Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Conference Record of the IEEE Photovoltaic Specialists Conference
Many popular models for photovoltaic system performance (e.g., [1], [2]) employ a single diode model (e.g., [3]) to compute the IV curve for a module or string of modules for given irradiance and temperature conditions. Most commonly (e.g., [4]), parameters are determined using only current and voltage at short circuit, open circuit and maximum power from a single IV curve at standard test conditions, along with reported temperature coefficients. In contrast, module testing frequently records IV curves at a wide range of irradiance and temperature conditions, such as those specified in IEC 61853-1 [5], which, when available, should also be used to parameterize the performance model. We propose a parameter estimation method that makes use of the full range of available IV curves, and demonstrate the accuracy of the resulting performance model. © 2013 IEEE.
World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conferen
Variability of photovoltaic (PV) power output is a potential concern to utilities because it can lead to voltage changes on the distribution system and have other adverse impacts on power quality unless additional equipment is added or operational practices are changed to mitigate these effects. This paper develops and evaluates a simple yet novel approach for quantifying irradiance variability over various timescales. The approach involves comparison between measured irradiance and a reference, clear sky irradiance, determined from a model. Conceptually, the "Variability Index" is the ratio of the "length" of the measured irradiance plotted against time divided by the "length" of the reference clear sky irradiance signal. Adjustments are proposed that correct for different measurement intervals. By evaluating the variability index at several sites, we show how annual and monthly distributions of this metric can help to classify sites and periods of time when variability is significant. Copyright © (2012) by American Solar Energy Society.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Reliability Engineering and System Safety
Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. As part of this development, a detailed performance assessment (PA) for the YM repository was completed in 2008 and supported a license application by the DOE to the U.S. Nuclear Regulatory Commission (NRC) for the construction of the YM repository. The following aspects of the 2008 YM PA are described in this presentation: (i) conceptual structure and computational organization, (ii) uncertainty and sensitivity analysis techniques in use, (iii) uncertainty and sensitivity analysis for physical processes, and (iv) uncertainty and sensitivity analysis for expected dose to the reasonably maximally exposed individual (RMEI) specified the NRC's regulations for the YM repository. © 2011 Elsevier Ltd.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
Proposed for publication in Reliability Engineering and System Safety.
Abstract not provided.
One year of power output was simulated at one-minute intervals for each of fourteen hypothetical utility-scale photovoltaic power plants and for the aggregate power output from a large number of distribution-connected photovoltaic systems. For utility-scale plants, the simulation first constructs one-year time series of global horizontal irradiance at one-minute intervals at each plant location, and a performance model translates irradiance and weather information to AC output power. Distribution-connected photovoltaic systems comprise a variety of system configurations: residential-scale rooftop systems at various tilts; commercial-scale flat-roof mounted systems; and commercial-scale ground-mounted tracked systems. For distribution-connected PV systems, the simulation estimates the time series of spatially-averaged irradiance for the region containing the systems, and the performance model is employed to estimate power aggregate power from all systems. The simulation results are validated by comparing statistics for the time series of irradiance with statistics for measured irradiance within the region.
Abstract not provided.
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Abstract not provided.
40th ASES National Solar Conference 2011, SOLAR 2011
Sandia National Laboratories has developed a modeling approach to simulate time-synchronized, 1-minute power output from large PV plants in locations where only hourly irradiance measurements are available via satellite sources. The approach uses 1-min irradiance measurements from analogue sites in a similar geographic area. PV output datasets generated for 2007 in southern Nevada are being used for a Solar PV Grid Integration Study to estimate the integration costs associated with various utility-scale PV generation levels. Plant designs considered include both fixed-tilt thin-film, and singleaxis- tracked polycrystalline Si systems ranging in size from 5 to 300 MWAC. Simulated power output profiles at 1-min intervals were generated for five scenarios (149.5 MW, 222 WM, 292 MW, 492 MW, and 892 MW) each comprising as many as 10 geographically separated PV plants. Copyright© (2011) by the American Solar Energy Society.
Abstract not provided.
This report describes in-depth analysis of photovoltaic (PV) output variability in a high-penetration residential PV installation in the Pal Town neighborhood of Ota City, Japan. Pal Town is a unique test bed of high-penetration PV deployment. A total of 553 homes (approximately 80% of the neighborhood) have grid-connected PV totaling over 2 MW, and all are on a common distribution line. Power output at each house and irradiance at several locations were measured once per second in 2006 and 2007. Analysis of the Ota City data allowed for detailed characterization of distributed PV output variability and a better understanding of how variability scales spatially and temporally. For a highly variable test day, extreme power ramp rates (defined as the 99th percentile) were found to initially decrease with an increase in the number of houses at all timescales, but the reduction became negligible after a certain number of houses. Wavelet analysis resolved the variability reduction due to geographic diversity at various timescales, and the effect of geographic smoothing was found to be much more significant at shorter timescales.