scholarly journals Analysis of the scientific production on renewable energies within the framework of sustainability in Mexico

Author(s):  
Hilario López-Xelo ◽  
Josemauel Luna-Nemecio ◽  
José Juan Hernández-Medina

With the turn of the 20th century to the 21st, the urgent need to carry out a critique of the current techno-energy pattern, which is based on the intensive use of fossil fuels, becomes more evident. Derived from this productive, energy and material consumption of gas and oil, the conditions have been generated for the configuration of an environmental crisis. In such a way that, there is an urgent need to carry out research that explores the various alternative sources of energy that today appear as an alternative to reduce the negative impact of industrial, agro-industrial and urban activities on the environment. This paper reflects on the problems that exist in Mexico around the development and marginal adoption of renewable energies as a productive source. While 91.2% of energy in Mexico is produced by burning fossil fuels, it can be established that the energy structure in Mexico is unsustainable. For this reason, a change in energy thinking based on efficiency and sustainability is required, considering both as axes for the use of renewable energies. The goals of the article are: 1) to present a context study, analyzing the production of electrical energy with fossil sources in Mexico, alluding to the difficulty of the transition towards the use of renewable energies. Second, the production of renewable energies in the country is analyzed to find out if investment in them is sustainable.

Author(s):  
Hossein Shahinzadeh ◽  
Gevork B. Gharehpetian ◽  
S. Hamid Fathi ◽  
Sayed Mohsen Nasr-Azadani

In recent years, several factors such as environmental pollution which is caused by fossil fuels and various diseases caused by them from one hand and concerns about the dwindling fossil fuels and price fluctuation of the products and resulting effects of these fluctuations in the economy from other hand has led most countries to seek alternative energy sources for fossil fuel supplies. Such a way that in 2006, about 18% of the consumed energy of the world is obtained through renewable energies. Iran is among the countries that are geographically located in hot and dry areas and has the most sun exposure in different months of the year. Except in the coasts of Caspian Sea, the percentage of sunny days throughout the year is between 63 to 98 percent in Iran. On the other hand, there are dispersed and remote areas and loads far from national grid which is impossible to provide electrical energy for them through transmission from national grid, therefore, for such cases the renewable energy technologies could be used to solve the problem and provide the energy. In this paper, technical and economic feasibility for the use of renewable energies for independent systems of the grid for a dispersed load in the area on the outskirts of Isfahan (Sepahan) with the maximum energy consumption of 3Kwh in a day is studied and presented. In addition, the HOMER simulation software is used as the optimization tool.


2017 ◽  
Vol 5 (1) ◽  
pp. 12-16
Author(s):  
Luboš Socha ◽  
Vladimír Socha ◽  
Peter Čekan ◽  
Daniela Čekanová ◽  
Lenka Hanáková ◽  
...  

The problem of environmental load is also reflected in air transport. Usage of fossil fuels, which are dominant nowadays, has a negative impact on the environment and also its resources are limited. Therefore, the article focuses on the prospective of use of other energy sources in aviation, such as alternative fuels (synthetic fuels, biofuels, alcohol, methane, hydrogen), solar energy and the use of fuel cells. Also, the paper briefly summarizes the approach of aircraft manufacturers to the use alternative sources.


Author(s):  
Benouaz Idriss Yassine ◽  
Allaoua Boumediene

To tackle the widespread challenges encountered during the management of power flow in electrical networks, the integration of smart grid (S.G)            is proposed as a viable solution to address the environmental and economic concerns. In order to enhance overall functionality of the electric power delivery system, operation of the smart grid is governed by data-driven algorithms where various sensors and smart meters are used to collect this data. On other hand, the fluctuating cost of fossil fuels and its negative impact on the environnement has incentivized the exploitation of renewable energies in the smart grid. In the present paper, a hybrid Photovoltaic/Wind (PV/Wind) is suggested to supply a smart grid. The objective of this study is to asses the feasibility of a smart grid supplied solely by renewable energy sources. Conceptual standings of this newly suggested model are validated by simulations.


2019 ◽  
Vol 17 (3) ◽  
Author(s):  
Lamhot P. Manalu

Crop drying is essential for preservation in agricultural applications. It is performed either using fossil fuels in an artificial mechanical drying process or by placing the crop under the open sun. The first method is costly and has a negative impact on the environment, while the second method is totally dependent on the weather. The drying process requires a lot of energy in relation to the amount of water that must be evaporated from the product. It is estimated that 12% of the total energy used by the food industries and agriculture absorbed in this process. Due to the limitation of energy resources, it is important to keep researching and developing of diversification and optimization of energy This study aims to assess the use of energy for cocoa drying using solar energy dryer and bin-type dryer, as well as to determine the drying efficiency of each type of dryer. The results showed that the efficiency of the solar dryer drying system ranges between 36% to 46%, while the tub-type dryers between 21.7% to 33.1%. The specific energy of solar dryer ranged from 6.17-7.87 MJ / kg, while the tub-type dryers 8.58-13.63 MJ / kg. Dryer efficiency is influenced by the level of solar irradiation and the amount of drying load, the higher the irradiation received and more cocoa beans are dried, the drying efficiency is also higher and the specific energy further down.Proses pengeringan memerlukan banyak energi sehubungan dengan banyaknya air yang harus diuapkan dari bahan yang dikeringkan. Pengeringan dapat dilakukan dengan menggunakan pengering mekanis berbahan bakar fosil atau dengan menempatkan produk di bawah matahari terbuka. Metode pertama adalah mahal dan memiliki dampak negatif pada lingkungan, sedangkan metode kedua sangat tergantung pada cuaca. Diperkirakan bahwa 12% dari total energi yang dipergunakan oleh industri pangan dan pertanian diserap untuk proses ini. Mengingat semakin terbatasnya sumber energi bahan bakar minyak maka usaha diversifikasi dan optimasi energi untuk pengeringan perlu terus diteliti dan dikembangkan. Salah satunya adalah pemanfaatan energi surya sebagai sumber energi terbarukan. Penelitian ini bertujuan untuk mengkaji penggunaan energi untuk pengeringan kakao dengan memakai pengering energi surya dan pengering tipe bak, serta untuk mengetahui efisiensi pengeringan dari masing-masing tipe pengering. Hasil kajian menunjukkan bahwa efisiensi total sistem pengeringan alat pengering surya berkisar antara 36% dan 46%, sedangkan pengering tipe bak antara 21.7% dan 33.1%. Kebutuhan energi spesifik alat pengering surya berkisar antara 6.17-7.87 MJ/kg, sedangkan alat pengering tipe bak 8.58-13.63 MJ/kg. Efisiensi alat pengering dipengaruhi oleh tingkat iradiasi surya dan jumlah beban pengeringan, semakin tinggi iradiasi yang diterima pengering serta semakin banyak biji kakao yang dikeringkan, maka efisiensi pengeringan juga semakin tinggi dan kebutuhan energi spesifik semakin turun.Keywords: energy, efficiency, cocoa, solar dryer, bin-type dryer.


Author(s):  
David Mares

This chapter discusses the role of energy in economic development, the transformation of energy markets, trade in energy resources themselves, and the geopolitical dynamics that result. The transformation of energy markets and their expansion via trade can help or hinder development, depending on the processes behind them and how stakeholders interact. The availability of renewable, climate-friendly sources of energy, domestically and internationally, means that there is no inherent trade-off between economic growth and the use of fossil fuels. The existence of economic, political, social, and geopolitical adjustment costs means that the expansion of international energy markets to incorporate alternatives to oil and coal is a complex balance of environmental trade-offs with no solutions completely free of negative impact risk. An understanding of the supply of and demand for energy must incorporate the institutional context within which they occur, as well as the social and political dynamics of their setting.


2020 ◽  
Vol 4 (1) ◽  
pp. 9
Author(s):  
Martina Habulan ◽  
Bojan Đurin ◽  
Anita Ptiček Siročić ◽  
Nikola Sakač

Particulate matter (PM) comprises a mixture of chemical compounds and water particles found in the air. The size of suspended particles is directly related to the negative impact on human health and the environment. In this paper, we present an analysis of the PM pollution in urban areas of Croatia. Data on PM10 and PM2.5 concentrations were measured with nine instruments at seven stationary measuring units located in three continental cities, namely Zagreb (the capital), Slavonski Brod, and Osijek, and two cities on the Adriatic coast, namely Rijeka and Dubrovnik. We analyzed an hourly course of PM2.5 and PM10 concentrations and average seasonal PM2.5 and PM10 concentrations from 2017 to 2019. At most measuring stations, maximum concentrations were recorded during autumn and winter, which can be explained by the intensive use of fossil fuels and traffic. Increases in PM concentrations during the summer months at measuring stations in Rijeka and Dubrovnik may be associated with the intensive arrival of tourists by air during the tourist season, and lower PM concentrations during the winter periods may be caused by a milder climate consequently resulting in lower consumption of fossil fuels and use of electric energy for heating.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110209
Author(s):  
Zain Ul Hassan ◽  
Muhammad Usman ◽  
Muhammad Asim ◽  
Ali Hussain Kazim ◽  
Muhammad Farooq ◽  
...  

Despite a number of efforts to evaluate the utility of water-diesel emulsions (WED) in CI engine to improve its performance and reduce its emissions in search of alternative fuels to combat the higher prices and depleting resources of fossil fuels, no consistent results are available. Additionally, the noise emissions in the case of WED are not thoroughly discussed which motivated this research to analyze the performance and emission characteristics of WED. Brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) were calculated at 1600 rpm within 15%–75% of the load range. Similarly, the contents of NOx, CO, and HC, and level of noise and smoke were measured varying the percentage of water from 2% to 10% gradually for all values of loads. BTE in the case of water emulsified diesel was decreased gradually as the percentage of water increased accompanied by a gradual increase in BSFC. Thus, WED10 showed a maximum 13.08% lower value of BTE while BSFC was increased by 32.28%. However, NOx emissions (21.8%) and smoke (48%) were also reduced significantly in the case of WED10 along with an increase in the emissions of HC and CO and noise. The comparative analysis showed that the emulsified diesel can significantly reduce the emission of NOx and smoke, but it has a negative impact on the performance characteristics and HC, CO, and noise emissions which can be mitigated by trying more fuels variations such as biodiesel and using different water injection methods to decrease dependency on fossil fuels and improve the environmental impacts of CI engines.


2014 ◽  
Vol 70 (a1) ◽  
pp. C20-C20
Author(s):  
Evgeny Antipov ◽  
Nellie Khasanova

Ninety percent of the energy produced today come from fossil fuels, making dramatically negative impact on our future due to rapid consumption of these energy sources, ecological damage and climate change. This justifies development of the renewable energy sources and concurrently efficient large storage devices capable to replace fossil fuels. Li-ion batteries have originally been developed for portable electronic devices, but nowadays new application niches are envisaged in electric vehicles and stationary energy storages. However, to satisfy the needs of these rapidly growing applications, Li-ion batteries require further significant improvement of their properties: capacity and power, cyclability, safety and cost. Cathode is the key part of the Li-ion batteries largely determining their performance. Severe requirements are imposed on a cathode material, which should provide fast reversible intercalation of Li-ions at redox potential close to the upper boundary of electrolyte stability window, possess relatively low molecular weight and exhibit small volume variation upon changing Li-concentration. First generation of the cathode materials for the Li-ion batteries based on the spinel (LiM2O4, M – transition metal) or rock-salt derivatives (LiMO2) has already been widely commercialised. However, the potential to further improve the performance of these materials is almost exhausted. The compounds, containing lithium and transition metal cations together with different polyanions (XmOn)p- (X=B, P, S, Si), are now considered as the most promising cathode materials for the next generation of the Li-ion batteries. Covalently-bonded structural frameworks in these compounds offer long-term structural stability, which is essential for good cyclability and safety. Further advantages are expected from combining different anions (such as (XO4)p- and F- ) in the anion sublattice, with the hope to enhance the specific energy and power of these materials. Various fluoride-phosphates and fluoride-sulphates have been recently discovered, and some of them exhibit attractive electrochemical performance. An overview of the research on the cathode materials for the Li-ion batteries will be presented with special emphasis on crystallography as a guide towards improved properties important for practical applications.


2012 ◽  
Vol 433-440 ◽  
pp. 7218-7222 ◽  
Author(s):  
Tahir Yavuza ◽  
Birol Kilkis ◽  
Emre Koc ◽  
Ozgur Erol

While our planet is rapidly approaching an environmental crisis under the dominant use of depleting fossil fuels, the need for exploiting all forms of new, small carbon foot-print, renewable, and clean energy resources are increasing in the same proportion. Therefore, the need for exploring all types of clean energy resources that the world has- some of which might have not attracted sufficient attention before- is essential in order to implement sufficient, efficient, and widely use all them. In this respect, operational effectiveness of the wind and hydrokinetic turbines depend on the performance of the airfoils chosen. Using double-blade airfoils in the wind and hydrokinetic turbines, minimum wind and hydrokinetic flow velocities to produce meaningful and practical mechanical power reduces to 3- 4 m /s for wind turbines and 1-1.5 m/s or less for hydrokinetic turbines. Consequently, double-blade hydrofoils may re-define the potentials of wind power and hydrokinetic power of the countries in positive manner.


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