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February 2016 Issue

Evaluating Environmental Risks for Marine Renewable Energy
James Joslin
Proposals to deploy devices that can convert the power in ocean waves and tides to renewable electricity inevitably raise a corollary question: Will these devices cause environmental harm?

Even for renewable energy projects, precaution is certainly warranted given the existing stresses that human activities have placed on the oceans. The initial answer to the question was: We can tell you after we deploy pilot projects. This, while honest, required regulatory agencies to shoulder significant risk in case a pilot project did cause environmental harm. This resulted in a “chicken and egg” problem in which device deployment was recognized as the best way to reduce uncertainty around environmental risks, but deployment could not be authorized if uncertainty was high.

The solution has been “adaptive management” for project proponents and regulatory agencies to responsibly identify significant risks and retire those proven to be insignificant.

Good news for proponents of development? Sort of. Environmental risks range from individual marine animal interactions with a device to ecosystem interactions. While adaptive management allows project developers and regulators to prioritize the highest risk interactions and bite off manageable chunks of the problem at a single time, the environmental monitoring solution chosen by the project developer needs to be nimble and adaptable.

Further, answering these questions often requires multiple sensors to act in concert, as no single data stream is likely to provide the information required to identify or retire the highest priority risks. Oceanographic sensing capabilities have advanced tremendously over the past decade, with cabled observatories providing unparalleled data from the oceans. Unfortunately, acquiring these data have obvious and hidden costs. Let’s say, for example, that a tidal energy project developer wants to address the risk of marine animal collision with an operating turbine. This might include active sonars and passive acoustics for animal detection, paired with optical cameras for short-range species identification. Running such a system continuously for a year would produce over 1 petabyte of data, or a metric ton of terabyte hard drives.

Because of these challenges, to date, the small number of marine energy projects that have successfully deployed have relied on complex custom monitoring systems. These are often outside the core project or technology development pathways for marine renewable energy.

Under the auspices of the Northwest National Marine Renewable Energy Center (NNMREC), researchers at the University of Washington have been developing innovative methods to address these industry needs for advanced marine monitoring capabilities. From the Center’s foundation in 2008 to 2013, Professors Brian Polagye and Jim Thomson deployed and maintained sea spiders equipped with an evolving suite of autonomous instrumentation in Puget Sound, Washington. This effort started as a tidal energy resource assessment and was continued to establish a baseline of the environmental conditions at the site for a future tidal energy deployment. During this same period, Thomson developed the SWIFT drifter to collect data on surface waves, currents and acoustics. These sea spiders and SWIFT drifters have also been deployed at marine energy sites in Alaska, Hawaii, Oregon and Chile.

In 2013, I was part of a team that set out to build a cabled, easily recoverable instrumentation platform designed for marine energy monitoring. Dubbed the Intelligent Adaptable Monitoring Package, or iAMP, this system leverages our previous experience deploying and maintaining instrumentation at marine energy sites along with technology from the cabled ocean observatories developed by the UW Applied Physics Laboratory (APL-UW).

As a cabled platform, the iAMP allows for real-time monitoring and data processing. The power and data backbone can accommodate most oceanographic sensors (pretty much anything that requires DC power and can communicate over a cable). Integration of these instruments and real-time data processing enables intelligent event triggering and target handoff that reduce data storage costs incurred by continuous archiving of sensor data.

To simplify the maintenance operations associated with a cabled system (and the need for system refinement through the adaptive management process), the iAMP includes a wet-mate power and fiber connector and is deployed to a subsea docking station by an ROV called the “Millennium” Falcon, built around a stock Saab Seaeye Falcon inspection-class ROV. The “Millennium” system is customized for iAMP deployments at tidal and wave energy sites, for example, with increased thrust capability and a payload bay to hold the iAMP securely until it can be connected to the docking station.

From January to March 2016, the iAMP is scheduled for deployment at the PNNL Marine Science Laboratory in Sequim Bay, Washington, for an endurance test and to evaluate target triggering algorithms. In 2016 and 2017, an autonomous version of the iAMP will be developed for sites without cabled infrastructure to allow for continuity of methods between pre- and post-installation monitoring at marine renewable energy projects.

MarineSitu, a new company spinoff from the University of Washington, has been founded to offer these environmental monitoring capabilities. Providing services to deploy instrumentation and collect information to identify and retire risks will reduce the cost and complexity of environmental monitoring. Companies like ours are in a unique position to address the evolving needs of a vibrant and sustainable marine renewable energy industry.

James Joslin received his doctorate from the University of Washington and his master’s and bachelor’s degrees from Dartmouth College. As a researcher at APL-UW and a founder of MarineSitu, he works on both the technology and business development of the iAMP and other marine monitoring technologies. Professor Brian Polagye and Dr. Andy Stewart are co-founders of MarineSitu.

2017:  JAN | FEB

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Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.