Documentation of the energy yield of a large photovoltaic (PV) system over a substantial period can be useful to measure a performance guarantee, as an assessment of the health of the system, for verification of a performance model to then be applied to a new system, or for a variety of other purposes. Although the measurement of this performance metric might appear to be straightforward, there are a number of subtleties associated with variations in weather and imperfect data collection that complicate the determination and data analysis. A performance assessment is most valuable when it is completed with a very low uncertainty and when the subtleties are systematically addressed, yet currently no standard exists to guide this process.This report summarizes a draft methodology for an Energy Performance Evaluation Method, the philosophy behind the draft method, and the lessons that were learned by implementing the method. The general philosophy behind the methodology includes the following features:• The method is performance-model agnostic.• The performance model must not be inadvertently modified, when being implemented on the measured meteorological data sets, relative to the model that was used on the historical data set.
The flow in the near wake of the blunt bodies of road vehicles like SUVs plays an important role in determining the pressure forces acting on the surface of the body. To better understand the wake profiles and stagnation pressure gradient of the vehicle, this paper performed numerical analysis on CAD model of a Generic SUV which was previously tested in the wind tunnel. Commercial software package of ANSYS® GAMBIT, T-grid and FLUENT® was used for multi cell meshing and solving of the governing equations. The pressure coefficient ‘Cp’ plots at the symmetry plane of the model were compared with experimental results from the wind tunnel tests to validate the simulation. Results and conclusions were presented from the simulations of the CAD model using upper and lower flat boat tail plates with gradual increment in the angle of inclination.
This paper describes ongoing research in the area of solar PV production forecasting intended to address a range of effects on the utility grid associated with high penetrations of PV. The ability to anticipate near-term -minutes ahead to hours ahead to day or multiple-day ahead--production of the variable solar resource will be key to successfully integrating ever larger PV capacities with minimal costs. A number of forecast methodologies are surveyed and a mechanism for validating their performance is described.
The performance of a photovoltaic (PV) system depends on the weather, seasonal effects, and other intermittent issues. Demonstrating that a PV system is performing as predicted requires verifying that the system functions correctly under the full range of conditions relevant to the deployment site. This paper discusses a proposed energy test that applies to any model and explores the effects of the differences between historical and measured weather data and how the weather and system performance are intertwined in subtle ways. Implementation of the Energy Test in a case study concludes that test uncertainty could be reduced by separating the energy production model from the model used to transpose historical horizontal irradiance data to the relevant plane.
The flows over a pickup truck with add-on devises were studied using computational fluid dynamics (CFD) with the objective of investigating the effect of these add-no devices on the flow structures around the vehicle, aerodynamic drag, and lift coefficient. All numerical simulations were performed using commercial CFD software Fluent [8]. A generic pickup model with extended cab was used as the base model and all the flow simulations were performed at zero degree yaw angle. The pickup configurations used in the present CFD simulation include Aerocap with different rear inclination angle α, Tonneau cover, Rear Roof Garnish, and Tail-plates. Results from numerical simulations indicated that Aerocap with inclination angle α = 12° and a reduced rear width has produced the minimum aerodynamic drag coefficient. It was also shown that the wake region decrease when the rear inclination angle increases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.