July 13, 2022
Research Highlight

Triton Field Trials Special Issue Makes a Splash for Marine Energy

Triton researcher prepares an underwater camera for deployment during the Triton Field Trials.

Triton researcher Lenaig Hemery prepares an underwater camera for deployment during the Triton Field Trials changes in habitat research. 

(Photo by Alicia Amerson | Pacific Northwest National Laboratory )

Every scientific research project has a mission. The Triton Initiative’s mission is to help reduce barriers to testing and permitting for commercial marine energy systems through the research and development of environmental monitoring technologies and methods.

The Department of Energy Water Power Technologies Office's Triton Initiative supports industry partners, innovates technologies, and performs field tests to explore monitoring methods and instrumentation optimization to help the marine energy industry better understand possible environmental effects. Proactive environmental monitoring support for the marine energy industry drives Triton. Each research project within Triton aims to expand knowledge bases addressing uncertainty around the potential impacts of this emerging renewable energy resource. 

At its core, Triton strives to help facilitate deployment of new marine energy solutions that will expand clean energy production and reduce carbon emissions. Critical to marine energy becoming a significant contributor to the United States’ energy portfolio is early technical support for the industry as it evolves from the testing phase to full-scale commercialization. Many devices have been designed and refined to harness power from waves, tides, currents, and more. However, one of the most significant barriers to deploying them is regulatory consenting and permitting—an extensive but necessary step in the safe, sustainable, and environmentally responsible advancement of marine energy. The uncertainty surrounding potential harmful impacts associated with introducing these novel systems into coastal, marine, and riverine habitats has resulted in expensive and rigorous environmental monitoring requirements prior to successfully deploying energy converters. One way to help the regulatory process move as smoothly as possible is to provide relevant data to advance understanding of potential environmental effects across marine energy device types and locations. To fill knowledge gaps around impacts, developers and regulators need recommendations on scientifically validated instruments and methodologies to collect and use data to inform permitting decision makers about a given device in a given setting. The Triton Field Trials, or TFiT, was created to address this need. 

Moving the needle with Triton Field Trials 

For the past four years, Triton has focused much of its research efforts on TFiT, a suite of projects that evaluated and field-tested commercially available sensors and technologies used to monitor several areas of environmental concern for marine energy regulators. The driving purpose of this work is to enable transferability and promote more consistent environmental data collection and analysis methodologies around marine energy devices. Transferability is the use of information from one location or device to inform the assessment of another. Recently, these research efforts culminated in the publication of 10 peer-reviewed research papers in a special issue in the Journal of Marine Science and Engineering.

Cost and lack of standardization are two significant challenges TFiT aimed to resolve. Initial start-up expenses are often too high for marine energy device developers to afford developing a viable technology and also conduct necessary environmental monitoring. Additionally, the lack of standard practices for monitoring around existing devices and settings make data sharing difficult, thus intensifying requirements for site-specific monitoring. In response, TFiT sought to identify the most effective and consistent methods for gathering relevant data needed to assess risk and uncertainty at various marine energy sites, with cost and data transferability in mind. 

TFiT specifically addressed four main stressors of concern as identified in the OES-Environmental "2020 State of the Science Report," including changes in habitat, collision risk, electromagnetic fields (EMF), and underwater noise. Beginning with in-depth literature reviews, TFiT researchers explored the standard sensors and methods used by 118 marine energy projects worldwide to assess these stressors. The approaches and technologies deemed most promising based on several criteria—such as cost, commercial availability, reliability, and others—were then tested at several field sites around the United States. Each site had diverse physical and biological characteristics, as well as resource conditions representing the diversity of marine energy deployment settings, with some sites including operational tidal turbines or wave energy converters. Ultimately, TFiT's research, field campaigns, and industry outreach informed recommendations for instrumentation and methodologies based on field trials at open ocean, riverine, and tidal project sites in Alaska, Washington, New Hampshire, and California.

Triton Field Trials locations and device types.
Technology and field trial locations and device types for each stressor studied under Triton Field Trials from Eaves et al., 2022. (Illustration by Stephanie King| Pacific Northwest National Laboratory)

As part of this effort, Triton researchers also identified opportunities to holistically assess marine energy environmental monitoring. TFiT included a preliminary investigation of anthropogenic light as a potential environmental consideration, reviewed predictive modeling methods, discussed the value of communications for marine energy projects, addressed setting-specific spatial and temporal data collection needs, and conducted discussions on sustainability and life cycle assessments. 

The 10 peer-reviewed papers are a part of a special issue in the Journal of Marine Science and Engineering titled "Technology and Methods for Environmental Monitoring of Marine Renewable Energy." The papers within this special provide open-access, peer-reviewed recommendations to promote consistent, transferable, and cost-efficient environmental monitoring data collection and analysis for the marine energy industry. The papers include: 

The scientists’ perspective

In the introductory paper of the special issue, environmental scientist and Environmental Research and Instrumentation Development Sub Activity lead with the Water Power Technologies Office Marine Energy program, Samantha Eaves, underscores the necessity of a project like TFiT. She explains how the adoption of consistent environmental monitoring methodologies by marine energy developers will help the industry avoid a trial-and-error approach to monitoring and enable more efficient processes to progress the industry. The goal of TFiT is to eliminate the need for extensive data collection at future deployments using transferability of information. The special issue recommendations are a tangible, results-based product used to achieve that goal. Eaves adds, “In the absence of international or industry accepted standards for environmental data collection, the recommendations from TFiT are a key step in promoting data collection consistency.”

Quote about the importance of Triton over a fiedlwork image.
(Graphic by Rachael Gallodoro | Pacific Northwest National Laboratory)

Marine scientist Alicia Amerson emphasizes that this is the first large-scale set of environmental monitoring methodology recommendations for the marine energy industry produced from field tests in the United States. "The diversity and complexity of each environment where marine energy is proposed presents several challenges," she explains. Amerson adds, "applying a field approach to addressing the uncertainty of marine energy impacts is useful for discussions among regulators, industry, academia, and federally funded institutions. TFiT demonstrates the need for environmental monitoring data to be collected consistently and transparently for the benefit of all." 

Collision risk is a particularly poignant topic because the risk of fish colliding with current energy converters, like tidal turbines, is one of high uncertainty and substantial concern for regulatory stakeholders and the public alike. Fish biologist Garrett Staines expresses, "this research is important to the general success of marine energy because it highlights sensor technology capabilities and data collection methods that researchers can leverage now and in the future." He explains that collision risk is currently considered a perceived risk based on a theoretical understanding of possible interactions. Risk cannot be concretely defined until there is a large enough pool of empirical data around operational turbines to understand the likelihood of collision in a variety of settings and scenarios. Staines notes, "continued progression on how to best monitor for collision risk along with data analysis on interactions will swing the balance from perceived risk to defined risk. Defined risk can be prevented or mitigated and addressed by technology developers, allowing for faster and iterative testing that brings marine energy closer to commercialization." Staines's paper on the use of acoustic cameras to inform understanding of collision risk offers practical applications to collect the necessary data for quantifying these risks.

TFiT’s EMF stressor research helped reinforce the value of baseline monitoring to assess post-installation impacts. "Better understanding of the background magnetic fields associated with cables and marine energy devices will help regulators understand what impact the introduction of these systems might have on the environment," says ocean engineer Molly Grear. In reference to her paper on monitoring of electromagnetic fields in a tidal environment, she adds, "knowledge gaps still exist surrounding the impacts of EMF on marine life.” The development of consistent instrumentation to measure magnetic fields from the variety of cable types and designs connected to marine energy applications is important for knowing potential exposure levels for marine life to better assess these impacts.  

For stressors like changes in habitat, guidance on monitoring methods is particularly important. Benthic ecologist Lenaïg Hemery explains, "there is an overwhelming number of possibilities and technologies for monitoring changes in habitats in relation to marine energy; I believe the recommendations from our review and field trials will aid in figuring out what to use, when, and why." Hemery's review of technologies for monitoring benthic and pelagic habitats at marine energy sites coupled with a use case for a 360-degree camera at an energetic wave site offers tools to assess options for studying habitat changes based on site-specific needs and challenges. Hemery adds, "these recommendations are intended to be used by all in the marine energy community: regulators, developers, researchers, environmental consultants—you name it.” They will help anyone in the process better understand how researchers gather and assess habitat data and the best tools for the job at a given site.

Triton researchers deploy a hydrophone to study underwater noise.
Triton researchers deploy a drifting hydrophone to characterize underwater noise around a tidal turbine in Portsmouth, New Hampshire. (Photo by Joe Haxel | Pacific Northwest National Laboratory)

These recommendations play a unique role in the underwater noise research area, which has an existing international technical specification that provides standard approaches for quantifying marine energy-associated noise. Triton deployed hydrophones to gather acoustic (sound) data around a deployed turbine in a high-energy port setting. This opportunity provided experience with the application of the International Electrotechnical Commission 62600-40 Technical Specification for characterizing acoustics around marine energy systems. "TFiT contributed an initial use case of this particular technical specification for monitoring acoustics emitted from marine energy converters using commercial-off-the-shelf hydrophone technology with modifications for applications in high-energy current environments," says marine scientist and Triton principal investigator Joe Haxel. The results from these underwater noise field trials provide a valuable use case and offer recommendations for readily available, low-cost monitoring options for characterizing underwater noise at tidal project sites.

Not only does Triton present technical methods, results, and recommendations for each of the primary stressors researched under the TFiT project, it acts as a toolkit for practical considerations to address remaining knowledge gaps and bolster impact.

While not currently included under the umbrella of marine energy stressors, Triton assessed anthropogenic light as a potential stressor to examine for marine energy applications. "As part of the mission to reduce carbon dependency, we want to minimize and/or prevent any harmful disturbances to wildlife and the environment," says Amerson. By informing marine energy developers and regulators on this topic now through a review of ecological impacts of marine energy lighting, proactive steps can be taken to reduce anthropogenic light impacts for the future installation of large arrays of marine energy devices.

The special issue also includes predictive modeling as a tool for tackling the challenge of addressing uncertainty. Due to the lack of empirical data and in-water deployments of marine energy devices, predictive modeling is a powerful tool that can be used to disentangle the complex interactions between marine energy devices and the environment. In a review of modeling techniques and information needs for estimating environmental effects and quantifying risks, predictive modeler Kate Buenau and her team identify primary modeling approaches and common techniques used across the range of marine energy stressor interactions. They provide insights into the roles and limitations of models in assessing uncertainty and risk.

Painting the big picture

The scope of the special issue extends beyond the initial mission of methods evaluation to include considerations for marine energy sustainability, as well as a framework for effective communications and engagement.

The three pillars of marine energy sustainability: environment, economy, and society.
The three pillars of sustainability and sustainable energy applied to marine energy from Amerson et al., 2022. (Illustration by Stephanie King | Pacific Northwest National Laboratory)

Through TFiT’s research, Triton identified several gaps regarding the implementation of environmental monitoring practices and long-term systematic relevancy. Due to the nascent nature of marine energy systems and lack of widespread environmental monitoring, there is a need for site-specific spatial and temporal monitoring, along with inclusion of life cycle sustainability assessments, to comprehensively address environmental uncertainty. Understanding the impacts of marine energy goes far beyond expanding datasets from field deployments. While this special issue only scratches the surface, it encourages discussions about diversity and inclusion, energy equity, and how Triton's work connects within the context of the environment, economy, and society—all to help inspire marine energy research to consider broader impacts and address them when possible.

The marine energy industry has a unique opportunity to consider the nuances of introducing an emerging renewable energy resource. Researchers must understand regulatory needs, regulators need to understand the approaches and outputs of research efforts, and the public needs to understand why it all matters. Overcoming disconnects between science, policy, and the public can be resolved through effective communication. While communications and social considerations are not typically a component of traditional research or engineering processes, complementary discussions about communication and outreach strategies, energy equity implications, and sustainability assessments can help paint a bigger picture of what a future with marine energy could look like.

Science is about asking pointed questions, considering all possibilities, and filling knowledge gaps. The Triton Initiative advances a specific pool of knowledge essential to making marine energy possible. And the Triton team hopes the recent TFiT special issue has a significant ripple effect in realizing renewable ocean-derived energy for the United States. 

Triton nautilus shell



Written by Cailene Gunn.

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Published: July 13, 2022