Assessing the effects of marine and hydrokinetic energy development on marine and estuarine resources

Abstract

The world's oceans and estuaries offer enormous potential to meet the nation's growing demand for energy. The use of marine and hydrokinetic (MHK) devices to harness the power of wave and tidal energy could contribute significantly toward meeting federaland state-mandated renewable energy goals while supplying a substantial amount of clean energy to coastal communities. Locations along the eastern and western coasts of the United States between 40° and 70° north latitude are ideal for MHK deployment, and recent estimates of wave and current energy resource potential in the US suggest that up to 400 terawatt hours could be generated, representing about 10% of national energy demand. Because energy derived from wave and tidal devices is highly predictable, their inclusion in our energy portfolio could help balance available sources of energy production, including hydroelectric, coal, nuclear, wind, solar, geothermal, and others. As an emerging industry, MHK energy developers face many challenges associated with the siting, permitting, construction, and operation of pilot and commercial-scale facilities. As the industry progresses, it will be necessary not only to secure financial support and develop robust technologies capable of efficient, continued operation in harsh environments, but also to implement effective monitoring programs to evaluate long-term effects of device operation and assure resource agencies and members of the public that potential environmental impacts are understood and can be addressed. At this time, little is known about the environmental effects of MHK energy generation at pilotor full-scale operational scenarios. Potential effects could include changes to aquatic species behavior from exposure to electromagnetic fields or operational noise; physical interaction of marine mammals, fish, and invertebrates with operating devices or mooring cables; or changes to beach characteristics and water quality from long-term deployment of devices in coastal locations. This lack of knowledge creates a high degree of uncertainty that affects the actions of regulatory agencies, influences the opinions and concerns of stakeholder groups, affects the commitment of energy project developers and investors, and ultimately, the solvency of the industry. To address the complexity of environmental issues associated with MHK energy, PNNL has received support from the Department of Energy Office of Energy Efficiency and Renewable Energy Waterpower Program to develop research and development that draws on the knowledge of the industry, regulators, and stakeholders. Initial research has focused on 1) the development of a knowledge management database and related environmental risk evaluation system, 2) the use of hydrodynamic models to assess the effects of energy removal on coastal systems, 3) the development of laboratory and mesocosm experiments to evaluate the effects of EMF and noise on representative marine and estuarine species, and 4) collaborative interaction with regulators and other stakeholders to facilitate ocean energy devices, including participation in coastal and marine spatial planning activities. In this paper, we describe our approach for initial laboratory investigations to evaluate potential environmental effects of EMFs on aquatic resources. Testing will be conducted on species that are a) easily procured and cultured, b) ecologically, commercially, recreationally or culturally valuable, and c) reasonable surrogates for threatened or endangered species. Biological endpoints of interest are those that provide compelling evidence of magnetic field detection and have a nexus to individual, community, or population-level effects. Through laboratory, mesocosm, and limited field testing, we hope to reduce the uncertainly associated with the development of ocean energy resources, and gain regulatory and stakeholder acceptance. We believe this is the best approach for moving the science forward and provides the best opportunity for successfully applying this technology toward meeting our country's renewable energy needs. During the project, the team will work closely with two other national laboratories (Sandia and Oak Ridge), the Northwest National Marine Renewable Energy Center at University of Washington and Oregon State University, and Pacific Energy Ventures.