Co-crystal engineering of a two-dimensional perovskite phase for perovskite solar modules with improved efficiency and stability
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Nia, Narges↗
SEARCH · Engineering Papers
Results for “module efficiency”
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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Row spacing as a controller of solar module temperature and power output in solar farms
We report that when the temperature of solar photovoltaic modules rises, efficiency drops and module degradation accelerates. The spatial arrangement of solar modules can affect convective cooling and, consequently, module temperatures. However, the impact of row spacing on convective cooling in realistic solar farms has not yet been studied. Here, we develop six solar farm arrangements consisting of a fixed number of rows with varying streamwise row spacing. We model the flow and heat transfer of each solar farm using high-resolution large-eddy simulations. Results indicate that increasing row spacing can enhance convective cooling by 14.8%, which reduces module temperature by 6.6 °C and increases power output by 4.0% on average.
14 SOLAR ENERGY↗
Barriers and variable spacing enhance convective cooling and increase power output in solar PV plants
When the temperature of solar photovoltaic (PV) modules rises, efficiency drops and module degradation accelerates. Thus, it is beneficial to reduce module operating temperatures. Previous studies of solar power plants have illustrated that incoming flow characteristics, turbulent mixing, and array geometry can strongly impact convective cooling, as measured by the convective heat transfer coefficient h. In the fields of heat transfer and plant canopy flow, previous work has shown that system-scale arrangement modifications—e.g., variable spacing, barriers, or windbreaks—can passively alter the flow, enhance turbulent mixing, and influence convection. However, researchers have not yet explored how variable spacing or barriers might enhance convective cooling in solar power plants. Here, high-resolution large-eddy simulations model the air flow and heat transfer through solar power plant arrangements modified with missing modules and barrier walls. We then perform a control volume analysis to evaluate the net heat flux and compute h, which quantifies the influence of these spatial modifications on convective cooling and, thus, module temperature and power output. Installing barrier walls yields the greatest improvements, increasing h by 3.4%, reducing module temperature by an estimated 2.5 °C, and boosting power output by an estimated 1.4% on average. These findings indicate that incorporating variable spacing or barrier-type elements into PV plant designs can reduce module temperature and, thus, improve PV performance and service life.
14 SOLAR ENERGY↗
Efficient CO2 laser modulation internal to the cavity by methyl chloride gas
Modulation of carbon dioxide laser with Stark cell internal to cavity, using methyl chloride electrooptical gas
Landman, A.↗
The investigation of bandwidth efficient coding and modulation techniques
The New Mexico State University Center for Space Telemetering and Telecommunications systems has been, and is currently, engaged in the investigation of trellis-coded modulation (TCM) communication systems. In particular, TCM utilizing M-ary phase shift keying is being studied. The study of carrier synchronization in a TCM environment, or in MPSK systems in general, has been one of the two main thrusts of this grant. This study has involved both theoretical modelling and software simulation of the carrier synchronization problem.
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High efficiency translucent solar module integrated with greenhouse roof structures
A translucent solar module assembly for integration with a greenhouse having a frame with a plurality of roof supports includes a pair of brackets attachable to each of the plurality of roof supports, a bi-facial solar panel attachable to the pair of brackets, and a pair of reflector rails attachable to each of the plurality of roof supports. A dichroic reflector is attachable to the pair of reflector rails.
Pan, Wei↗
Ultra-Efficient Intra-Module Balancing DC Optimizer for Solar Systems
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Solar Optimizer, Shade Tolerance, Max Power Point ↗
Bandwidth efficient trellis-coded modulation with prescribed decoding delay - new interpretations and results
Motivated by previous work of Li and Rimoldi for obtaining bandwidth efficient TCM signals with finite decoding delay, we present an alternative representation for their encoder/signal mapper transmitter structure which merely consists of a single filter having an input equal to the equivalent of the inoput data bits in their implementation.
trellis coding bandwidth efficient modulation digi↗
High efficiency low cost monolithic module for SARSAT distress beacons
The program objectives were to develop a highly efficient, low cost RF module for SARSAT beacons; achieve significantly lower battery current drain, amount of heat generated, and size of battery required; utilize MMIC technology to improve efficiency, reliability, packaging, and cost; and provide a technology database for GaAs based UHF RF circuit architectures. Presented in viewgraph form are functional block diagrams of the SARSAT distress beacon and beacon RF module as well as performance goals, schematic diagrams, predicted performances, and measured performances for the phase modulator and power amplifier.
Petersen, Wendell C.↗
Systems and methods for reworking shingled solar cell modules
A high efficiency configuration for a solar cell module comprises solar cells arranged in a shingled manner to form super cells, which may be arranged to efficiently use the area of the solar module, reduce series resistance, and increase module efficiency. Removing a defective solar cell from a super cell may be difficult, however. It may therefore be advantageous to bypass defective solar cells in a super cell rather than remove and replace them. A bypass conductor may be applied to the rear surface of the super cell to bypass one or more defective solar cells in a super cell or in a solar module comprising super cells.
Caswell, Nathaniel Alexis↗
Large-area high-efficiency ion-implanted cells and flat-plate modules
This paper reports the development of a flat-plate module based on highly efficient ion-implanted silicon solar cells. The cells are 53 sq cm in area and have exhibited AM 1.5 efficiencies of over 18 percent. The use of back surface reflectors to reduce module operating temperature is discussed. A comparison of various approaches to cell design is made, and module test data for these designs are presented. Module efficiency of 14 percent (25 C) is reported.
Spitzer, M. B.↗
Basic concepts for the design of high-efficiency single-junction and multibandgap solar cells
Concepts for obtaining practical solar-cell modules with one-sun efficiencies up to 30 percent at air mass 1 are now well understood. Such high-efficiency modules utilize multibandgap structures. To achieve module efficiencies significantly above 30 percent, it is necessary to employ different concepts such as spectral compression and broad-band detection. A detailed description of concepts for the design of high-efficiency multibandgap solar cells is given.
Fan, J. C. C.↗
High efficiency solar photovoltaic power module concept
The investigation of a preliminary concept for high efficiency solar power generation in space is presented. The concept was a synergistic combination of spectral splitting, tailored bandgap cells, high concentration ratios, and cool cell areas.
Bekey, I.↗
Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells
The use of molecular modulators to reduce the defect density at the surface and grain boundaries of perovskite materials has been demonstrated to be an effective approach to enhance the photovoltaic performance and device stability of perovskite solar cells. Herein, we employ crown ethers to modulate perovskite films, affording passivation of undercoordinated surface defects. This interaction has been elucidated by solid-state nuclear magnetic resonance and density functional theory calculations. The crown ether hosts induce the formation of host-guest complexes on the surface of the perovskite films, which reduces the concentration of surface electronic defects and suppresses nonradiative recombination by 40%, while minimizing moisture permeation. As a result, we achieved substantially improved photovoltaic performance with power conversion efficiencies exceeding 23%, accompanied by enhanced stability under ambient and operational conditions. This work opens a new avenue to improve the performance and stability of perovskite-based optoelectronic devices through supramolecular chemistry.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
POTATO: A Unified Assessment System for HL-LHC Outer Tracker Module Productions
The CMS detector s silicon tracker will be replaced in preparation for the upcoming High-Luminosity LHC (HL LHC) upgrade. The inner tracker will include a new pixel detector while the outer tracker (OT) will feature 5,592 pixel strip (PS) and 7,608 strip strip (2S) sensor modules with production distributed across 7 sites worldwide, requiring standardized grading and testing. One testing apparatus the burn-in box replicates the temperature cycling conditions that successful modules must withstand. The Phase-II Outer Tracker Analyzer of Test Outputs (POTATO) standardizes module evaluation and grading among testing sites. Given burn-in box test output, POTATO analyzes the results and assigns a letter grade to a module and its sub-components. POTATO's grading process must adapt to evolving standards for module evaluation; hence, we detail work on POTATO's database and grading functionality that will facilitate the unified assessment of Phase-II OT module assembly and testing worldwide. Once completed, POTATO will allow technicians to interact with a database of all graded modules and efficiently assess the global module assembly effort.
Clark, Olivia J. [U. Tennessee, Knoxville]↗
The hydrogen-bond configuration modulates the energy transfer efficiency in helical protein nanotubes
As fundamental building blocks of proteins, helices take different forms including the 3 10 -, α-, and π-helices that feature distinct H-bond networks. The H-bond connectivity is shown to modulate energy transfer efficiency in protein helical structures.
He, Jinlong↗
Low-Complexity, High-Performance Bandwidth Efficient Coding and Coded Modulation Techniques for Satellite and Space Communications
The semi-annual progress report for NASA grant NAG5-557 is presented. The report contains three papers concerning bandwidth efficient coding and coded modulation techniques for satellite and space communications.
Costello, Daniel J., Jr.↗
Thermal Modulation Methods To Improve the Efficiency of a Gas Chromatograph
Thermal modulation techniques can be used to improve capacity, resolution, and time of analysis of a gas chromatograph. Two of-the techniques developed in our laboratories include using a GC column to store a sample (sample storage system) and applying temperature programming directly onto the wall of a capillary column. The storage system developed allowed the continuous collection of a sample profile for about 3 hours and storing it for as long as 20 hours. Thereafter, the samples were eluted maintaining the individual characteristics of the components present in it. Moreover, temperature programming was done directly on a capillary column improving the time of analysis and resolution of a mixture containing light hydrocarbons.
Valentin, J. R.↗