Browsing by Author "Ozcan, Zeynep"

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Citation - WoS: 36
Citation - Scopus: 42
Cooling channel effect on photovoltaic panel energy generation
(PERGAMON-ELSEVIER SCIENCE LTD, 2021) Zeynep Ozcan; Miray Gulgun; Ecem Sen; Nezir Yagiz Cam; Levent Bilir; Gulgun, Miray; Sen, Ecem; Ozcan, Zeynep; Bilir, Levent; Cam, Nezir Yagiz
It is a well-known fact that even though the electricity generation is higher when the solar radiation is high on a photovoltaic panel its efficiency drops as its temperature increases. In this study it is intended to achieve cooling effect using an air duct placed under a photovoltaic panel thereby increase its efficiency. Hourly electricity generation PV efficiency and cell temperature values over a year are calculated using annual temperature and radiation data by using MATLAB and PV Sol software. Maximum cell temperature for the uncooled case is determined as 57.91 degrees C on July 21st at 1p.m. as a result of hourly calculations. The incident solar radiation is 976 W/m(2) when the panel reached its maximum temperature. The PV panel and cooling channel are modelled in ANSYS Fluent software and cooling effect was investigated for different air velocities and air-cooling channel geometries for the hour when maximum cell temperature is reached. Environmental analyses are also made. It is observed that with finned cooling channel it is possible to cool PV temperature more than with the flat cooling channel. Cooling the PV panel from its maximum cell temperature to 39.82 degrees C with 5 m/s air velocity and 82 fins cooling channel is achieved and new PV panel efficiency is recorded as 18.92 %. Environmentally considerations show that the use of solar energy provides the reduction of coal and natural gas-based CO2 emissions as 15 and 8 tons respectively.
Citation - WoS: 9
Citation - Scopus: 11
Modelling and analysis of heat pump integrated Photovoltaics-Wind systems for an agricultural greenhouse in Turkey
(Elsevier Ltd, 2024) Zeynep Özcan; Levent Bilir; Başar Ca̧ǧlar; Bilir, Levent; Caglar, Basar; Ozcan, Zeynep
This study focused on modelling and analysing photovoltaics and wind systems to meet the heating demand of a commercial greenhouse. The aim is to evaluate technical economic and environmental performances of the related systems and to determine the optimum configuration. A novel approach was introduced by integrating hybrid energy systems with large-scale wind turbines and developing a dynamic heat transfer model. A large commercial greenhouse with an area of 26640 m2 located in Izmir Turkey was selected for considering Mediterranean climate and a detailed heat transfer model of the greenhouse were developed considering heat transfers by convection radiation ventilation and infiltration. A combination of air source heat pumps photovoltaic panels and wind turbines were used for meeting the heating demand of the related greenhouse. Five different on-grid energy systems scenarios namely (i) Photovoltaics-Heat Pump (ii) Photovoltaics-Wind Turbine- Heat Pump (iii) Wind Turbine- Photovoltaics- Heat Pump (iv) Wind Turbine- Heat Pump and (v) only Heat Pump were considered. The system modelling with a detailed heat transfer analysis of the greenhouse was made by MATLAB. The energy analysis of the systems was performed on an hourly basis for one calendar year. The annual heating demand and the corresponding electricity consumption of the greenhouse were calculated as 497.37 and 114.07 kWh/m2 respectively. Net Present Value Levelized Cost of Energy and CO2 savings were used to evaluate economic and environmental performances of the systems. Among five on-grid energy system scenarios the first scenario consisting of 5271 photovoltaic panels and 20 heat pumps emerged as the most economically attractive choice with Net Present Value and Levelized Cost of Energy of $547440.40 and 0.080146 $/kWh respectively. Critical parameters affecting the economy of this scenario were found to be electricity prices tomato yield and photovoltaic panel prices. For environmental evaluation the fourth scenario integrating wind turbines and heat pumps achieves the highest CO2 savings of 2064.73 tons due to increased renewable electricity production and lower life-cycle CO2 emissions of wind turbines compared to photovoltaic systems. This analysis enhanced the understanding of energy dynamics in greenhouse environments contributing to the advancement of sustainable practices in agriculture. © 2024 Elsevier B.V. All rights reserved.