Renewable and Sustainable Energy Reviews, cilt.67, ss.651-661, 2017 (SCI-Expanded)
Photovoltaic (PV) panel efficiency has been tested in the laboratory at standard test conditions (STC) (25 °C, 1000 W/m2 and AM:1.5). However, PV panels are used in different regions and climatic conditions quite different from STC. Due to that, panel efficiency is not observed same with manufacturer catalogue data. This study focus on outdoor testing of PV panels performances at literature, in addition, one-year results of mono-crystalline (2.35 kW), polycrystalline (2.64 kW) and amorphous silicon (2.40 kW) photovoltaic panels were analysed. These PV panels were placed on the roof of Düzce University Scientific and Technological Researches Application and Research Centre (DUBİT) in Düzce Province, in Turkey, one of the countries with the highest solar power potential in Europe and connected to power grid. Amounts of energy produced by the panels over a day, a month and a year as well as inverter efficiency and performance ratios were calculated. Performance ratios were found out as 73%, 81% and 91% for a-Si, polycrystalline and mono-crystalline PV panels, respectively. Panel efficiency was calculated as 4.79%, 11.36% and 13.26% in the same order. All results were compared with Previous studies. Statistical analysis was made to state relationship between efficiency and performance ratios of panel types, environmental temperature, panel temperature and amount of radiation. As a result of the statistical analysis, it was observed that temperature increase of 1 °C increased the efficiency of a-Si panels 0.029% and the efficiency of polycrystalline panels 0.033%, yet, decreased the efficiency of mono-crystalline panels 0.084%.