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Screening Analysis for the Environmental Risk Evaluation System Task 2.1.1.2: Evaluating Effects of Stressors Fiscal Year 2011 Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

Description: Potential environmental effects of marine and hydrokinetic (MHK) energy development are not well understood, and yet regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term consequences. An understanding of risks associated with interactions between MHK installations and aquatic receptors, including animals, habitats, and ecosystems, can help define key uncertainties and focus regulatory actions and scientific studies on interactions of most concern. As a first step in developing the Pacific Northwest National Laboratory (PNNL) Environmental Risk Evaluation System (ERES), PNNL scientists conducted a preliminary risk screening analysis on three initial MHK cases. During FY 2011, two additional cases were added: a tidal project in the Gulf of Maine using Ocean Renewable Power Company TidGenTM turbines and a wave project planned for the coast of Oregon using Aquamarine Oyster surge devices. Through an iterative process, the screening analysis revealed that top-tier stressors in the two FY 2011 cases were the dynamic effects of the device (e.g., strike), accidents/disasters, and effects of the static physical presence of the device (e.g., habitat alteration). Receptor interactions with these stressors at the highest tiers of risk were dominated by threatened and endangered animals. Risk to the physical environment from changes in flow regime also ranked high. Peer review of this process and results will be conducted in early FY 2012. The ERES screening analysis provides an analysis of vulnerability of environmental receptors to stressors associated with MHK installations, probability analysis is needed to determine specific risk levels to receptors. “Risk” has two components: (1) The likelihood, or “probability”, of the occurrence of a given interaction or event, and (2) the potential “consequence” if that interaction or event were to occur. During FY 2011, the ERES screening analysis focused primarily on the second component of risk, “consequence”, with ...
Date: September 1, 2011
Creator: Copping, Andrea E.; Blake, Kara M.; Anderson, Richard M.; Zdanski, Laura C.; Gill, Gary A. & Ward, Jeffrey A.
Partner: UNT Libraries Government Documents Department

Abrasion Testing of Critical Components of Hydrokinetic Devices

Description: The objective of the Abrasion Testing of Critical Components of Hydrokinetic Devices (Project) was to test critical components of hydrokinetic devices in waters with high levels of suspended sediment – information that is widely applicable to the hydrokinetic industry. Tidal and river sites in Alaska typically have high suspended sediment concentrations. High suspended sediment also occurs in major rivers and estuaries throughout the world and throughout high latitude locations where glacial inputs introduce silt into water bodies. In assessing the vulnerability of technology components to sediment induced abrasion, one of the greatest concerns is the impact that the sediment may have on device components such as bearings and seals, failures of which could lead to both efficiency loss and catastrophic system failures.
Date: December 6, 2013
Creator: Worthington, Monty; Ali, Muhammad & Ravens, Tom
Partner: UNT Libraries Government Documents Department

Multnomah County Hydrokinetic Feasibility Study: Final Feasibility Study Report

Description: HDR has completed a study of the technical, regulatory, and economic feasibility of installing hydrokinetic turbines under the Morrison, Broadway, and Sellwood bridges. The primary objective of installing hydrokinetic turbines is a demonstration of in-stream hydrokinetic technologies for public education and outreach. Due to the low gradient of the Lower Willamette and the effects of the tide, velocities in the area in consideration are simply not high enough to economically support a commercial installation. While the velocities in the river may at times provide enough energy for a commercial turbine to reach capacity, the frequency and duration of high flow events which provide suitable velocities is not sufficient to support a commercial hydrokinetic installation. We have observed that over an 11 year period, daily average velocities in the Lower Willamette exceeded a nominal cut-in speed of 0.75 m/s only 20% of the time, leaving net zero power production for the remaining 80% of days. The Sellwood Bridge site was estimated to have the best hydrokinetic resource, with an estimated average annual production of about 9,000 kWh. The estimated production could range from 2,500 kWh to 15,000 kWh. Based on these energy estimates, the amount of revenue generated through either a power purchase agreement (PPA) or recovered through net metering is not sufficient to repay the project costs within the life of the turbine. The hydrokinetic resource at the Morrison and Broadway Bridges is slightly smaller than at the Sellwood Bridge. While the Broadway and Morrison Bridges have existing infrastructure that could be utilized, the project is not expected to generate enough revenue to repay the investment. Despite low velocities and energy production, the sites themselves are favorable for installation of a demonstration or experimental project. With high public interest in renewable energy, the possibility exists to develop a hydrokinetic test ...
Date: March 15, 2012
Creator: Spain, Stephen
Partner: UNT Libraries Government Documents Department

2011 Marine Hydrokinetic Device Modeling Workshop: Final Report; March 1, 2011

Description: This report summarizes the NREL Marine and Hydrokinetic Device Modeling Workshop. The objectives for the modeling workshop were to: (1) Review the designs of existing MHK device prototypes and discuss design and optimization procedures; (2) Assess the utility and limitations of modeling techniques and methods presently used for modeling MHK devices; (3) Assess the utility and limitations of modeling methods used in other areas, such as naval architecture and ocean engineering (e.g., oil & gas industry); and (4) Identify the necessary steps to link modeling with other important components that analyze MHK devices (e.g., tank testing, PTO design, mechanical design).
Date: October 1, 2011
Creator: Li, Y.; Reed, M. & Smith, B.
Partner: UNT Libraries Government Documents Department

Regulatory Assistance, Stakeholder Outreach, and Coastal and Marine Spatial Planning Activities In Support Marine and Hydrokinetic Energy Deployment: Task 2.1.7 Permitting and Planning Fiscal Year 2012 Year-End Report

Description: This fiscal year 2012 year-end report summarizes activities carried out under DOE Water Power task 2.1.7, Permitting and Planning. Activities under Task 2.1.7 address the concerns of a wide range of stakeholders with an interest in the development of the MHK industry, including regulatory and resource management agencies, tribes, NGOs, and industry. Objectives for 2.1.7 are the following: • To work with stakeholders to streamline the MHK regulatory permitting process. • To work with stakeholders to gather information on needs and priorities for environmental assessment of MHK development. • To communicate research findings and directions to the MHK industry and stakeholders. • To engage in spatial planning processes in order to further the development of the MHK industry. These objectives are met through three subtasks, each of which are described in this report: • 2.1.7.1—Regulatory Assistance • 2.1.7.2—Stakeholder Outreach • 2.1.7.3—Coastal and Marine Spatial Planning As the MHK industry works with the regulatory community and stakeholders to plan, site, permit and license MHK technologies they have an interest in a predictable, efficient, and transparent process. Stakeholders and regulators have an interest in processes that result in sustainable use of ocean space with minimal effects to existing ocean users. Both stakeholders and regulators have an interest in avoiding legal challenges by meeting the intent of federal, state, and local laws that govern siting and operation of MHK technologies. The intention of work under 2.1.7 is to understand these varied interests, explore mechanisms to reduce conflict, identify efficiencies, and ultimately identify pathways to reduce the regulatory costs, time, and potential environmental impacts associated with developing, siting, permitting, and deploying MHK systems.
Date: September 1, 2012
Creator: Geerlofs, Simon H.; Hanna, Luke A.; Judd, Chaeli R. & Blake, Kara M.
Partner: UNT Libraries Government Documents Department

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint

Description: Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a power-take-off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drivetrain, power generator, and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost, and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency and low maintenance and cost, with a low impact on the device cost-of-energy (CoE).
Date: February 1, 2013
Creator: Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M. et al.
Partner: UNT Libraries Government Documents Department

Attraction to and Avoidance of instream Hydrokinetic Turbines by Freshwater Aquatic Organisms

Description: The development of hydrokinetic (HK) energy projects is under consideration at over 150 sites in large rivers in the United States, including the Mississippi, Ohio, Tennessee, and Atchafalaya Rivers. These waterbodies support numerous fish species that might interact with the HK projects in a variety of ways, e.g., by attraction to or avoidance of project structures. Although many fish species inhabit these rivers (about 172 species in the Mississippi River alone), not all of them will encounter the HK projects. Some species prefer low-velocity, backwater habitats rather than the high-velocity, main channel areas that would be the best sites for HK. Other, riverbank-oriented species are weak swimmers or too small to inhabit the main channel for significant periods of time. Some larger, main channel fish species are not known to be attracted to structures. Based on a consideration of habitat preferences, size/swim speed, and behavior, fish species that are most likely to be attracted to HK structures in the main channel include carps, suckers, catfish, white bass, striped bass, smallmouth bass, spotted bass, and sauger. Proper siting of the project in order to avoid sensitive fish populations, backwater and fish nursery habitat areas, and fish migration corridors will likely minimize concerns about fish attraction to or avoidance of HK structures.
Date: May 1, 2011
Creator: Cada, Glenn F & Bevelhimer, Mark S
Partner: UNT Libraries Government Documents Department

Environmental Effects of Hydrokinetic Turbines on Fish: Desktop and Laboratory Flume Studies

Description: This 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. The studies: (1) conducted an assessment of potential injury mechanisms using available data from studies with conventional hydro turbines; (2) developed theoretical models for predicting blade strike probabilities and mortality rates; and (3) performed flume testing with three turbine designs and several fish species and size groups in two laboratory flumes to estimate survival rates and document fish behavior. The project yielded three reports which this document comprises. The three constituent documents are addressed individually below Fish Passage Through Turbines: Application of Conventional Hydropower Data to Hydrokinetic Technologies Fish passing through the blade sweep of a hydrokinetic turbine experience a much less harsh physical environment than do fish entrained through conventional hydro turbines. The design and operation of conventional turbines results in high flow velocities, abrupt changes in flow direction, relatively high runner rotational and blade speeds, rapid and significant changes in pressure, and the need for various structures throughout the turbine passageway that can be impacted by fish. These conditions generally do not occur or are not significant factors for hydrokinetic turbines. Furthermore, compared to conventional hydro turbines, hydrokinetic turbines typically produce relatively minor changes in shear, turbulence, and pressure levels from ambient conditions in the surrounding environment. Injuries and mortality from mechanical injuries will be less as well, mainly due to low rotational speeds and strike velocities, and an absence of structures that can lead to grinding or abrasion injuries. Additional information is needed to rigorously ...
Date: December 31, 2012
Creator: Jacobson, Paul T.; Amaral, Stephen V.; Castro-Santos, Theodore; Giza, Dan; Haro, Alexander J.; Hecker, George et al.
Partner: UNT Libraries Government Documents Department

Identification and Prioritization of Analysis Cases for Marine and Hydrokinetic Energy Risk Screening

Description: In this report we describe the development of the Environmental Risk Evaluation System (ERES), a risk-informed analytical process for estimating the environmental risks associated with the construction and operation of marine and hydrokinetic energy generation projects. The development process consists of two main phases of analysis. In the first phase, preliminary risk analyses will take the form of screening studies in which key environmental impacts and the uncertainties that create risk are identified, leading to a better-focused characterization of the relevant environmental effects. Existence of critical data gaps will suggest areas in which specific modeling and/or data collection activities should take place. In the second phase, more detailed quantitative risk analyses will be conducted, with residual uncertainties providing the basis for recommending risk mitigation and monitoring activities. We also describe the process used for selecting three cases for fiscal year 2010 risk screening analysis using the ERES. A case is defined as a specific technology deployed in a particular location involving certain environmental receptors specific to that location. The three cases selected satisfy a number of desirable criteria: 1) they correspond to real projects whose deployment is likely to take place in the foreseeable future; 2) the technology developers are willing to share technology and project-related data; 3) the projects represent a diversity of technology-site-receptor characteristics; 4) the projects are of national interest, and 5) environmental effects data may be available for the projects.
Date: June 16, 2010
Creator: Anderson, Richard M.; Unwin, Stephen D. & Van Cleve, Frances B.
Partner: UNT Libraries Government Documents Department

Field Measurements at River and Tidal Current Sites for Hydrokinetic Energy Development: Best Practices Manual

Description: In this report, existing data collection techniques and protocols for characterizing open channel flows are reviewed and refined to further address the needs of the MHK industry. The report provides an overview of the hydrodynamics of river and tidal channels, and the working principles of modern acoustic instrumentation, including best practices in remote sensing methods that can be applied to hydrokinetic energy site characterization. Emphasis is placed upon acoustic Doppler velocimeter (ADV) and acoustic-Doppler current profiler (ADCP) instruments, as these represent the most practical and economical tools for use in the MHK industry. Incorporating the best practices as found in the literature, including the parameters to be measured, the instruments to be deployed, the instrument deployment strategy, and data post-processing techniques. The data collected from this procedure aims to inform the hydro-mechanical design of MHK systems with respect to energy generation and structural loading, as well as provide reference hydrodynamics for environmental impact studies. The standard metrics and protocols defined herein can be utilized to guide field experiments with MHK systems.
Date: September 1, 2011
Creator: Neary, Vincent S & Gunawan, Budi
Partner: UNT Libraries Government Documents Department

Inflow Characterization for Marine and Hydrokinetic Energy Devices. FY-2011: Annual Progress Report

Description: The Pacific Northwest National Laboratory (PNNL), in collaboration with the Applied Physics Laboratory at the University of Washington (APL-UW), has carried out a detailed preliminary fluid flow field study at site selected for testing of marine and hydrokinetic turbines using Acoustic Doppler Velocimetry (ADV) measurements, Acoustic Doppler Current Profiler (ADCP) measurements, and Conductivity, Temperature and Depth (CTD) measurements. In FY-2011 these measurements were performed continuously for two weeks, in order to collect data during neap and spring tides, as well as during diurnal tidal variations.
Date: June 9, 2011
Creator: Richmond, Marshall C.; Durgesh, Vibhav; Thomson, Jim & Polagye, Brian
Partner: UNT Libraries Government Documents Department

Assssment and Mapping of the Riverine Hydrokinetic Resource in the Continental United States

Description: The U.S. Department of Energy (DOE) funded the Electric Power Research Institute and its collaborative partners, University of Alaska ? Anchorage, University of Alaska ? Fairbanks, and the National Renewable Energy Laboratory, to provide an assessment of the riverine hydrokinetic resource in the continental United States. The assessment benefited from input obtained during two workshops attended by individuals with relevant expertise and from a National Research Council panel commissioned by DOE to provide guidance to this and other concurrent, DOE-funded assessments of water based renewable energy. These sources of expertise provided valuable advice regarding data sources and assessment methodology. The assessment of the hydrokinetic resource in the 48 contiguous states is derived from spatially-explicit data contained in NHDPlus ?a GIS-based database containing river segment-specific information on discharge characteristics and channel slope. 71,398 river segments with mean annual flow greater than 1,000 cubic feet per second (cfs) mean discharge were included in the assessment. Segments with discharge less than 1,000 cfs were dropped from the assessment, as were river segments with hydroelectric dams. The results for the theoretical and technical resource in the 48 contiguous states were found to be relatively insensitive to the cutoff chosen. Raising the cutoff to 1,500 cfs had no effect on estimate of the technically recoverable resource, and the theoretical resource was reduced by 5.3%. The segment-specific theoretical resource was estimated from these data using the standard hydrological engineering equation that relates theoretical hydraulic power (Pth, Watts) to discharge (Q, m3 s-1) and hydraulic head or change in elevation (??, m) over the length of the segment, where ? is the specific weight of water (9800 N m-3): ??? = ? ? ?? For Alaska, which is not encompassed by NPDPlus, hydraulic head and discharge data were manually obtained from Idaho National Laboratory?s Virtual Hydropower Prospector, ...
Date: December 14, 2012
Creator: Jacobson, Paul T.; Ravens, Thomas M.; Cunningham, Keith W. & Scott, George
Partner: UNT Libraries Government Documents Department

Experimental Test Plan DOE Tidal and River Reference Turbines

Description: Our aim is to provide details of the experimental test plan for scaled model studies in St. Anthony Falls Laboratory (SAFL) Main Channel at the University of Minnesota, including a review of study objectives, descriptions of the turbine models, the experimental set-up, instrumentation details, instrument measurement uncertainty, anticipated experimental test cases, post-processing methods, and data archiving for model developers.
Date: September 1, 2012
Creator: Neary, Vincent S; Hill, Craig; Chamorro, Leonardo & Gunawan, Budi
Partner: UNT Libraries Government Documents Department

FFP/NREL Collaboration on Hydrokinetic River Turbine Testing: Cooperative Research and Development Final Report, CRADA Number CRD-12-00473

Description: This shared resources CRADA defines collaborations between the National Renewable Energy Laboratory (NREL) and Free Flow Power (FFP) set forth in the following Joint Work Statement. Under the terms and conditions described in this CRADA, NREL and FFP will collaborate on the testing of FFP's hydrokinetic river turbine project on the Mississippi River (baseline location near Baton Rouge, LA; alternate location near Greenville, MS). NREL and FFP will work together to develop testing plans, instrumentation, and data acquisition systems; and perform field measurements.
Date: April 1, 2013
Creator: Driscoll, F.
Partner: UNT Libraries Government Documents Department

Performance Evaluation of HYCOM-GOM for Hydrokinetic Resource Assessment in the Florida Strait

Description: The U.S. Department of Energy (DoE) is assessing and mapping the potential off-shore ocean current hydrokinetic energy resources along the U.S. coastline, excluding tidal currents, to facilitate market penetration of water power technologies. This resource assessment includes information on the temporal and three-dimensional spatial distribution of the daily averaged power density, and the overall theoretical hydrokinetic energy production, based on modeled historical simulations spanning a 7-year period of record using HYCOM-GOM, an ocean current observation assimilation model that generates a spatially distributed three-dimensional representation of daily averaged horizontal current magnitude and direction time series from which power density time series and their statistics can be derived. This study ascertains the deviation of HYCOM-GOM outputs, including transport (flow) and power density, from outputs based on three independent observation sources to evaluate HYCOM-GOM performance. The three independent data sources include NOAA s submarine cable data of transport, ADCP data at a high power density location, and HF radar data in the high power density region of the Florida Strait. Comparisons with these three independent observation sets indicate discrepancies with HYCOM model outputs, but overall indicate that the HYCOM-GOM model can provide an adequate assessment of the ocean current hydrokinetic resource in high power density regions like the Florida Strait. Additional independent observational data, in particular stationary ADCP measurements, would be useful for expanding this model performance evaluation study. ADCP measurements are rare in ocean environments not influenced by tides, and limited to one location in the Florida Strait. HF radar data, although providing great spatial coverage, is limited to surface currents only.
Date: June 1, 2012
Creator: Neary, Vincent S; Gunawan, Budi & Ryou, Albert S
Partner: UNT Libraries Government Documents Department

Final Technical Report: The Water-to-Wire (W2W) Project

Description: The purpose of the Free Flow Power (FFP) Water-to-Wire Project (Project) was to evaluate and optimize the performance, environmental compatibility, and cost factors of FFP hydrokinetic turbines through design analyses and deployments in test flumes and riverine locations.
Date: December 24, 2013
Creator: Lissner, Daniel N. & Edward, Lovelace C.
Partner: UNT Libraries Government Documents Department

Improved Structure and Fabrication of Large, High-Power KHPS Rotors - Final Scientific/Technical Report

Description: Verdant Power, Inc, working in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories (SNL), and the University of Minnesota St. Anthony Falls Laboratory (SAFL), among other partners, used evolving Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) models and techniques to improve the structure and fabrication of large, high-power composite Kinetic Hydropower System (KHPS) rotor blades. The objectives of the project were to: design; analyze; develop for manufacture and fabricate; and thoroughly test, in the lab and at full scale in the water, the improved KHPS rotor blade.
Date: January 29, 2013
Creator: Corren, Dean; Colby, Jonathan & Adonizio, Mary Ann
Partner: UNT Libraries Government Documents Department

Investigating the Influence of the Added Mass Effect to Marine Hydrokinetic Horizontal-Axis Turbines Using a General Dynamic Wake Wind Turbine Code

Description: This paper describes a recent study to investigate the applicability of a horizontal-axis wind turbine (HAWT) structural dynamics and unsteady aerodynamics analysis program (FAST and AeroDyn respectively) to modeling the forces on marine hydrokinetic (MHK) turbines. This paper summarizes the added mass model that has been added to AeroDyn. The added mass model only includes flow acceleration perpendicular to the rotor disc, and ignores added mass forces caused by blade deflection. A model of the National Renewable Energy Laboratory's (NREL) Unsteady Aerodynamics Experiment (UAE) Phase VI wind turbine was analyzed using FAST and AeroDyn with sea water conditions and the new added mass model. The results of this analysis exhibited a 3.6% change in thrust for a rapid pitch case and a slight change in amplitude and phase of thrust for a case with 30{sup o} of yaw.
Date: October 1, 2011
Creator: Maniaci, D. C. & Li, Y.
Partner: UNT Libraries Government Documents Department

Development and Verification of a Computational Fluid Dynamics Model of a Horizontal-Axis Tidal Current Turbine

Description: This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.
Date: October 1, 2011
Creator: Lawson, M. J.; Li, Y. & Sale, D. C.
Partner: UNT Libraries Government Documents Department

Structural Design of a Horizontal-Axis Tidal Current Turbine Composite Blade

Description: This paper describes the structural design of a tidal composite blade. The structural design is preceded by two steps: hydrodynamic design and determination of extreme loads. The hydrodynamic design provides the chord and twist distributions along the blade length that result in optimal performance of the tidal turbine over its lifetime. The extreme loads, i.e. the extreme flap and edgewise loads that the blade would likely encounter over its lifetime, are associated with extreme tidal flow conditions and are obtained using a computational fluid dynamics (CFD) software. Given the blade external shape and the extreme loads, we use a laminate-theory-based structural design to determine the optimal layout of composite laminas such that the ultimate-strength and buckling-resistance criteria are satisfied at all points in the blade. The structural design approach allows for arbitrary specification of the chord, twist, and airfoil geometry along the blade and an arbitrary number of shear webs. In addition, certain fabrication criteria are imposed, for example, each composite laminate must be an integral multiple of its constituent ply thickness. In the present effort, the structural design uses only static extreme loads; dynamic-loads-based fatigue design will be addressed in the future. Following the blade design, we compute the distributed structural properties, i.e. flap stiffness, edgewise stiffness, torsion stiffness, mass, moments of inertia, elastic-axis offset, and center-of-mass offset along the blade. Such properties are required by hydro-elastic codes to model the tidal current turbine and to perform modal, stability, loads, and response analyses.
Date: October 1, 2011
Creator: Bir, G. S.; Lawson, M. J. & Li, Y.
Partner: UNT Libraries Government Documents Department

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint

Description: Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a Power-Take-Off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drive train, power generator and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency, low maintenance and cost with a low impact on the device Cost-of-Energy (CoE).
Date: April 1, 2012
Creator: Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M. et al.
Partner: UNT Libraries Government Documents Department

The Development of Open Water-lubricated Polycrystalline Diamond (PCD) Thrust Bearings for Use in Marine Hydrokinetic (MHK) Energy Machines

Description: Polycrstalline diamond (PCD) bearings were designed, fabricated and tested for marine-hydro-kinetic (MHK) application. Bearing efficiency and life were evaluated using the US Synthetic bearing test facility. Three iterations of design, build and test were conducted to arrive at the best bearing design. In addition life testing that simulated the starting and stopping and the loading of real MHK applications were performed. Results showed polycrystalline diamond bearings are well suited for MHK applications and that diamond bearing technology is TRL4 ready. Based on life tests results bearing life is estimated to be at least 11.5 years. A calculation method for evaluating the performance of diamond bearings of round geometry was also investigated and developed. Finally, as part of this effort test bearings were supplied free of charge to the University of Alaska for further evaluation. The University of Alaska test program will subject the diamond bearings to sediment laden lubricating fluid.
Date: November 28, 2012
Creator: Cooley, Craig, H.; Khonsari, Michael,, M & Lingwall, Brent
Partner: UNT Libraries Government Documents Department

Marine and Hydrokinetic Technology (MHK) Instrumentation, Measurement, and Computer Modeling Workshop

Description: The Marine and Hydrokinetic Technology (MHK) Instrumentation, Measurement, and Computer Modeling Workshop was hosted by the National Renewable Energy Laboratory (NREL) in Broomfield, Colorado, July 9-10, 2012. The workshop brought together over 60 experts in marine energy technologies to disseminate technical information to the marine energy community and collect information to help identify ways in which the development of a commercially viable marine energy industry can be accelerated. The workshop was comprised of plenary sessions that reviewed the state of the marine energy industry and technical sessions that covered specific topics of relevance. Each session consisted of presentations, followed by facilitated discussions. During the facilitated discussions, the session chairs posed several prepared questions to the presenters and audience to encourage communication and the exchange of ideas between technical experts. Following the workshop, attendees were asked to provide written feedback on their takeaways and their best ideas on how to accelerate the pace of marine energy technology development. The first four sections of this document give a general overview of the workshop format, provide presentation abstracts and discussion session notes, and list responses to the post-workshop questions. The final section presents key findings and conclusions from the workshop that suggest how the U.S. Department of Energy and national laboratory resources can be utilized to most effectively assist the marine energy industry.
Date: February 1, 2013
Creator: Musial, W.; Lawson, M. & Rooney, S.
Partner: UNT Libraries Government Documents Department