Update on NREL Outdoor Exposure Campaign of Solar Mirrors

Author(s):  
Daniel Celvi ◽  
Christa Schreiber ◽  
Robert Tirawat ◽  
Guangdong Zhu

Abstract Beginning in 2018, the National Renewable Energy Laboratory restarted exposure campaigns on new and archived samples as part of a multiyear project, some with outdoor exposure for more than a decade. By resuming exposure and collecting and analyzing data on thousands of samples going back decades, several goals can be advanced that can be difficult to determine within the timeline of most projects: 1) correlating an accelerated exposure campaign to outdoor aging, specifically with xenon arc lamp exposure chambers; 2) drawing conclusions between specific corrosion mechanisms and weather patterns; and 3) finding novel relationships between mirror composition and performance. In addition to building and mining a database, we will experiment with new characterization techniques, primarily focused on macroscopic and microscopic imaging. In introducing these techniques more broadly, it may be possible to reveal a more direct line between optical performance and exposure campaigns by better understanding the degradation mechanisms occurring.

2021 ◽  
pp. 1-18
Author(s):  
ShuoYan Chou ◽  
Truong ThiThuy Duong ◽  
Nguyen Xuan Thao

Energy plays a central part in economic development, yet alongside fossil fuels bring vast environmental impact. In recent years, renewable energy has gradually become a viable source for clean energy to alleviate and decouple with a negative connotation. Different types of renewable energy are not without trade-offs beyond costs and performance. Multiple-criteria decision-making (MCDM) has become one of the most prominent tools in making decisions with multiple conflicting criteria existing in many complex real-world problems. Information obtained for decision making may be ambiguous or uncertain. Neutrosophic is an extension of fuzzy set types with three membership functions: truth membership function, falsity membership function and indeterminacy membership function. It is a useful tool when dealing with uncertainty issues. Entropy measures the uncertainty of information under neutrosophic circumstances which can be used to identify the weights of criteria in MCDM model. Meanwhile, the dissimilarity measure is useful in dealing with the ranking of alternatives in term of distance. This article proposes to build a new entropy and dissimilarity measure as well as to construct a novel MCDM model based on them to improve the inclusiveness of the perspectives for decision making. In this paper, we also give out a case study of using this model through the process of a renewable energy selection scenario in Taiwan performed and assessed.


Author(s):  
Stephanie Drozek ◽  
Christopher Damm ◽  
Ryan Enot ◽  
Andrew Hjortland ◽  
Brandon Jackson ◽  
...  

The purpose of this paper is to describe the implementation of a laboratory-scale solar thermal system for the Renewable Energy Systems Laboratory at the Milwaukee School of Engineering (MSOE). The system development began as a student senior design project where students designed and fabricated a laboratory-scale solar thermal system to complement an existing commercial solar energy system on campus. The solar thermal system is designed specifically for educating engineers. This laboratory equipment, including a solar light simulator, allows for variation of operating parameters to investigate their impact on system performance. The equipment will be utilized in two courses: Applied Thermodynamics, and Renewable Energy Utilization. During the solar thermal laboratories performed in these courses, students conduct experiments based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) 93-2010 standard for testing and performance characterization of solar thermal systems. Their measurements are then used to quantify energy output, efficiency and losses of the system and subsystem components.


2016 ◽  
Vol 688 ◽  
pp. 44-49 ◽  
Author(s):  
Iveta Čabalová ◽  
František Kačík ◽  
Tereza Tribulová

Samples prepared from oak (Quercusrobur L.) wood were exposed to heat treatment at temperatures of 160, 180, 200 and 220 oC for 3, 6, 9 and 12 hours. In both untreated and thermally treated wood there were determined extractives and lignin by National Renewable Energy Laboratory (NREL) procedures, cellulose by Seifert's method, holocellulose according to Wise, hemicelluloses as difference between holocellulose and cellulose. Monosaccharides were determined by high performance liquid chromatography (NREL).The results show that hemicelluloses are less stable at thermal treatment than cellulose. The amounts of lignin and extractives rose by increasing both temperature and time of the treatment while the amounts of hemicelluloses decreased. Thermal treatment also resulted in significant decreases of the yields of non-glucosic saccharides. Degradation of carbohydrates can cause the deterioration of mechanical properties of wood.


MRS Bulletin ◽  
2008 ◽  
Vol 33 (4) ◽  
pp. 389-395 ◽  
Author(s):  
Ralph E.H. Sims

AbstractSome forms of renewable energy have long contributed to electricity generation, whereas others are just emerging. For example, large-scale hydropower is a mature technology generating about 16% of global electricity, and many smaller scale systems are also being installed worldwide. Future opportunities to improve the technology are limited but include upgrading of existing plants to gain greater performance efficiencies and reduced maintenance. Geothermal energy, widely used for power generation and direct heat applications, is also mature, but new technologies could improve plant designs, extend their lifetimes, and improve reliability. By contrast, ocean energy is an emerging renewable energy technology. Design, development, and testing of a myriad of devices remain mainly in the research and development stage, with many opportunities for materials science to improve design and performance, reduce costly maintenance procedures, and extend plant operating lifetimes under the harsh marine environment.


2017 ◽  
Vol 867 ◽  
pp. 191-194
Author(s):  
Anbu Manimaran Sukanta ◽  
M. Niranjan Sakthivel ◽  
Gopalsamy Manoranjith ◽  
Loganathan Naveen Kumar

Solar Energy is one of the forms of Renewable Energy that is available abundantly. This work is executed on the enhancement of the performance of solar parabolic trough collector using Intensified Ray Convergence System (IRCS). This paper distinguishes between the performance of solar parabolic trough collector with continuous dual axis tracking and a fixed solar parabolic trough collector (PTC) facing south (single axis tracking). The simulation and performance of the solar radiations are visualized and analyzed using TRACEPRO 6.0.2 software. The improvement in absorption of solar flux was found to be enhanced by 39.06% in PTC using dual axis tracking, absorption of solar flux increases by 52% to 200% in PTC receiver using perfect mirror than PTC using black chrome coating.


2014 ◽  
Vol 29 (1) ◽  
pp. 139-152 ◽  
Author(s):  
Luiz Martins de Araújo Júnior ◽  
Emerson Mariano da Silva ◽  
Alexandre Araújo Costa ◽  
Domingo Cassain Sales ◽  
Francisco da Chagas Vasconcelos Junior ◽  
...  

Este estudo foi desenvolvido no intuito de avaliar o potencial eólico do estado do Ceará nos períodos chuvoso e seco em eventos de El Niño e La Niña. Para isso é utilizado o modelo de área limitada, Regional Modelling System (RAMS 6.0), forçado pela reanálise ERA-Interim, para simular a densidade do ar e a velocidade do vento em diferentes níveis atmosféricos. Para avaliação do desempenho do modelo, os dados simulados de velocidade do vento são comparados com dados observados, a 10 m da superfície, de estações climatológicas do Instituto Nacional de Meteorologia (INMET), por meio de gráficos e um conjunto de índices estatísticos. Adicionalmente, mapas mensais de velocidade média a 50 m da superfície foram feitos, classificando o potencial eólico de acordo com o National Renewable Energy Laboratory (NREL). Os resultados apresentados para avaliação do desempenho do modelo mostraram que apesar do modelo superestimar os dados observados, o índice de concordância ou Wilmott e o coeficiente de correlação apresentam valores que variam de moderado (0,40 < r < 0,69) a forte (0,70 < r < 0,89). Através do conjunto de índices estatísticos ainda foi possível extrair que nos semestres mais chuvosos e/ou em período de ocorrência do fenômeno La Niña o desempenho do modelo é melhor. Com relação à avaliação do potencial eólico, notou-se que em ocorrência de ENOS positivo há uma condição mais favorável de geração de energia do que em evento de ENOS na fase fria, principalmente na região litorânea do estado do Ceará. Com isso, conclui-se que o desempenho do modelo foi satisfatório, mostrando ser uma possível ferramenta para futuras rotinas operacionais de previsão dos recursos eólicos do Estado.


2017 ◽  
Vol 56 (10) ◽  
pp. 2869-2881
Author(s):  
Janel Hanrahan ◽  
Alexandria Maynard ◽  
Sarah Y. Murphy ◽  
Colton Zercher ◽  
Allison Fitzpatrick

AbstractAs demand for renewable energy grows, so does the need for an improved understanding of renewable energy sources. Paradoxically, the climate change mitigation strategy of fossil fuel divestment is in itself subject to shifts in weather patterns resulting from climate change. This is particularly true with solar power, which depends on local cloud cover. However, because observed shortwave radiation data usually span a decade or less, persistent long-term trends may not be identified. A simple linear regression model is created here using diurnal temperature range (DTR) during 2002–15 as a predictor variable to estimate long-term shortwave radiation (SR) values in the northeastern United States. Using an extended DTR dataset, SR values are computed for 1956–2015. Statistically significant decreases in shortwave radiation are identified that are dominated by changes during the summer months. Because this coincides with the season of greatest insolation and the highest potential for energy production, financial implications may be large for the solar energy industry if such trends persist into the future.


Author(s):  
Kevin Regimbal ◽  
Ilene Carpenter ◽  
Christopher Chang ◽  
Steve Hammond

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