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At least 1,045 records · Page 58

NREL-Prime Next-Generation Drivetrain Dynamometer Test Report

Advances in wind turbine drivetrain technologies are necessary to improve reliability and reduce the cost of energy for land-based and offshore wind turbines. The NREL-Prime Next-Generation Drivetrain team developed a geared, medium-speed drivetrain that is lighter, more reliable and more efficient than existing designs. One of the objectives of Phase II of the project was to complete the detailed design, fabrication, and dynamometer testing of a 750 kilowatt (kW) drivetrain that includes the key gearbox innovations designed by Romax Technology and power converter innovations designed by DNV Kema Renewables. The purpose of this document is to summarize these tests completed in NREL's National Wind Technology Center 2.5 megawatt (MW) dynamometer.

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Evaluation of New Opportunities for Marine Energy To Power the Blue Economy: Green Hydrogen and Marine Carbon Dioxide Removal

This report examines the intersection of marine energy and the sectors of green hydrogen and marine Carbon Dioxide Removal, taking into account potential synergies, market maturity, barriers, policy enablers, and sustainability perspectives. Through desk research and interviews with a diverse range of subject matter experts from academia, government, industry, venture capital, and non-profit sectors, these emergent sectors were identified as the most promising new opportunities for marine energy integration beyond those explored in the 2019 Powering the Blue Economy Report. The findings presented are the combined result of desk research and information gathered through these interviews.

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Minimal spectrum of long-wave perturbations - Is linear growth correct only in the nonlinear regime?

Very high resolution two-dimensional simulations are used to test the generation and growth of the so-called 'minimal' k exp 4 power spectrum which develops from initial conditions which have power only on small scales, such as might result from some process in the early universe. It is confirmed that the amplitude of minimal long-wave power grows proportionally to a exp 4, not a-squared, where a is the scale factor of the expanding universe. It reverts to a-squared only after the short-wave modes are effectively saturated, and by that time an effective long-wave power law closer to k-cubed is found. Small-scale perturbations may result in much more long-wave power than has been generally assumed.

Shandarin, Sergei F.↗

Motion Tracking Above and Below Water Dataset

This data set includes one trial of above and under water motion tracking measurements from a Qualysis motion tracking system. The Qualisys native .qtm file can be opened by the Qualisys Track Manager software. Data from this file has been exported to a tab separated value (.tsv) file which is a generic ASCII file format that can be read by a text editor, MATLAB, Excel, etc... Also exported is a native MATLAB formatted file (.mat) which can be loaded directly into MATLAB. The trial is from a three body wave energy converter device, using the underwater system for the central nacelle data, and above water system for the fore and aft floats.

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Hydrodynamic Analysis and Optimization of Aquantis Marine Turbine: Cooperative Research and Development (Final Report)

The primary aim of this proposal is to improve the accurate prediction of hydrodynamic performance and dynamic load responses of the AQ10 floating axial-flow tidal turbine with a tri-cat mooring configuration. The validation of reduced-order modeling approaches with high-fidelity model will be implemented. Additionally, the frequency response domain, Response Amplitude Floating Wind (RAFT) toolbox plus an optimizer expanded for marine hydrokinetic turbines under the Submarine Hydrokinetic And Riverine Kilo-megawatt. Systems (SHARKS) program will be used for designing and exploring different key design parameters (platform dimension, mooring layout and its parameters) of next marine hydrokinetic (MHK) turbine generation.

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Tidal Currents in San Juan Archipelago, Washington

Re-analyzed acoustic Doppler current profiler (ADCP) data originally collected by NOAA CO-OPS (Center for Operational Oceanographic Products and Services) and equivalent point data from Pacific Northwest National Laboratory's FVCOM (Finite Volume Community Ocean Model) model of the region. Data are processed to products describing characteristics of tidal currents relevant to tidal turbines, as well as power output estimates for a notional turbine deployed from a surface platform or from the seabed at each location. These data underpin the results presented in their associated paper - see below.

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Verdant Power TriFrame, Gen5 KHPS Turbine, and BOP System Content Models

This submission includes System Content Models with data following manufacture for the Verdant Power TriFrame, Gen5 Kinetic Hydropower System (KHPS) Turbines, and Balance of Plant (BOP). The TriFrame installs 3 Gen5 KHPS Turbines. The BOP system controls the turbines and interconnects the TriFrame to shoreline with supervisory control and data acquisition (SCADA).

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In-Situ Blade Strain Measurements of a Crossflow Turbine Operating in a Tidal Flow

This data was collected between October 25 and December 12 of 2022 at the University of New Hampshire (UNH) and Atlantic Marine Energy Center (AMEC) turbine deployment platform (TDP). The goal was to collect blade strain data from a crossflow turbine operating in a tidal flow. A table in ('Deployment Schedule.PNG') outlines the various dates when each instrument was operational, and more details can be found via literature listed in 'Related Publications'.txt. This dataset includes zipped folders for each instrument containing data in .csv files for the relevant duration specific to each instrument, along with separate README file for each measurement. Some instrument files are quite large and can pose a challenge for a visual spreadsheet editor to open. A processing software like MATLAB or Python is recommended. All data contained in this submission is unfiltered/unprocessed data unless otherwise noted in the README file. Blade strain was measured using 8 foil-based strain gauges along the span of a single turbine blade. Water currents were measured using Acoustic Doppler Current Profilers (ADCP's) and Acoustic Doppler Velocimeters (ADV's) both upstream and downstream of the turbine for inflow, wake and turbulence measurements. Electrical power output was measured using the Voltsys rectifier. Shaft speed was calculated based on the Voltsys measurements of the permanent magnet three phase generator AC generation frequency, coupled directly to the cross flow turbine under test (i.e., no gear box). Platform motions were captured using a Yost IMU (inertial measurement unit). Turbine thrust loading was measured using a reaction arm about the turbine deployment platform spanning beam, where two bi-directional load cells were connected to the system via a pinned connection. The TDP is a floating structure moored on the Portsmouth facing side of Memorial Bridge pier #2, which spans the Piscataqua River between Portsmouth, NH and Kittery, ME. The Piscataqua River connects the Great Bay Estuary to the Gulf of Maine and the river currents are dominated by tidal flow with water velocities exceeding 2.5 m/s during spring ebb tides at this site which were previously characterized by Chancey 2019. The turbine under test was a modified New Energy Corporation (Calgary, CA) model EVG-025 4-blade H-Darrius type vertical axis cross flow turbine that rotates in the clockwise direction with a rotor diameter of 3.2m and blade length of 1.7m. The hydro-foil profile was a NACA 0021 with a 10 inch chord length and a blade preset pitch angle of +4deg with a positive angle corresponding with the toe in direction. The standard EVG-025 has a rotor diameter of 3.4m and its rated power output is 25kW at 3 m/s. The rotor diameter was reduced to accommodate the size of the existing TDP moon-pool. A single blade of this turbine was further modified to accommodate 8 full-bridge strain gauges (Bharath et al 2023, Bichanich et al 2024). For power performance and other relevant details on the turbine and its characteristics, see O'Byrne 2022.

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Effects of Large Energetic Vortices on Axial-Flow Hydrokinetic Turbines

Large scale coherent motions around marine and hydrokinetic (MHK) machines can significantly increase the structural loading and affect the overall performance of the machines. Characterization of the approach turbulence and their impact on the instantaneous response of MHK devices is essential for improving their design and performance. This preliminary study investigates the effect of turbulence and dominant energetic coherent structures induced by a vertical cylinder on the structural load and energy production in a model MHK turbine. Results show that the power generated by the turbine is significantly reduced by the presence of the cylinder. This reduction depends on the distance from the cylinder and the level of turbulence around the rotor area.

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Stochastic microhertz gravitational radiation from stellar convection

High Reynolds-number turbulence driven by stellar convection in main-sequence stars generates stochastic gravitational radiation. We calculate the wave-strain power spectral density as a function of the zero-age main-sequence mass for an individual star and for an isotropic, universal stellar population described by the Salpeter initial mass function and redshift-dependent Hopkins-Beacom star formation rate. The spectrum is a broken power law, which peaks near the turnover frequency of the largest turbulent eddies. The signal from the Sun dominates the universal background. For the Sun, the far-zone power spectral density peaks at S(f {sub peak}) = 5.2 × 10{sup –52} Hz{sup –1} at frequency f {sub peak} = 2.3 × 10{sup –7} Hz. However, at low observing frequencies f < 3 × 10{sup –4} Hz, the Earth lies inside the Sun's near zone and the signal is amplified to S {sub near}(f {sub peak}) = 4.1 × 10{sup –27} Hz{sup –1} because the wave strain scales more steeply with distance (∝d {sup –5}) in the near zone than in the far zone (∝d {sup –1}). Hence the Solar signal may prove relevant for pulsar timing arrays. Other individual sources and the universal background fall well below the projected sensitivities of the Laser Interferometer Space Antenna and next-generation pulsar timing arrays. Stellar convection sets a fundamental noise floor for more sensitive stochastic gravitational-wave experiments in the more distant future.

79 ASTRONOMY AND ASTROPHYSICS↗

Prizes Power NREL Water Power Innovation

NREL administered and managed several DOE American-Made Challenges prizes in Fiscal Year 2021, which support a number of DOE initiatives and administration goals. NREL's contributions to the success of these prizes included preparing and disseminating communications materials to and between competitors, partners, supporting institutions, sponsors, and the public.

HYDRO ENERGY,TIDAL AND WAVE POWER↗

An Intelligent Adaptable Monitoring Package. Final Report

The “Intelligent Adaptable Monitoring Package” project was a four-year effort that demonstrated the feasibility of integrated sensing packages at tidal and wave energy sites. Such integration is generally required by the breadth of sensors required to understand environmental effects at marine energy sites and the operational difficulty of deploying, maintaining, and recovering such sensors. Over the course of the project, the Adaptable Monitoring Package (AMP) was deployed in multiple settings, each corresponding to a project budget period: - Budget Period 1: Demonstration of cabled deployment at Pacific Northwest National Laboratory’s Marine Science Laboratory. The deployment highlighted AMP hardware endurance over a 4-month deployment in a tidally-dominated environment and laid the groundwork for machine learning algorithms to detect and classify targets present in active sonar data. - Budget Period 2: Demonstration of an autonomous deployment at PacWave South off the coast of Newport, Oregon. The deployment highlighted the stability of AMP hardware and software, with the autonomous package collecting data on a duty cycle over a 1.5-month deployment. - Budget Period 3: Demonstration of an autonomous deployment powered by a wave energy converter at the U.S. Navy’s Wave Energy Test Site. The deployment highlighted the potential of wave energy to power ocean observatories and led to the development of machine learning algorithms to detect and classify targets in optical camera data. In aggregate, this project’s greatest success was demonstrating the AMP’s flexibility in a range of deployment scenarios. Each budget period represented a “first of a kind” demonstration of integrated instrumentation – cabled AMP, autonomous AMP, wave-energy powered AMP – and each deployment helped to identify and set goals for the next. Further, despite the exploratory nature of these deployments, each one achieved high system up-time and proved that flexible integration of multiple sensors in a single package represents a viable strategy for marine energy environmental monitoring. The key lessons learned from the project are: - Without continuous power, either from a shore cable or in situ source, many of the benefits of integration are lost (If continuous power is not available, the ability to detect rare events is lost, as is the ability to minimize the risk of behavioral changes through adaptive sensing. However, even on a duty cycle, there is still value in being able to acquire synchronous data from multiple sensors.); and - Observations from a moving platform present substantially greater data processing challenges than those from stationary platforms. Finally, these deployments also demonstrate an important truth: successful integration alone does not guarantee that relevant data are collected. To grow the knowledge base about environmental interactions with marine energy converters, integrated systems, like the AMP, need to include the right sensor mix and connect the data pipelines to effective processing algorithms. These deployments establish a strong foundation for future collaborations with the environmental research community: not only to understand the environmental effects of marine energy, but also to improve our general ability to study life in the sea.

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Direct Drive Wave Energy Buoy

Presentation from the 2011 Water Peer Review in which principal investigator discusses project progress and results for this project which will be used to inform the utility-scale design process, improve cost estimates, accurately forecast energy production and to observe system operation and survivability.

buoy↗

Multi-static Serial LiDAR for Surveillance and Identification of Marine Life at MHK Installations

Final Report for project DE-EE0006787: Multi-static Serial LiDAR for Surveillance and Identification of Marine Life at MHK Installations. This project developed and tested an optical monitoring system prototype that will be suitable for marine and hydrokinetic (MHK) full project lifecycle observation (baseline, commissioning, and decommissioning), with automated real-time classification of marine animals. This system can be deployed to collect pre-installation baseline species observations at a proposed deployment site with minimal post-processing overhead. To satisfy deployed MHK project species of concern (e.g. Endangered Species Act-listed) monitoring requirements, the system provides automated tracking and notification of the presence of managed animals within established perimeters of MHK equipment and provides high resolution imagery of their behavior through a wide range of conditions. During a project’s decommissioning stage, the system can remain installed to provide resource managers with post-installation data. Our technology, known as an Unobtrusive Multi-static Serial LiDAR Imager (UMSLI), is a technology transfer of underwater distributed LiDAR imaging technology that preserves the advantages of traditional optical and acoustic solutions while overcoming associated disadvantages for MHK environmental monitoring applications. This new approach is a purposefully-designed, reconfigurable adaptation of an existing technology that can be easily mounted on or around different classes of MHK equipment. The system uses low average power red (638nm) laser illumination to be invisible and eye-safe to marine animals and is compact and cost effective. The equipment is designed for long term, maintenance-free operations, to inherently generate a sparse primary dataset that only includes detected anomalies (animal presence information), and to allow robust real-time automated animal classification/identification with a low data bandwidth requirement. Advantages of the technology over others currently being used or being considered for MHK monitoring include: Unlike a conventional camera, the depth of field is near-infinite and limited by attenuation (approximately 5-8 m) rather than focal properties of a lens; Operation in an adaptive mode which can project a sparse grid of pulses with higher peak power for longer range detection (>10 meters) and track animals within a zone of interest with high resolution imagery for identification of marine life at closer range (<5m); System detection limit and Signal-to-Noise-Ratio is superior to a camera, due to rejection of both backscattering component and ambient solar background; Multiple wide-angle pulsed laser illuminators and bucket detectors can be flexibly configured to cover a 4pi steradian (i.e. omnidirectional) scene volume, while also retrieving 3D features of animal targets from timing information; Process and classification framework centered around a novel active learning and incremental classification classifier that enables accurate identification of a variety of marine animals automatically; A two-tiered monitoring architecture and invisible watermarking-based data archiving and retrieving approach ensures significant data reduction while preserving high fidelity monitoring. A methodology to train and optimize the classifier for target species of concern to optimize site monitoring effectiveness. This technological innovation addresses a high priority regulatory requirement to observe marine life interaction near MHK projects. Our solution improves resource manager confidence that any interactions between marine animals and equipment are observed in a cost-effective and automated manner. Without EERE funding, this novel application of multi-static LiDAR would not have been available to the MHK community for environmental monitoring.

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A Review of Modeling Approaches for Understanding and Monitoring the Environmental Effects of Marine Renewable Energy

Understanding the environmental effects of marine energy (ME) devices is fundamental for their sustainable development and efficient regulation. However, measuring effects is difficult given the limited number of operational devices currently deployed. Numerical modeling is a powerful tool for estimating environmental effects and quantifying risks. It is most effective when informed by empirical data and coordinated with the development and implementation of monitoring protocols. We reviewed modeling techniques and information needs for six environmental stressor–receptor interactions related to ME: changes in oceanographic systems, underwater noise, electromagnetic fields (EMFs), changes in habitat, collision risk, and displacement of marine animals. This review considers the effects of tidal, wave, and ocean current energy converters. We summarized the availability and maturity of models for each stressor–receptor interaction and provide examples involving ME devices when available and analogous examples otherwise. Models for oceanographic systems and underwater noise were widely available and sometimes applied to ME, but need validation in real-world settings. Many methods are available for modeling habitat change and displacement of marine animals, but few examples related to ME exist. Models of collision risk and species response to EMFs are still in stages of theory development and need more observational data, particularly about species behavior near devices, to be effective. We conclude by synthesizing model status, commonalities between models, and overlapping monitoring needs that can be exploited to develop a coordinated and efficient set of protocols for predicting and monitoring the environmental effects of ME.

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Dynamic characteristics of an orthogonal turbine and output-control systems for TPP with high-voltage frequency converter

A mathematical description of a closed control system with allowance for pressure fluctuations in the head system, which makes it possible to analyze the regime stability of orthogonal generating sets at tidal electric power plants when operating in the complete range of heads, outputs, and rotational speeds, and to select parameters of the control system, is obtained for an orthogonal hydroturbine and a generator with a load regulator.

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RivGen Acoustic Measurements, Igiugig, AK

Drifting hydrophone measurements obtained around the Ocean Renewable Power Company RivGen turbine near the village of Igiugig, Alaska in August, 2014. Each data set contains hydrophone voltage (as well as gain and sensitivity), position on the river (LAT, LONG, and proximity to turbine [xt, yt]), drift velocity, and contextual meteorological data.

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Triton Field Trials Changes in Habitat 360-degree Underwater Videos

This dataset contains the underwater 360-degree video files recorded with a Boxfish 360 camera in La Jolla, CA, near a gravity base anchor of the CalWave xWave wave energy converter in December 2021 over three days, at dawn, noon, and dusk. It was generated to test the ability of using this type of camera mounted on an aluminum frame as a video lander to monitor the artificial reef effect of marine energy devices and associated seafloor structures. The Boxfish 360 is made of 3 cameras each recording its own set of videos. The videos are MOV files that can be viewed individually with any video reader but need to be stitched together to create the 360-degree footage. This dataset contains all the raw video files collected at dawn, noon and dusk on 11/30/2021, 12/01/2021 and 12/02/2021, for about 1h each time. This dataset is associated with the journal manuscript below (linked in resources): Hemery, L.G.; Mackereth, K.F.; Gunn, C.M.; Pablo, E.B. Use of a 360-Degree Underwater Camera to Characterize Artificial Reef and Fish Aggregating Effects around Marine Energy Devices. J. Mar. Sci. Eng. 2022, 10, 555. https://doi.org/10.3390/jmse10050555

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