Water currents are now affecting aquaculture operations in more than one way at a local Outer Banks oyster lease. While a balanced flow of water has always delivered essential nutrients to oysters and assisted with their shell growth, currents are now also powering a small marine renewable energy device to charge water quality sensors for the lease operators.
Over the last several years, the NC Renewable Ocean Energy Program (NCROEP) has funded research and development at partner institution N.C. State of low-flow current harvesters, such as the FLOSS and the coaxial turbine. While neither technology has been optimized for grid-scale use, prototypes of both devices have demonstrated a level of readiness for small-scale applications.
Many of the original sixteen OpenCTDs were constructed by students, staff, and faculty during a two-day workshop led by Dr. Andrew Thaler (back row, fourth from left) at CSI.
At the same time, starting in 2024, NCROEP also funded a project at CSI, led by Lindsay Wentzel and Trip Taylor, to build and deploy 16 CTDs to characterize wave energy in Outer Banks’ sounds. A CTD is an instrument with conductivity, temperature, and depth probes, which collect readings for salinity, temperature, and pressure at a given site. Wentzel and Taylor opted to create their proposed network using OpenCTDs, an open-source, low-cost, “do it yourself” CTD developed by Dr. Andrew Thaler of Oceanography for Everyone and composed of PVC and off-the-shelf parts. Over time, the team further tailored their OpenCTDs into moored, wave-sensing instruments by developing new code, adding to the existing battery capacity, and modifying the pressure sensor to rapidly collect wave height and period data.
Meanwhile, Herring Shoal Shellfish Co. owners James Clower and Aaron Hopkins were searching for a way to inform their operations in Blossie Creek near Oregon Inlet. Herring Shoal Shellfish Co. produces boutique oysters using adjustable longline gear to raise and lower their oyster cages to take advantage of optimal environmental conditions. Parameters such as salinity, temperature, and dissolved oxygen are critical for oyster growth, formation, and flavor profile, but monitoring such environmental conditions can often be challenging and costly.
As fate would have it, Hopkins and Clower were connected with Wentzel and Taylor through a series of professional and personal introductions. One conversation led to another, and Wentzel and Taylor wondered if they could build a sensor platform to meet the oyster farm’s needs. They took the lessons learned from the CTD project and created a new sensing platform that could provide the needed water quality data and be powered by one of the NCROEP marine current devices. There was just one problem. Where would all the data collected then be stored so Herring Shoal Shellfish Co. could access it in real time?
Further leveraging partnerships made through CSI, the lab team contacted the ECU Water Resources Center (WRC), which maintains a cloud-based, environmental, telemetry data network with receivers at CSI.
With partnerships forged and ideas streamlined, the collaborative work began to create a self-sustaining monitoring system designed for NC oyster farms. CSI developed the sensor platform based on the needs of Herring Shoal Oyster Co.; NC State handled the energy harvester; and ECU WRC would manage the data telemetry with their existing online dashboard
Wentzel and Taylor’s developed a new sensor platform, a watertight and modular system that included eight sensor wells. Six of the wells contained removable probes for oxidation-reduction potential, or ORP, dissolved oxygen, temperature, conductivity, pH, and pressure. The remaining two wells were for the data transmission and power input. Once the device was built and waterproofed, the team added a layer of biofouling spray and a copper cage around the protruding sensors to further protect the instrument from the elements.
During initial testing of the new sensor platform prototype, the team discovered that Blossie Creek was slightly out of range, at almost nine miles away, for a reliable, strong connection to the WRC receiver at CSI. The solution was to install an additional solar-powered relay node halfway between the oyster farm and CSI to help bridge the network connection and thus efficiently supply the customized online dashboard with real-time data for Hopkins and Clower.
The final step of the system construction was to integrate an energy harvester that could supply power to the sensor platform, thereby extending its battery life. After careful consideration of site characteristics, including the water flow rate in Blossie Creek, the team decided the coaxial turbine developed by the Intelligent Structures and Systems Research Lab and the Engineering Mechanics and Space Systems Lab at NC State would best suit their needs. The coaxial turbine utilizes water currents to rotate external blades which in turn spins a generator inside the device. Simply speaking, the power produced by the generator would charge the sensor platform.
The sensing platform was deployed by Wentzel (pictured) and Taylor in Blossie Creek earlier this spring. It samples and transmits data every ten minutes.
Upon complete assembly, the sensor platform and its energy harvester were deployed in Blossie Creek in Spring 2026 and are set to sample and transmit data every ten minutes. Initial results indicate the prototype is not only viable but also helpful to oyster cultivators at Herring Shoal Shellfish Co. There are, however, tweaks that will need to be made. Ongoing adjustments include changes to the data dashboard, including a public-facing component, and turbine design optimization to reliably capture Blossie Creek’s current resource.
“Ultimately, this [project] is about turning accessible technology into something that can deliver real, usable data in real time and support the people who rely on these environments every day,” says Wentzel.
While the system’s hydrodynamic efficiency isn’t yet maximized, and it could certainly be more durable, it already works to meet the needs of a community partner. Because of its small-scale application, optimization is not required for the system to serve its purpose. Though there is still much to be done before the sensor platform setup is “perfect”, the project is a clear example of developing practical marine energy usage across NC working waterfronts.
The preceding story first appeared in the Spring 2026 edition of CoastLines, published in June.
Based at the Coastal Studies Institute (CSI), the North Carolina Renewable Ocean Energy Program (NCROEP) advances inter-disciplinary marine energy solutions across UNC System partner colleges of engineering at NC State University, UNC Charlotte, and NC A&T University. Click on the links below for more information.
ECU's Integrated Coastal Programs (ECU ICP) is a leader in coastal and marine research, education, and engagement. ECU ICP includes the Coastal Studies Institute, ECU's Department of Coastal Studies, and ECU Diving and Water Safety.
The ECU Outer Banks campus is home to the Coastal Studies Institute.
