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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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NASA NTRS1975

Application of solar energy; Proceedings of the First Southeastern Conference, Huntsville, Ala., March 24-26, 1975

Topics related to architectural and institutional considerations are discussed along with studies of components and subsystems. Subjects in the area of system design and analysis are also explored. Residential and commercial applications are considered, taking into account hot-water usage in a typical single-family residence, solar heating and cooling of mobile homes, aspects of design and performance in the case of a solar heating system using a reflective pyramid optical condenser, solar heating in a Boston school, a performance analysis of solar service hot water systems, comparative performance analyses of three solar heated and cooled buildings, and the use of solar energy in a soybeam processing operation. Applications related to power generation are also examined, giving attention to solar thermal electric power systems and photovoltaic research. Individual items are announced in this issue.

Wu, S. T.↗

NASA NTRS2023

Type II Radio Bursts and Their Association With Coronal Mass Ejections in Solar Cycles 23 and 24

Context. Meter-wavelength type II solar radio bursts are thought to be the signatures of shock-accelerated electrons in the corona. Studying these bursts can give information about the initial kinematics, dynamics, and energetics of coronal mass ejections (CMEs) in the absence of white-light observations. Aims. We investigate the occurrence of type II bursts in solar cycles 23 and 24 and their association with CMEs. We also explore whether type II bursts might occur in the absence of a CME. Methods. We performed a statistical analysis of type II bursts that occurred between 200 and 25 MHz in solar cycles 23 and 24 and determined the temporal association of these radio bursts with CMEs. We categorized the CMEs based on their linear speed and angular width and studied the distribution of type II bursts with fast (≥500 km s−1 ), slow (<500 km s−1), wide (≥60◦), and narrow (<60◦) CMEs. We explored the dependence of type II bursts occurrence on the phases of the solar cycle. Results. Our analysis shows that during solar cycles 23 and 24, 768 and 435 type II bursts occurred, respectively. Of these, 79% were associated with CMEs in solar cycle 23, and 95% were associated with CMEs in solar cycle 24. However, only 4% and 3% of the total number of CMEs were accompanied by type II bursts in solar cycle 23 and 24, respectively. Most of the type II bursts in both cycles were related to fast and wide CMEs (48%). We also determined the typical drift rate and duration for type II bursts, which is 0.06 MHz s−1 and 9 min. Our results suggest that type II bursts dominate at heights ≈1.7−2.3±0.3 R . A clear majority have an onset height around 1.7 ± 0.3 R assuming the four-fold Newkirk model. Conclusions. The results indicate that most of the type II bursts had a white-light CME counterpart, but a few type II bursts lacked a clear CME association. There were more CMEs in cycle 24 than in cycle 23. However, cycle 24 contained fewer type II radio bursts than cycle 23. The onset heights of type II bursts and their association with wide CMEs reported in this study indicate that the early lateral expansion of CMEs may play a key role in the generation of these radio bursts.

Sun: activity↗

DOE OSTI2014

Validity of the Taylor hypothesis for linear kinetic waves in the weakly collisional solar wind

The interpretation of single-point spacecraft measurements of solar wind turbulence is complicated by the fact that the measurements are made in a frame of reference in relative motion with respect to the turbulent plasma. The Taylor hypothesis—that temporal fluctuations measured by a stationary probe in a rapidly flowing fluid are dominated by the advection of spatial structures in the fluid rest frame—is often assumed to simplify the analysis. But measurements of turbulence in upcoming missions, such as Solar Probe Plus, threaten to violate the Taylor hypothesis, either due to slow flow of the plasma with respect to the spacecraft or to the dispersive nature of the plasma fluctuations at small scales. Assuming that the frequency of the turbulent fluctuations is characterized by the frequency of the linear waves supported by the plasma, we evaluate the validity of the Taylor hypothesis for the linear kinetic wave modes in the weakly collisional solar wind. The analysis predicts that a dissipation range of solar wind turbulence supported by whistler waves is likely to violate the Taylor hypothesis, while one supported by kinetic Alfvén waves is not.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2021

REopt ® Lite Overview - Resilience Analysis: Clear Sky Tampa Bay [Slides]

Through the Solar Energy Innovation Network (SEIN), the Clear Sky Tampa Bay team, led by the Tampa Bay Regional Planning Council (TBRPC), developed a toolkit to help local governments prioritize sites for solar photovoltaics (PV) and battery energy storage in the context of resilience and emergency management. At a high level, the Clear Sky Tampa Bay process involves: (1) Identifying sites based on community resilience needs and priorities ("Where do we need a resilient energy solution?"); (2) Screening and prioritizing sites for solar PV and storage suitability based on site conditions and other factors; and (3) Using REopt Lite to screen down-selected facilities to prioritize sites based on resilience project economics. This slide deck focuses on Step 3 above, and provides a general overview of REopt Lite and suggestions and examples tailored to the Clear Sky Tampa Bay team about how to use REopt Lite for additional analysis.

14 SOLAR ENERGY↗

NASA NTRS1992

Variations in solar Lyman alpha irradiance on short time scales

Variations in solar UV irradiance at Lyman alpha are studied on short time scales (from days to months) after removing the long-term changes over the solar cycle. The SME/Lyman alpha irradiance is estimated from various solar indices using linear regression analysis. In order to study the nonlinear effects, Lyman alpha irradiance is modeled with a 5th-degree polynomial as well. It is shown that the full-disk equivalent width of the He line at 1083 nm, which is used as a proxy for the plages and active network, can best reproduce the changes observed in Lyman alpha. Approximately 72 percent of the solar-activity-related changes in Lyman alpha irradiance arise from plages and the network. The network contribution is estimated by the correlation analysis to be about 19 percent. It is shown that significant variability remains in Lyman alpha irradiance, with periods around 300, 27, and 13.5d, which is not explained by the solar activity indices. It is shown that the nonlinear effects cannot account for a significant part of the unexplained variation in Lyman alpha irradiance. Therefore, additional events (e.g., large-scale motions and/or a systematic difference in the area and intensity of the plages and network observed in the lines of Ca-K, He 1083, and Lyman alpha) may explain the discrepancies found between the observed and estimated irradiance values.

Pap, J. M.↗

NASA NTRS1986

Analysis and interpretation of the shocklike electrostatic noise observed during the AMPTE solar wind lithium releases

During the AMPTE (Active Magnetospheric Particle Tracer Explorers) solar wind lithium release on September 11, and again on September 20, 1984, an intense burst of electrostatic noise was observed near the upstream edge of the ion cloud. Comparisons with measurements by the IMP-6 and ISEE-1 spacecraft show that the spectrum and overall features of this noise are very similar to electrostatic noise observed at the Earth's bow shock. A stability analysis using realistic parameters shows that the electrostatic noise can be accounted for by an ion beam-plasma instability caused by the solar wind proton beam streaming through the nearly stationary lithium cloud. The growth rate of this instability is largest when the ion density and solar wind proton density are similar, which explains why the noise only occurs near the outer edge of the ion cloud. The similarity to the noise in the Earth's bow shock suggest that a shock may exist in the solar wind plasma flow upstream of the ion cloud. If the noise is associated with a shock, then it must be an electrostatic shock, since the ion cyclotron radii are too small for the existence of a MHD shock. Since the electrostatic instability occurs at phase velocities near the lithium thermal velocity, the electrostatic turbulence may play a role in heating the lithium ions and transferring momentum from the solar wind to the ion cloud.

Gurnett, D. A.↗

NASA NTRS1992

Cosmic dust

Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component.

Brownlee, Donald E.↗

DOE OSTI2023

Ultracompact hybrid stars consistent with multimessenger astrophysics

In this work, we consider the consequences of phase transition in dense QCD on the properties of compact stars and implications for the observational program in gravitational wave and x-ray astrophysics. The key underlying assumption of our modeling is a strong first-order phase transition past the point where the hadronic branch of compact stars reaches the two-solar mass limit. Furthermore, our analysis predicts ultracompact stars with very small radii—in the range of 6–9 km—living on compact star sequences that are entirely consistent with the current multimessenger data. We show that sequences featuring two-solar mass hadronic stars consistent with radio-pulsar observations are also consistent with the inferences of large radii for massive neutron stars by NICER x-ray observations of neutron stars and the small radii predicted by gravitational waves analysis of the binary neutron star inspiral event GW170817 for our models that feature a strong first-order QCD phase transition.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2024

Optical properties enhancement of thermal energy media for consistently high solar absorptivity

This study aimed to evaluate the optical properties of particles intended for use as thermal energy absorbers in generation 3 concentrated solar power systems. Their characterization involved UV–Vis NIR measurements with an integrating sphere for solar absorptivity, while a reflectometer was employed to measure thermal emittance. By combining absorptivity and emittance data, the solar absorption efficiency was calculated. Laser flash analysis, differential scanning calorimetry, and thermogravimetric analysis were utilized to determine thermal conductivity and specific heat. The solar absorptivity of the particles was initially measured at 0.90. After exposure to air at 1000 °C, it decreased to 0.73. However, following a reduction process, the particle recovered absorptivity of 0.90. The thermal aging and recovery were repeated multiple times, consistently achieving an absorptivity of 0.90. The thermal conductivity of the particles ranged from 0.50 to 0.88 W/(m-K). Solar absorptivity was found to be influenced by the types of iron oxide present in the particles. Particles with a predominance of hematite exhibited decreased solar absorptivity, while those containing magnetite, wüstite, and iron showed increased absorptivity. The estimated cost of the developed particles was more than ten times lower than that of current products. Given that component costs significantly impact the levelized cost of electricity (LCOE), this price reduction corresponded to an 8 % decrease in LCOE compared to other products. The low-cost thermal energy media show great promise for contributing to a reduced LCOE in the third generation of concentrating solar power systems.

14 SOLAR ENERGY↗

DOE OSTI2016

Modeled Performance of the Hathaway Solar Patriot house - Washington D.C

This Dataset contains field research raw data, analysis spreadsheet, photos, and final report from the Hathaway Solar Patriot House Building America Case Study project. This dataset details the monitored and modeled performance of a solar home outside of Washington, D.C. We modeled the home energy performance using DOE 2.2, performed numerous short-terms tests on the home, and monitored its occupied performance for 29 months. The home used modular construction, solar water heating, a ground-coupled heat pump, efficient appliances, and compact fluorescent lighting to reduce its energy consumption by 35% compared to the Building America research benchmark home. The addition of 6kW of photovoltaics (PV) increased the savings to 67% compared to the Building America research benchmark. A more efficient shell to reduce space conditioning loads would have brought the home closer to its zero energy goals. However, even with efficient lighting and appliances, the lights, appliance and plug loads were a significant energy consumer. About 4 kW of PV was required to meet the needs of these loads alone. To achieve the zero energy goal with no further efficiency increases, the Hathaway house would need about 2.6 kW of PV in addition to the 6.0 kW it now has. Applying advanced efficiency measures available or being developed, such as heat-recovery ventilation, superinsulation, and electrochromic windows, could reduce the heating, cooling, and domestic hot water (DHW) energy use to less than 1700 kWh per year, an 88% reduction in these loads from the Building America Benchmark. At this efficiency level, the appliance and plug loads come to dominate energy consumption and account for nearly 70% of the total energy use. This analysis points out that even with highly effective energy-savings technologies (pushed beyond levels currently practical), whole-house energy use reduction by efficiency measures is only about 60% without also reducing the energy use of appliances and plug loads largely considered outside the designers jurisdiction.

Array↗

NASA NTRS1978

Possible measurements of J sub 2 and the sun's angular momentum with the solar probe

The metric tensor is given for describing the dynamical effects of the sun on a solar probe and the gravitational redshift of a probe-based clock in a covariance analysis for the detectability of the solar quadrupole moment and the solar angular momentum. Unknown parameters were determined by least squares fit to the probe tracking data. A polar orbit was assumed with perihelion at 5 solar radii and with an earth-sun-probe angle of 135 deg at perihelion. Tracking was assumed to be Doppler only, with a basic uncertainity of .1 mm/sec in the radial velocity. A drag-free system which could reduce nongravitational forces below the level of 2 times 10 to the minus 12th power was found necessary to preserve this same level of accuracy. Both one way and two way Doppler were supposed in order to determine the gravitational redshift as well as the pure spacecraft dynamics.

Nordtvedt, K.↗

NASA NTRS1988

Science and applications on the space station: A strategic vision

The central themes relating to science and applications on the Space Station for fiscal year 1989 are discussed. Materials science research is proposed in a wide variety of subfields including protein crystal growth, metallurgy, and properties of fluids. Also proposed are the U.S. Polar Platform, an Extended Duration Crew Operations Project, and a long-range Space Biology Research Project to investigate plant and animal physiology, gravitational biology, life support systems, and exobiology. The exterior of the Space Station will provide attachment points for payloads to study subjects such as the earth and its environment, the sun, other bodies in the solar system, and cosmic objects. Examples of such attached payloads are given. They include a plasma interaction monitoring system, observation of solar features and properties, studies of particle radiation from the sun, cosmic dust collection and analysis, surveys of various cosmic and solar rays, measurements of rainfall and wind and the study of global changes on earth.

Source record↗

NASA NTRS1999

Data Reduction and Analysis from the SOHO Spacecraft

This paper presents a final report on Data Reduction and Analysis from The SOHO Spacecraft from November 1, 1996-October 31, 1999. The topics include: 1) Instrumentation; 2) Health of Instrument; 3) Solar Wind Web Page; 3) Data Analysis; and 4) Science. This paper also includes appendices describing routine SOHO (Solar and Heliospheric Observatory) tasks, SOHO Science Procedures in the UMTOF (University Mass Determining Time-of-Flight) System, SOHO Programs on UMTOF and a list of publications.

Ipavich, F. M.↗

NASA NTRS2012

VHF Radio Response of the near Earth Space During Solar Activity Growth in October, 2003

The analysis of observations of very high frequency radio noise intensity at the middle latitude on a frequency f = 500 MHz from 14th till 26th of October, 2003 is presented. These data are compared with the solar radio bursts in the range of frequencies 1-14 MHz registered by RAD2 receiver of the WAVES device installed on board the WIND spacecraft. The sporadic enhancement of near Earth very high frequency radio noise were observed with the help of ground radio telescope preferably either in pre mid night hours or at daytime. In many cases between October 17 and 22 short-term increases of the fluxes of low energy electrons, protons and ions in the interplanetary space by hundreds of times, corresponded to VHF radio bursts. At the same time slow increasing of solar cosmic rays streams at Lagrange point L1 and on geostationary orbit during October, 21 and 22, did not affect the usual radio noise level. A strong solar flare of 1B/X5.5 class on October 23 contributed to a prolonged rise of the intensity level of spectral radio emission, including the night sector of magnetosphere. It is assumed that very high frequency radio bursts in the near Earth space may appear when the processes of penetration of interplanetary low energy charge particles into Earth plasmasphere take place.

Dudnik, O. V.↗

DOE OSTI2025

Photometry of Outer Solar System Objects from the Dark Energy Survey. II. A Joint Analysis of Trans-Neptunian Absolute Magnitudes, Colors, Light Curves and Dynamics

For the 696 trans-Neptunian objects (TNOs) with absolute magnitudes 5.5 < H r < 8.2 detected in the Dark Energy Survey, we characterize the relationships between their dynamical state and physical properties—namely H r , indicating size; colors, indicating surface composition; and flux variation semiamplitude A, indicating asphericity and surface inhomogeneity. We seek “birth” physical distributions that can recreate these parameters in every dynamical class. We show that the observed colors of these TNOs are consistent with two Gaussian distributions in griz space, “near-infrared bright” (NIRB) and “near-infrared faint” (NIRF), presumably an inner and outer birth population, respectively. We find a model in which both the NIRB and NIRF H r and A distributions are independent of current dynamical states, supporting their assignment as birth populations. All objects are consistent with a common rolling p(H r ), but NIRF objects are significantly more variable. Cold classicals (CCs) are purely NIRF, while hot classical (HC), scattered, and detached TNOs are consistent with ≈ 70% NIRB and the resonance NIRB fractions show significant variation. The NIRB components of the HCs and of some resonances have broader inclination distributions than the NIRFs, i.e. their current dynamics retains information about birth location. We find evidence for radial stratification within the birth NIRB population, in that HC NIRBs are on average redder than detached or scattered NIRBs; a similar effect distinguishes CCs from other NIRFs. We estimate total object counts and masses of each class within our H r range. These results will strongly constrain models of the outer solar system.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS2005

Manufacture of Solar Cells on the Moon

In support of the space exploration initiative a new architecture for the production of solar cells on the lunar surface is devised. The paper discusses experimental data on the fabrication and properties of lunar glass substrates, evaporated lunar regolith thin film (antireflect coatings and insulators), and preliminary attempts in the fabrication of thin film (silicon/II-VI) photovoltaic materials on lunar regolith substrates. A conceptual design for a solar powered robotic rover capable of fabricating solar cells directly on the lunar surface is provided. Technical challenges in the development of such a facility and strategies to alleviate perceived difficulties are discussed. Finally, preliminary cost benefit ratio analysis for different in situ solar cell production scenarios (using exclusively in-situ planetary resources or hybrid) are discussed.

Freundich, Alex↗

NASA NTRS2011

A Contemporary Analysis of the O'Neill-Glaser Model for Space-Based Solar Power and Habitat Construction

In 1975 Gerard O Neill published in the journal Science a model for the construction of solar power satellites. He found that the solar power satellites suggested by Peter Glaser would be too massive to launch economically from Earth, but could be financially viable if the workforce was permanently located in free space habitats and if lunar and asteroid materials were used for construction. All new worldwide electrical generating capacity could be then achieved by solar power satellites. The project would financially break even in about 20 years after which it would generate substantial income selling power below fossil fuel prices. Two NASA / Stanford University led studies at Ames Research center during the summers of 1974 and 1976 found the concept technically sound and developed a detailed financial parametric model. Although the project was not undertaken when suggested in the 1970s, several contemporary issues make pursuing the O Neill -- Glaser concept more compelling today. First, our analysis suggests that if in the first ten years of construction that small habitats (compared to the large vista habitats envisioned by O Neill) supporting approximately 300 people were utilized, development costs of the program and the time for financial break even could be substantially improved. Second, the contemporary consensus is developing that carbon free energy is required to mitigate global climate change. It is estimated that 300 GW of new carbon free energy would be necessary per year to stabilize global atmospheric carbon. This is about 4 times greater energy demand than was considered by the O Neill Glaser model. Our analysis suggests that after the initial investments in lunar mining and space manufacturing and transportation, that the profit margin for producing space solar power is very high (even when selling power below fossil fuel prices). We have investigated the financial scaling of ground launched versus space derived space solar power satellites. We find that for the carbon mitigation case even modernized ground launched space solar power satellites are not financially viable. For space derived solar power satellites, however, the increased demand makes them break even substantially sooner and yield much higher profit. Third, current awareness is increasing about the dangers of humanity remaining a single planet species. Our technological power has been increasing relative to the size of the planet Earth. Since the middle of the 20th century our technological power has grown large relative to our planet's size. This presents a very real potential for human self-extinction. We argue that the potential for human self-extinction is increasing with time in proportion to the exponential growth of our technological power making self-extinction likely within this century if humanity remains a single planet species. The O Neill model of multiple independent free space habitats, it is argued, can protect humanity from extinction in the same way that portfolio diversification protects ones assets from total loss. We show that about 1 million people for the electricity only case, and about 1 billion people for the carbon mitigation case, can be provided with permanent space habitats and transportation from Earth in 30 years and can be funded by the space derived solar power satellite program. 1.2 Scope of this Chapter The goal of this chapter is to illustrate the power and importance of the O'Neill-Glaser concept in the context of human survival and maintaining a healthy planet Earth. We argue that at this point in human history our technological power is too dangerous to our selves and our home planet for us not to expand into space. We show by the models presented in the chapter that the imminent dangers of global warming and human self-extinction mandate that humanity move aggressively into the solar system in this generation. We show that the production of solar power satellites using space resources and with a work foe living in space provides a viable financial model to mitigate CO2 preventing the worst global warming scenarios, and safeguards humanity against self-extinction by providing hundreds of habitats and a billion people living in space within about 35 years. To accomplish this goal we need only consider the classic O'Neill-Glaser model which was parameterized for 1970's technological projections. Only habitat size optimization for the first ten years of production is added. This is a conservative approach since the innovations of the last 30 years will make the financial projections more favorable. However, the classic O'Neill-Glaser model represented a broad technological consensus. The model is well documented in the references and our calculations can be easily reproduced In this chapter the economics of the O Neill - Glaser model is compared with models that rely exclusively on Earth launched materials. Although many studies of Earth launched Solar Power Satellites have been made, we found that the NASA "Fresh Look Study" was the most comprehensive and well documented. It also provided one of the most optimistic Earth launch financial projections. We thus chose it for comparison purposes.

Curreri, Peter A.↗

DOE OSTI2018

Performance Analysis of Photovoltaic Thermal System Using Silicone Oil Spectrum Filter

The paper reports use of silicone oil as spectrum filter and heat absorber for photovoltaic thermal systems. The terrestrial solar spectrum is in the wavelength range of 0.25 to 2.5 μm. The response range of C-Si solar cell is 0.75 to 1.125 μm. In the current study, the feasibility of Silicone oil (Transformer oil) as spectrum filter cum heat absorber for C-Si solar cell is investigated. The spectroscopic analysis of 1 cm thick Silicone oil sample with UV-VIS-NIR spectrophotometer is carried out. This analysis concludes that the Silicone oil is transparent to the response range of C-Si solar cell. Also, it shows a significant absorption for UV and IR part of the spectrum. A glass container with 1 cm thick Silicone oil layer is mounted on the C-Si PV module. The performance of the system is analyzed using solar simulator at irradiance of 1000 W/m{sup 2}, AM 1.5 G and in natural sunlight at Nagpur (21.10 N, 79.090 E). The experiments were performed for the entire year for time period of one hour in the noon. With Silicone oil spectrum filter, the average electrical efficiency of the PV module was found increase marginally. However, for 10 W module, 27 W average heat gain was recorded. In this study, the surface area of PV module (30 × 35 cm = 0.105 m{sup 2}) was very small. In actual practice, for large scale installations, significant heat gain is possible. The experimentation and significant outcomes are discussed in this article.

14 SOLAR ENERGY↗