scholarly journals Evaluación de sistemas térmicos y fotovoltaicos solares en unidades de producción agropecuaria, Región Huetar Norte, Costa Rica

2017 ◽  
Vol 28 (3) ◽  
pp. 535
Author(s):  
Tomás De Jesús Guzmán Hernández ◽  
Freddy Araya Rodríguez ◽  
Javier Mauricio Obando Ulloa ◽  
Mikel Rivero Marcos ◽  
Guillermo Castro Badilla

The dependence on fossil fuels urges society to seek for clean energy alternatives, in order to mitigate the effects of climate change. The objective of this study was to determine the potential of solar energy used for water heating and electricity generation. The study was conducted at the dairy of the Technology Institute of Costa Rica, San Carlos Headquarter, from May 15 to April 2016. The data related to the amount of the electricity produced and the temperature reached by water was obtained from the installed photovoltaic and thermal systems, the data was recorded by a computerized register. The obtained information about electricity production allowed researchers to calculate the amount of carbon dioxide equivalent that was not emitted into the atmosphere, and also the acquired economic saving on consumption. The use of these systems allowed the production unit have a self- sufficient source of electrical energy percentage, actually around 30 to 40% of the total electrical consumption. According to the energy production, the solar thermal system was capable to increase water temperature between 20 to 37 °C, temperature that represents more than 70% of the energy needed in order to reach the required water temperature (70 °C) for cleaning and sanitizing the milking equipment, and also an economical saving around $90 per month was achieved. The results showed that these systems allow to improve the economical and productive efficiency of agricultural production units in the Northern Huetar Region of Costa Rica.

2021 ◽  
Vol 11 (4) ◽  
pp. 4456-4464
Author(s):  
S.V.G.V.A. Prasad

In recent years the use of solar energy is found to have grown by a large amount. Solar energy is renewable energy and the demand for it as clean energy shows its growth by nearly 50 percent in the past decade. It is estimated that the sun is able to generate energy within 24 hours that the entire population of the world could consume in 27 years. Solar power is the energy from the sun that is converted into thermal or electrical energy. The energy harnessed from the sun's rays is used for a variety of applications like electricity generation, to provide light for the interior environment, and many other domestic, commercial, and industrial purposes. Usage of fossil fuels for electricity production results in increased pollution and this mandates many governments to encourage moving to electricity generation using solar power. The large amount of solar energy that is available is found to be the most appealing source of electricity. Solar panels form a major part of the solar energy setup. Hence in this article let us review the various types of solar panels. This paper also deals with comparing the merits and demerits of the different types of solar panels that are available in the market. A section that presents the efficiency of the different kinds of the solar panel is also present in this paper. The role of temperature coefficient, fire rating, and hail rating in the performance of the solar panel is also addressed in this paper.


2015 ◽  
Vol 10 (2) ◽  
pp. 414-421
Author(s):  
Bahareh Hashemlou ◽  
Hossein Sadeghi ◽  
Arashk Masaeli ◽  
Mohammadhadi Hajian ◽  
Shima Javaheri

Organizations, institutions, and different sectors of manufacturing, services and agriculture are constantly making decisions. Each of the aforementioned sectors, have strategies, tactics, and various functions that play a basic role in reaching the objectives. On the other hand, energy demand in developing countries is increasing day by day. The exact calculation of the cost per unit of electricity generated by power plants is not easy. Therefore, this study according to four sources of natural gas, nuclear energy, renewable energy and other fossil fuels other than natural gas that are used in a variety of electricity production plants is trying to clarify the ranking of generation electricity approach using "fuzzy preference relations" analysis. Accordingly, three models were used and the results showed that natural gas, with regard to the four criteria of low investment cost, low power, lack of pollution and the safety and reliability of electrical energy has priority over other alternatives. Full preferred model results also suggested that the energy of natural gas, renewable energies, nuclear and other fossil fuels should be considered in a priority for power generation. Sensitivity analysis results moreover demonstrated that the above models are not affected by the threshold values ​​and the full stability of the models is observed.


2012 ◽  
Vol 52 (1) ◽  
pp. 195
Author(s):  
Doug Young

The Clean Energy Act (CEA) and its related legislation received royal assent on 18 November 2011, ushering in a new era for the Australian industry, and for those who deal with it. Building on the 2007 National Greenhouse and Energy Reporting Scheme (NGERS), which mandates the measurement and reporting of greenhouse gas emissions and electricity production and consumption, the CEA imposes direct obligations on: individual industrial operations (facilities) that emit more than 25,000 tonnes of carbon dioxide, or its other equivalent greenhouse gases, from particular sources, in a year; suppliers of natural gas (at the point of last supply before the gas is burnt or otherwise used), for the emissions that will be generated when the gas is burnt; and, operators of land-fill facilities, such as local councils. While the primary emissions targeted by the scheme are produced by burning fossil fuels, they also include emissions such as the methane released when coal is mined. The obligations include the option of surrendering carbon units for each tonne of emissions, however, if this optional step is not performed, the mandatory payment of a tax, which far exceeds the cost of a unit, is enforced. The Australian Government will sell carbon units at a fixed price for the first three years, starting at $23, after which units will be auctioned for between $15 and the expected international unit price, plus $20. The supply of domestic units will be unlimited for the three fixed price years, but will be subject to a reducing cap in following years, consistent with the Government policy of reducing Australia’s emissions. The Government has created a monopoly for the supply of units for the first three years by prohibiting the use of overseas-sourced carbon units, and by only allowing 5% of the unit surrender requirements to be comprised of Australian generated carbon credits. Thereafter, for the first five of the flexible-charge years, only half the units can be sourced from overseas, with any apparent saving likely to be offset by the various taxes and charges applicable to the use of those units. Certain fuels will also be separately taxed. Entities, however, which acquire, manufacture or import fuels and would otherwise be entitled to a fuel tax credit, may be able to assume direct liability thus enabling them to acquire or manufacture fuel, free of the carbon tax component. Where the imposts will cause competitive disadvantage to industries that compete with entities from other countries that do not have similar imposts, some assistance is provided in the form of allocated units provided at no charge. Assistance is also available to coal-fired electricity generators, producers of liquefied natural gas, operators of gassy coal mines, and the steel industry (not discussed in this paper). This paper also explains, in detail, how liability is created, how to determine which entities are liable, the means of assigning liability to other entities, and the assistance available to various industries to help deal with the financial impact of the scheme on their operations. It also outlines the key concepts that underpin the scheme.


Author(s):  
Bhuvnesh Ratho ◽  

The focus of this is to make available clean energy, where there is a need for electricity production or energy infrastructure. An anaerobic digester contains an oxygen free environment that allows microorganisms to break down the organic material to harvest biogas (methane). Once the biogas is formed it can be used for different applications to aid the developing world. There are already millions of biogas plants in operation throughout the world. In Germany and other industrialized countries, power generation is the main purpose of biogas plants; conversion of biogas to electricity has become a standard technology. Biomass can become a reliable and renewable local energy source to replace conventional fossil fuels in local industries and to reduce reliance on overloaded electricity grids. The concept presented is to use manure from farms to produce methane gas using anaerobic digestion.


Author(s):  
Ari Ramadhani

Abstract - Automatic system have grown widespread across all sector so do water heater. Traditionally, heating water is done by utilizing fire as heat source. As the growing of technology, the heating process could be done by manipulating electrical energy by convert it to heat. Electrical energy is flown to a metal rod that contact directly with the water which increase the water temperature. On some case, appropiate water temperature is needed. Altough, a thermometer is needed to read the actual temperature as a feedback value for the system and a system that can control the electricity current flow through the heater that the heat produced is linear to the current flow. With implementing microcontroller as a process node for generating PWM signal, this problem can be solved. Also, Labview is needed as an interface for monitoring and bursting an output which have been processed by Proportional, Integral, and Devivative (PID) controller to producing accurate and stable heat. Based on the results of testing, the system is able to provide a rapid response to any changes that occur, both changes in set-point and changes in water temperature (actual value). Another test is done by comparing the temperature value detected by the temperature sensor in this device with an external digital thermometer placed in the same place, and from some of the tests the temperature value detected by the temperature sensor in this device has a difference of ± 0.19 ℃ with a digital thermometer. Keyword : Water Heater, Thermometer, Microcontroller, LabView, PID.


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.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 996
Author(s):  
Venera Giurcan ◽  
Codina Movileanu ◽  
Adina Magdalena Musuc ◽  
Maria Mitu

Currently, the use of fossil fuels is very high and existing nature reserves are rapidly depleted. Therefore, researchers are turning their attention to find renewable fuels that have a low impact on the environment, to replace these fossil fuels. Biogas is a low-cost alternative, sustainable, renewable fuel existing worldwide. It can be produced by decomposition of vegetation or waste products of human and animal biological activity. This process is performed by microorganisms (such as methanogens and sulfate-reducing bacteria) by anaerobic digestion. Biogas can serve as a basis for heat and electricity production used for domestic heating and cooking. It can be also used to feed internal combustion engines, gas turbines, fuel cells, or cogeneration systems. In this paper, a comprehensive literature study regarding the laminar burning velocity of biogas-containing mixtures is presented. This study aims to characterize the use of biogas as IC (internal combustion) engine fuel, and to develop efficient safety recommendations and to predict and reduce the risk of fires and accidental explosions caused by biogas.


2020 ◽  
Vol 92 (8) ◽  
pp. 1305-1320 ◽  
Author(s):  
Yulia H. Budnikova ◽  
Vera V. Khrizanforova

AbstractNowadays, hydrogen has become not only an extremely important chemical product but also a promising clean energy carrier for replacing fossil fuels. Production of molecular H2 through electrochemical hydrogen evolution reactions is crucial for the development of clean-energy technologies. The development of economically viable and efficient H2 production/oxidation catalysts is a key step in the creation of H2-based renewable energy infrastructure. Intrinsic limitations of both natural enzymes and synthetic materials have led researchers to explore enzyme-induced catalysts to realize a high current density at a low overpotential. In recent times, highly active widespread numerous electrocatalysts, both homogeneous or heterogeneous (immobilized on the electrode), such as transition metal complexes, heteroatom- or metal-doped nanocarbons, metal-organic frameworks, and other metal derivatives (calix [4] resorcinols, pectates, etc.), which are, to one extent or another, structural or functional analogs of hydrogenases, have been extensively studied as alternatives for Pt-based catalysts, demonstrating prospects for the development of a “hydrogen economy”. This mini-review generalizes some achievements in the field of development of new electrocatalysts for H2 production/oxidation and their application for fuel cells, mainly focuses on the consideration of the catalytic activity of M[P2N2]22+ (M = Ni, Fe) complexes and other nickel structures which have been recently obtained.


Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 75
Author(s):  
Duarte Carreira ◽  
Paulo A. Ribeiro ◽  
Maria Raposo ◽  
Susana Sério

It is currently of huge importance to find alternatives to fossil fuels to produce clean energy and to ensure the energy demands of modern society. In the present work, two types of hybrid solar cell devices were developed and characterized. The photoactive layers of the hybrid heterojunctions comprise poly (allylamine chloride) (PAH) and graphene oxide (GO) and TiO2 or ZnO films, which were deposited using the layer-by-layer technique and DC-reactive magnetron sputtering, respectively, onto fluorine-doped tin oxide (FTO)-coated glass substrates. Scanning electron microscopy evidenced a homogeneous inorganic layer, the surface morphology of which was dependent on the number of organic bilayers. The electrical characterization pointed out that FTO/(PAH/GO)50/TiO2/Al, FTO/(PAH/GO)30/ZnO/Al, and FTO/(PAH/GO)50/ZnO/Al architectures were the only ones to exhibit a diode behavior, and the last one experienced a decrease in current in a low-humidity environment. The (PAH/GO)20 impedance spectroscopy study further revealed the typical impedance of a parallel RC circuit for a dry environment, whereas in a humid environment, it approached the impedance of a series of three parallel RC circuits, indicating that water and oxygen contribute to other conduction processes. Finally, the achieved devices should be encapsulated to work successfully as solar cells.


2021 ◽  
Vol 13 (11) ◽  
pp. 2070
Author(s):  
Ana Basañez ◽  
Vicente Pérez-Muñuzuri

Wave energy resource assessment is crucial for the development of the marine renewable industry. High-frequency radars (HF radars) have been demonstrated to be a useful wave measuring tool. Therefore, in this work, we evaluated the accuracy of two CODAR Seasonde HF radars for describing the wave energy resource of two offshore areas in the west Galician coast, Spain (Vilán and Silleiro capes). The resulting wave characterization was used to estimate the electricity production of two wave energy converters. Results were validated against wave data from two buoys and two numerical models (SIMAR, (Marine Simulation) and WaveWatch III). The statistical validation revealed that the radar of Silleiro cape significantly overestimates the wave power, mainly due to a large overestimation of the wave energy period. The effect of the radars’ data loss during low wave energy periods on the mean wave energy is partially compensated with the overestimation of wave height and energy period. The theoretical electrical energy production of the wave energy converters was also affected by these differences. Energy period estimation was found to be highly conditioned to the unimodal interpretation of the wave spectrum, and it is expected that new releases of the radar software will be able to characterize different sea states independently.


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