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In this study, a comprehensive exergy analysis was applied to a solar power system (SPS) located in the city of Van, Turkey. Van was always known as a sun city throughout history with the name of TUSBA. It has an average of 300 sunny days a year, an altitude of 1727 m, and an average daily temperature of 9.85°C. Considering how the need for sustainable and renewable energy sources - and knowledge over them - constantly increases, this SPS was built to reveal the true solar potential of the campus area of Yuzuncu Yil University of the city of Van, hopefully as a precursor for further large-scale SPS constructions in the region. A daily analysis considering energy production and global radiation was applied to the system in 2013 for 365 days. It was found that the yearly exergy efficiency of the system was 10% and total electrical energy production was 31,038.95 kWh, averaging 1763.5 kWh/kWp yearly.

Beyond the anticipated experience associated with tourism destinations, the United Nations World Tourism Organization (UNWTO) has further tasked (especially the destination countries) on the importance of tourism to achieving the 2030 Sustainable Development Goals (SDGs). From this dimension, this study employed the ecological footprint of the 10 most visited countries (France, Spain, United States, China, Italy, Mexico, United Kingdom, Turkey, Germany, and Thailand) over the period 1995-2016. Specifically, the study employed an econometric approach and found that increase in tourism arrivals and globalization is detrimental to the attainment of sustainable environmental quality in a long term. Precisely, a 1% increase in international arrivals and globalization is responsible for a 0.18 and 0.89% increase in ecological footprint in the long-run. These impacts of tourism activities and globalization are detrimental to the environmental quality of the destination countries. Meanwhile, the real income per capita and biocapacity in the destination countries improve the environmental quality of the panel of destination countries in the long-run. In addition, the study found significant evidence of Granger causality from tourism and real income to ecological footprint without feedback, the globalization-ecological footprint Granger causality nexus is with feedback. Moreover, potentially effective policies for government and other stakeholders especially toward attaining Global goals were proffered in the study.

With the development of technology, some important developments occur in electrical energy systems. Especially smart grids and micro grids will be an important part of energy systems in the following years. With the increasing use of micro grids, more renewable power plants will be included in the system. However, the production of renewable energy sources varies according to the weather conditions. Therefore, the generated energy is not known beforehand. Increasing single-phase loads (such as electric vehicle charging stations), unpredictable renewable generation and uncertainty of consumption can lead to problems of voltage unbalance in the micro grid. This problem can damage the network in many ways. In this study, the problem of voltage unbalance occurring in the microgrid was tried to be reduced by demand side management. The comfort of the customer should not be affected when demand side management is performed. For this reason, the most suitable load for demand side management is thermostatically controlled loads (TCL). An algorithm has been proposed to reduce voltage unbalance by using these loads. This algorithm was tested with the help of PSCAD/EMTDC program.

Renewable energy has become more popular since it is cost-effective and more efficient than conventional energy sources. Biomass-based renewable energy is primarily used in emerging economies to ensure environmental sustainability. This study examines the asymmetric correlation between biomass energy consumption and CO2 emissions in the top-10 biomass energy consumer countries (Brazil, Canada, Thailand, China, Italy, India, Germany, USA, UK, and Japan). A new approach "Quantile-onQuantile (QQ)" is employed by utilizing the data from 1991 to 2018. Biomass energy consumption, with the exception of Thailand, significantly mitigates CO2 emissions at various quantiles in selected countries. As a robustness check, we used the quantile regression test, whose findings are consistent with the outcomes from the quantile-on-quantile method. However, the degree of asymmetry in the biomass energy-CO2 nexus varies by country, necessitating extra attention and government vigilance when developing biomass energy and environmental policies.

The aim of this study was to examine the risk of heavy metal, ammonia and sulfate transition from underground coal gasification (UCG) chars and process water of Malkara lignite to the groundwater around the UCG cavity. The residues were collected during laboratory-scale underground coal gasification studies of Malkara lignite in ex situ gasification simulator. In order to compare gasification with combustion in terms of water pollution, ash samples were obtained by combustion of Malkara lignite. To determine the leaching behavior of the char and ash samples, two leaching tests (EPA TCLP and EN 12457-2 methods) were applied. The concentration of heavy metals in char, ash and process water samples was determined by ICP-OES. Additionally, ammonia and sulfate analyses were conducted for process water. Based on the results of this study, it has been found that the concentration of some elements, such as B, Sb and Al in char and ash eluates exceeded the maximum level of drinking water standards. However, there is no landfill concern about char samples according to EU Landfill Directive. A significant increase in B concentration was observed in ash samples. Considering B and some other elements combustion residues were identified with much higher water contamination ability, compared to gasification residues. Ammonia concentration was observed extremely high in process water of the gasification tests. UCG technique may be more environmentally applicable technology compared to combustion for Malkara lignite reserves. However, further detailed studies are necessary in the early stage of the UCG field test design and application.

AbstractThe Environmental Kuznets Curve hypothesis suggests that, as a country's national income grows, environmental degradation subsides as the population demands a cleaner environment. On the other hand, critics of the Environmental Kuznets Curve claim that many polluting industries simply relocate offshore, where environmental compliance is less costly. They then export their products back to their previous home countries. This is known as the Pollution Haven hypothesis. This article demonstrates how pollution havens can falsely give the appearance of an Environmental Kuznets Curve by analysing lead emissions from the US automotive tyre manufacturing industry.

Abstract Conventional room air conditioners consume a significant amount of energy, and thereby negatively affect the environment. In this perspective, passive air conditioning systems using phase change material (PCM) are very promising and widely investigated recently. In this study, influence of a PCM-based passive air conditioner on temperature distribution was experimentally studied in a test room under the local tropical climatic conditions. Coconut oil and water were used for latent heat storage and sensible heat storage, respectively. A storage panel was constructed with two openings—an outlet for conditioned air and an inlet for indoor air, then filled with coconut oil or water to create an additional internal thermal mass (ITM) in the room. The storage material was discharged at night in the indoor or outdoor, and stratum air circulation was utilized to provide the conditioned air into the room during diurnal period. Temperature measurements were conducted at five vertical and five horizontal points. The gained results showed that employing ITM heat storage panel in the room reduced peak temperatures and enhanced the thermal environment. Coconut oil ITM provided 0.5 °C lower peak temperature in the occupant zone while greater temperature reductions were observed in the upper zone compared to the reference case. In addition, ITM panel significantly decreased the observed temperature fluctuations throughout a day. This study revealed that ITM-based stratum air circulation can be a profound solution to the existing high energy consumption problem of conventional air conditioners used in the small urban houses under tropical climate.

Abstract In this paper, energy and exergy analyses of the geothermal-based hydrogen production via thermochemical water decomposition using a new, four-step copper–chlorine (Cu–Cl) cycle are conducted, and the respective cycle energy and exergy efficiencies are examined. Also, a parametric study is performed to investigate how each step of the cycle and its overall cycle performance are affected by reference environment temperatures, reaction temperatures, as well as energy efficiency of the geothermal power plant itself. As a result, overall energy and exergy efficiencies of the cycle are found to be 21.67% and 19.35%, respectively, for a reference case.

Abstract In order to improve the energy characteristics for low-power ozone generators, it is proposed to use a continuous discharge burning mode. It is due to a significant phase shift between the currents and voltages on the ozone generator. Conditions for conducting the continuous discharge mode were identified.