, with the appropriate level of data made available to clients through OEG’s online dashboard in near real-time, and the full complement of quality-controlled data made available following download of data from each device.
The Inch Cape Offshore Wind Farm, which is Scotland's largest infrastructure project currently under construction, located 15 kilometres east of Montrose, illustrates this in practice. OEG is supplying and maintaining the aids to navigation buoys marking the farm's perimeter, alongside three metocean buoys with data via satellite communications feeding the Edinburgh control room throughout the construction phase.
As a project moves into long-term operations, the measurement infrastructure evolves with it. Once a fixed structure is in place, a fixed metocean system delivers lower operating costs, hardwired communications and a continuous data thread through into operations and maintenance and for the long term purposes of life extension.
For projects where a fixed structure is not an option, as is the case with floating wind developments, OEG’s metocean service gathers wave direction measurements by integrating a satellite compass alongside a wave radar sensor with motion compensation technology. This ensures accurate readings regardless of whether the platform moves with the wind the waves and the currents.
From the first wind resource assessment to the final decommissioning operation, metocean data runs through every major decision on an offshore wind farm, its very purpose is to utilise the energy that makes the environment so dynamic. The role of metocean data is to make sure the right decisions are being made, by the right people at the right time.