Irish company Green Rebel specializes in offshore wind site surveys. Their floating Lidar buoys, equipped with Nortek’s Signature ADCPs, gather wind speed profiles above and current profiles below mean sea level to enable the installation and operation of offshore wind farms globally.
According to Dr. Luke O’Reilly, Operational Oceanographer at Green Rebel, many of Green Rebel’s clients are in the pre-planning or site selection phase of the offshore wind process. In support of the development, Green Rebel conducts the necessary surveys to determine if a site is suitable for a turbine.
Green Rebel’s metocean team’s main focus is building and deploying floating Lidar buoys that gather wind speed profiles, as well as oceanographic data such as current profiles collected by Nortek ADCPs.
“The buoys are fitted out with all the necessary technology required to provide the data our clients need. There is ample power onboard the buoys to provide measurement capabilities beyond the standard (e.g., wind, wave, current, etc.) such as bird monitoring, passive acoustic monitoring, and biofouling, to list a few,” says Dr. O’Reilly. “Notably, we have a dual Lidar assembly, which is cutting edge in its own right, and we collect oceanographical data concurrent with that wind data.”
The ability to measure both wind velocity data and oceanographic data from these buoys is advantageous to Green Rebel’s clients, who often require both types of information to determine the suitability of a site and understand if and how turbines can be installed in the area.
Crucial Measurements for Site Characterization
Green Rebel’s Lidar buoys are equipped with Nortek Signature 250 and 500 ADCPs, which can sample current profiles of up to 70 m at up to 8 Hz. They use the ADCPs to gather current profiles with approximately one-meter resolution to gain a full picture of ocean processes throughout the water column where the wind turbines are to be installed.
“Assessing ocean dynamics is the bread and butter of using the Signature series—but at a very high-resolution scale,” says Dr. O’Reilly.
According to Dr. O’Reilly, the metocean team often uses modeled datasets to look at ocean processes but finds using these models to determine what’s happening throughout the water column to be a challenge. In-situ measurements from ADCPs solve this problem by improving the vertical element of hydrodynamic models.
“Our clients benefit from having the meter-sized ADCP cells that provide this rich understanding of what’s happening down through the water mass,” explains Dr. O’Reilly. “I can’t emphasize enough how important those meter-by-meter cells are to creating a rich model for your site.”
In addition to mounting Signature ADCPs on the Lidar buoys themselves, the team also uses bottom-mounted ADCP setups, which allow for wave measurements using the Signature’s vertical beam to capture the sea-air interface. These bottom frames are complete with side-looking Aquadopps to capture the current speed at the level of the frame. In some cases, Nortek Signature 250 ADCPs (which offer a profiling range of up to 200 m) are used on projects where clients require longer-range measurements.
Effective Site Selection and Installation
“When we integrate our wind data and our Signature data, we’re actually seeing oceanographical phenomena like Ekman processes in our data across several of our sites,” says Dr. O’Reilly. “For our clients, it’s imperative to know how wind influences complex current profiles and how, in turn, these impact the integrity of installed structures throughout their lifecycle.”
Connecting data from the Signature ADCPs, Lidar wind velocity profiles, and modeled data is crucial to client success. Having a complete picture of metocean conditions at a site allows clients to understand whether the location of wind turbines has the potential to be profitable and sustainable.
Intuitive Software, Responsive Support
Dr. O’Reilly emphasizes his positive experience with Nortek’s instrument quality, Signature Deployment Ocean Contour software, and responsive support team. He says his experience with the accuracy of Nortek’s deployment software allows their team to make the most of every deployment, and the post-processing capabilities of Ocean Contour allow him to look at results in the field and make any necessary adjustments.
“It’s also worth mentioning that the responsiveness of the Nortek support team is just 10 out of 10,” he adds. “When people see Nortek ADCPs, they need to understand it’s the full package you’re getting. It’s the proprietary software and all the support that goes along with that.”
The Green Rebel team also relies on Signature ADCPs for their proven track record. According to Dr. O’Reilly, the Green Rebel team uses a custom filtering system to determine “data availability,” i. e., their confidence level that the collected data matches the expected conditions.
“It’s hard to think of instances where Nortek ADCPs weren’t at close to a 99.9% data availability rate, which is really reassuring. It allows us to approach our clients very confidently,” he says.
The offshore wind industry is far from stagnating, and more and more areas will require services like those offered by Green Rebel. Reliable and field-proven oceanographic sensors, like Nortek’s Signature ADCPs, will be a key piece of the offshore wind puzzle moving forward.
To get in touch, visit: nortekgroup.com/contact info@greenrebel.ie
This feature appeared in environment coastal & offshore (eco) magazine’s 2025 spring edition The Blue Economy, to read more access the magazine here.
