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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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The PV lifetime project must select a sample size (number of PV modules) for each PV system to be deployed. In this memorandum, we show how the uncertainty in measured degradation depends on the selected sample size.
LLNL and Optiphase resarched fiber optic based fluorescence lifetime instrumentation which, through the incorporation of innovative technology supplied by Optiphase Inc., could lead to a reliable, simplified, and low-cost system mutually compatible with future interests of the company and the long-term stability requirements of ESP sensors.
Started in 2016, the PV Lifetime Project is measuring PV module and system degradation profiles over time with the aim of distinguishing different module types and technology. Outdoor energy monitoring in different climates is supplemented with regular testing under repeatable test conditions indoors. The focus is on the PV module, as well as other hardware components (junction boxes, bypass diodes, and module-level electronics) attached to it. Hardware is installed at Sandia National Laboratories in New Mexico, at the National Renewable Energy Laboratory in Colorado, and at the University of Central Florida. The systems are continuously monitored for DC current and voltage, as well as periodic I-V curves at the string level. In the future, once degradation trends have been identified with more certainty, results will be made available to the public online. This data is expected to enable an increase in the accuracy and precision of degradation profiles used in yield assessments that support investments made in new PV plants. Current practice is to assume that degradation is constant over the life of the system. Forthcoming results in the next few years will help to determine whether this assumption is still appropriate.
This paper is focused on the measurements of the major machine parameters under influence of the Damping Wigglers and their comparison with analytic estimates. We present analysis of the impact of the Damping Wigglers on the beam emittance and lifetime in the NSLS-II storage ring. We conclude that these parameters for the NSLS-II follow well-known dependencies as described, for example, by Weidemann and Touschek. Appendices A and B show details of the experiment and the estimates.
This paper draws on a survey of wind industry professionals to clarify trends in the expected useful life of land-based wind power plants in the United States. The expected useful life of a project affects expectations about its profitability, the timing of possible decommissioning or repowering, and its levelized costs. We find that most wind project developers, sponsors and long-term owners have increased project-life assumptions over time, from a typical term of ~20 years in the early 2000s to ~25 years by the mid-2010s and ~30 years more recently. Current assumptions range from 25 to 40 years, with an average of 29.6 years. The estimated average levelized cost of energy (LCOE) for new wind projects built in 2018 is $\$ $40.4/MWh (real 2018$\$ $), assuming a 20-year project life. With a 25-year useful life and no change in assumed operations and maintenance (O&M) expenditures or wind plant performance over time, LCOE declines by 10%, to $\$ $36.2/MWh, because capital costs are recovered over five additional years of production. At the now-common 30-year assumed life, levelized costs decrease another 7%, to $\$ $33.5/MWh (under the same unaltered assumptions about O&M and performance). Even longer assumed lifetimes lead to further (but diminishing) LCOE reductions—e.g., to $\$ $31.7/MWh and $\$ $30.3/MWh for 35- and 40-year lives, respectively. The data and trends presented here may inform assumptions used by electric system planners, modelers and analysts. The results may also provide useful benchmarks to the wind industry, helping developers and assets owners to compare their expectations with those of their peers.
The major goal of this project was to develop and apply the moments-based calculation of frequencies and lifetimes of vibrational modes in solids. Most of the effort went into calculation of frequencies (dependence on temperature) and in comparing to experiment. We were successful in reaching that goal. There were three stage: 1) Test levels of approximation and understand their range of validity; 2a) Write an application program for empirical potentials (Jazz, a wrapper for LAMMPS) and use it to perform calculations for interesting materials; 2b) Write a similar application program for a first-principles electronic structure code; 3) Apply the codes to the study of anharmonicity in a variety of materials (bulk silicon, graphene, fullereness, and carbon nanotubes).
High-purity liquid argon is critical for the operation of a liquid argon time projection chamber (LArTPC). At MicroBooNE, we have achieved an electron drift lifetime of at least 6 ms without evacuation of the detector vessel. Measurements of the electronegative contaminants oxygen and water are described and shown as the gas and liquid argon stages of filtration progressed.
This study’s objective is to develop current and projected performance, cost, and lifetime characteristics for residential and commercial building technologies and equipment with the potential to provide grid services.
The Georgia Institute of Technology assembled a multidisciplinary team with complementary expertise in the areas of multi-level molecular simulations (Brédas), chemical synthesis and material characterization (Marder), and device physics and engineering (Kippelen). The team engaged in a two-year integrated theoretical and experimental program to develop blue-emissive layers that can yield simultaneously near 100% internal quantum efficiency (IQE) and short excited-state lifetimes to overcome the existing efficiency vs. stability tradeoff displayed by blue-emitting OLEDs and by WOLEDs, and to demonstrate stable WOLEDs that fulfill or exceed the 2020 target metrics (RDP 2016 section C.1.2) ahead of schedule. In this program, we investigated two general approaches involving the development of wide-bandgap ambipolar hosts with a low ΔEST. Ambipolar host achieved by intermolecular through-space D:A interactions and by intramolecular through-bond interactions between covalently linked D and A segments. Novel hosts were incorporated in to blue-emissive layers (EML) by combining them with suitable fluorescent guest emitters having high quantum yields of emission (Φem) to demonstrate blue-emitting OLEDs with high EQE and low roll-off. This final report describes the most important results achieved during this program
For most storage ring design purposes it is sufficient to assume a Gaussian distribution of the electrons in a bunch. However, a more detailed knowledge of the population in the transverse tails beyond a few sigma is necessary to predict the beam lifetime and the synchrotron radiation load in the interaction region due to beam-gas scattering and the beam-beam interaction. This report presents simulations to determine the required vacuum level as well as to serve as input data for detailed synchrotron radiation simulations.
A report that investigates the long-term reliability and aging characteristics of chip-on-board LEDs over the operating lifetime.
Silicone rubbers are important materials within the complex and are used in various applications due to wide operating temperatures, favorable aging characteristics, and chemical inertness. However, silicone rubbers are susceptible to degradation in the presence of acid or base. The goal of the project is to design outgassing vessels to probe material degradation byproducts from additively manufactured (AM) silicones compressed against Arrhenius base under dry (sub 100 ppm moisture) environments. The overarching goal of this task is to develop a mechanistic understanding of degradation from experimental data that will be used to inform predictive lifetime and aging models. An outgassing chamber for multi-material compressive aging was designed. The chamber consists of a stainless-steel enclosure, which is hermetically sealed once AM silicone samples are compressed against Arrhenius base pellets in compression rigs (Fig. 1). Outgassing chambers, compression rigs, and accessories were procured, arrived onsite, and received surface treatments. Outgassing of degradation byproducts will be monitored over 12 weeks at 35 °C and 70 °C.
In this project, OLEDWorks and partners made significant progress in advancing OLED light extraction technology. Improving light extraction efficiency remains one of the most important research topics for OLEDs. Current state-of-the-art white OLED products extract only about 50% of the photons that are generated within the device. Promising new light extraction concepts, such as those based on sub electrode micro lens arrays (SEMLAs), were explored in this project with the potential to achieve extraction efficiency of 60% or higher. Flexible thin glass substrates with integrated SEMLAs were successfully fabricated and scaled to large area. When combined with optimized high efficiency stacked white OLED structures, we achieved the program goals of 120 LPW efficacy and long lifetime more than 100,000 hours.
This document will briefly discuss the observations and results from an NREL conducted accelerated lifetime testing of the main shaft seal for the Verdant Power fifth generation Gen5 underwater Tidal Energy Converter (TEC) turbine, which successfully performed at the RITE project in 2020-2021. In order to evaluate a 5-year Service Interval ( SI) for this component, testing at NREL operated the main shaft seal nearly continuously for over 135 (text says 130 days on page 5 and 125 days on page 7 and 137 days on page 11) days at a rotational velocity of 160 rpm while the test stand recorded water pressure, barrier fluid pressure, temperature, and number of cycles., representing ~ 40% of the SI. An additional separate test was conducted to measure the aging behavior of the rubber drive rings. The water pressure reservoir was held constant as 29 psi. Barrier fluid pressure remained relatively constant throughout the duration of the test but was seen to sink to as low as 10.1 psi. No barrier fluid leakage was observed throughout the test. A sudden failure occurred within the seal after the power to test machine was interrupted for a scheduled building maintenance procedure. Upon restarting, the main shaft seal lost all ability to prevent water ingress. The exact cause is not known but is believed to be either a seal assembly issue or a change in the alignment of the seal components during or following the power outage. Following seal disassembly, significant wear was seen on one of the graphite sealing rings. Based on these results it is recommended that a follow-on TEAMER be conducted to rectify protocol and assembly issues to further evaluate SI of this component. The support and participation of Verdant Power Inc, Dovetail Solutions LLC and Garlock Manufacturing Inc were instrumental in understanding the results. NREL thanks them for their significant effort.
DOE’s PV Lifetime project was initiated in 2016 with the goal of accurately characterizing the early-life evolution of photovoltaic (PV) field performance. Different PV cell and module technologies result in different initial degradation rates due to effects like light-induced degradation (LID) and light & elevated temperature-induced degradation (LeTID). To accurately characterize the initial field degradation of maximum power (Pmp) requires the use of high-accuracy indoor IV curve measurements at standard test conditions. Therefore, PV modules involved in this study are removed from the field once or twice per year and brought indoors for measurement under constant temperature and irradiance conditions.
In this effort Pacific Northwest National Laboratory (PNNL) developed and demonstrated an anti-fouling coating that is effective on fish diversion structures. The coating was based on a previously developed superhydrophobic lubricant infused composite (SLIC) coating but modified for application to flexible substrates. We showed that the new reformulated coating – FlexiSLIC – can be applied to flexible fibrous structures to significantly reduce biofouling of netting and anchor lines, to enable longer operational lifetimes, reduced costs, and more reliable operations. The coating developed in this effort was tested on relevant fish diversion structural netting and rope materials (e.g. nylon, Dyneema, polypropylene) to reduce biofouling. Engagement with industry in the development and demonstration further supported progress toward commercialization of the materials.
A 5Qt Hagan container with a 20-year history of nuclear material storage was challenged with three successive drop tests at a height of 3.7 meters. The total mass of the test package was 12.1 kg. The 1st and 2nd drop tests (center of gravity over the container bottom corner but 180 degrees apart on the container bottom face) passed the pre- and post- impact helium leak criterion at less than 1.00E-6 atm-cc/sec (ambient cubic centimeters per second). The 3rd and final test (center of gravity over top corner) failed with a post-impact gross leak of 1.1E-1 atmcc/sec. The RRFMC (Respirable Release Fraction Measurement Chamber) is a drop tower test system that is critical for the sustainability of the SAVY-4000™ series and Hagan-type (NFT Inc. Golden CO) nuclear material storage containers. These are the primary in-use nuclear material storage container types at the Los Alamos National Laboratory TA-55 facility. Results are presented to expand the technical knowledge basis for container lifetime, regarding actual exposure to corrosive gas species on the container inner surfaces. The primary source of general corrosion throughout the container is gaseous hydrogen chloride (HCl). This gas is generated by the degradation of the polyvinylchloride (PVC) bag-out bag. Additionally, in most cases, the nuclear material itself also releases HCl gas (due to residual chemical components associated with the material formation). The RRFMC drop tower gives the end-user the ability record and analyze high-speed video and photography and if needed aerosol mass release measurements. In this report the principal issue is the physical deformation of the 5Qt Hagan container. There were no mass release experiments of test aerosol mass in the present study.
The SAVY-4000 (hereafter “SAVY) was granted a 15 year design life as of June 11, 2019. Since that time, a concerted effort to evaluate the SAVY lifetime beyond 15 years initiated. Several key gaps in knowledge were identified by subject matter expert reviewers across the complex, along with testing that should be included or addressed in the next technical basis. While surveillance has not fundamentally changed since the last life extension, many key techniques have since been identified as necessary to evaluate key container performance requirements not addressed previously (i.e. drop qualification release rate). FY23 provided an opportunity to establish the groundwork for the development of those key techniques that aid in addressing DOE Manual 441.1-1 (hereafter “Manual”) requirements for safe storage of nuclear material.