Outdoor performance evaluation of a novel photovoltaic heat sinks to enhance power conversion efficiency and temperature uniformity

The non-uniformity of photovoltaic (PV) temperature can further deteriorate its power conversion efficiency and technical lifetime over long field exposures. This study proposed novel fins for a PV module temperature reduction and enhancing temperature uniformity. The proposed multi-level fin heat sinks (MLFHS) consist of a novel geometry of extruded aluminum material attached to the rear side of the PV module. The developed outdoor experimental setup consists of two identical 120 Wp monocrystalline PV modules; one served as a reference module for comparison against the module with the proposed novel heat sink geometry. The temperature distributions across PV modules and the electrical parameters were then recorded and analysed. A substantial drop in the module temperature of 8.45 ◦C was observed at solar irradiance and ambient temperature of 941 W/m2 and 36.17 ◦C, respectively. As a result, the heat sink improved the overall power output up to 9.56% under outdoor operating conditions. Furthermore, the prominent effect of temperature uniformity was perceived for solar irradiance greater than 600 W/m2 and improved by 14.8%. These findings are foundational for passive cooling methodologies to guide further research and development of an efficient PV cooling methodology

Coding Template Of Sensorless Sun Tracking Using Azimuth-Elevation Mode

The next explosion in solar power research was in 1997 as consequence to Kyoto Protocol. This protocol outlined the effect of greenhouse emission which endangers our Earth. As the result, research in solar power field started to take its path again. This work is a part of the UTeM project to build the first CST model in South East Asia and was aimed to develop an azimuth-elevationmode-based template using MATLAB programming for the calculation of the heliostat position with respect to the heat absorber mounted at the top of the CST. This template will serve as the calculation platform to control the movement of the heliostat using a two-axis motion system so that the sun light will be redirected perfectly to the absorber all day long. Since the heliostat normal vector depends on sun position vector, both vectors were calculated by the program and were set as the output of the program. The input from the user will be the Cartesian coordinate of the heliostat and absorber by taking the absorber tower frontal surface and its base as the origin and also the date. The result will be in vector form and will change automatically according to the Sun movement. These values will be programmed in the micro controller which will control the motion system of the heliostat, which will be done by the Control Department of UTeM. The program´s functionality was proved via several verifications and its accuracy which is 0.0005 as stated and verified via comparison with analytical calculations. From the verifications, it can be seen that difference of the numerical and analytical results varied from 0.0000 to 0.0005 which validates the statement of minimum accuracy of the numerical calculated results is 5/10,000

Recent advances in passive cooling methods for photovoltaic performance enhancement

The electrical output performance of photovoltaic (PV) modules are sensitive to temperature variations and the intensity of solar irradiance under prolonged exposure. Only 20% of solar irradiance is converted into useful electricity, and the remaining are dissipated as heat which in turns increases the module operating temperature. The increase in module operating temperature has an adverse impact on the open-circuit voltage (Voc), which results in the power conversion efficiency reduction and irreversible cell degradation rate. Hence, proper cooling methods are essential to maintain the module operating temperature within the standard test conditions (STC). This paper presents an overview of passive cooling methods for its feasibility and economic viability in comparison with active cooling. Three different passive cooling approaches are considered, namely phase change material (PCM), fin heat sink, and radiative cooling covering the discussions on the achieved cooling efficiency. The understanding of the above-mentioned state-of-the-art cooling technologies is vital for further modifications of existing PV modules to improve the efficiency of electrical output

Techno-economic analysis of a hybrid solar dryer with a vacuum tube collector for Hibiscus Cannabinus L Fiber

Solar energy is one of several types of renewable energy and has numerous applications. Types of solar energy include photovoltaic, thermal, and thermophotovoltaic modes. Drying is an application of thermal solar energy which is used to remove water from a sample. The main reason this study was done was due to the lack of use of hybrid solar dryers for high load keno fibers. This dryer is capable of extracting water from the sample with a maximum load of up to 1400 kg. This study aims to evaluate certain open drying methods as compared with modern thermal drying methods. The dried samples were a type of natural fiber commonly known as kenaf (Hibiscus Cannabinus L). The test amounts were 175 kg and 1400 kg, respectively. The solar thermal drying uses several components, including an evacuated tube collector, water storage tank, heater, air intake, pump, and a drying chamber. The parameters to be measured included weight, water content, time, and electricity usage. Dryer performance was evaluated in terms of water extraction rate, exact water extraction rate, specific energy usage, dryer operational costs, and specific operational costs. The results of the evaluations indicate that drying with the maximum load of 1400 kg increased the extracted water, exact water extraction rate, and dryer operational costs by 97.27 kg/hour, 39.86 kg/kWh, and 3.72 Malaysian ringgit (approximately 0.90 USD), respectively. Specific energy consumption and specific operating costs fell by 0.10 kWh/kg and 0.05 RM/kg (0.012 USD/kg), respectively. Based on these findings, economic analysis was carried out to estimate the profitability and frequency of drying. The results indicate that a maximum load of 1400 kg is superior to the open drying method, with an annual yield and return of investment period of RM 64992 (15,723 USD) and 3.7 years, respectivel

Comparative Performance Of ARIMA And DES Models In Forecasting Electricity Load Demand In Malaysia

Malaysia is a developing country which is having a high level of energy demand. Load demand forecasting is essential that is also in line with increasing demand of electricity. The purpose of the current study is to compare the performance of two time series models in forecasting electricity load demand in Malaysia. Two methods are considered, which are Box-Jenkins Autoregressive Integrated Moving Average (ARIMA) and Double Exponential Smoothing (DES). Using Mean Absolute Percentage Error (MAPE) as the forecasting performance measure, the study concludes that ARIMA is more appropriate model

ARAR Algorithm In Forecasting Electricity Load Demand In Malaysia

Electricity load demand has grown more than four-fold over the last 20 years period. The purpose of the current study is to evaluate the performance of ARAR model in forecasting electricity load demand in Malaysia. Box-Jenkins Autoregressive Integrated Moving Average (ARIMA) will be used as a benchmark model since the model has been proven in many forecasting context. Using Root Mean Square Error (RMSE) as the forecasting performance measure, the study concludes that ARAR is more appropriate model

Experimental investigation of passively cooled photovoltaic modules on the power output performance

The power output performance of a photovoltaic (PV) module decreases as the temperature increases. The increase in module temperature above the standard test conditions (25 °C) could reduce the average power output by at least 0.2% for each 1 °C rise. Hence, keeping the module temperature low is necessary for PV systems exposed to high solar irradiance throughout the year. Therefore, this study aims to experimentally analyse the eletctrical performance of passively cooled PV modules in the tropics. The developed cooling approach consists of rectangular plate fins made of aluminum 6061, attached to the rear surface of tedlar layer. The results indicated that the average module temperature reduction of 3.25 °C was observed under outdoor exposures. As a result, the heat sink improved the overall power output up to 14.2%. As the PV performances are site-dependent, these findings are beneficial as it provides a thorough explanation of fin heat sink behavior under long-term field exposures of tropics

Modelling And Simulation Of A Wind Turbine With Doubly Fed Induction Generator In Full Load Operation

The paper focuses on modelling and simulation of a 5 MW wind turbine with doubly fed induction generator (DFIG) in full load operation. The wind turbine model is described mathematically and presented in simulation blocks. Through a computer simulation, the wind turbine behavior in full load operation is investigated. A speed controller is used to adjust the pitch angle of a rotor blade in high wind speed to limit the wind energy captured by the turbine to the nominal power value. By adjusting the pitch angle to 18.26° at wind speed 20 m/s, the wind turbine is protected from mechanical damage due to torque and power limitation. The simulation results obtained can be used as references for future optimization for the variable speed wind turbine operation

Modeling and simulation of doubly fed induction generator for wind turbine

The construction of modern wind turbine is costly, complex and risky. In this paper, modeling and simulation of doubly fed induction generator (DFIG) for wind turbine is presented to investigate the dynamic behavior of the system. The behavior of the system is described in mathematical equations, modeled and simulated in MATLAB/Simulink using field orientation principle. Simulation results are presented in two operation modes namely below and above synchronous speed. Measurement obtained from 5 MW wind turbine confirmed the theoretical result. The created modeled can be used to simulate the behavior of DFIG for wind turbine inexpensively, efficiently and safely

Performance enhancement of photovoltaic modules with passive cooling multidirectional tapered fin heat sinks (MTFHS)

The electrical output of photovoltaic (PV) modules degrades with continued exposure to extreme temperatures caused by solar radiation. The uniqueness of this research lies in the utilization of multidirectional fins with varying heights, which effectively accelerate heat transfer in PV cooling systems by inducing a transition in the boundary layer within the confined zone of the fins. The research aims to investigate the effect of using Multidirectional Tapered Fin Heat Sinks (MTFHS) to improve the efficiency of PV modules by utilizing aluminum alloy material as heatsinks. The proposed multidirectional design aims to facilitate enhanced heat transfer by promoting airflow in the central area of the PV module. The experimental procedures in our study differ from previous research as we utilized the latest generation of PV modules (405 Wp, PERC Half-cut cells) to fill the discrepancy between laboratory-based investigations and practical applications. Two PV modules were tested for an outdoor parametric analysis under outdoor operating conditions, with solar irradiance recorded from 200 to 1000 W/m2 and ambient temperatures ranging from 26° to 38 °C. Findings indicated that the proposed MTFHS could lower PV module temperatures by 12 ⁰C. Reduced temperature boosts PV module efficiency by 1.53%. Cooling advancements proved vital in contributing to sustainability in PV system installations