Economic and performance evaluation of an automated PV cleaning system with water recycling in Islamabad, Pakistan

At present, the use of solar photovoltaic (PV) modules plays an important role in the field of utilization of solar energy and transformation of this energy into electricity. The main characteristic of PV modules is the work efficiency. It strongly depends on external influences such as the degree of contamination on the glass surface and the operating temperature of the PV modules. Accumulation of dust particles on the surface of PV modules has a very negative effect on their efficiency. At high ambient temperatures, solar PV modules heat up, and the efficiency of modules is reduced. This problem is very substantial for the countries with high temperature conditions and dusty climate. In this paper, the influence of dust and temperature on the efficiency of solar PV modules is investigated. The new-type economically viable system for cleaning and cooling PV modules is used during the experiments. The conducted experimental studies under actual operating conditions during the rainiest period of the year in Yerevan, have shown that due to the cleaning of dust, the efficiency of PV modules is increasing on average by 6.7%. Due to rapid cooling by water in two minutes, the efficiency of PV modules is increased by 2.5%. To improve the operation efficiency, the PV modules must be cooled periodically, taking into consideration the quantity of the consumed water in order to get the maximal economic effect.

Solar photovoltaic (PV) power generation is an attractive technique to reduce consumption of fossil fuels and as a renewable energy. PV system is convert photo energy into direct-current energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. The overall power output and efficiency of the PV module can decrease by ~0.5%/ C and ~0.05%/ C when the ambient temperature of module increases. In fact the efficiency of the general PV modules is only between 13% until 20%. This caused will affected the PV module lifespan. In this work, the performance of PV output power is analysis by using PVsyst software. The open-circuit voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oc</sub> ) of PV module, short circuit current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub> ) and every change temperature on PV module are measure and record. In this work, the result of efficiency of PV under cooling system is 14% while the efficiency of PV under without cooling system is 10.3%. The incident irradiance is 1000 W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , the efficiency of PV module is 13.05% while the incident irradiance is 200 W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and the efficiency of PV module is 10.45%. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.

This paper evaluates the photovoltaic (PV) module operating temperature’s relation to efficiency via a numerical heat transfer model. The literature reports that higher PV module operating temperatures impact PV module efficiency. There are dozens of explicit and implicit equations used to determine the PV module operating temperature. However, they are not universal, and for each application, it is necessary to insert a correction coefficient based on the environment and boundary conditions. Using a numerical method covering a more comprehensive range of PV module operation conditions to estimate a global equation, this study considers the solar radiation flux, Gt, solar ray direction with respect to the ground level, γ, convective heat transfer coefficient, h, tilt angle, β, ambient temperature, Ta, PV power output, Ppv, PV panel efficiency, η, and environmental properties. The results match the extant empirical work and related literature. PV module efficiency is found to have a linear relationship to the PV module operating temperature via a numerical heat transfer model corresponding to the well-known PV module. It specifies that heat transfer convection changes with PV module tilt angle, causing PV module operating temperature effects. It also represents the PV module operating temperature variations with ambient temperature and solar flux, like those reported in the literature.

The snow falling on the surface of photovoltaic modules tends to reduce the output power. In order to understand the process of snow accumulating on solar photovoltaic modules and reveal the impact of snow accumulation on photovoltaic conversion efficiency, the snow-cover process was simulated on the surface of photovoltaic modules with different tilt angles by computational fluid dynamics (CFD). On this basis, the relationship between the amount of snow and tilt angle was explored. The snow effect of photovoltaic modules on photoelectric conversion efficiency was studied by building a test platform. At the same time, a measurement platform of snow accumulation on photovoltaic modules and photoelectric conversion efficiency was constructed. Through the experiment of the relationship between snow thickness and snow sliding distance and the power generation efficiency of photovoltaic (PV) modules, the influence of snow thickness and snow area on the power generation efficiency of PV modules is discussed. The results show that the larger angle between the photovoltaic panel and the ground is adverse to the accumulation of snow on the panel. When the thickness of snow reaches 1 cm, the power generation efficiency of the entire photovoltaic module reduces to 7.1% of that as normal. At the same time, the sliding of snow on the photovoltaic panel improves the efficiency of photoelectric conversion. Through the analysis of numerical simulation and experimental results, targeted suggestions are made on how to improve the efficiency of power generation for photovoltaic power stations under snowy conditions, which may provide a reference for engineering work.

Some of the recent challenges encountered in research and development of the solar photovoltaic (PV) industry include the decrease in electrical output efficiency of a conventional solar PV module due to the rise in its surface temperature. The main objective of this research work is to enhance and improve the electrical output efficiency of a common silicon-based solar PV module by lowering the operating temperature of the PV module, which was accomplished by attaching hollow rectangular aluminum tubes as a fin to the rear surface of the solar PV panel. The proposed geometrical configuration of tubes helped to increase the PV module heat transfer rate to the surrounding air by increasing the effective heat transfer area without increasing the overall weight of the PV module. In this experimental study, a comparative analysis has been presented for PV modules with fins and without fins. The results obtained from experiments demonstrated that the attached fins reduced the average temperature of the front and rear surfaces up to 8.97% and 8.41%, respectively. The cooling effect produced due to fins improved the open circuit voltage up to 12.97% and the electrical output efficiency up to 2.08%. Furthermore, the results are thoroughly compared with other published studies, which revealed that the proposed configuration is cost effective and structurally sound.

Experimental investigation of soiling impact on PV module performance in Yanbu Al Sinaiyah, Saudi Arabia

Performance evaluation of photovoltaic module integrated with phase change material-filled container with external fins for extremely hot climates

Climate and weather conditions greatly affect photovoltaic (PV) module performance and efficiency, particularly in desert environments. Dust accumulation, which significantly reduces power generation efficiency, is currently the main issue facing photovoltaic modules since it affects the return on investment of PV systems. It is believed that the tilt angle of solar PV panels can be helpful in reducing the effect of soiling using the gravitational force experienced by the dust particles, mainly in dry environments. In this work, experimental studies were conducted to investigate the effects of the tilt angle and dust deposition on the electrical power generation performance of photovoltaic modules under weather conditions in Al Seeb, Oman. The study was conducted by exposing solar PV panels to outdoor sunlight for two weeks. Two of the PV panels with fixed and different tilt angles were cleaned on a daily basis, while another panel was left uncleaned. A comparison was made with the panel that was not cleaned for an extended time. Measurements included solar irradiance, solar panel temperature, voltage, and current. The output power and efficiency reached 93.5 W and 24.5%, respectively, for the panel cleaned daily. Furthermore, soiling resulted in an 18.8% power loss. The results showed that the highest output power of 79.75 W was observed at an angle of 25°, with an efficiency of up to 20.5%. Moreover, the power generated was up to 9.8% higher than that at different tilt angles.

A well‐known fact is that the electrical performance of the solar photovoltaic (PV) module reduces with an increase of its operating surface temperature, hence to obtain better electrical performance from PV module; it becomes necessary to maintain its surface temperature within the recommended limit. The present experimentation is focused on the application of phase change materials (PCM) to improve the electrical conversion efficiency of the PV module. The performance analysis of the polycrystalline silicon PV module integrated with the finned heat sink embedded in the PCM bath has been carried out, particularly for Indian climatic conditions (21°N, 79°E). Four different organic PCM‐filled PV modules (PV‐PCM) have been selected for performance comparison with conventional PV modules toward their electrical conversion efficiency. All the PV modules are tested with different tilt angles to obtain the lowest operating temperature afterwards the PV‐PCM module with the lowest temperature at particular tilt angle was compared with conventional PV module for output power. Among all investigated PV modules, calcium chloride hexahydrate‐filled PV system exhibits the highest electrical performance at an angle of 90° with the horizontal. The relative and improved average electrical efficiency of 7.5% was recorded with the novel designed PV‐PCM system.

A b s t r a c t: Taking into account the substantial cost of a photovoltaic (PV) system, should maximise module efficiency. The experimental tests are conducted with the group of 10 photovoltaic panels installed on the roof of the building of the Electrical Engineering Faculty resided on the Polytechnic University of Tirana. The PV panels are split in groups of two with 5 different tilt angles, respectively 0°, 30°, 45°, 60° and 90°. To view the pollution and the tilt angle effects, one of the panels is cleaned every day. Monitoring the group of panels gives interesting conclusion about the impact of the dust and the tilt angle on PV production efficiency, as well as, the impact of the tilt angle to the dust settlement. The results show an increase in the performance of clean panel. The I-V and P-V characteristics curves were constructed and compared. A b s t r a c t: Taking into account the substantial cost of a photovoltaic (PV) system, should maximise module efficiency. The experimental tests are conducted with the group of 10 photovoltaic panels installed on the roof of the building of the Electrical Engineering Faculty resided on the Polytechnic University of Tirana. The PV panels are split in groups of two with 5 different tilt angles, respectively 0°, 30°, 45°, 60° and 90°. To view the pollution and the tilt angle effects, one of the panels is cleaned every day. Monitoring the group of panels gives interesting conclusion about the impact of the dust and the tilt angle on PV production efficiency, as well as, the impact of the tilt angle to the dust settlement. The results show an increase in the performance of clean panel. The I-V and P-V characteristics curves were constructed and compared. Key words: photovoltaic module; dust; module performance; tilt angle; I-V characteristics REFERENCES : [1]Tian, W., Wang, Y., Ren, J., Zhu, L.: Effect of urban climate on building integrated photovoltaics performance. Energy Conversion and Management, vol. 48 (1), pp. 1–8, (2007). [2]Kaldellis, J. K., Kokala, A.: Quantifying the Decrease of the Photovoltaic Panels’ Energy Yield Due to Phenomena of Natural Air Pollution Disposal, Energy, vol. 35, pp. 4862–4869, (2010). [3]Betul Bektas Ekici: Variation of photovoltaic system performance due to climatic and geographical conditions in Turkey, Turk J Elec Eng & Comp Sci, Vol. 24, Num. 6, pp. 4693–4706 (2016). [4]SunPower Limited Product and Power Warranty for PV Modules, Sun Power®, July 2010. [5]Miqdam T. Chaichan, Bashar A. Mohammed, Hussein A. Kazem: Effect of pollution and cleaning on photovoltaic performance based on experimental study, International Journal of Scientific & Engineering Research, Vol. 6, Issue 4, pp. 594–601 (2015). [6]Cano, J.: Photovoltaic Modules: Effect of Tilt Angle on Soiling, Master thesis, Arizona State University: August 2011. [7]AlAiawy, I. T.: Wind and other factor requrements to solar energy applications in Iraq, Solar and Wind Technology, vol. 7, pp. 597–600 (1990). [8]Mani, M. and Pillai, R.: Impact of dust on solar photo-voltaic (PV) performance: Research status, challenges and recommendations, Renewable Sustainable Energy Rev., vol. 14, pp. 3124–3131 (2010). [9]John, J. J.: Characterization of Soiling Loss on Photo-voltaic Modules, and Development of a Novel Cleaning System, Ph.D. Thesis, Department of Electrical Engineering, Indian Institute of Technology Bombay, 2015 [10]www.geo.edu.al/site/, Institute of GeoSciences, Energy, Water and Enviroment, 2015. [11]Laudani, A., Fulginei, F. R., Salvini, A.: Identification of the one-diode model for photovoltaic modules from datasheet values. Sol Energy, vol 108, pp. 432–446 (2014). [12]Guide to Interpreting I-V Curve Measurements of PV Arrays, Solmetric Corporation, 2010. [12]Pantic, Lana S., Pavlovic, Tomislav M.: Determination of physical characteristics of horizontally positioned solar module in real climate conditions in Nis, Serbia, Physics, Chemistry and Technology, vol. 14, No 1, pp. 37–51 (2016).

Experimental Study of Using Passive Cooling of the Photovoltaic Module Under Hot Climate Conditions

The object of this study is photovoltaic modules with different seasonal tilt angles at different geographical latitudes. The average annual efficiency of photovoltaic modules with different seasonal angles set at different geographical latitudes has been determined as the annual weighted average value of the cosine of the angle of incidence of solar rays on the plane of the photovoltaic module. The influence of seasonal tilt angles of photovoltaic modules at different geographical latitudes on their average annual efficiency was analyzed. Approximate values of the seasonal tilt angles of photovoltaic modules at different geographic latitudes take values that differ from the geographic latitude value by plus 15° for the winter period and minus 15° for the summer period. Modeling the average annual efficiency of photovoltaic modules depending on the seasonal tilt angles at different geographical latitudes made it possible to obtain refined values of the seasonal tilt angles of photovoltaic modules. Thus, at the latitude of 0°, 10°, 20°, 30°, 40°, 50°, and 60°, the tilt angle of photovoltaic modules for the winter period will be 14.8°, 24.6°, 34.5°. 44.4°, 54.1°, 63.6°, and 73°, respectively, and for summer ‒ minus 14.5°, minus 4.6°, 5°, 15.1°, 25.1°, 34.9°, and 44.7°. Dependences were obtained for determining the seasonal tilt angles of photovoltaic modules depending on the value of geographic latitude. The difference in the average annual efficiency of photovoltaic modules, which are installed at seasonal angles, and photovoltaic modules, which track the position of the Sun in the vertical plane, is 0.4 %. The results could be used as a basis for evaluating the efficiency of photovoltaic modules when determining the seasonal tilt angle at different geographic latitudes

Experimental investigation of soiling losses and a novel cost-effective cleaning system for PV modules

The artificial neural network model to estimate the photovoltaic modul efficiency for all regions of the Turkey

Determination of the working temperature of photovoltaic (PV) modules is an essential task in research and engineering projects. It acquires more relevance in the current environment, characterized by increasing figures of installed PV power, module efficiency, solar applications, and operational configurations. However, most of the current procedures for temperature determination of PV modules are simply based on empirical correlations, carried out at conditions defined by some specific standards, with the corresponding lack of accuracy when modules work under real conditions. Thus, the present work looks into a formal procedure for temperature determination by conducting a power balance between the dynamic incoming and outgoing power fluxes. Some additional parameters are included when compared with classic expressions. In particular, the spectral reflectance of the tandem glass-semiconductor is measured to determine the reflected fraction of solar irradiance. The relationship between reflectance and equilibrium temperature is determined for a representative group of PV modules, and the influence that the working point exerts on the module temperature has also been taken into account. Finally, the influence of spectral distribution on module temperature has been quantified by simulations carried out by using a spectral model. In this way, determination of absolute temperature is achieved within a ±2°C range, regardless of module characteristics and climatic or operational conditions. In addition, temperature differences between PV modules that work under the same external conditions can be predicted within ±0.5°C. To summarize, a thermal model suitable for different PV modules and working configurations is presented. Some new parameters are introduced in the calculus process, and the influence of the most relevant ones has been quantified. In this way, the present work is aimed at making a contribution to the study of PV module temperature.