Signature ADCPs used in offshore wind site surveys
Green Rebel specializes in collecting geophysical and metocean data in areas slated to become wind farms. Our floating Lidar buoys, equipped with Nortek Signature ADCPs, gather wind speed profiles above and current profiles below mean sea level to inform the safe and profitable installation and operation of offshore wind farms globally.
Gathering wind and current velocity data from floating Lidar buoys
Green Rebel’s metocean team’s main focus is building and deploying floating Lidar buoys which 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 our 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.
Detailed current profiles are crucial for site characterization
Green Rebel’s Lidar buoys are equipped with Nortek Signature 250 and Signature 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.
“The bread and butter of using the Signature series is assessing ocean dynamics, but at a very high-resolution scale,” says Dr. O’Reilly.
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 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.
Connecting wind and current data for 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 is allows clients to understand whether that site has the potential to be a profitable and sustainable wind turbine site.
