تجزیه و تحلیل عملکرد از یک ماژول چندگانه فتوولتائیک سی کریستالی در شرایط اقلیمی مولا در ترکیه

Commercially available, a multi crystalline silicon (mc-Si) photovoltaic (PV) module has been monitored outdoors under Mugla climatic conditions in Turkey. Electricity yield of this module is calculated from the uninterruptible measured current–voltage curves from sunrise to sunset during a year. Calculated electricity yield from the measured plane of array or in-plane (POA) irradiation is compared with the calculated electricity from the manufacturer’s electrical values of the module and the measured electricity from the photovoltaic system consisting 26 mc-Si PV modules from the same manufacturer. Calculated annual energy rating for the PV system is 1415.79 kW h/kW p and 1414.18 kW h/kW p from the manufacturer data and tested module respectively. The measured energy rating value is 1412.78 kW h/kW p. Comparison of results from this study with those obtained from the measurements show that the average difference in monthly electricity values varies between ±12% with an annual average value less than 1% and a performance ratio (PR) of 0.72.

Manufacturers of photovoltaic modules typically provide electrical parameters at only one operating condition. PV modules operate over a large range of conditions so the manufacturer’s information is not sufficient to determine their overall performance. Designers need a reliable tool to predict energy production from a PV module under all conditions in order to make a sound decision on whether or not to incorporate this technology. PV modules are currently rated by power rating given by an output power under the standard test condition (STC), i.e., incident solar irradiance: 1 kW/m2; solar spectrum distribution: AM1.5G; and module temperature: 25 °C. The performances of PV modules depend on these three environmental factors; thus the condition to measure the PV performance is important [1] and [2]. Theoretical models for PV modules have been widely validated at a laboratory level, but little has been done in the application. There are various empirical models to simulate the DC output current–voltage characteristics of a PV module under different radiation levels and temperatures [3], [4], [5], [6], [7], [8] and [9]. The models were based on three basic parameters, which are generally available by the manufacturer. But actual outdoor conditions change from hour to hour. Electricity consumers and suppliers buy and sell energy in units. Thus, energy rating given by an actual electrical energy generated by PV modules is appropriate for the rating of PV modules. However, energy rating is more complicated than power rating because energy rating needs actual operation data for PV modules and environmental factors where the PV modules are installed. In this study, commercially available, a multi crystalline silicon (mc-Si) photovoltaic module has been monitored outdoors under Mugla climatic conditions in Turkey [10], [11] and [12]. Energy yield of this module is calculated from the uninterruptible measured current–voltage curves from sunrise to sunset during a year. At Mugla Sıtkı Kocman University PV outdoor test centre, the actual field performances of several PV modules/systems of various technologies. The facility also includes a mc-Si PV module and a PV system including 26 modules from the same manufacturer. Measured POA radiation is used to calculate the electricity output and the manufacturer’s electrical values of the module and photovoltaic system and calculated electricity yield is compared with the measured electricity.

A grid connected PV system with 26 mc-Si photovoltaic modules (2.73 kW p rated power) has been installed and monitored outdoors between January 2008 and December 2008 under Mugla climatic conditions in Turkey. Electricity yield of one module is calculated from the uninterruptible measured current–voltage curves from sunrise to sunset during a year and the calculated electricity yield is compared with the measured electricity from the PV system. The performance parameters of thePV module were evaluated on monthly, seasonal and annual basis. Site data during the monitored period showed that annual total PV module POA radiation, calculated electricity and the average efficiency of the module were 1963.90 kW h/m2, 182.83 kW h and 9.54% respectively. PV module operating temperature varies between 50.5 °C and 80.5 °C under 1000 W/m2 POA radiation in a year. The monthly total generated electricity of the PV system varied between 78.47 kW h/kW p in December and 206.19 kW h/kW p in August while the annual total generated electricity was 1741.24 kW h/kW p. Low levels of solar irradiation during winter resulted in low final yield but higher operating temperature decreases the performance of the PV module. The PV module efficiency was calculated as 7.57% in January and 10.96% in February 2008. The annual POA radiation for the 2.73 kW p array is about 52950 kW h and the calculated annual electricity is 3885.28 kW h with an annual efficiency of 7.33%. Besides this, measured annual electricity is 3856.90 kW h and the annual efficiency is about 7.3%. Calculated annual energy rating for the PV system is about 1414.18 W h/kW p where the measured was 1412.78 kW h/kW p. Comparison of results from this study with those obtained from the measurements show that the average difference in monthly electricity values varies between ±12% with an annual average value less than 1% and a PR of 0.72.