Offshore wind has significant potential to bring abundant, renewable power into homes and businesses in coastal communities. But wind power plant operators need solid information about conditions, such as wind speeds at various times of day, to confidently make sound investments in technology and wind plant locations. Such is the case for California, which is looking to add offshore wind to its power resources. In fall 2020, DOE’s PNNL partnered with WETO and the Bureau of Ocean Energy Management to deploy two offshore wind research buoys off the northern and central California coastlines — near Humboldt and Morro Bay, California, respectively.
Earlier this year, the buoy stationed near Humboldt was taken offline for some technical upgrades. A research team streamlined that buoy’s power use and incorporated more efficient data management capabilities.
The buoy also invited a new passenger on board.
Hitchin’ a Ride Is for the Birds (and Bats)
Enter ThermalTracker-3D, a technology developed by PNNL and supported by WETO. ThermalTracker-3D is designed to track bird (avian) and bat behaviors and attributes — such as flight height and speed — needed for assessing potential risks from offshore wind energy development.
The prototype technology, equipped with specialized software and a pair of thermal, stereovision cameras, hitched a ride on the Morro Bay buoy 20 miles off the coast of Humboldt County with the purpose of collecting information about seabird and bat activity. Paired with the buoy, avian and bat activity can be correlated with various weather and ocean conditions.
This image, created from a sequence of ThermalTracker-3D photo frames, shows the flight track of a bird over the Pacific Ocean. Image courtesy of Shari Matzner, PNNL
The Results Bob In
The yearlong deployment is ending in fall 2021 for the Morro Bay buoy, with those results starting to land in the team’s hands in real time.
“So far, we’ve noted a lot of variability in daily wind speed, especially in the upper part of the turbine rotor layer, at Morro Bay,” said Raghu Krishnamurthy, a PNNL Earth scientist who is analyzing the data. “We are also finding that the wind speed increased roughly one and a half times at night.”
At the Humboldt location off the northern coast, steady-state winds — winds that provide consistent power production during all hours of the day — are being observed at each altitude. These data will provide further insight about the minimum daily power production available from offshore wind power plants in California during all seasons.
The PNNL team continues to thoroughly analyze the buoy data as it comes in and will publish a technical report at the end of 2021.
ThermalTracker-3D also continues to pull in avian data — recording data continuously and transmitting the flight data to shore every hour. In its first 30 days at sea, the system recorded 699 flight tracks — the first time that continuous, “24/7” observations have been made in U.S. coastal waters.
One of two offshore wind research buoys that are managed by the Pacific Northwest National Laboratory (PNNL), as depicted in an artist’s rendering. The buoys are equipped with instrumentation that can take wind speed measurements as high as 250 meters, the height of today’s wind turbines. Results will help wind power plant operators make decisions for states such as California on investments and locations. Image by Mike Perkins, PNNL
Floating — and Flying — Into the Future
The Morro Bay buoy will also be recovered from the ocean and undergo similar upgrades as the Humboldt buoy, which will remain deployed until spring 2022. It will then take a tropical trip to the coast off Oahu, Hawaii, to support offshore wind energy planning for that state.
ThermalTracker-3D is installed on the Humboldt buoy as part of its update. Photo by Shari Matzner, PNNL
Meanwhile, once ThermalTracker-3D completes its first California stint, the research team plans to develop a system for potential future deployment on an offshore wind turbine. This effort will compare postconstruction seabird behavior with the baseline data collected off the buoy — completing the understanding of how seabirds are affected by offshore wind energy development.
The data from the buoy and ThermalTracker-3D deployments will be available to the wind energy research community on the Data Archive and Portal, which is managed by PNNL. In August, R&D World Magazine announced that ThermalTracker-3D is a finalist for an R&D 100 award in the Software/Services category; winners will be announced later this year.