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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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This profile provides a snapshot of the energy landscape of the Commonwealth of Puerto Rico - a U.S. territory located about 60 miles east of the Dominican Republic and directly west of the U.S. Virgin Islands.
This profile provides a snapshot of the energy landscape of American Samoa, the southernmost territory of the United States. American Samoa's residential electricity rates are approximately $0.33 U.S. dollars (USD) per kilowatt-hour (kWh), more than twice the average U.S. residential rate of $0.13 USD/kWh.
With the advent of powerful computers, first principle calculations have become a robust and reliable tool to complement experiments in the study of materials. First principle calculations such as density functional theory can be used to guide experiments to save time and effort when it comes to new and advanced materials discovery. Study of charge defects in materials and crystal structure prediction are such areas in which density functional theory calculations facilitate the prediction of defect formation energy, charge transition levels and elemental site occupations. Experimentally, studying charge defects requires inferring results from various techniques. Likewise, determining site occupancies for similar elements using experimental techniques is challenging and sometimes impossible. In this work, we study the charged intrinsic and extrinsic defects and defect complexes in phosphorene and determine the site occupancies of Al, Fe and Si in the τ11 phase using density functional theory. In the defect work, we calculate the defect formation energy, charge transition level, binding energies and Stokes shift for vacancy, dopant substitution and dopant-vacancy defect complexes in phosphorene. We found that vacancy defect in phosphorene becomes negatively charged in n-type doping and may passivate the dopants and reduce carrier concentration and mobility. For non-metal dopants in phosphorene, we predict that O, S and Si prefer to form dopant-vacancy complexes removing the vacancy defect states from the band gap. Mn dopant-vacancy defect complex exhibits possibility of switching between two magnetic spin states. Lastly, using density functional theory, we complement the results from neutron powder diffraction to determine the site occupancies of Al and Si in τ11 phase which was used to determine the alloying element to develop a high temperature and low density alloy.
This profile provides a snapshot of the energy landscape of Belize, a Central American country bordering Mexico to the north, Guatemala to the west and south, and the Caribbean Sea to the east. Although not an island nation, Belize is included in this energy snapshot series because it is a member of the Caribbean Community (CARICOM), an alliance of 15 Caribbean nations in the region.
This profile provides a snapshot of the energy landscape of Anguilla, a British overseas territory in the Caribbean.
This profile provides a snapshot of the energy landscape of Bonaire, a special municipality of the Kingdom of the Netherlands located off the coast of Venezuela. Bonaire’s utility rates are approximately $0.22 per kilowatt-hour (kWh), plus fixed use monthly charges that are based upon connection capacity.
This profile provides a snapshot of the energy landscape of Barbados, an independent nation in the Lesser Antilles island chain in the eastern Caribbean. Barbados' residential electricity rates are approximately $0.25 per kilowatt-hour (kWh).
This profile provides a snapshot of the energy landscape of the northeast Caribbean island Saint Martin. The island is divided between two nations, France in the north (Saint-Martin) and the Netherlands in the south (Sint Maarten).
This profile provides a snapshot of the energy landscape of Aruba, an autonomous member of the Kingdom of the Netherlands located off the coast of Venezuela.
This profile provides a snapshot of the energy landscape of Jamaica, an island nation located in the north Caribbean Sea. Jamaica has set a national target of producing 30% of the country's electricity from renewable energy by 2030.
This profile provides a snapshot of the energy landscape for Guyana, a country on the northern mainland of South America that is culturally tied to the Caribbean. In the Nationally Determined Contributions, Guyana has committed to develop a mix of wind, solar, biomass and hydro-power to supply both demand of the national grid and the energy requirements for towns and villages in Guyana’s hinterland. Guyana has set an ambitious target of achieving close to 100% renewable energy in the power sector by 2025.
This profile provides a snapshot of the energy landscape of Antigua and Barbuda, an independent nation in the Leeward Islands in the eastern Caribbean Sea. Antigua and Barbuda's base residential utility rates are approximately $0.15 U.S. dollars (USD) per kilowatt-hour (kWh) plus a variable fuel charge.
This profile provides a snapshot of the energy profile of the Cayman Islands, a British Overseas Territory, encompasses 3 islands in the western Caribbean Sea. Grand Cayman, Cayman Brac, and Little Cayman.
Puerto Rico has committed to meeting its electricity needs with 100% renewable energy by 2050, along with realizing interim goals of 40% by 2025, 60% by 2040, the phase-out of coal-fired generation by 2028, and a 30% improvement in energy efficiency by 2040, as established in Puerto Rico Energy Public Policy Act (Act 17). Since hurricanes Irma and Maria in September 2017, DOE and its national laboratories have provided Puerto Rico energy system stakeholders with tools, training, and modeling support to enable planning and operation of the electric power grid with more resilience against further disruptions. On February 2, 2022, DOE, FEMA, and six national laboratories launched the two-year Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy Study (PR100) to conduct comprehensive analysis of stakeholder-driven pathways to Puerto Rico's energy future. The robust and objective energy analysis entails five activities, with an emphasis on power system reliability, resilience, and generation planning. This presentation provides a six-month progress update on the study, including presentation of four initial scenario frameworks defined with extensive stakeholder input.
Studies exploring long-term energy system transitions rely on resource cost-supply curves derived from estimates of renewable energy (RE) potentials to generate wind and solar power projections. However, estimates of RE potentials are characterized by large uncertainties stemming from methodological assumptions that vary across studies, including factors such as the suitability of land and the performance and configuration of technology. Based on a synthesis of modeling approaches and parameter values used in prior studies, we explore the implications of these uncertain assumptions for onshore wind and solar photovoltaic electricity generation projections globally using the Global Change Analysis Model. We show that variability in parametric assumptions related to land use (e.g. land suitability) are responsible for the most substantial uncertainty in both wind and solar generation projections. Additionally, assumptions about the average turbine installation density and turbine technology are responsible for substantial uncertainty in wind generation projections. Under scenarios that account for climate impacts on wind and solar energy, we find that these parametric uncertainties are far more significant than those emerging from differences in climate models and scenarios in a global assessment, but uncertainty surrounding climate impacts (across models and scenarios) have significant effects regionally, especially for wind. Our analysis suggests the need for studies focusing on long-term energy system transitions to account for this uncertainty.
Atomically-thin two-dimensional (2D) materials face significant energy barriers for synthesis and processing into functional metastable phases such as Janus structures. Here, in this study, the controllable implantation of hyperthermal species from pulsed laser deposition (PLD) plasmas is introduced as a top-down method to compositionally engineer 2D monolayers. The kinetic energies of Se clusters impinging on suspended monolayer WS 2 crystals were controlled in the <10 eV/atom range with in situ plasma diagnostics to determine the thresholds for selective top layer replacement of sulfur by selenium for the formation of high quality WSSe Janus monolayers at low (300 °C) temperatures, and bottom layer replacement for complete conversion to WSe 2 . Atomic-resolution electron microscopy and spectroscopy in tilted geometry confirm the WSSe Janus monolayer. Molecular dynamics simulations reveal that Se clusters implant to form disordered metastable alloy regions, which then recrystallize to form highly ordered structures, opening the door for low-energy implantation by PLD as a novel method to explore the synthesis of 2D Janus layers and alloys of variable composition.
This profile provides a snapshot of the energy landscape of the British Virgin Islands (BVI), one of three sets of the Virgin Island territories in an archipelago making up the northern portion of the Lesser Antilles.
The current worldwide energy supply is insufficient to meet the rising demand. As a result, the energy prices are expected to keep soaring despite the recent increases in a variety of renewable energy resources. Although not renewable, shale oil and gas — “unconventional” hydrocarbon resources are relatively clean forms of energy resources, which still hold a vast share of the energy market. For many oil and gas companies, meeting profitable production goals from shale reservoirs is sometimes challenging, due to the loss of fracture conductivity and premature declines in the production. In this paper we investigate the stress-dependent changes in the hydraulic conductivity of proppant-filled fractures and mechanical fracture–proppant interactions in Caney Shale, a calcareous, organic-rich mudrock, through laboratory experiments and numerical modeling. American Petroleum Institute (API) fracture conductivity tests were conducted using 2% KCl on five locations within the Caney Shale that consisted of selecting three brittle (reservoir) zones and two ductile zones. Confining pressures ranged from 1,000 psi to 12,000 psi at 210 °F. Conductivity, permeability as well as embedment were measured during the test. Also, an additional, laboratory in-situ visualization test was conducted to examine the detailed proppant-shale matrix interaction under elevated stress (3,920 psi effective stress) and temperature (252 °F), with a synthetic reservoir fluid. Our experimental results have confirmed that improved fracture conductivity is attributed to proppant size, and that the increase in porosity of the proppant pack, closure pressure changes and the reduction in fracture conductivity are a function of many factors such as fracture closure stress.