Sea Technology

JUN 2018

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www.sea-technology.com June 2018 | ST 49 Dr. Andrea E. Cop- ping is a senior re- search scientist at Pacific Northwest National Labo- ratory's Marine Sciences Labora- tory in Sequim, Washington, and a Distinguished Research Fellow at the University of Washington. Her research is on environmental effects from wave, tidal, offshore wind, ocean current and riverine energy installations and how installations may influence technology development. M arine renewable energy (MRE) is expected to become a key player in the U.S. and international renewable energy portfolio. It's still a relative "youngster," with tech- nology development and testing of wave and tidal devices occurring in just the past 10 to 15 years. The most developed technologies in- clude tidal turbines and wave ener- gy converters (WECs). While these technologies can significantly con- tribute to energy production, the in- dustry has a responsibility to protect marine animals, their habitats and essential ecosystem services. As technologies are tested and evaluated, regulators are requesting data to investigate impacts to the marine environment. But collect- ing significant amounts of pre- and post-installation monitoring data in turn impacts this young industry— posing substantial costs, delaying permits and threatening its financial viability. A solution is to leverage data from existing marine technol- ogy deployments. MRE development requires data collection to satisfy licensing re- quirements. Data from existing marine technology deployments, versus exhaustive data collection, could bolster knowledge about potential effects of wave and tidal device deployments. An example is buoys, platforms, piers and docks. Their hard substrates attract biofoul- ing communities made up largely of invertebrates and algae. These structures function as fish-aggregat- ing devices or artificial reefs. Data from these structures provide un- derstanding that no obvious harm would occur from MRE devices, but some changes in nearby popula- tions is possible. Another example is export ca- bles for MRE installations that gen- erate electromagnetic fields (EMF) that could affect the orientation, navigation or hunting ability of sen- sitive species. EMF signatures are not new to the marine environment. Many existing undersea cables used for power and telecommunications, bridges, tunnels and offshore wind farms emit measurable electro- magnetic signatures. These existing cables on the seafloor can better inform researchers of impacts on marine animals from exposure to MRE export cables. Another example is that anthro- pogenic noise has been shown to affect marine animal communica- tion, navigation and hunting. The sounds emitted by operational MRE devices are found to be of lower amplitude than sounds made by other marine industries like com- mercial shipping. But while the impacts of some MRE components can be deter- mined with existing data, there isn't typically an apples-to-apples comparison for other components; for example, conventional hydro turbines and ship propellers are far more dangerous to marine species than tidal turbines. Understanding how marine mammals, fish, div- ing seabirds and sea turtles behave around these devices may be the key to determining whether they will be harmed. WECs and associated floating tidal devices could also introduce the risk of marine animal interac- tion with mooring lines and draped electrical cables in the water col- umn. There is concern that large marine mammals can become en- tangled in them, but they are under tension and have no loose ends. This makes entanglement less like- ly than encounters with lost fishing gear or other ropes and nets in the marine environment. There are ecosystem concerns as well. Researchers have found that tidal turbines capture kinetic energy from the movement of water caused by tidal currents, causing devia- tions in water flow and potentially resulting in changes to sediment transport, basin flushing and marine food webs. WECs capture energy from wave propagation and may af- fect shoreline erosion. Both effects appear to be unmeasurably small with the addition of small numbers of turbines or WECs. The path forward for responsibly developing MRE involves key activ- ities. Sharing existing information among developers, regulators and researchers can help accelerate the deployment process. One such in- formation-sharing outlet is Tethys, https://tethys.pnnl.gov, which hous- es all known environmental risk in- formation. The effort to transfer and consistently collect data is under- way through the International Ener- gy Agency's Ocean Energy Systems/ Annex IV, with international partners examining how their learning can inform new projects in their juris- diction and apply to other locations and countries. The industry relies heavily on numerical models that simulate environmental impacts at proposed MRE locations, but better models are needed to more close- ly describe real-world interactions. More importantly, monitoring data from existing and planned projects is needed to calibrate models. Fi- nally, we need strategically planned international research studies to rapidly and accurately build on the existing knowledge base. Govern- ments must help shoulder the fund- ing burden with industry to help move MRE forward as a viable en- ergy resource and industry. ST soap box Harnessing MRE While Protecting the Ocean Environment—Dr. Andrea E. Copping

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