Optical-Mechanical Analysis of Parabolic Trough Solar Concentrators to Support Commercial Development

Author(s):  
Kenneth Biggio ◽  
Rachel Backes ◽  
Jennifer Crawford

The thermal performance of parabolic trough concentrating solar collectors depends on both the structural and optical characteristics of the design. In order to reduce the cost of energy, advanced concentrating structures must significantly reduce the cost of collectors while maintaining good optical performance. This paper discusses a Finite Element Ray Tracer (FERT) that has been developed specifically to support the commercial design process. This is achieved by tying the whole of the support structure directly to its optical effects. Consequently, the optical performance metrics go beyond the typical reflector slope error RMS or average intercept factor to present the designer with spatially resolved analysis of localized performance. By incorporating this analytical method into the structural design process, collector cost and performance can be balanced efficiently and rapidly, allowing for an accelerated design period. At times, this insight has driven better, albeit unexpected, design decisions. The paper presents an overview of the development process that Abengoa R&D uses to take advantage of its analytical optical analysis capability throughout all phases of a project, as well as a review of its implementation. A selection of case studies is also presented to illustrate how FERT enables the designer to identify local areas of concern, diagnose the cause, and quickly develop possible redesign strategies. Finally, the significance of various parameters within the ray tracer are discussed.

Author(s):  
Henry Price ◽  
David Kearney

Parabolic trough solar technology is the most proven and lowest cost large-scale solar power technology available today, primarily because of the nine large commercial-scale solar power plants that are operating in the California Mojave Desert. However, no new plants have been built during the past ten years because the cost of power from these plants is more expensive than power from conventional fossil fuel power plants. This paper reviews the current cost of energy and the potential for reducing the cost of energy from parabolic trough solar power plant technology based on the latest technological advancements and projected improvements from industry and sponsored R&D. The paper also looks at the impact of project financing and incentives on the cost of energy.


Author(s):  
Roberto Porto ◽  
Jose M. Molina ◽  
Antonio Berlanga ◽  
Miguel A. Patricio

Learning systems have been very focused on creating models that are capable of obtaining the best results in error metrics. Recently, the focus has shifted to improvement in order to interpret and explain their results. The need for interpretation is greater when these models are used to support decision making. In some areas this becomes an indispensable requirement, such as in medicine. This paper focuses on the prediction of cardiovascular disease by analyzing the well-known Statlog (Heart) Data Set from the UCI’s Automated Learning Repository. This study will analyze the cost of making predictions easier to interpret by reducing the number of features that explain the classification of health status versus the cost in accuracy. It will be analyzed on a large set of classification techniques and performance metrics. Demonstrating that it is possible to make explainable and reliable models that have a good commitment to predictive performance.


Author(s):  
Julius Yellowhair ◽  
Charles E. Andraka

Heliostat reflective facets have traditionally been constructed with glass/silver and a metal back support. During the past year, Sandia National Laboratories evaluated low-cost materials and alternative manufacturing methods to construct facets with the goal of reducing current facet cost by at least 25% while maintaining surface slope errors at 1 milli-radians rms or below. Several companies developed prototype facet samples, which were optically evaluated at Sandia and compared to baseline facet samples using a proposed cost-to-performance metric. A cost-performance metric for comparing facets was developed by modeling and optimizing a 200 MWe power tower plant scenario in DELSOL, a computer code for system-level modeling of power tower systems. We varied the slope error on the facets and adjusted the cost on the facets to maintain the constant plant levelized cost of energy. The result of these models provides a chart of the facet optical performance and the allowable facet cost for a constant plant LCOE. The size of the prototype facet samples ranged from 1.4 to 3 m2. The measured optical slope errors were between 1 and 2 milli-radians rms when compared to a flat mirror design shape. Despite slope errors greater than 1 mrad rms, some of the prototype samples met the cost goals for this project using the cost-performance metric. Next steps are to work with the companies to improve the manufacturing processes and further reduce the cost and improve on the optical performance to reach DOE SunShot goal of $75/m2 for heliostats.


2021 ◽  
Vol 11 (3) ◽  
pp. 1285
Author(s):  
Roberto Porto ◽  
José M. Molina ◽  
Antonio Berlanga ◽  
Miguel A. Patricio

Learning systems have been focused on creating models capable of obtaining the best results in error metrics. Recently, the focus has shifted to improvement in the interpretation and explanation of the results. The need for interpretation is greater when these models are used to support decision making. In some areas, this becomes an indispensable requirement, such as in medicine. The goal of this study was to define a simple process to construct a system that could be easily interpreted based on two principles: (1) reduction of attributes without degrading the performance of the prediction systems and (2) selecting a technique to interpret the final prediction system. To describe this process, we selected a problem, predicting cardiovascular disease, by analyzing the well-known Statlog (Heart) data set from the University of California’s Automated Learning Repository. We analyzed the cost of making predictions easier to interpret by reducing the number of features that explain the classification of health status versus the cost in accuracy. We performed an analysis on a large set of classification techniques and performance metrics, demonstrating that it is possible to construct explainable and reliable models that provide high quality predictive performance.


2021 ◽  
Vol 13 (17) ◽  
pp. 9918
Author(s):  
Chinnasamy Subramaniyan ◽  
Jothirathinam Subramani ◽  
Balasubramanian Kalidasan ◽  
Natarajan Anbuselvan ◽  
Thangaraj Yuvaraj ◽  
...  

The design of solar concentrating collectors for the effective utilization of solar energy is a challenging condition due to tracking errors leading to different divergences of the solar incidence angle. To enhance the optical performance of solar parabolic trough collectors (SPTC) under a diverged solar incidence angle, an additional compound parabolic concentrator (CPC) is introduced as a secondary reflector. SPTC with CPC is designed and modeled for a single axis-tracking concentrating collector based on the local ambient conditions. In this work, the optical performance of the novel SPTC system with and without a secondary reflector is investigated using MATLAB and TRACEPRO software simulations for various tracking errors. The significance parameters such as the solar incidence angle, aperture length, receiver tube diameter, rim angle, concentration ratio, solar radiation, and absorbed flux are analyzed. The simulation results show that the rate of the absorbed flux on the receiver tube is significantly improved by providing the secondary reflector, which enhances the optical efficiency of the collector. It is found that the optical efficiency of the SPTC with a secondary reflector is 20% higher than the conventional collector system for a solar incidence angle of 2°. This work can effectively direct the choice of optimal secondary reflectors for SPTC under different design and operating conditions.


2015 ◽  
Vol 9 (1) ◽  
pp. 2303-2310
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio

The vanadium dioxide VO₂ currently became very motivating for the nanotechnologies’ researchers. It makes party of the intelligent materials because these optical properties abruptly change semiconductor state with metal at a critical  temperature θ = 68°C. This transition from reversible phase is carried out from a monoclinical structure characterizing its semiconductor state at low temperature towards the metal state of this material which becomes tétragonal rutile for  θ ˃ 68°C ; it is done during a few nanoseconds. Several studies were made on this material in a massive state and a thin layer. We will simulate by Maple the constant optics of a thin layer of VO₂ thickness z = 82 nm for the metal state according to the energy ω of the incidental photons in the energy interval: 0.001242 ≤ ω(ev) ≤ 6, from the infra-red (I.R) to the ultra-violet (U.V) so as to be able to control the various technological nano applications, like the detectors I.R or the U.V,  the intelligent windows to  increase  the energy efficiency in the buildings in order to save the cost of energy consumption by electric air-conditioning and the paintings containing nano crystals of this material. The constant optics, which we will simulate, is: the index of refraction, the reflectivity, the transmittivity, the coefficient of extinction, the dielectric functions ԑ₁ real part and  ԑ₂  imaginary part of the permittivity complexes ԑ of this material and the coefficient absorption. 


2015 ◽  
Vol 6 (1) ◽  
pp. 50-57
Author(s):  
Rizqa Raaiqa Bintana ◽  
Putri Aisyiyah Rakhma Devi ◽  
Umi Laili Yuhana

The quality of the software can be measured by its return on investment. Factors which may affect the return on investment (ROI) is the tangible factors (such as the cost) dan intangible factors (such as the impact of software to the users or stakeholder). The factor of the software itself are assessed through reviewing, testing, process audit, and performance of software. This paper discusses the consideration of return on investment (ROI) assessment criteria derived from the software and its users. These criteria indicate that the approach may support a rational consideration of all relevant criteria when evaluating software, and shows examples of actual return on investment models. Conducted an analysis of the assessment criteria that affect the return on investment if these criteria have a disproportionate effort that resulted in a return on investment of a software decreased. Index Terms - Assessment criteria, Quality assurance, Return on Investment, Software product


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