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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Evaluation of Multi-Inverter Anti-Islanding with Grid Support and Ride-Through and Investigation of Island Detection Alternatives

As utility interconnected photovoltaic systems (PV) become integrated into the electrical power system (EPS) at an increasing rate, utilities and regulators have become concerned about the potential for increased voltage and frequency deviations as well as EPS reliability and resiliency. These concerns have initiated the need to amend the utility interconnection standard to allow advanced inverter control functionalities that provide: (1) reactive power control for voltage support, (2) real (active) power control for frequency support and (3) voltage and frequency ride- through for bulk system support. The new real and reactive power modulation are intended to reduce EPS voltage and frequency deviations by mimicking the droop and excitation controls of conventional generation. The new ride-through capabilities are needed to prevent a large quantity of generation from autonomously de-energizing or disconnecting in response to a voltage or frequency deviation. These changes, however, may have the potential to interfere with autonomous anti-islanding, especially when multiple inverters from different vendors are co-located on one bus. This report presents results from an investigation of multi-inverter autonomous anti- islanding with advanced functions, and the development of a means to mitigate adverse interaction between the two.

14 SOLAR ENERGY↗
DOE OSTI2021

Marshall Islands Dose Assessment and Radioecology Program: Report on the (i) 2018 Visual Study of Exterior Concrete of the Cactus Crater Containment Structure (ii) Periodic Monitoring of Groundwater on Runit Island and (iii) Initial Health Risk Assessment from Contaminants in the Cactus Crater Containment Structure

In 2012, Congress passed P.L. 112-149, Insular Areas Act of 2011, which amended the Compact of Free Association Amendments Act of 2003 by assigning Cactus Crater containment monitoring and reporting requirements to the Secretary of Energy (Secretary). Effective January 1, 2012, the Secretary was required to “periodically (but not less frequently than every 4 years) conduct -- (I) a visual study of the concrete exterior of the Cactus Crater Containment Structure on Runit Island; and (II) a radiochemical analysis of the groundwater surrounding and in the Cactus Crater Containment Structure on Runit Island.” 48 U.S.C. 1921b(f)(1)(B)(i). The Secretary was also directed to submit to Congress a report describing the results of each visual survey and the radiochemical analysis and “a determination on whether the surveys and analyses indicate any significant change in the health risks to the people of Enewetak from the contaminants within the Cactus Crater Containment Structure.” 48 U.S.C. 1921b(f)(1)(B)(ii)(II).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1984

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island.

Wilreker, V. F.↗
NASA NTRS2022

Padre Island Water Resources: Monitoring Historic Shoreline Change and Suspended Sediment Patterns along Padre Island National Seashore

Land loss along Padre Island National Seashore threatens the safety of the recreational beach for the general public and endangers wildlife habitats and nesting sites. Historically, the Army Corps of Engineers has conducted dredging efforts to thwart erosion. Quantifying spatial and temporal variations of shoreline change is vital to understanding the interaction of land loss and historical dredging efforts. NASA DEVELOP collaborated with the National Park Service to use remote sensing to investigate the impact of dredging on Padre Island National Seashore’s shoreline. The team utilized high-resolution imagery from Maxar and Planet to create a time series of shoreline changes between 2011 and 2020, conduct shoreline extraction, and quantify shoreline changes. Additionally, the team monitored turbidity and sediment dynamics using Landsat 8 Operational Land Imager (OLI), Landsat 4 Thematic Mapper (TM), Landsat 5 TM, and Sentinel-2 MultiSpectral Instrument (MSI). Shoreline change results demonstrated an average change between 4.5 to 32 meters annually. Meanwhile, the dredging area directly north of the seashore’s Port Mansfield Channel experienced an areal gain of 152,000 m² between 2010 and 2021. The team also observed that turbidity values increased in areas close to the channel where dredging occurred, especially in the 2018 and 2021 dredging years. Dredging years corresponded with less shoreline change than years without dredging. These results will be used to better inform future partner-designed shoreline management projects in the face of continued erosion and sea level rise.

Lisa Tanh↗
DOE OSTI2012

Distributed Wind Case Study: Cross Island Farms, Wellesley Island, New York

Installing a small wind turbine can sometimes be challenging due to economics, zoning issues, public perception, and other barriers. Persistence and innovation, however, can result in a successful installation. Dani Baker and David Belding own Cross Island Farms, a 102-acre certified organic farm on Wellesley Island in northern New York. In 2009, they took their interest in renewable energy to the next level by researching the logistics of a small wind installation on their land to make their farm even more sustainable. Their renewable energy system consists of one 10-kilowatt Bergey Excel wind turbine, a solar array, and a propane-powered generator. This case study describes funding for the project and the installation process.

distributed wind↗
DOE OSTI2015

Energy Transition Initiative: Island Energy Snapshot - Commonwealth of the Northern Mariana Islands; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

This profile provides a snapshot of the energy landscape of the Commonwealth of the Northern Mariana Islands (CNMI), a commonwealth in political union with the United States that is located in the northern Pacific Ocean. CNMI’s electricity rates for residential customers range from $0.19 to $0.33 U.S. dollars (USD) per kilowatt-hour (kWh), above the average U.S. residential rate of $0.13 USD/kWh.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2016

Tectonic tremor on Vancouver Island, Cascadia, modulated by the body and surface waves of the M w 8.6 and 8.2, 2012 East Indian Ocean earthquakes: Tectonic Tremor on Vancouver Island

The 2012 East Indian Ocean earthquake (M w 8.6), so far the largest intraoceanic plate strike-slip event ever recorded, modulated tectonic tremors in the Cascadia subduction zone. The rate of tremor activity near Vancouver Island increased by about 1.5 times from its background level during the passage of seismic waves of this earthquake. In most cases of dynamic modulation, large-amplitude and long-period surface waves stimulate tremors. However, in this case even the small stress change caused by body waves generated by the 2012 earthquake modulated tremor activity. The tremor modulation continued during the passage of the surface waves, subsequent to which the tremor activity returned to background rates. Similar tremor modulation is observed during the passage of the teleseismic waves from the M w 8.2 event, which occurs about 2 h later near the M w 8.6 event. We show that dynamic stresses from back-to-back large teleseismic events can strongly influence tremor sources.

58 GEOSCIENCES↗
DOE OSTI2022

Islands Within Islands: Bacterial Phylogenetic Structure and Consortia in Hawaiian Lava Caves and Fumaroles

Lava caves, tubes, and fumaroles in Hawai‘i present a range of volcanic, oligotrophic environments from different lava flows and host unexpectedly high levels of bacterial diversity. These features provide an opportunity to study the ecological drivers that structure bacterial community diversity and assemblies in volcanic ecosystems and compare the older, more stable environments of lava tubes, to the more variable and extreme conditions of younger, geothermally active caves and fumaroles. Using 16S rRNA amplicon-based sequencing methods, we investigated the phylogenetic distinctness and diversity and identified microbial interactions and consortia through co-occurrence networks in 70 samples from lava tubes, geothermal lava caves, and fumaroles on the island of Hawai‘i. Our data illustrate that lava caves and geothermal sites harbor unique microbial communities, with very little overlap between caves or sites. We also found that older lava tubes (500–800 yrs old) hosted greater phylogenetic diversity (Faith's PD) than sites that were either geothermally active or younger (<400 yrs old). Geothermally active sites had a greater number of interactions and complexity than lava tubes. Average phylogenetic distinctness, a measure of the phylogenetic relatedness of a community, was higher than would be expected if communities were structured at random. This suggests that bacterial communities of Hawaiian volcanic environments are phylogenetically over-dispersed and that competitive exclusion is the main driver in structuring these communities. This was supported by network analyses that found that taxa (Class level) co-occurred with more distantly related organisms than close relatives, particularly in geothermal sites. Network “hubs” (taxa of potentially higher ecological importance) were not the most abundant taxa in either geothermal sites or lava tubes and were identified as unknown families or genera of the phyla, Chloroflexi and Acidobacteria. These results highlight the need for further study on the ecological role of microbes in caves through targeted culturing methods, metagenomics, and long-read sequence technologies.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Energy Resilience Planning For Remote, Island, And Islanded Communities

This webinar is intended to educate prospective applicants on the Energy Transitions Initiative Partnership Project (ETIPP). It includes a general description of what ETIPP does, who the ETIPP partners are, the types of technical assistance ETIPP might provide communities, and what the technical assistance application process involves.

44 EE - Strategic Programs, Energy Transition Init↗