Marine Hydrokinetic Energy

Ocean waves contain tremendous energy potential. Wave power devices extract energy directly from the surface motion of ocean waves. In many areas of the world, the wind blows with enough consistency and force to provide continuous waves along the shoreline.

Hydrokinetic energy is the energy generated by the movement of a body of water. Marine hydrokinetic energy is generated by the ocean’s tides, waves, and currents.

Ocean tidal and current energy can be exploited by building semi-permeable barrages (dam-like structures) across estuaries with a high tidal range. During high tides, barrages allow tidal waters to fill an estuary through sluices which then close when the tide begins to fall. Once the tide is low enough, the stored water is released at pressure through turbines.

Tidal energy may also be harnessed using offshore underwater devices similar to wind turbines. Submerged rotating devices capture energy through the processes of hydrodynamic lift or drag.

The relatively constant flow of ocean currents carries large amounts of water across the earth’s oceans. Technologies are being developed so that this energy can be extracted from ocean currents and converted to usable power. Some of the ocean currents on the Outer Continental Shelf are the Gulf Stream, Florida Straits Current, and California Current.

Wave power devices extract energy directly from the surface motion of powerful ocean waves or from pressure fluctuations below the surface. All wave energy technologies are intended to be installed at or near the water’s surface, in waters more than 40 meters deep. These technologies differ in their orientation to the waves with which they are interacting and the manner in which they convert wave energy into electricity.

Publications

TitleDescriptionYear
Wave and tidal current energy – A review of the current state of research beyond technologyThe oceans of the earth offer vast amounts of renewable energy. Technologies to harness the power of the seas are at an early stage of development. Even the most advances technologies, namely tidal current and ocean wave still face considerable barriers and many obstacles remain. Research, development and innovation can help overcome those barriers. This review provides an overview over the current state of research in the field of ocean energy. In particular, the authors focus on research beyond technology or technological improvements. This article also highlights areas where research gaps exists and where future research efforts should be directed to.2016
Capturing Energy from the Motion of the Ocean in a Crowded SeaIn this study, we used a spatially explicit, open source decision support tool to evaluate wave energy facility development off the U.S. west coast. We then used this output to identify potential conflicts between wave energy facilities and the existing marine uses in the context of marine planning. We found that regions with the highest wave energy potential were distant from major cities and that infrastructure limitations (cable landing sites) restrict integration with the existing power grids. We also identified multiple potential conflicts, including commercial fishing, shipping and transportation, and marine conservation areas. While wave energy generation facilities may be economically viable, we must also incorporate costs associated with conflicts that arise with the existing marine uses.2016
Co-located wind and wave energy farms: Uniformly distributed arraysCo-located wave and wind energy farms can serve to tackle one of the downsides of offshore wind energy relative to its onshore counterpart: the longer non-operational periods. These are partly caused by delays to maintenance tasks due to energetic sea states preventing access. By co-locating Wave Energy Converters (WECs) in an appropriate configuration it may be possible to reduce the wave heights within the wind farm area (shielding effect) and thereby increase the weather windows for maintenance. Previous works analysed the improvements in accessibility obtained by configuring the co-located WECs as a peripheral barrier or interspersed within the farm. However, the former led to an insufficient wave height reduction as the distance to the barrier increased and the latter presented other handicaps, notably in respect of the submarine cable installation and the navigation of workboats. The objectives of this work are: (i) to analyse whether a uniformly distributed array may be more convenient in these respects and (ii) to carry out a comparative economic assessment. This investigation is carried out through a case study at the Horns Rev 1 wind farm by means of a high-resolution spectral wave model. Annual cost savings of up to 900,000 € are found.2016
Are Wave and Tidal Energy Plants New Green Technologies?This study aims at quantifying their various potential environmental impacts. Three tidal stream devices, one tidal range plant and one wave energy harnessing device are analyzed over their entire life cycles, using the ReCiPe 2008 methodology at midpoint level. The impacts of the tidal range plant were on average 1.6 times higher than the ones of hydro-power plants (without considering natural land transformation). A similar ratio was found when comparing the results of the three tidal stream devices to offshore wind power plants (without considering water depletion). The wave energy harnessing device had on average 3.5 times higher impacts than offshore wind power. On the contrary, the considered plants have on average 8 (wave energy) to 20 (tidal stream), or even 115 times (tidal range) lower impact than electricity generated from coal power. Further, testing the sensitivity of the results highlighted the advantage of long lifetimes and small material requirements. 2016
Establishing a legal research agenda for ocean energyThe literature on ocean energy has, to date, largely focused on technical, environmental, and, increasingly, social and political aspects. Legal and regulatory factors have received far less attention, despite their importance in supporting this new technology and ensuring its sustainable development. Building on the social sciences research agenda developed by the International network for Social Studies of Marine Energy (ISSMER) and published in Energy Policy, a complementary agenda for legal research linked to ocean energy was set out. Key directions for future research structured around the core themes of marine governance: (i) international law; (ii) environmental impacts; (iii) rights and ownership; (iv) consenting processes; and (v) management of marine space and resources were identified.2016
Resource assessment for future generations of tidal-stream energy arrayshe tidal-stream energy resource of the Irish Sea, a key strategic region for development, was analyzed using a 3D hydrodynamic model assuming existing, and potential future technology. Three computational grid resolutions and two boundary forcing products were used within model configuration, each being extensively validated. A limited resource (annual mean of 4 TJ within a 90 km2 extent) was calculated assuming current turbine technology, with limited scope for long-term sustainability of the industry. Analysis revealed that the resource could increase seven-fold if technology were developed to efficiently harvest tidal-streams 20% lower than currently required (SV > 2 m/s) and be deployed in any water depths greater than 25 m. 2015
Catching the Right Wave: Evaluating Wave Energy Resources and Potential Compatibility with Existing Marine and Coastal UsesThe aim of this study is to explore the issue of the provision of benefit packages to local fishing communities and financial compensation measures for fishermen who may be impacted by MRE projects. Semi-structured interviews were conducted with fourteen fishermen from three separate case study sites around the island of Ireland where MRE projects were being developed. In addition, ten company fisheries liaison officers (CFLOs) who have worked on MRE projects in the UK and Ireland were also interviewed. The interviews were analysed under the headings of local employment, benefits in kind, compensation and community funds and ownership of projects. Analysis shows that there is uncertainty among fishermen over whether they would benefit or gain employment from MRE. 2016
2014 JRC Ocean Energy Status ReportThis report stems from the need of monitoring the evolution of the ocean energy technology, industry and market in Europe, with an eye at its global development. It aims to portray the state-of-play of the sector, key achievements, and mechanisms that have been put in place to overcome documented gaps and barriers in the sector towards commercialization.2015
Hydrokinetic energy conversion systems: A technology status reviewHydrokinetic energy conversion systems are the electromechanical devices that convert kinetic energy of river streams, tidal currents, man-made water channels or waves into electricity without using a special head and impoundment. This new technology became popular especially in the last two decades and needs to be well investigated. In this study, the hydrokinetic energy conversion systems were reviewed broadly. They have been categorized into two main groups as current and wave energy conversion devices. Their technology, working principles, environmental impacts, source potential, advantages, drawbacks and related issues were detailed.2015
The challenging life of wave energy devices at sea: A few points to considerWave power devices offer great prospects for the marine renewable energy sector. But in comparison to wind energy, wave power is still in its infancy, mainly prototype-based, with technological gaps akin to those experienced in the wind sector some 15 years ago. Several aspects that did not seem significant at a first glance in the design phase, such as the interaction with the marine environment, turned out to be important when the first prototypes were put in the water. In fact, these devices have to face great challenges once at sea and several prototypes have not survived. Firstly, ocean waves are not such an innocuous, predictable flow of water and secondly, life thrives in the ocean. Wave power devices are perfect artificial reefs suitable for algal growth and colonization by many species. And they will have to sustain harsh conditions for over two decades while producing energy. For obvious reasons, there is a lack of existing literature on the subject. In this short review we address a simple question: how tough will the life of wave power devices at sea be? The answer is based on available evidence. 2014
Potential Sites for Tidal Power Generation: A Thorough Search at Coast Of New Jersey, USAThe current paper makes a thorough search for potential sites for actual tidal power generation along the entire shorelines of NJ and partial coast of New York, with special attention to locations near transportation infrastructures, and it evaluates their power density, surface area, water depth, distance to environmentally sensitive zones, etc. Based on results, the approaches for a high-resolution survey for MHK energy are also summarized and their future development is discussed.2014
High-resolution survey of tidal energy towards power generation and influence of sea-level-rise: a case study at coast of New Jersey, USAThis paper first reviews the advance in assessment of tidal energy, in particular marine hydrokinetic (MHK) energy, and discusses involved challenges and necessary approaches, and then it makes a thorough survey as an illustrative case study on distributions and top sites of MHK energy within the Might-Atlantic-Bight (MAB) with emphasis on the New Jersey (NJ) coastlines.Data with best available accuracy for coastlines, bathymetry, tributaries, etc. are used, meshes as fine as 20 m and less for the whole NJ coast are generated, and the unstructured grid finite volume coastal ocean model (FVCOM) and high performance computing (HPC) facilities are employed. Besides comparison with observation data, a series of numerical tests have been made to ensure reliability of the modeling results. A detailed tidal energy distribution and a list of top sites for tidal power are presented. It is shown that indeed sea-level-rise (SLR) affects the tidal energy distribution significantly. With SLR of 0.5 m and 1 m, tidal energy in NJ coastal waters increases by 21% and 43%, respectively, and the number of the top sties tends to decrease along the barrier islands facing the Atlantic Ocean and increase in the Delaware Bay and the Delaware River. On the basis of these results, further discussions are made on future development for accurate assessment of tidal energy.2014
Global Review of Recent Ocean Energy ActivitiesThis article focuses on the latest developments and projects in ocean energy - in particular, open-sea testing facilities set up by several countries as a measure to encourage deployment and streamlining procedures. In addition, the article highlights the importance of collaborative research and development on ocean energy projects and the unique role of the Ocean Energy Systems Implementing Agreement as an intergovernmental organization promoting the use of ocean energy (wave, marine currents, tidal, ocean thermal gradients and salinity gradients) for energy extraction.2013
Global Status and Critical Developments in Ocean EnergyThis report compiles five Ocean Energy System (OES) sponsored articles together into a single volume as a reference source, which records the recent developments in ocean energy in OES countries. The OES is an intergovernmental collaboration between 20 member countries (as of Feb 2013) with the purpose of advancing research, development and demonstration of conversion technologies to harness energy from all forms of ocean renewable resources, such as tides, waves, currents, temperature gradient (ocean thermal energy conversion and submarine geothermal energy) and salinity gradient for electricity generation, as well as for other uses, such as desalination, through international cooperation and information exchange.2013
Environmental Effects of Hydrokinetic Turbines on Fish: Desktop and Laboratory Flume StudiesThis collection of three reports describes desktop and laboratory flume studies that provide information to support assessment of the potential for injury and mortality of fish that encounter hydrokinetic turbines of various designs installed in tidal and river environments. Behavioral responses to turbine exposure also are investigated to support assessment of the potential for disruptions to upstream and downstream movements of fish. 2012
Catching the Right Wave: Evaluating Wave Energy Resources and Potential Compatibility with Existing Marine and Coastal UsesIn this study, the authors developed a decision-support tool to assist siting wave energy facilities, which allows the user to balance profitability with the need to minimize conflicts with other ocean uses. Their wave energy model quantifies harvestable wave energy at local, regional, and global scales and evaluates the net present value (NPV) of a wave energy facility based on a capital investment analysis. An application of the model and compatibility analysis on the west coast of Vancouver Island, British Columbia, Canada found that wave power and harvestable wave energy gradually increase offshore as wave conditions intensify. However, areas with high economic potential for wave energy facilities were closer to cable landing points because of the cost of bringing energy ashore and thus near to shore areas that support a number of different human uses. The authors believe their tools will help decision-makers explore alternative locations for wave energy facilities by mapping expected wave energy NPV and helping to identify sites that provide maximal returns yet avoid spatial competition with existing ocean uses.2012
An Overview of Ocean Renewable Energy TechnologiesOcean energy is a term used to describe renewable energy derived from the sea, including ocean wave energy, tidal and open-ocean current energy (sometimes called marine hydrokinetic energy), tidal barrages, offshore wind energy, and ocean thermal and salinity gradient energy. This paper highlights the technology development status of various energy conversion technologies.2010

Tools

NameDescription
Estimation of tidal power potentialSeveral approaches can be used for estimating tidal power potential. From a theoretical point of view, others have shown that the problem can be reduced to a single or multiple boundary problem with simple geometry where each case has a well-defined maximum power potential. From a practical point of view, the potential can be approximated from the ambient flow. Questions naturally arise whether the theoretical approach can be applied to a typical field-scale problem, and whether the practical approach has any validity. In order to provide more insight into these questions, form drag representing tidal turbines has been introduced into a numerical flow model. This is an unstructured grid model with an implicit treatment of wetting and drying that has been shown to be robust, accurate, and efficient for highly irregular coastal ocean environments and is well suited for this problem. The field site that has been examined is Minas Passage in the Bay of Fundy which provides an interesting practical perspective for this problem. In the end, only a fraction of the theoretical maximum power potential can be realized in practice because of physical constraints on the maximum form drag for tidal turbines.
WEC-Sim: The Open-Source Wave Energy Converter SimulatorWEC-Sim (Wave Energy Converter Simulator) is an open-source wave energy converter (WEC) simulation tool. The code is developed in MATLAB/SIMULINK using the multi-body dynamics solver SimMechanics. WEC-Sim has the ability to model devices that are comprised of rigid bodies, power-take-off systems, and mooring systems. Simulations are performed in the time-domain by solving the governing WEC equations of motion in 6 degrees-of-freedom as described in the WEC-Sim Theory Manual. The WEC-Sim project is funded by the U.S. Department of Energy’s Wind and Water Power Technologies Office and the code development effort is a collaboration between the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL).
Marine and Hydrokinetic Technology Database, U.S. Department of EnergyThe U.S. Department of Energy’s Marine and Hydrokinetic Technology Database provides up-to-date information on marine and hydrokinetic renewable energy, both in the U.S. and around the world. The database includes wave, tidal, current, and ocean thermal energy, and contains information on the various energy conversion technologies, companies active in the field, and development of projects in the water. Depending on the needs of the user, the database can present a snapshot of projects in a given region, assess the progress of a certain technology type, or provide a comprehensive view of the entire marine and hydrokinetic energy industry.
Marine and Hydrokinetic Atlas, National Renewable Energy Laboratory (DOE)The Energy Department’s National Renewable Energy Laboratory incorporated the data from the wave resource assessment into its U.S. Renewable Resource atlas, where viewers can pan, zoom, and filter through graphically displayed data layers. The atlas includes data about wave energy (e.g., wave hindcast direction and wave power density) and ocean thermal energy conversion including sea surface temperatures and cold water depth. In the future, 30 years of wave and weather data will be incorporated into the database to inform technological requirements and risks associated with wave energy development projects.
2011 Marine and Hydrokinetic Device Modeling Workshop Summary ReportThe purpose of this workshop was to provide a forum for numerical modeling experts, from industry, national laboratories, the Department of Energy, and academia, to identify areas where improvements in numerical modeling technologies are possible, and which improvements can provide maximum benefit to the marine and hydrokinetic industry. During the workshop, three priority action items for improving the present set of numerical modeling tools were identified: (1) provide benchmark experimental results that can be used to validate numerical models; (2) develop a computationally efficient numerical method that can accurately simulate non-linear interactions between marine and hydrokinetic devices and the wave and current environments, in which the devices operate; and (3) develop systems-level engineering modeling approaches that integrate different disciplines, such as power systems, hydrodynamics, and structures into a single numerical modeling package.
Tethys DatabaseTethys is a publicly available searchable online database of environmental effects information developed by the Pacific Northwest National Laboratory to support the U.S. Department of Energy’s Wind and Water Power Program. It houses scientific literature pertaining to the environmental effects of marine energy systems, as well as metadata on international ocean energy projects and research studies. The primary function of Tethys is to facilitate data sharing and the exchange of information on the environmental effects of marine hydrokinetic and offshore wind technology. In addition to the Knowledge Base, Tethys supports a Map Viewer website which compiles documents, U.S. permitting sites, and international project sites and research studies that are associated with a geographic location. This view allows panning and zooming, while results can be narrowed by keyword searches.

Projects

TitleDescriptionYear
Harnessing wave energy to light up coastal communitiesOscilla Power develops a wave energy converter sturdy enough for the ocean, practical enough for the grid. 2016
Calming the Waters: The Impact of Turbulence on Tidal Energy SystemsNew research is helping the emerging tidal energy industry learn from their counterparts in the wind industry. By considering the effects of atmospheric turbulence when developing turbine designs, the wind industry has lowered the cost of energy to record lows and deployed turbines broadly across much of the nation.2016
Not Just Riding the Waves, These Competitors Seek to Harness Their EnergyNine finalists were named in the Department of Energy’s Wave Energy Prize competition awarding technologies most likely to make a commercial reality out of wave energy. Proposed projects include barges on the ocean surface and bobbing buoy-like devices to air bags tethered to the sea floor. Three winners, to be announced November, will receive grants of $1.5 million for first place, $500,000 for second and $250,000 for third. The money will be used as seed capital to build demonstration projects, which could attract private investment. The technologies will be judged on how much the project costs per meter to build relative to how much power it generates.2016
Plugging into the Gulf Stream?The Gulf Stream passes as close as 12 miles off Cape Hatteras carrying more water than all the rivers on Earth. A team of researchers and scientists from the Coastal Studies Institute, N.C. State University and the Institute of Marine Sciences in Morehead City has been studying for the last two years whether all that water could be used to create electricity. Whether the Gulf Stream can be utilized as an energy resource is still up in the air. While there are several hurdles that must be crossed before energy will surge from the waters of the Atlantic Ocean the research team is conducting engineering and biological assessments of using the Gulf Stream off Cape Hatteras as a source of hydrokinetic energy. 2015
Energy Department Awards $7.4 Million to Develop Advanced Components for Wave and Tidal Energy SystemsThe Energy Department announced four entities selected to receive $7.4 million to spur innovation of next-generation water power component technologies, designed for manufacturability and built specifically for marine and hydrokinetic (MHK) systems. The projects will address technical challenges in three areas: advanced controls, crosscutting power take-off (PTO)—which converts mechanical motion into electrical power—and innovative structures. Waves, tides, and ocean currents represent a largely untapped renewable energy resource that could provide clean, affordable energy to U.S. homes and businesses across the country. Advancements in MHK technologies will help these devices effectively and sustainably harness increased amounts of renewable energy from marine environments.2015
UMaine debuting ocean simulator to test sea-bound technologyThe University of Maine’s Advanced Structures and Composites Center has created a miniature indoor ocean that will simulate a stormy ocean to help innovators find out if their creations can withstand the sea's strength. The indoor facility, six years in the making, will be able to simulate waves over 100 feet tall and winds of more than 200 mph on scale models to test products such as offshore wind, tidal and wave energy facilities; aquaculture ventures; oil and gas equipment and critical infrastructure such as ports and bridges.2015
Mapping and Assessment of the United States Ocean Wave Energy ResourceThis project estimates the naturally available and technically recoverable U.S. wave energy resources, using a 51-month database developed especially for this study by NOAA’s National Centers for Environmental Prediction. The assessment determined the total amount of available wave energy resource along the U.S. continental shelf edge, and broke this number into subtotals for the West Coast, the East Coast, the Gulf of Mexico, Alaska, Hawaii, and Puerto Rico. 2011
Assessment of Energy Production Potential from Tidal Streams in the United States - Final Project ReportThis project created a national database of tidal stream energy potential, as well as a GIS tool. Tidal currents are numerically modeled with the Regional Ocean Modeling System and calibrated with the available measurements of tidal current speed and water level surface. The database is published on an interactive website that includes tools to select, query and download the data. The results of the regional assessment show that Alaska contains the largest number of locations with considerably high kinetic power density, followed by, Maine, Washington, Oregon, California, New Hampshire, Massachusetts, New York, New Jersey, North and South Carolina, Georgia, and Florida. 2011
Innovative Wave Power Device Starts Producing Clean Power in HawaiiA prototype wave energy device called Azura, was recently launched and installed in a 30-meter test berth at the U.S. Navy’s Wave Energy Test Site (WETS) in Kaneohe Bay, off the island of Oahu, Hawaii. This pilot testing is now giving U.S. researchers the opportunity to monitor and evaluate the long-term performance of the nation’s first grid-connected wave energy converter device to be independently tested by a third party—the University of Hawaii—in the open ocean. The data from this testing will be used to further optimize Azura’s performance and refine existing wave energy computer simulations, ultimately supporting commercialization of this technology.

Resources

TitleDescriptionYear
Calming the Waters: The Impact of Turbulence on Tidal Energy SystemsNew research is helping the emerging tidal energy industry learn from their counterparts in the wind industry. By considering the effects of atmospheric turbulence when developing turbine designs, the wind industry has lowered the cost of energy to record lows and deployed turbines broadly across much of the nation.2016
Harnessing wave energy to light up coastal communitiesOscilla Power is developing a utility-scale wave energy harvester called the Triton. It's a sturdy system with few moving parts -- rugged enough to stand up to harsh seas with little need for maintenance. This technology shows promise as a means for delivering utility-scale electric power to the grid at a price that is competitive with conventional fossil or renewable technologies.
The team plans more tests with increasingly larger and more sophisticated prototypes. At full scale, each Triton system will be 30 yards wide and will power more than 650 homes.
2016
Innovative Wave Power Device Starts Producing Clean Power in HawaiiA prototype wave energy device called Azura, was recently launched and installed in a 30-meter test berth at the U.S. Navy’s Wave Energy Test Site (WETS) in Kaneohe Bay, off the island of Oahu, Hawaii. This pilot testing is now giving U.S. researchers the opportunity to monitor and evaluate the long-term performance of the nation’s first grid-connected wave energy converter device to be independently tested by a third party—the University of Hawaii—in the open ocean. The data from this testing will be used to further optimize Azura’s performance and refine existing wave energy computer simulations, ultimately supporting commercialization of this technology.2015
Plugging Into the Gulf Stream?The Gulf Stream passes as close as 12 miles off Cape Hatteras carrying more water than all the rivers on Earth. A team of researchers and scientists from the Coastal Studies Institute, N.C. State University and the Institute of Marine Sciences in Morehead City has been studying for the last two years whether all that water could be used to create electricity. Whether the Gulf Stream can be utilized as an energy resource is still up in the air. While there are several hurdles that must be crossed before energy will surge from the waters of the Atlantic Ocean the research team is conducting engineering and biological assessments of using the Gulf Stream off Cape Hatteras as a source of hydrokinetic energy. 2015
Assessment of Energy Production Potential from Tidal Streams in the United States - Final Project ReportThis project created a national database of tidal stream energy potential, as well as a GIS tool. Tidal currents are numerically modeled with the Regional Ocean Modeling System and calibrated with the available measurements of tidal current speed and water level surface. The database is published on an interactive website that includes tools to select, query and download the data. The results of the regional assessment show that Alaska contains the largest number of locations with considerably high kinetic power density, followed by, Maine, Washington, Oregon, California, New Hampshire, Massachusetts, New York, New Jersey, North and South Carolina, Georgia, and Florida. 2011
Mapping and Assessment of the United States Ocean Wave Energy ResourceThis project estimates the naturally available and technically recoverable U.S. wave energy resources, using a 51-month database developed especially for this study by NOAA’s National Centers for Environmental Prediction. The assessment determined the total amount of available wave energy resource along the U.S. continental shelf edge, and broke this number into subtotals for the West Coast, the East Coast, the Gulf of Mexico, Alaska, Hawaii, and Puerto Rico. 2011
National Renewable Energy Laboratory (NREL)NREL was designated a national laboratory in 1991. Today, NREL advances the science and engineering of renewable power technologies including ocean and wind power.
Marine and Hydrokinetic Technology GlossaryLearn about the basic technologies and key terms used to describe marine and hydrokinetic technologies.