Final Report

The tidal energy environmental effects workshop report has been released. The workshop brought together over seventy experts from around the world to establish what is known about environmental effects of tidal energy development and determine high-priority areas for future research. The report lays out a prioritization for environmental effects studies, describes the challenges in trying to close knowledge gaps, and provides recommendations on how to move forward.

Download a copy here.


There is an increasing need to reduce carbon emissions and power the nation from clean renewable sources. Ocean energy can help provide part of the solution. Clean, reliable power can be generated by using turbines in the water column to convert tidal currents into electricity. However, the risk to the marine environment and marine organisms is not well known. The tidal power industry, regulators, and stakeholders need guidance to explore the potential contribution tidal power can make to a renewable energy portfolio. In order to appropriately site and operate tidal power installations, we need to better understand the risks of the technology. This workshop will bring together scientific expertise to assess environmental effects on the marine systems in which tidal power may be generated, to determine risks to marine organisms and communities, to determine the uncertainties associated with our knowledge base, and to recommend future research and monitoring needs.

This workshop follows the successful model used to address the environmental effects of wave energy development, held in 2007 in Newport, OR.


March 22 - 24, 2010
University of Washington
Seattle, Washington
Contact: Brian Polagye (


The Environmental Effects of Tidal Energy Development workshop will be held on the University of Washington campus in Seattle in March 2010. Attendance at the workshop is by invitation only. The goals of the two-day meeting are to:

  1. Develop an initial assessment of the potential environmental effects of installation, operation, and maintenance of tidal power generating devices;
  2. Determine the specific marine organisms and system components that may be affected; and
  3. Develop a general framework of interactions against which specific tidal generation projects might plan their environmental assessments and monitoring programs.

Workshop participants will share their understanding of tidal system effects, invoke the latest research in the area, and contribute to a broad discussion of the potential environmental effects of tidal energy.

The first morning will include plenary talks that provide a common understanding of tidal energy technology and the scientific issues involved. Facilitated breakout groups targeting specific stressors and marine receptors will take up the first afternoon and the following day. These discipline-based groups will generate written summaries that will be collected into a volume of workshop results for wide dissemination.

Many workshop participants may be relatively new to ocean energy; they will bring their expertise and perspectives on vulnerable resources or effects of specific stressors to the discussion. The workshop also will help to make the broader US marine science community aware of the momentum building around tidal energy generation. The community will benefit from understanding the proposed projects and a framework for the ecological context in which they will operate.

This workshop will focus on building capacity to address the potential ecosystem impacts of tidal energy from turbines placed in the water column throughout the US; it will not address policy, details of technology engineering, or the socioeconomic impacts of in-stream tidal energy. Separate meetings to address these topics might be a recommended next step.


Tidal energy is highly predictable and could contribute sizable amounts of renewable power to the electrical grid in selected parts of the country. Nationally, the US Department of Energy is encouraging the development of tidal power, alongside other marine renewables. There are currently a number of proposed tidal energy projects along the US coast. Most projects are pursuing pilot licenses (through the Federal Energy Regulatory Commission or FERC), which allow a site developer to test a limited installation over a period of approximately five years to gain operational knowledge about the technology and environment. Later, sites may be developed for commercial scale power generation, if environmental and technical uncertainties can be addressed.

Pilot projects nearing license application include:

Many stakeholders, regulators and the public are interested in the potential renewable electrical power that tidal energy can contribute, but express significant concerns about the uncertainties surrounding potential environmental effects and other impacts. This workshop will take the first step to systematically address the issues of concern, and will help define a methodology for answering questions about the impact that tidal energy may have on the marine environment and marine organisms. The workshop presentations and discussions will highlight knowledge acquired from undersea cable projects and other existing ocean technologies that have established bodies of literature on environmental impacts, which may be applicable to tidal generation installations.

This workshop will provide an initial opportunity for scientific community to respond to commonly asked questions about the potential impacts of tidal energy generation.


The use of turbines placed in the water column to generate electricity is very young. European countries are leading the world in developing and deploying the technology. In the United States there is a single operational pilot project: a small array of Verdant Power turbines operating in the East River of New York. Expertise in understanding environmental impacts is still in the formative stages and developing the scientific capacity to better understand tidal energy's potential environmental impacts is the primary objective of this meeting.

Invitees to this meeting include scientists with expertise in environmental impacts of tidal energy, as well as those without direct experience in tidal generation effects, but whose expertise will help expand the understanding of effects of tidal turbines on marine systems and marine organisms.


This workshop is generously supported by:

Steering Committee

George Boehlert
Director, Hatfield Marine Science Center
Northwest National Marine Renewable Energy Center, Oregon State University
Andrea Copping
Program Director
Marine Sciences Laboratory, Pacific Northwest National Laboratory
Keith Kirkendall
NOAA Fisheries
Chief, FERC and Water Diversions Branch, Hydropower Division, Northwest Region
Brian Polagye
Research Assistant Professor, Department of Mechanical Engineering
Northwest National Marine Renewable Energy Center, University of Washington
Michelle Wainstein
Washington Sea Grant, University of Washington
Senior Program Coordinator
Sue Walker
NOAA Fisheres
Hydropower Coordinator, Alaska Region