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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Seasonal variation in sea turtle density and abundance in the southeast Florida current and surrounding waters

Assessment and management of sea turtle populations is often limited by a lack of available data pertaining to at-sea distributions at appropriate spatial and temporal resolutions. Assessing the spatial and temporal distributions of marine turtles in an open system poses both observational and analytical challenges due to the turtles’ highly migratory nature. Surface counts of marine turtles in waters along the southern part of Florida’s east coast were made in and adjacent to the southeast portion of the Florida Current using standard aerial surveys during 2011 and 2012 to assess their seasonal presence. This area is of particular concern for sea turtles as interest increases in offshore energy developments, specifically harnessing the power of the Florida Current. While it is understood that marine turtles use these waters, here we evaluate seasonal variation in sea turtle abundance and density over two years. Density of sea turtles observed within the study area ranged from 0.003 turtles km-2 in the winter of 2011 to 0.064 turtles km-2 in the spring of 2012. As a result, this assessment of marine turtles in the waters off southeast Florida quantifies their in-water abundance across seasons in this area to establish baselines and inform future management strategies of these protected species.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Time Scale Dependence of the Meridional Coherence of the Atlantic Meridional Overturning Circulation

The Atlantic Meridional Overturning Circulation (AMOC) variability is suggested to be incoherent between the subpolar and subtropical gyres in the Atlantic on interannual and even decadal time scales, questioning the representativeness of AMOC variability at a single latitude in modern observation and paleoreconstruction. Paleoreconstructions of the Florida Current transport suggest that Florida Current variability is associated with the AMOC on the millennial time scale, but the Rapid Climate Change (RAPID) mooring array suggests a weak correlation between the Florida Current and the AMOC. In this study, we investigate the meridional coherence of AMOC variability and the relationship between the Florida Current variability and the AMOC variability on different time scales in a transient 20,000-year simulation. We find that with the increase of time scales, the meridional coherence of the AMOC increases. On decadal and longer time scales, the coherent subtropical and subpolar AMOC is caused by the coherent buoyancy forcing in the subpolar gyre. Also, the Florida Current transport is highly correlated with AMOC variability on decadal and longer time scales, suggesting that observations of the Florida Current can be used to indicate AMOC variability on long time scales.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

The Grid Value of Ocean Current Energy in Florida

Ocean current energy technology has been proposed as a potential contributor to Florida's energy portfolio. There has been limited investigation of how this energy would be valued when integrated into the Florida electrical grid. This study assesses three future grid scenarios to evaluate the impact of adding zero-cost ocean current energy to each. The Resource Planning Model, a tool developed by the National Renewable Energy Laboratory, is used to identify the least-cost generation mix through 2050, with and without ocean current energy. The first scenario is a base case and assumes existing policies in which the addition of ocean current energy does not retire fossil-based technologies but variable generation technologies. In the second scenario, solar and storage technologies are lower cost, and the addition of ocean current generation enables those technologies along with wind to retire existing natural gas units earlier. In the third scenario, which requires a 95% reduction in carbon emissions from 2020 levels by 2050, ocean current energy can play a role in decarbonization along with other variable generation technologies. This analysis is intended to inform stakeholders on the opportunity, potential challenges, and overall value to the grid of ocean current technology from a reliability and availability focused perspective.

capacity expansion model↗
DOE OSTI2025

Site Identification framework and environmental compliance for floating ocean turbines in US Waters (Abstract)

Like all potential marine energy deployment sites, characterizing the site, understanding the environmental interactions with floating tidal technology, and mapping a pathway towards regulatory acceptance will be needed to site and permit ocean current development within the Florida Current. The proposed work will be based on a modeling analysis, a desk-top review and analysis, focusing on the characteristics of the ocean current technology and environmental monitoring information on the marine animals and habitats that are specific to the appropriate latitude, particularly those that are endemic to the offshore Florida area. The analysis will also describe the state and federal authorizations required for deploying a floating tidal energy technology, with an emphasis on how they differ from those in Washington, Alaska, and Maine. Environmentally compliant sites within Florida Current will be selected based on environmental, logistical, and regulatory criteria. Recommendations on monitoring needs and adaptive management practices will be provided. The need to acquire social acceptance for the Orbital Marine Power technology will also be explored and general recommendations prepared to encourage the best acceptance in the communities of interest.

16 TIDAL AND WAVE POWER↗
DOE OSTI2019

Assessing the Ability of Zonal δ 18 O Contrast in Benthic Foraminifera to Reconstruct Deglacial Evolution of Atlantic Meridional Overturning Circulation

δ 18 O in foraminifera δ 18 O c ) is a useful proxy for density, and the strength of the Atlantic Meridional Overturning Circulation (AMOC) can be reconstructed by the zonal density contrast in the Atlantic. However, whether the deglacial zonal δ 18 O c contrast can represent the AMOC change is still unclear. δ 18 O c contrast across the Florida Straits has been hypothesized as a proxy for the AMOC evolution during the last deglaciation, but the strength of Florida Current could also be influenced by wind forcing. In this work, we examine the ability of the zonal δ 18 O c contrast to reconstruct AMOC in a deglacial model simulation. The model simulation suggests that the deglacial variation of the Florida Current strength is dominated by AMOC, with the wind effect on the variation of the Florida Current being negligible. Furthermore, the δ 18 O c contrast across the western boundary along the entire Atlantic and the basin-wide δ 18 O c contrast in the North Atlantic in the upper ocean can also be used to reconstruct AMOC. However, using basin-wide δ 18 O c contrast to reconstruct AMOC in the South Atlantic is not possible at all water depths. In the subtropical South Atlantic, the basin-wide δ 18 O c contrast is decoupled from the density contrast between 400 to 600 m through the deglaciation because of the deglacial change of the Antarctic Intermediate Water. Thus, δ 18 O c is a useful proxy to reconstruct past density and in turn past AMOC, but caution has to be used when using the basin-wide δ 18 O c contrast to reconstruct the basin-wide density contrast in the South Atlantic.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

The Grid Value of Ocean Current Energy in Florida: Preprint

Ocean current technology has been proposed as a potential contributor to Florida's energy portfolio. There has been limited investigation of how this energy would be valued when integrated into the Florida electrical grid. This study assesses three future grid scenarios to evaluate the impact of adding ocean current to each. NREL's capacity expansion model, Resource Planning Model, is used to identify the least-cost generation mix through 2050, with and without ocean current. The first scenario, Business as Usual, Base case assuming current policies, ocean current does not replace fossil-based technologies. In the second scenario, we allow solar and storage to have lower costs than the first scenario which allows ocean current to retire gas earlier and more variable generation technologies to be deployed. In the third scenario, the Florida carbon constraint 95 by 2050 from 2020 levels case, ocean current can play a bigger role in decarbonization than the two other cases when coupled with other technologies.

capacity expansion model↗
DOE OSTI2013

National Open-ocean Energy Laboratory (Final Technical Report)

Under the authorization provided by Section 634 of the Energy Independence and Security Act of 2007 (P.L. 110-140), in 2009 FAU was awarded U.S. Congressionally Directed Program (CDP) funding through the U.S. Department of Energy (DOE) to investigate and develop technologies to harness the energy of the Florida Current as a source of clean, renewable, base-load power for Florida and the U.S. A second CDP award in 2010 provided additional funding in order to enhance and extend FAU’s activities. These two CDPs in 2009 and 2010 were combined into a single DOE grant, DE-EE0000319, and are the subject of this report. Subsequently, in July 2010 funding was made available under a separate contract, DE-EE0004200. Under that funding, DOE’s Wind and Water Power Program designated FAU’s state of Florida marine renewable energy (MRE) center as the Southeast National Marine Renewable Energy Center (SNMREC). This report discusses SNMREC activities funded by the DE-EE0000319 grant, but will make reference, as appropriate, to activities that require further investigation under the follow-on grant. The concept of extracting energy from the motions of the oceans has a long history. However, implementation on large scales of the technologies to effect renewable energy recovery from waves, tides, and open-ocean currents is relatively recent. DOE’s establishment of SNMREC recognizes a significant potential for ocean current energy recovery associated with the (relatively) high-speed Florida Current, the reach of the Gulf Stream System flowing through the Straits of Florida, between the Florida Peninsula and the Bahamas Archipelago. The proximity of the very large electrical load center of southeast Florida’s metropolitan area to the resource itself makes this potential all the more attractive. As attractive as this potential energy source is, it is not without its challenges. Although the technology is conceptually simple, its design and implementation in a commercially-viable fashion presents a variety of challenges. Beyond the technology itself (and, especially, the effects on the technology of the harsh oceanic environment), it is important to consider the possible environmental impacts of commercial-scale implementation of oceanic energy extraction. Further, because such implementation represents a completely new undertaking, the human resources required do not exist, so education and training programs are critical to eventual success. This project, establishing a national open-ocean energy laboratory, was designed to address each of these three challenges in a flexible framework allowing for adaptive management as the project proceeded. In particular: the technology challenge, including resource assessment, evolved during the project to recognize and address the need for a national testing facility in the ocean for small-scale prototype MRE systems developed by industry; the environmental challenge became formalized and expanded during the permitting process for such a testing facility; and the human resources/societal challenges, both in terms of the need for education and training and in terms of public acceptance of MRE, stimulated a robust outreach program far beyond that originally envisioned at SNMREC. While all of these activities at SNMREC are ongoing, a number of significant milestones (in addition to the contributions listed in the appendices) were achieved under the auspices of this award. These include: Planning and site selection for the first-phase test facility, offshore of Dania Beach, FL, including some equipment for the facility, submission of an Interim Policy Lease Application to the U.S. Department of Interior’s Bureau of Ocean Energy Management (BOEM), and completion of an Environmental Assessment by BOEM and a positive Consistency Determination by the State of Florida; Measurements using acoustic profilers of the current structure and variability in the vicinity of the site under a variety of weather conditions, seasons and time durations; Design and implementation of instrumentation for the first phase of the offshore testing facility, the wet- and top-side data acquisition systems, and shore-based analysis systems; Implementation of a laboratory-scale dynamometer system to test generators of up to 25 kW capacity using real-world (simulated) forcing; Completion of 24 months of (airborne) marine vertebrate surveys and associated analysis of sea turtle offshore activity, marine mammal vocalization research, and ocean current turbine hydrodynamic noise characterization; Development of a secondary-school (nominally grade 10) curriculum about hydrokinetic MRE, “Energy from the Oceans: The New Renewable”, and training of over 200 high-school teachers in its use and in how to educate their colleagues in application of the material in the classroom; Presentations to over 50 interested civic groups in the region on various aspects of MRE in SE Florida A series of public lectures to over 600 residents of south Florida to provide broader education on MRE. Development of an interactive kiosk for installation in local science museums. These, and other accomplishments detailed in this report contribute to a comprehensive ongoing program at the SNMREC to support the affordable, responsible, and achievable commercialization of MRE. Many of the tasks of this award are continued or will be verified with follow-on funding DE-EE0004200, and its goal: the installation of the world’s first offshore ocean current turbine testing and validation capability.

16 TIDAL AND WAVE POWER↗
DOE OSTI2011

100% DD Energy Model Update

The Miami Science Museum energy model has been used during DD to test the building's potential for energy savings as measured by ASHRAE 90.1-2007 Appendix G. This standard compares the designed building's yearly energy cost with that of a code-compliant building. The building is currently on track show 20% or better improvement over the ASHRAE 90.1-2007 Appendix G baseline; this performance would ensure minimum compliance with both LEED 2.2 and current Florida Energy Code, which both reference a less strict version of ASHRAE 90.1. In addition to being an exercise in energy code compliance, the energy model has been used as a design tool to show the relative performance benefit of individual energy conservation measures (ECMs). These ECMs are areas where the design team has improved upon code-minimum design paths to improve the energy performance of the building. By adding ECMs one a time to a code-compliant baseline building, the current analysis identifies which ECMs are most effective in helping the building meet its energy performance goals.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Measurements of Propanal Ignition Delay Times and Species Time Histories Using Shock Tube and Laser Absorption

Propanal is an aldehyde intermediate formed during the hydrocarbon combustion process. Potentially, the use of oxygenated biofuels reduces greenhouse gas emissions; however, it also results in increased toxic aldehyde by-products, mainly formaldehyde, acetaldehyde, acrolein, and propanal. These aldehydes are carcinogenic, and therefore it is important to understand their formation and destruction pathways in combustion systems. In this work, ignition delay times were measured behind reflected shock waves for stoichiometric (Φ = 1) mixtures of propanal (CH 3 CH 2 CHO) and oxygen (O 2 ) in argon bath gas at temperatures of 1129 K < T < 1696 K and pressures around 1 and 6 atm. Measurements were conducted using the kinetics shock tube facility at the University of Central Florida. Current results were compared to available data in the literature as well as to the predictions of three propanal combustion kinetic models: Politecnico di Milano (POLIMI), National University of Ireland at Galway, and McGill mechanisms. In addition, a continuous wave-distributed feedback interband cascade laser centered at 3403.4 nm was used for measuring methane (CH 4 ) and propanal time histories behind the reflected shock waves during propanal pyrolysis. Concentration time histories were obtained at temperatures between 1192 and 1388 K near 1 atm. Sensitivity analysis was carried for both ignition delay time and pyrolysis measurements to reveal the important reactions that were crucial to predicting the current experimental results. Adjustments to the POLIMI mechanism were adopted to better match the experimental data. Further research was suggested for the H abstraction reaction rates of propanal. Finally, in addition to extending the temperature and pressure region of literature ignition delay times, we provide the first high-temperature species concentration time histories during propanal pyrolysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Florida Atlantic University-Southeast National Marine Renewable Energy Center: Cooperative Research and Development Final Report, CRADA Number CRD-10-377

Florida Atlantic University's Southeast National Marine Renewable Energy Center (SNMREC) and the National Renewable Energy Laboratory's National Wind Technology Center (NWTC) will collaborate to advance research and development (R&D) of marine and hydrokinetic (MHK) renewable energy technology, specifically renewable energy captured from oceanic currents such as the Florida Current. SNMREC is endeavoring to establish infrastructure and capabilities that will form the base of a marine energy technology testing center focused on energy production from open-ocean currents and ocean thermal resources. As part of this effort, SNMREC is also aiming to create technology development tools and an experimental hydrokinetic device to operate in the Florida Current. NWTC has experience in developing testing infrastructure and modeling tools. SNMREC has expertise in ocean engineering and operations, a large inventory of ocean instrumentation, and ready access to the ocean. NWTC and SNMREC will therefore work together on numerical modeling, technology design review and testing, the development of standardized MHK instrumentation, field testing, establishing testing protocols, and moving the SNMREC testing capability through A2LA accreditation.

16 TIDAL AND WAVE POWER↗
DOE OSTI2013

Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States.

16 TIDAL AND WAVE POWER↗
DOE OSTI2023

Development of an Unmanned Mobile Current Turbine Platform: Preprint

The design and development of a prototype unmanned mobile floating platform, equipped with a custom low-flow marine current turbine for autonomously seeking and harnessing tidal/coastal currents is described. The platform is an unmanned surface vehicle in the form of a catamaran with two electric outboard motors and capabilities for autonomous navigation. An undershot water wheel, aided by a custom flow concentrator, has been selected as the basic design for the marine current turbine, which is mounted on the stern of the unmanned surface vehicle platform. The concept of operation is that the platform would navigate to a designated marine current resource, autonomously anchor at the location, align itself in the current and deploy the current turbine using a custom cable-lift deployment mechanism. As the turbine harnesses the local current, an onboard power-take-off device converts the harnessed mechanical energy to electricity which is stored in onboard batteries. Considerations of deployment in tidal and coastal waters required obtaining the necessary environmental permits for conducting in-water testing; developing required mitigation measures in protecting local wildlife and their habitats; and identifying potential in-water test sites and surveying them for their suitability in terms of the current resource, bottom type, water depth, and local boat traffic. The design and development of the turbine and the results of initial in-water testing are discussed. The potential for scaling up the system for extended capacity is presented.

ENGINEERING,TIDAL AND WAVE POWER↗
DOE OSTI2014

Anchor selection study for ocean current turbines

This paper compares anchoring systems suitable for ocean current turbines, specifically those proposed to be installed off the coast of Southeast Florida near latitude 26° 5’ N. This location boasts one of the most energy dense ocean current resources, with a mean kinetic energy flux of approximately 2.34 kW/m2. Seafloor types ranging from unconstrained sediment to high relief ledges were observed during regional benthic surveys for which applicable anchor types would include deadweight, plate, pile, and drag embedment. Numerical simulations of single point moored marine hydrokinetic devices were used to extract anchor loading at a likely deployment location for mooring scopes from 1.25 to 2.0 and turbine rotor diameters between 3–50m. These anchor loading data were used for preliminary sizing of deadweight and driven plate anchors on both cohesionless and cohesive soils. Finally, the capabilities of drag embedment and pile anchors relevant to ocean current turbines are discussed. Multiple types of drag embedment anchors can support all of the predicted loads if adequate sediment exists and the loading is horizontal, while pile and H-type anchors can support all of the evaluated loading scenarios and chain-in-hole anchors can support turbines with rotor diameters up to 30m.

Florida Current↗
DOE OSTI2022

Microdroplet Electrospray Localized Laser Printing and Sintering of Nanoparticles for Passivating, Carrier-Selective Contacts (Final Technical Report)

In this project, the team used a nanoparticle electrospray laser deposition (NELD) process developed at the University of Central Florida (UCF) to address current limitations of passivating, carrier-selective contact technologies for crystalline silicon (c-Si) photovoltaic (PV) cells. The NELD process was used to print low bulk line resistivity Ag contacts directly onto transparent conductive oxides (TCOs), like indium tin oxide (ITO), for hydrogenated amorphous silicon (a-Si:H) based c-Si heterojunction (SHJ) cells without any subsequent contact firing step needed.

14 SOLAR ENERGY↗
DOE OSTI2020

Localized Flow Modification to Increase Power Capture of a Small-Scale Floating Undershot Waterwheel

The goal of the work described in this thesis is to design a flow augmentation device to increase the power capture and efficiency of a small-scale floating Under-Shot Water Wheel (USWW) currently being developed by Florida Atlantic University research funded by the U.S Department of Energy. The flow concentrator subsystem is intended to maximize the kinetic energy extracted by the marine hydrokinetic (MHK) energy collection device through modification of the local flow field across the capture plane. The primary objective is to increase the velocity and/or rate of mass inflow through the turbine through inserting a streamlined body in the region of interest. By utilizing the resulting flow field to increase hydraulic forcing on the waterwheel blades, the torque and/or RPM of the USWW can be increased. Based on experimental testing in the FAU wave tank at 1:5 prototype scale (280 mm wheel diameter) the flow concentrator was shown to produce an increase in device power coefficient of 17-55% measured over a velocity range of 0.16-0.45 m/s.

Hess, Sullivan↗
DOE OSTI2014

Trade-offs between Biofuels Energy Production, Land Use and Water Use in Florida

Objective of the presentation is to document land use and water use implications of biomass production to demonstrate the overall resources implications associated with bioethanol production for Florida’s transportation sector needs. Rationale for using biofuels (BF) is explained, so are advantages & challenges of BF production and use. Land use changes (LUC) in Florida are presented and consequences outlined. It is documented that Florida’s agricultural land is a very limited resource, with only 0.43 ac/person comparing to the global average of 1.71 ac/person. The direct relation of increased biofuels production causing increased water use is explained. Favorable climate, water resources, advanced research, traditional leading agricultural role, minor oil reserves, no refineries and increasing energy demands are the main reasons why Florida considers pursuing BF production in large scale. Eight various bioethanol crops produced in Florida were considered in this study (Miscanthus, Switchgrass, Sweet Sorghum, Corn, Elephantgrass, Sugarcane, Energycane, Eucalyptus). Biomass yield and bioethanol yield of these crops are documented. Bioethanol needs of Florida are estimated and related land requirements for the needed bioethanol production calculated. Projections for various bioethanol blends (E15 to E85) are then presented. Finally, water demand for biofuels production is quantified. It is concluded that land use requirement for production of all ethanol in E85 fuel blend in Florida is roughly the same as the total available ag land in Florida for the best yielding biofuels crops (energycane, eucalyptus). Water demand for production of all ethanol needed for E100 would increase current overall water consumption in Florida between 65% and 100% for the most common biofuels crops. Vehicular energy is only 33% of Floridians energy consumption, so even all Florida’s agricultural land was given up for biofuels, it would still produce only 33% of Florida’s total energy needs. Still, bioethanol (primarily cellulosic) produced in Florida has a potential to meet a significant portion of the State’s transportation needs. Assuming no change in food production and consumption habits in Florida, the likely result of biofuels sector expansion would be the conversion of natural lands or low-intensity agricultural lands into high-intensity biomass production and the associated increased water consumption and water quality implications.

09 BIOMASS FUELS↗
DOE OSTI2013

Design Optimization of Innovative High-Level Waste Pipeline Unplugging Technologies - 13341

Florida International University (FIU) is currently working on the development and optimization of two innovative pipeline unplugging methods: the asynchronous pulsing system (APS) and the peristaltic crawler system (PCS). Experiments were conducted on the APS to determine how air in the pipeline influences the system's performance as well as determine the effectiveness of air mitigation techniques in a pipeline. The results obtained during the experimental phase of the project, including data from pipeline pressure pulse tests along with air bubble compression tests are presented. Single-cycle pulse amplification caused by a fast-acting cylinder piston pump in 21.8, 30.5, and 43.6 m pipelines were evaluated. Experiments were conducted on fully flooded pipelines as well as pipelines that contained various amounts of air to evaluate the system's performance when air is present in the pipeline. Also presented are details of the improvements implemented to the third generation crawler system (PCS). The improvements include the redesign of the rims of the unit to accommodate a camera system that provides visual feedback of the conditions inside the pipeline. Visual feedback allows the crawler to be used as a pipeline unplugging and inspection tool. Tests conducted previously demonstrated a significant reduction of the crawler speed with increasing length of tether. Current improvements include the positioning of a pneumatic valve manifold system that is located in close proximity to the crawler, rendering tether length independent of crawler speed. Additional improvements to increase the crawler's speed were also investigated and presented. Descriptions of the test beds, which were designed to emulate possible scenarios present on the Department of Energy (DOE) pipelines, are presented. Finally, conclusions and recommendations for the systems are provided. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗