scholarly journals Solar Dish Field System Model for Spacing Optimization

Author(s):  
John Igo ◽  
Charles E. Andraka

Dish Stirling power generation systems have been identified by DOE, Sandia National Laboratories, and Stirling Energy Systems (SES) as having the capability of delivering utility-scale renewable energy to the nation’s electrical grid. SES has proposed large plants, 20,000 units or more (0.5 GW rated power) in one place, in order to rapidly ramp up production automation. With the large capital investment needed in such a plant it becomes critical to optimize the system at the field level, as well as at the individual unit level. In this new software model, we provide a tool that predicts the annual and monthly energy performance of a field of dishes, in particular taking into account the impact of dish-to-dish shading on the energy and revenue streams. The Excel-based model goes beyond prior models in that it incorporates the true dish shape (flexible to accommodate many dish designs), multiple-row shading, and a revenue stream model that incorporates time-of-day and time-of-year pricing. This last feature is critical to understanding key shading tradeoffs on a financial basis. The model uses TMY or 15-minute meteorological data for the selected location. It can incorporate local ground slope across the plant, as well as stagger between the rows of dish systems. It also incorporates field-edge effects, which can be significant on smaller plants. It also incorporates factors for measured degraded performance due to shading. This tool provides one aspect of the decision process for fielding many systems, and must be combined with land costs, copper layout and costs, and O&M predictions (driving distance issues) in order to optimize the loss of power due to shading against the added expense of a larger spatial array. Considering only the energy and revenue stream, the model indicates that a rectangular, unstaggered field layout maximizes field performance. We also found that recognizing and accounting for true performance degradation due to shading significantly impacts plant production, compared with prior modeling attempts.

2020 ◽  
Vol 29 (2) ◽  
pp. 223-233
Author(s):  
Ewa Figiel ◽  
Dorota Leciej-Pirczewska

New demands for lowering energy consumption of buildings lead to many new solutions including, amongst others, the introduction of an outer wall thermal barrier for both heating and cooling effect. The analysed thermo-active-wall-barrier is a water-based system, where the pipes are embedded in the wall construction. It enables the use of a low-temperature barrier medium for space heating, thereby increasing the efficiency of all potential energy supply systems using renewable energy sources. The pipes form an active thermal barrier for heat transfer between the outer and the heated space. There are many possibilities to place the pipes in the wall for example in the case of energetic thermo-modernisation. Our research and calculations have shown that thermo-active-wall-barrier is sensitive to the location of pipes. The following paper also provides a study of the impact of thermal barrier on a building’s energy performance. The analysis was conducted for a single-family house in a temperate climate based on parameters taken from one of the Polish meteorological data-bases. Calculations using current procedure of evaluating building energy performance show, that the thermal barrier can contribute to signifi cant reduction of transmission energy loss thus lowering the environmental impact.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1142
Author(s):  
Elena Mania ◽  
Fabio Petrella ◽  
Matteo Giovannozzi ◽  
Mauro Piazzi ◽  
Alena Wilson ◽  
...  

Topography may induce variability in meteorological conditions at the meso-scale level and could influence grape quality. Understanding the impact of topography on grape ripening allows for the development of sustainable management practices that include topographical influences in their consideration. This is also important for applying proactive strategies able to counter the expected changes of climate. This study was conducted on cv. Nebbiolo vineyards in North-West Italy. The topographic traits were performed in 17 vineyards within the region, which had previously been identified as belonging to different terroir units. An analysis of historical meteorological data series was also carried out to characterize the units from the meteorological point of view. The grape composition was investigated during 2012 and 2013. Based on the topography traits, a Cluster Analysis classified the 17 vineyards into four groups. Differences among groups mainly concerned insolation and heat accumulation. Topography influenced the individual components of grape quality differently depending on the seasonal weather trend. Interactions between topography and vintage were observed for a few parameters. Better understanding the grapevine reaction to external factors/site characteristics can allow for improved site and season-specific management decision making and can contribute to improving vineyard sustainability while maintaining winery objectives and wine typicity.


2019 ◽  
Vol 37 (8) ◽  
pp. 851-859
Author(s):  
Markéta Šerešová ◽  
Miloš Polák ◽  
Vladimír Kočí

Managing waste electrical and electronic equipment is currently one of the top priority challenges of waste management in the European Union. The collection and subsequent processing of waste electrical and electronic equipment are realized by means of the so-called collective systems that employ collection boxes varying in size and materials used for their production. This study focuses on quantifying and comparing environmental impacts of often-used collection boxes on the example of mobile phone collection. The comparison was based on volume (20 l, 60 l, and 70 l) and on the material used for the construction of the box (polypropylene, corrugated cardboard, and stainless steel). Other parameters, such as lifetime, material and energy performance for production, end of life stage, and waste generation were taken in account. The evaluation was carried out using the method of life cycle assessment with the characterization model CML 2001 created in GaBi 8. The goal of the study was to identify the box with the smallest environmental impact and to identify the hotspots in the life cycles of the individual collection boxes. The results of the study show that polypropylene boxes are the most environmentally suitable for collecting small waste electrical and electronic equipment as they produce the lowest environmental impacts in all of the impact categories evaluated, while boxes made of stainless steel have been found to represent the least environmentally friendly option. The results of the study provide and suggest to the collective system basic data for choosing the type of collection box.


1988 ◽  
Vol 23 (4) ◽  
pp. 383-393 ◽  
Author(s):  
Jeffrey A. Lockwood

Nonsexual interactions of the big-headed grasshopper, Aulocara elliotti (Thomas), were examined under natural conditions in context of intrinsic (age and conspecificity of grasshoppers, speed and direction of movement and duration of interaction) and extrinsic (date, time of day, soil and air temperature, relative humidity, wind speed and sunlight) factors. With respect of intrinsic factors, the developmental stage and conspecificity of interacting grasshoppers and the direction of approach by the individual initiating an interaction significantly affected interactive behaviors, including kicking, shifting, approaching, contact and pursuit. These three factors also influenced the outcome of interaction, especially the frequency of avoidance by residents. Among the extrinsic factors, time of day, soil temperature and relative humidity had the greatest affects on the aforementioned interactive behaviors. The time of year, relative humidity and wind speed significantly affected the outcome of interactions. Physical contact and pursuit were the only behaviors to significantly affect the outcome of interactions. Inferential evidence indicates that aggressive interactions may be the result of defense of territories based on limited, suitable microhabitats.


Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.


Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.


2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.


2020 ◽  
Vol 17 (3) ◽  
pp. 445-460
Author(s):  
Mohd Imran Khan ◽  
Valatheeswaran C.

The inflow of international remittances to Kerala has been increasing over the last three decades. It has increased the income of recipient households and enabled them to spend more on human capital investment. Using data from the Kerala Migration Survey-2010, this study analyses the impact of remittance receipts on the households’ healthcare expenditure and access to private healthcare in Kerala. This study employs an instrumental variable approach to account for the endogeneity of remittances receipts. The empirical results show that remittance income has a positive and significant impact on households’ healthcare expenditure and access to private healthcare services. After disaggregating the sample into different heterogeneous groups, this study found that remittances have a greater effect on lower-income households and Other Backward Class (OBC) households but not Scheduled Caste (SC) and Scheduled Tribe (ST) households, which remain excluded from reaping the benefit of international migration and remittances.


2014 ◽  
Vol 23 (1) ◽  
pp. 103-124 ◽  
Author(s):  
Daniel Kopasker

Existing research has consistently shown that perceptions of the potential economic consequences of Scottish independence are vital to levels of support for constitutional change. This paper attempts to investigate the mechanism by which expectations of the economic consequences of independence are formed. A hypothesised causal micro-level mechanism is tested that relates constitutional preferences to the existing skill investments of the individual. Evidence is presented that larger skill investments are associated with a greater likelihood of perceiving economic threats from independence. Additionally, greater perceived threat results in lower support for independence. The impact of uncertainty on both positive and negative economic expectations is also examined. While uncertainty has little effect on negative expectations, it significantly reduces the likelihood of those with positive expectations supporting independence. Overall, it appears that a general economy-wide threat is most significant, and it is conjectured that this stems a lack of information on macroeconomic governance credentials.


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