A5071261712- Photovoltaic System Optimization Techniques
- Solar Radiation and Photovoltaics
- Solar Thermal and Photovoltaic Systems
- solar cell performance optimization
- Radio Astronomy Observations and Technology
- Photovoltaic Systems and Sustainability
- Astrophysics and Cosmic Phenomena
- Cryospheric studies and observations
- Smart Grid Energy Management
- Icing and De-icing Technologies
- Antenna Design and Optimization
- Gyrotron and Vacuum Electronics Research
- Silicon Carbide Semiconductor Technologies
- Advanced Measurement and Metrology Techniques
- Particle Accelerators and Free-Electron Lasers
- Energy Load and Power Forecasting
- Silicon and Solar Cell Technologies
- Electromagnetic Compatibility and Measurements
- Infrared Target Detection Methodologies
- Chalcogenide Semiconductor Thin Films
- Advanced Battery Technologies Research
- Power Systems and Renewable Energy
- Superconducting and THz Device Technology
- Pulsed Power Technology Applications
- Energy and Environment Impacts
Sandia National Laboratories
2014-2024
National Renewable Energy Laboratory
2024
Massachusetts Institute of Technology
2021-2024
Made In Space (United States)
2020
Sandia National Laboratories California
2002-2016
Technical University of Denmark
2015
University of Rochester
2008
The proper modeling of Photovoltaic(PV) systems is critical for their financing, design, and operation. PV_LIB provides a flexible toolbox to perform advanced data analysis research into the performance operations PV assets, this paper presents extension python programming language. common repository release published algorithms, thus can also help improve quality frequency model validation inter comparison studies. Overall, goal accelerate pace innovation in sector.
Abstract This paper presents the design and deployment of Hydrogen Epoch Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements Reionization. First results from I array are published early 2022, system nearing completion. We describe discuss progress on commissioning future upgrades. As designated Square Kilometre pathfinder instrument, we also show number “case studies” that investigate systematics seen while system, which...
The U.S. Department of Energy has supported development the Solar Advisor Model (SAM) to provide a common platform for evaluation solar energy technologies being developed with support Department. This report describes detailed comparison performance-model calculations within SAM actual measured PV system performance in order evaluate ability models accurately predict production. was accomplished by using meteorological and irradiance data as an input models, then comparing model predictions...
A novel model-based prognostics and health management (PHM) system has been designed to monitor the of a photovoltaic (PV) system, measure degradation, indicate maintenance schedules. Current state-of-the-art PV monitoring systems require module array topology details or extensive modeling system. We present method using an artificial neural network (ANN) which eliminates need for priori information by teaching algorithm "good" performance behavior based on initial array. The PHM was tested...
Bifacial PV modules and systems deliver more energy than equivalent monofacial in the same orientation. However, bifacial performance models are not yet mature enough to predict gains for all system configurations. Field data is needed at a variety of different spatial scales order improve validate these models. This paper reports on number field installations intended this purpose.
Bifacial photovoltaic dual-axis tracker systems have the potential to out-perform other module/mounting configurations at high latitudes, where reflectivity of snow in winter boosts bifacial performance and low solar angle-of-incidence favors tracking. Two years empirical data from experimental Vermont support this assertion, demonstrating that modules on a produced 14 percent more electricity year than their monofacial counterparts as much 40 during peak months. These gains are addition...
Abstract We identify the key inputs and measurement data needed for accurate energy rating of concentrator photovoltaic (CPV) modules based on field observations multiple CPV modules. Acceptance angle is shown to correlate with observed module‐level performance ratio (PR) studied. Using power ratings standard test conditions, PRs between 90% 95% were during summers up ~10% lower winters. A module fabricated by Semprius showed 94% ±0.7% PR over almost 2 years seasonal variation in less than...
We describe and validate a method for modeling irradiance on the back surface of bifacial PV modules at scale individual cells using view factors. compare model results with measurements in various configurations. Our analysis illustrates relative accuracy as well potential variation among cells.
Accurate modeling of photovoltaic (PV) performance requires the precise calculation module temperature. Currently, most temperature models rely on steady-state assumptions that do not account for transient climatic conditions and thermal mass module. On other hand, complex physics-based are computationally expensive difficult to parameterize. In order address this, a new approach was developed, in which predictions from previous timesteps weighted averaged accurately predict at finer time...
In this paper, we use a model based on view factors to estimate the irradiance incident both surfaces of singleaxis tracker PV array for given direct and diffuse light components sky dome. We describe mathematical formulation factor that assumes 2D geometry with Lambertian while accounting reflections from all surrounding surfaces. The allows specifically calculate back surface modules as well shading effects caused by presence neighboring rows in array. present preliminary results an...
This paper presents the design of a new dual-polarised Vivaldi feed for Hydrogen Epoch Reionization Array (HERA) radio-telescope. wideband has been developed to replace Phase I dipole feed, and is used illuminate 14-m diameter dish. It aims improve science capabilities HERA, by allowing it characterise redshifted 21-cm hydrogen signal from Cosmic Dawn as well Reionization. achieved increasing bandwidth 100 -- 200 MHz 50 250 MHz, optimising time response antenna - receiver system, improving...
Interferometric experiments designed to detect the highly redshifted 21-cm signal from neutral hydrogen are producing increasingly stringent constraints on power spectrum, but some k-modes remain systematics-dominated. Mutual coupling is a major systematic that must be overcome in order signal, and simulations reproduce effects seen data can guide strategies for mitigating mutual coupling. In this paper, we analyse 12 nights of Hydrogen Epoch Reionization Array compare against include...
Through simulations and measurements, we show that in multi-slot thin film waveguides, the TM polarized modes can be confined mostly low refractive index layers of waveguide. The structure consisted alternating a-Si SiO(2), thickness range between 3 40 nm, for which slots were SiO(2) layers. Simulations performed using transfer matrix method experiments m-line technique at 1.55 mum. dependence birefringence power confinement was studied as a function waveguide thickness, Si layer...
Photovoltaic (PV) system modeling is used throughout the photovoltaic industry for prediction of PV output under a given set weather conditions. has wide range uses including: prepurchase comparisons components, health monitoring, and payback (return on investment) times. In order to adequately model system, must be characterized establish relationship between inputs (e.g., irradiance, spectrum, temperature) desired outputs AC power, module temperature). Traditional approaches...
Photovoltaic (PV) system modeling is used throughout the photovoltaic industry for prediction of PV output under a given set weather conditions. has wide range uses including: pre-purchase comparisons components, health monitoring, and estimation payback (return on investment) times. In order to adequately model system, must be characterized establish relationship between inputs (e.g., irradiance, spectrum, temperature) desired outputs AC power, module temperature). Traditional approaches...
Sandia National Laboratories, the Renewable Energy Laboratory, and University of Iowa are collaborating to develop a performance model for bifacial PV modules. As with monofacial modules, consists sequential operation component sub-models. Bifacial modules accept light on both their front rear surfaces which presents unique modeling challenge. This paper describes approach Sandia, NREL, create verify its accuracy measured field data.
Reflection losses from a PV module become increasingly pronounced at solar incident angles >60°. However, accurate measurement in this region can be problematic due to tracker articulation limits and irradiance reference device calibration. We present the results of method enabling modules tested over full range 0-90° by articulating elevation only. This facilitates use shaded pyranometer make direct diffuse component, reducing uncertainty. further real-time intercomparison performed two...
This paper presents the design and deployment of Hydrogen Epoch Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements Reionization. First results from I array are published early 2022, system nearing completion. We describe discuss progress on commissioning future upgrades. As designated Square Kilometer (SKA) pathfinder instrument, we also show number "case studies" that investigate systematics seen while system, which may...
Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different timescales. These can be isolated by designing appropriate Fourier filters in fringe-rate (FR) space, pair local sidereal time (LST). Applications FR filtering include separating correlated with rotating sky vs. those relative ground, down-weighting emission primary beam sidelobes, and suppressing noise. causes noise...
ABSTRACT Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different time-scales. These can be isolated by designing appropriate Fourier filters in fringe-rate (FR) space, pair local sidereal time. Applications FR filtering include separating correlated with rotating sky versus those relative ground, down-weighting emission primary beam sidelobes, and suppressing noise. causes noise...
Energy losses due to snow coverage can be high in climates with large annual snowfall. These may reduced region-specific system design guidelines. One possible factor retention on PV systems could frame presence and/or shape. Sandia is studying the effect of module photovoltaic shedding for a pair otherwise-identical Vermont. The results this study provide summary findings after 2018-2019 winter period. clearly show that inhibits performance mild conditions.
Semprius, a producer of high concentration photovoltaic (CPV) modules with world record efficiency, has developed capabilities for modeling field performance CPV using two models: PVsyst and Semprius Performance Model (SPM). Modeling relies on the definition PAN file which is described here. SPM result Semprius' collaboration Sandia National Laboratory to develop software that can accurately model systems. The both demonstrated by validation against actual systems operating in field, one...
Modeling and predicting snow-related power loss is important to economic calculations, load management system optimization for all scales of photovoltaic (PV) plants. This paper describes a new method measuring snow shedding from fielded modules also the application this commercial scale PV plant in Vermont with two subsystems, one portrait orientation other landscape. The relies on time-series images taken at 5 minute intervals capture dynamics module-level accumulation shedding....
Cloud cover significantly affects the solar irradiance incident on a photovoltaic (PV) module, so identifying and predicting cloud motion is useful for PV applications, such as informing tracker movements short-term power. This work presents two algorithms to aid in real-time weather predictions, i.e., convolutional autoencoder (CAE) identify clouds particle predict movement. The CAE model integrates information from multiple segmentation approaches, then utilizes transfer learning these...
The Sandia Array Performance Model (SAPM) describes the DC output of a PV module under range irradiance and temperature conditions. Coefficients for SAPM are normally obtained through sequence on-sun tests, which can be expensive time-consuming. We report progress towards developing test methods analysis procedures to obtain coefficients from indoor testing. compared predictions with extracted results, measured output, found biases in predicted performance. hypothesize that these result...