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Agbulut, Umit/0000-0002-6635-6494 WOS: 000518657000001 The generation of electrical energy with photovoltaic modules is a highly useful and environmentally friendly method. For this reason, studies to increase the electrical energy production from photovoltaic (PV) modules have gained great importance. Concentrated PV systems constitute a significant part of these studies. The major problems with the concentrated PV systems are the risks of lowering the efficiency of the cells (i.e., concentration process increases PV cell temperature) and the thermal damage that can occur with sudden temperature increases. In order to avoid these risks, various applications are used to cool concentrated PV modules. In this study, an active system, which was developed for cleaning and cooling PV modules, was tested. The aim of the present study was to ensure that the surfaces were clean and free of external, contaminating factors such as dust and dirt, and that the PV cells were cooled. During the experiments, two different systems were compared: the system with the cleaning-cooling processes and the one without these processes. Prior to starting experiments, a hydrophobic liquid onto the surfaces of the PV modules was applied to facilitate the cleaning process. The results of the experiments revealed that the temperature of the PV module was 50 degrees C in the cleaning-cooling process and 67 degrees C in the system without the cleaning-cooling process. On the other hand, it was observed that the proposed design increased the power output of PV module up to 40%.

Gurel, Ali Etem/0000-0003-1430-8041 WOS: 000358483200040 Photovoltaic (PV) module converts the incoming solar radiation into heat and electric energy. Due to this heating feature of photovoltaic modules, it is likely to produce heat energy from PV modules as well. Such systems are known as photovoltaic and thermal systems in the literature. In this study, a new design PV/T system was experimentally analyzed for cooling photovoltaic modules while heating water at the same time. PV/Tis a forced circulation system without pump. Therefore, these systems are different from those described in the literature. For all PV/T system, step-by-step exergy analysis has been performed according to obtained experimental results. PV module thermal exergy, solar collector thermal exergy, and PV module electrical exergy variations have been calculated for this exergy analysis. Overall, exergy efficiency was obtained as about 17% for 45 degrees C set temperature and 21% for 55 degrees C set temperature. (c) 2015 American Institute of Chemical Engineers Environ Prog, 34: 1249-1253, 2015

Gurel, Ali Etem/0000-0003-1430-8041 WOS: 000317851600027 In this study, optimum insulation thicknesses, energy savings, and payback periods have been investigated based on life-cycle cost analysis for an external wall in four various cities from four climate zones of Turkey. Also, the study have been analyzed the effect of insulation thickness on release of CO2 and SO2 emissions. The results show that insulation thicknesses vary between 0.045 and 0.195 m, life-cycle energy savings between 13.26 and 248.9 $/m2, payback periods between 1.19 and 1.97 years when used extruded polystyrene as insulation material. When the optimum insulation thickness was used, emissions were reduced by 6292% depending on the city, fuel type, and insulation material. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 365-372, 2013