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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Strip sensor performance in prototype modules built for ATLAS ITk

ATLAS experiment is preparing an upgrade of its detector for High-Luminosity LHC (HL-LHC) operation. The upgrade involves installation of the new all-silicon Inner Tracker (ITk). In the context of the ITk preparations, more than 80 strip modules were built with prototype barrel sensors. They were tested with electrical readout on a per-channel basis. In general, an excellent performance was observed, consistent with previous ASIC-level and sensor-level tests. However, the lessons learned included two phenomena important for the future phases of the project. First was the need to store and test the modules in a dry environment due to humidity sensitivity of the sensors. The second was an observation of high noise regions for 2 modules. The high noise regions were tested further in several ways, including monitoring the performance as a function of time and bias voltage. Additionally, direct sensor-level tests were performed on the affected channels. The inter-strip resistance and bias resistance tests showed low values, indicating a temporary loss of the inter-strip isolation. A subsequent recovery of the noise performance was observed. Here we present the test details, an analysis of how the inter-strip isolation affects the module noise, and the relationship with sensor-level quality control tests.

47 OTHER INSTRUMENTATION↗
DOE OSTI2023

The MOOSE electromagnetics module

The Multiphysics Object-Oriented Simulation Environment (MOOSE) electromagnetics module has been developed to increase MOOSE physics module capabilities, enabling standalone and coupled computational electromagnetics within the MOOSE multiphysics ecosystem. The module is actively being utilized in the areas of plasma physics and advanced manufacturing, and it currently provides initial demonstrated capability in multi-dimensional, complex-valued electromagnetic wave propagation, electrostatic contact, reflection and transmission, and electromagnetic eigenvalue problems. Two-dimensional wave propagation and one-dimensional wave reflection and transmission are showcased as examples in this work. The modularity, parallelism, and plug-in infrastructure for custom future development is inherited from MOOSE itself, and the module can be used with both MOOSE-based and external codes, giving great flexibility.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

Numerical method for angle-of-incidence correction factors for diffuse radiation incident photovoltaic modules

Here, a numerical method is provided for solving the integral equation for the angle-of-incidence (AOI) correction factor for diffuse radiation incident photovoltaic (PV) modules. The types of diffuse radiation considered include sky, circumsolar, horizon, and ground-reflected. The method permits PV module AOI characteristics to be addressed when calculating AOI losses associated with diffuse radiation. Pseudo code is provided to aid users in the implementation, and results are shown for PV modules with tilt angles from 0° to 90°. Diffuse AOI losses are greatest for small PV module tilt angles. Including AOI losses associated with the diffuse irradiance will improve predictions of PV system performance.

14 SOLAR ENERGY↗
DOE OSTI2017

Identification and Analysis of Partial Shading Breakdown Sites in CuIn x Ga (1-x) Se 2 Modules

In this paper, CuIn x Ga (1-x) (CIGS) mini-modules are stressed under reverse bias, resembling partial shading conditions, to predict and characterize where failures occur. Partial shading can cause permanent damage in the form of 'wormlike' defects on thin-film modules due to thermal runaway. This results in module-scale power losses. We have used dark lock-in thermography (DLIT) to spatially observe localized heating when reverse-bias breakdown occurs on various CIGS mini-modules. For better understanding of how and where these defects originated and propagated, we have developed techniques where the current is limited during reverse-bias stressing. This allows for DLIT-based detection and detailed studying of the region where breakdown is initiated before thermal runaway leads to permanent damage. Statistics of breakdown sites using current-limited conditions has allowed for reasonable identification of the as-grown defects where permanent breakdown will likely originate. Scanning electron microscope results and wormlike defect analysis show that breakdown originates in defects such as small pits, craters, or cracks in the CIGS layer, and the wormlike defects propagate near the top CIGS interface.

14 SOLAR ENERGY↗
DOE OSTI2022

Cell dark current–voltage from non-calibrated module electroluminescence image analysis

Here, we present a fast, accurate, and reliable method of obtaining cell dark current–voltage (I–V) curves from module electroluminescence (EL) images without requiring calibration or correction. For a pristine module, EL-derived dark I–V are compared to directly probed data for a variety of changing imaging parameters: camera sensor, lens, filter, aperture width, exposure time (level of sensor saturation), number of images used, and various combinations of these. Pristine modules and those experiencing different modes and degrees of degradation are examined. A recent study of modules using five different cell technologies demonstrates the practicality of our “EL sweep” technique for performance and degradation studies.

14 SOLAR ENERGY↗
DOE OSTI2019

Thermomechanical residual stress evaluation in multi-crystalline silicon solar cells of photovoltaic modules with different encapsulation polymers using synchrotron X-ray microdiffraction

Photovoltaic (PV) module reliability issues, due to silicon cell cracking, are gaining more and more attention due to increasing demand for solar power and reduction of cell thickness to reduce cost. Recent reports show significant effect of encapsulation polymer material on cell cracks leading to the idea of tailoring encapsulation materials for more reliable PV modules. This paper investigates the effect of encapsulation modulus on the cell residual stress using Synchrotron scanning X-ray microdiffraction (µSXRD), which has been proven to be an effective technique to probe the stress in silicon solar cells, especially once they are encapsulated. The post lamination residual stress in the encapsulated multi-crystalline silicon (mc-Si) solar cells was reported for the first time using µSXRD in this manuscript and provide quantitative evaluation of the effect of encapsulation modulus on the cell residual stress. Further, simple approximate finite element (FE) model was also developed to evaluate the effect of the encapsulation polymer on the cell stress. The FE simulations predict the trend of the stress variation with encapsulation polymer modulus very well. Dynamic mechanical analysis and rheological testing of the encapsulation polymers was also performed to correlate the polymer behaviour with the experimental and simulated stresses. Both experimental and simulation results show a similar trend of significant cell stress variation with encapsulation polymer modulus. In the case of external loading, the temperature of load application is observed to be very significant as it dictates the elastic state of the encapsulant, leading to critical conclusion that the encapsulant needs to be selected based on elastic behaviour over the temperature history of the encapsulant during module fabrication and operation. Furthermore, the results and discussion presented are expected to be very useful for development of more reliable PV modules.

14 SOLAR ENERGY↗
DOE OSTI2020

Long-lasting strong electrostatic attraction and adhesion forces of dust particles on photovoltaic modules

Photovoltaic (PV) energy-yield loss due to solar module soiling has become increasingly important as solar module deployment is now at the hundreds of gigawatts scale and continues to grow rapidly. The electrostatic attraction and adhesion force (F es ) of dust particles by the high voltages from solar panels have been reported to be 1 to 2 orders of magnitude stronger than the van der Waals and water capillary forces, which has been corroborated by observing the increase in system voltage-induced soiling rate by setting up an outdoor test. Here, we report another characteristic of F es on soiling - long-lasting or slow decay after turning off the high voltage applied to solar panels. The F es decay time varies across a wide time range of 1 to 10 h, depending on two factors: 1) whether the cell, the particle, or both were charged with high voltage before the voltages were turned off; and 2) how the cell was connected to the ground after the voltage was turned off - either connected through the power-supply electronics, directly connected to the ground, or electrically floated. The Fes decay is understood in terms of 1) net electrical charge dissipations in both particle and cell, 2) thermal disordering of dipole polarization in the module glass dielectrics, and 3) charge redistribution by the electrostatic interaction of particle and module glass. This long-lasting F es for hours can affect the solar panel soiling after sunset, and it can have an even greater effect when combined with water condensation at night.

14 SOLAR ENERGY↗
DOE OSTI2022

Technoeconomic Analysis of High-Value, Crystalline Silicon Photovoltaic Module Recycling Processes

Recycling is an important circular economy strategy, and for photovoltaics (PV), the one that has received the greatest research attention. Recycling of PV modules is required in Europe; everywhere else it competes in the market of end-of-life options, where cost is a primary decision factor. The vast majority of PV modules sold globally are crystalline-silicon (c-Si); most of the rest of the market are cadmium telluride thin film modules whose primary manufacturer runs its own commercial-scale recycling program. While many different c-Si recycling approaches and technologies have been proposed, they generally lack accompanying cost estimates or enough process information to model costs. Herein we develop detailed estimates of seven categories of capital and operating costs along with estimates of revenue from recovered materials for each step in two proposed recycling processes for c-Si PV modules. Using these results, we develop a hypothetical third recycling process merging process steps from the original two, estimate surcharges required to achieve minimum sustainable prices for each recycling process, as well as consider how economies of scale could reduce costs. Increasing the purity of and identifying higher-value markets for recovered materials are approaches to reducing costs and increasing recycling rates in voluntary markets.

crystalline silicon↗
DOE OSTI2022

Dependence of adhesion on degradation mechanisms of ethylene co-vinyl acetate encapsulants over the lifetime of photovoltaic modules

The long-term reliability of encapsulation has a critical impact on the overall cost and effectiveness of photovoltaic modules. An often overlooked but important element of this reliability concerns adhesive degradation of the encapsulant, which results in delamination. This work critically examines the degradation mechanisms – deacetylation, β-scission, and hydrolytic depolymerization – primarily responsible for adhesion loss in ethylene co-vinyl acetate (EVA) encapsulants to provide evidence and clarity regarding the contribution of these mechanisms to the adhesive degradation over the lifetime of a module. EVA samples obtained from mini-modules exposed in two sets of controlled, accelerated conditions – with and without ultraviolet (UV) radiation – are characterized to find specific evidence for the proposed degradation mechanisms. The mini-modules were exposed up to 10,000 h, which represents up to 15–20 years in the field. Results affirm that initially, deacetylation dominates the degradation before scission takes over, followed by hydrolytic depolymerization. Additional analysis highlights the climacteric interdependency between deacetylation and hydrolytic depolymerization as it relates to eventual delamination, where deacetylation products catalyze interfacial hydrolysis reactions. Furthermore, effects occurring at a given interface are isolated, explicitly providing evidence for how these mechanisms are nonuniform throughout the thickness of the EVA. Results demonstrate that the EVA that interfaces with the glass as opposed to the cell experiences increased levels of degradation, explaining why this initially stronger interface becomes the preferential interface for delamination after longer periods of exposure. Additionally, elevated temperatures alone are shown to induce limited migration of sodium ions across the glass/EVA interface.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Protective effects of tocotrienols against lipid-induced nephropathy in experimental type-2 diabetic rats by modulation in TGF-β expression

Dyslipidemia is common in patients with diabetes mellitus (DM) and is considered a risk factor for the progression of diabetic nephropathy (DN). Hyperlipidemia and hyperglycemia act synergistically to induce renal injury. The present study was designed to investigate the protective effects of tocotrienols as tocotrienol-rich fraction (TRF) extracted from palm (PO) and rice bran oils (RBO) against lipid induced nephropathy in type-2 diabetic rats and its probable molecular mechanism. Male Wistar rats (175–200 g) were divided into four groups. The first group served as diabetic control, while the second and third groups received PO-TRF and RBO-TRF, respectively by gavage over a period of sixteen weeks post-induction of diabetes. The fourth group comprised of age-matched rats that served as normal control. The effects of TRF on serum lipid profile, oxidative stress markers, expression of TGF-β, fibronectin and collagen type IV were analyzed in the kidney of diabetic rats. Treatment with PO-TRF and RBO-TRF significantly improved glycemic status, serum lipid profile and renal function in type-2 diabetic rats. In addition, TRF supplementation down-regulated the expression of TGF-β, fibronectin and collagen type IV in the kidney of diabetic rats. Transforming growth factor-β (TGF-β) plays a critical role in progression of DN, but its modulation by tocotrienols in DN remains unexplored. TRF ameliorated lipid induced nephropathy in type-2 diabetes by its hypoglycemic, hypolipidemic and antioxidant activities as well as by modulation of TGF-β to prevent increased expression of collagen type IV and fibrinogen. We finally propose a mechanism for the expression of molecular markers that are significant in the events leading to diabetic nephropathy and its modulation by tocotrienols/TRF. - Highlights: • The nephroprotective effect of TRF in type-2 diabetic rats was investigated. • Treatment with TRF improved glycemic status, lipid profile and renal functions in rats. • TRF down-regulated the expression of TGF-β, fibronectin and collagen in rats' kidney. • TRF ameliorated nephropathy by hypoglycemic, hypolipidemic and antioxidant activity. • Tocotrienols modulate the expression of TGF-β in DN in type-2 diabetic rats.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Modulation of expression and activity of intestinal multidrug resistance-associated protein 2 by xenobiotics

The multidrug resistance-associated protein 2 (MRP2/ABCC2) is a transporter that belongs to the ATP-binding cassette (ABC) superfamily. In the intestine, it is localized to the apical membrane of the enterocyte and plays a key role in limiting the absorption of xenobiotics incorporated orally. MRP2 may also play a role in systemic clearance of xenobiotics available from the serosal side of the intestine. MRP2 transports a wide range of substrates, mainly organic anions conjugated with glucuronic acid, glutathione and sulfate and its expression can be modulated by xenobiotics at transcriptional- and post-transcriptional levels. Transcriptional regulation is usually mediated by a group of nuclear receptors. The pregnane X receptor (PXR) is a major member of this group. Relevant drugs described to up-regulate intestinal MRP2 via PXR are rifampicin, spironolactone and carbamazepine, among others. The constitutive androstane receptor (CAR, NR1I3) was also reported to modulate MRP2 expression, phenobarbital being a typical activator. Dietary compounds, including micronutrients and other natural products, are also capable of regulating intestinal MRP2 expression transcriptionally. We have given them particular attention since the composition of the food ingested daily is not necessarily supervised and may result in interactions with therapeutic drugs. Post-transcriptional regulation of MRP2 activity by xenobiotics, e.g. as a consequence of inhibitory actions, is also described in this review. Unfortunately, only few studies report on drug-drug or nutrient-drug interactions as a consequence of modulation of intestinal MRP2 activity by xenobiotics. Future clinical studies are expected to identify additional interactions resulting in changes in efficacy or safety of therapeutic drugs. - Highlights: • Intestinal MRP2 (ABCC2) expression and activity can be regulated by xenobiotics. • PXR and CAR are major MRP2 modulators through a transcriptional mechanism. • Rifampicin, spironolactone and carbamazepine among others up-regulate MRP2 via PXR. • MRP2 activity influences the availability and efficacy of drugs administered orally.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Resource recovery from urban stock, the example of cadmium and tellurium from thin film module recycling

Highlights: ► The semiconductor layer on thin-film photovoltaic modules can be removed from the glass-plate by vacuum blast cleaning. ► The separation of blasting agent and semiconductor can be performed using flotation with a valuable yield of 55%. ► PV modules are a promising source for the recovery of tellurium in the future. - Abstract: Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources.

36 MATERIALS SCIENCE↗
DOE OSTI2018

PRP4 kinase induces actin rearrangement and epithelial-mesenchymal transition through modulation of the actin-binding protein cofilin

Highlights: • PRP4 is involved in pre-mRNA splicing and cell signalling. • PRP4 modulates the actin cytoskeleton of cancer cells via RhoA activity inhibition. • PRP4 induces cofilin dephosphorylation by inhibiting the Rho-ROCK-LIMK-cofilin pathway in HCT116 cells. • Dephosphorylation of cofilin results in F-actin stabilization, re-distribution of cytoplasmic actin, formation of actin stress fibers, and inhibition of cell motility. • PRP4 over-expression induces the expressions of PP1A, which directly or indirectly dephosphorylates cofilin, resulting in actin cytoskeleton rearrangement, downregulation of E-cadherin, and EMT induction. Cofilin activation may be associated with EMT properties, and promotes the progression of human colon cancer. Cell actin cytoskeleton is primarily modulated by Rho family proteins. RhoA regulates several downstream targets, including Rho-associated protein kinase (ROCK), LIM-Kinase (LIMK), and cofilin. Pre-mRNA processing factor 4B (PRP4) modulates the actin cytoskeleton of cancer cells via RhoA activity inhibition. In this study, we discovered that PRP4 over-expression in HCT116 colon cancer cells induces cofilin dephosphorylation by inhibiting the Rho-ROCK-LIMK-cofilin pathway. Two-dimensional gel electrophoresis, and matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) analysis indicated increased expression of protein phosphatase 1A (PP1A) in PRP4-transfected HCT116 cells. The presence of PRP4 increased the expression of PP1A both at the mRNA and protein levels, which possibly activated cofilin through dephosphorylation and subsequently modulated the cell actin cytoskeleton. Furthermore, we found that PRP4 over-expression did not induce cofilin dephosphorylation in the presence of okadaic acid, a potent phosphatase inhibitor. Moreover, we discovered that PRP4 over-expression in HCT116 cells induced dephosphorylation of migration and invasion inhibitory protein (MIIP), and down-regulation of E-cadherin protein levels, which were further restored by the presence of okadaic acid. These findings indicate a possible molecular mechanism of PRP4-induced actin cytoskeleton remodeling and epithelial-mesenchymal transition, and make PRP4 an important target in colon cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Membrane cholesterol modulates STEAP2 conformation during dynamic intracellular trafficking processes leading to broad subcellular distribution

Highlights: • STEAP2 distributes broadly into multiple subcellular compartments at steady state. • Cell surface STEAP2 is a minor constituent of the total cellular STEAP2 protein pool. • STEAP2 conformation is modulated within the membrane by its cholesterol content. • STEAP2's metalloreductase activities are suppressed at the plasma membrane. • STEAP2 properties are controlled in a localization-dependent manner by cholesterol. STEAP2 is a member of the Six-Transmembrane Epithelial Antigen of the Prostate (STEAP) protein family that is proposed to function as metalloreductase. While STEAP2 shows a complex subcellular distribution pattern localizing to both secretory and endocytic pathway organelles, how such broad steady-state distribution is maintained is unknown. Similarly, whether STEAP2 undergoes any compartment-specific modulation during intracellular trafficking has not been reported. Leveraging a newly-identified monoclonal antibody that recognizes a conformation-sensitive epitope nested in the second extracellular loop of STEAP2, we demonstrate that the epitope formation was dependent on the cholesterol content of the membrane in which STEAP2 was embedded. Monitoring the STEAP2-dependent internalization of this antibody uncovered STEAP2's rapid internalization from the cell surface and their subsequence trafficking to the Golgi region and endosome-like puncta. Acute inhibition of endocytosis also increased the detectable amount of STEAP2 at the plasma membrane. Collectively, these experiments demonstrate that an intricate balance of membrane flux between the secretory and endocytic pathways underlies the characteristic broad subcellular localization of STEAP2. By using a cell-based assay that detects the metalloreductase functions of cell surface-localizing STEAP4, STEAP2's metalloreductase activities were not detectable, suggesting that its enzymatic function is suppressed at the plasma membrane. The conformational modulation of STEAP2 by the local membrane cholesterol content can therefore serve as a potential mechanism to modulate STEAP2 function in a compartment-restricted manner, by coupling a pre-existing difference in cholesterol content among different cellular membranes to a dynamic trafficking process leading to broad subcellular distribution.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

On reduced modelling of the modulational dynamics in magnetohydrodynamics

This paper explores structure formation in two-dimensional magnetohydrodynamic (MHD) turbulence as a modulational instability (MI) of turbulent fluctuations. We focus on the early stages of structure formation and consider simple backgrounds that allow for a tractable model of the MI while retaining the full chain of modulational harmonics. This approach allows us to systematically examine the validity of popular closures such as the quasilinear approximation and other low-order truncations. We find that, although such simple closures can provide quantitatively accurate approximations of the MI growth rates in some regimes, they can fail to capture the modulational dynamics in adjacent regimes even qualitatively, falsely predicting MI when the system is actually stable. We find that this discrepancy is due to the excitation of propagating spectral waves (PSWs) which can ballistically transport energy along the modulational spectrum, unimpeded until dissipative scales, thereby breaking the feedback loops that would otherwise sustain MIs. The PSWs can be self-maintained as global modes with real frequencies and drain energy from the primary structure at a constant rate until the primary structure is depleted. To describe these waves within a reduced model, we propose an approximate spectral closure that captures them and MIs on the same footing. We also find that introducing corrections to ideal MHD, conservative or dissipative, can suppress PSWs and reinstate the accuracy of the quasilinear approximation. In this sense, ideal MHD is a ‘singular’ system that is particularly sensitive to the accuracy of the closure within mean-field models.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2016

Gigahertz acoustic vibrations of elastically anisotropic Indium–tin-oxide nanorod arrays [Gigahertz modulation of the full visible spectrum via acoustic vibrations of elastically anisotropic Indium-tin-oxide nanorod arrays]

Active control of light is important for photonic integrated circuits, optical switches,. and telecommunications. Coupling light with acoustic vibrations in nanoscale optical resonators offers optical modulation capabilities with high bandwidth and Small footprint Instead of using noble metals, here we introduce indium tin-oxide nanorod arrays (ITO-NRAs) as the operating media;and demonstrate optical modulation covering the visible spectral range (from 360 to 700 nm), with similar to 20 GHz bandwidth through the excitation of coherent acoustic vibrations in ITO-NRAs. This broadband modulation results from the collective optical diffraction by the dielectric ITO-NRAs, and a high differential transmission modulation up to 10% is achieved through efficient near-infrared, on-plasmon-resonance pumping. By combining the frequency signatures Of the vibrational modes with finite-element simulations, we,further determine the anisotropic elastic constants for single-crystalline ITO, which are not known-for the bulk phase. Furthermore, this technique to determine elastic constants using Coherent acoustic vibrations of uniform nanostructures can be generalized to the study of other inorganic materials.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Advanced X-ray Scattering and Spectroscopy Characterization of an Antisoiling Coating for Solar Module Glass

When dust and other particulates accumulate on the surface of solar modules, the power output of these soiled modules is significantly reduced. To combat this issue, antisoiling coatings can be placed on the top glass surface of solar modules. While there exists some understanding of how antisoiling coatings reduce soiling and reflection losses, approaches to characterize the durability and stability of the chemistry and morphology of antisoiling PV glass module coatings and how they evolve in response to soiling interactions are currently underdeveloped. Here we present the use of small-angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) as a methodology for studying the morphology and chemistry of pristine and soiled antisoiling coatings. Here, this work demonstrates the effectiveness of SAXS in observing coating morphology despite the presence of soil surface layers—a capability which sets it apart as a strong characterization tool for antisoiling coatings on PV glass. XPS and XAS are used as complementary techniques to characterize the evolution of coating surface chemistry before and after soiling. XAS is shown to detect subtle chemical changes in the coating surface that cannot be detected by XPS.

14 SOLAR ENERGY↗
DOE OSTI2021

Conformal High-Power-Density Half-Heusler Thermoelectric Modules: A Pathway toward Practical Power Generators

Thermoelectric generators (TEGs) exploiting the Seebeck effect provide a promising solution for waste heat recovery. Among the large number of thermoelectric (TE) materials, half-Heusler (hH) alloys are leading candidates for medium- to high-temperature power generation applications. However, the fundamental challenge in this field has been inhomogeneous material properties at large wafer diameters, insufficient power output from the modules, and rigid form factors of TE modules. This has restricted the transition of TEGs in practical applications for over three decades. Here, we successfully demonstrate large diameter wafers with uniform TE properties, high-power conformal hH TE modules for high-temperature application, and their direct integration on flue gas platforms, such as cylindrical tubes, to form large area flexible TEGs. This new conformal architecture design provides a breakthrough toward medium-/high-temperature TEGs over the conventional BiTe- and polymer-based flexible TEG design. In this work, a variable fill factor and greater flexibility due to the conformal design result in higher device performance as compared to conventional rigid TEG devices. Modules with 72-couple hH legs exhibit a device high-power-density of 3.13 W cm-2 and a total output power of 56.6 W under a temperature difference of 570 degrees C. These results provide a promising pathway toward widespread utilization of thermoelectric technology into the waste heat recovery application and will have a significant impact on the development of practical thermal to electrical converters.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗