Applied Solar Energy最新文献

Considering the global fuel crisis, countries have made it imperative to exploit solar energy correctly, which has emerged as the most significant renewable energy source in recent times. Utilizing solar energy to heat the water appropriately to reduce global energy consumption is a challenge most countries face. Research has, therefore, been done extensively to maximize the performance of solar water heating through various applications. Several methods were enumerated and applied in this review study to determine how to enhance the performance of solar water heaters. Eleven techniques for improvement were identified. They are as follows: using nanofluid with phase change material; improving the collector design; coating; lowering the inlet water temperature; switching to a combined system in place of the conventional gas heating system; utilizing a dual glass cover; utilizing the upstream delta wing; utilizing the evacuated tube collector; utilizing the heat exchanger; utilizing the photovoltaic glass unit; and integrating the solar water heater and tubular lighting device into one unit. According to the essential results, using an absorption cooling system with solar power resulted in 34% electricity savings. The absorption system was enhanced, and the COP was raised to 2.75 by implementing the solar water heating system. Solar heating systems combined with PCM achieved the highest efficiency rating of 65%. The dryer system’s CO₂ emissions were lowered by about 34% when adding a solar collector. The solar water heater’s thermal efficiency was increased by 22.53% by a CuO/H₂O nanofluid.

The solar drying method consists of removing gartially and non-bound water with a small impact on the chemical structure and compositions, thus reducing the mass and minimizing the risk of numerous transformations. Taraxacum officinale leaves are well-known in the fields of pharmacology, herbal medicine, and traditional soft drinks. Since it is a seasonal plant, plants from these regions have become an indispensable element after drying and storing. The objective of this paper is to determine both total and specific energy consumption of the hybrid solar convection dryer in drying Taraxacum officinale leaves. The paper investigates the energy analysis of the leaves of Taraxacum solar drying, which includes the investigation of the impact of the aerothermal parameters’ variations: 4 temperatures (50, 60, 70, and 80°C) and 2 drying airflows (150 and 300 m³ h^–1) on the specific energy utilization in the drying process. Furthermore, this work studies the thermal efficiency as well as the energy efficiency of the solar dryer which gives room to maximize the performance of the dryer chamber. The results indicate minimal values of total energy consumption are achieved at higher temperatures and airflow rates. The findings reveal that lower total energy consumption is achieved at higher temperatures and airflow rates. Moreover, the study delves into thermal efficiency and energy efficiency, highlighting a thermal efficiency of approximately 5.58% at lower temperatures 50°C.

The accuracy of hourly global horizontal irradiance forecasts provided by the ICON (Icosahedral Nonhydrostatic Weather and Climate Model), GFS (Global Forecast System), and MeteoFrance Global models for Moscow, Russia, over a 36-h forecast horizon, is analyzed. The study investigates the suitability of these freely available global Numerical Weather Prediction (NWP) models for predicting the output of PV power plants, considering the standards of the Russian wholesale electricity and capacity market. The study conducts a comparative assessment of the forecasts from the mentioned models. A notable conclusion drawn from the study is the superior performance of all the NWP models over the naive 36-h persistence forecast, as indicated by the root mean square error, mean absolute error and mean bias error metrics. The overall findings suggest a higher accuracy of hourly global horizontal irradiance forecasts from the ICON model compared to the others under the investigated conditions.

This study aims to examine the performance of a parabolic solar trough collector (PSTC) for the efficient use of green renewable solar energy. The study investigates the energy taken by water (ETW), receiver efficiency (RE), cumulative heat gain (CHG) by water in the tank, receiver terminal temperature difference (RTTD), and percentage of electric energy saving (PEES) at various mass flow rates (MFR) with and without coating of the receiver. The study found that the PSTC performed best with a coating (WC) of the receiver at a mass flow rate of 18.72 kg/h compared to the case without coating (WOC). At the mass flow rate of 18.72 kg/h, significant increases in ETW, RE, CHG of water in the tank, and RTTD were observed for the case WC compared to WOC, at 25.88, 25.87, 23.96, and 20.56%, respectively. Meanwhile, the maximum PEES of 66.8% was observed at the MFR of 18.72 kg/h for the case WC. There is a 23.45% reduction in the annual cost per kWh of energy used for the case with coating compared to the case without coating. In addition, a substantial amount of CO₂, equivalent to 3,121.03 kg, can be offset by using the PSTC to heat water over its entire useful life. Pure titanium powder was used as the coating material.

Aims investigation study to predict the albedo number as a function of latitude and longitude coordinates of the Algeria area, which is situated in North Africa. The estimated range of latitude is between 18.5° and 37.7° whereas the longitude is between –8.5° and 10.5°. The study takes the database as the real data, which is considered comparable values as a reference of the confirmation. An ideal reflector is going to have an albedo of 1, whereas an object that has an albedo of 0 is going to absorb any radiation that strikes it. Albedo is a measure of how much solar radiation, or sunlight, a surface reflects. It can be stated as a percentage or a decimal number, where 0 represents complete absorption of all incoming light and 1 represents a perfect reflector. The prediction model is divided into two parts the first part gives two formulas g₁ and g₂ which depend on the longitude and latitude of the coordinates of the area, respectively, and then added together g₁, and g₂, and divided by 2 to take the albedo number. for the second part do the correction between the model and experimental data, which gives us some errors, in this case, create a new correlation of the errors estimate f₁, and f₂ and add in the old correlation. Finally, a new correlation is corrected and the results give a perfect approximation of the best way.

Currently, there is widespread interest in developing efficient technologies for harnessing solar energy, both in direct conversion of solar energy into electrical energy and in solar thermal power plants (STPPs). STPPs are sustainable sources of electricity due to the accumulation of heat in a heat carrier, which can be water, molten salt, or oil. The key to increasing the attractiveness of this technology lies in replacing the method of directly generating steam by heating water with solar radiation, with a receiver method using an intermediate heat transfer fluid. The technology of transferring heat obtained from solar radiation through liquid salt (a mixture of potassium nitrate and sodium nitrate, among others) imposes high demands on the pipes of this system that carry the heat transfer fluid, particularly regarding their corrosion resistance and service life. Using pipes made of ordinary steel grades with a special anti-corrosion coating applied to their inner surface can significantly reduce costs and increase the service life of the pipes, as well as the efficiency and reliability of STPPs. The study demonstrates that the method of comprehensive plasma vacuum arc treatment of the inner surface of metal pipes of various configurations, and the application of special coatings, ensures high anti-corrosion protection. For instance, applying a thin-layer coating of austenitic steel with a high chromium content (up to 28%) to samples of martensitic steel pipes resulted in 100% retention of the original sprayed material composition. Thus, the mechanical strength of the base material of the metal pipes in salt STPPs is combined with the high anti-corrosion properties of the applied material. Recommendations are provided for using plasma vacuum arc technology to ensure high operational properties of the circulating pipe systems in salt STPPs.

The accelerated transformation of the world’s energy system, associated with events observed over the past 10 years, such as the global energy crisis that began in 2021, the COVID-19 pandemic, and others, have influenced a noticeable change in the face of global energy, dictating the introduction of renewable energy sources at a rapid pace for a “post-crisis” recovery of the global economy. As in other countries of the world, the fourth energy transition in Uzbekistan is also accompanied in accordance with the Sustainable Development Goals. The state plans to install renewable energy sources with a capacity of 4300 MW in 2023, which ultimately contributes to the diversification of energy resources and will make it possible to assess the country’s energy security level, taking into account the share of newly introduced renewable energy capacities. However, if we take into account the peculiarity of the “instability” of renewable energy sources, the energy security of the state may remain under threat. The purpose of this work is to identify the most significant indicators of energy security in assessing its level for Uzbekistan, taking into account the geostrategic, political, technical, and technological features of the country’s energy system based on a detailed and critical review of existing global methodologies regarding the comparison of primary data from two or more samples. It has been revealed that the weight of the indicator “Ratio of primary energy production (extraction) from renewable energy sources to gross fuel and energy consumption” has a significantly comparable role with the indicators of the blocks “Block of diversification of suppliers and types of energy resources,” “Block of reliability of electricity supply,” and “Block of reproduction of the main fund of production (MFP)” due to the political course of Uzbekistan in recent years. Based on the selected indicators, a methodology for assessing the level of energy security of the Republic of Uzbekistan is proposed, which allows one to obtain a transparent picture of energy security in economic sectors. As a result of which it is possible to identify strengths and weaknesses in various areas and timely prevent expected negative results through energy scenarios with a stable and reliable indicator of electricity supply, contributing to an increase in the level of energy security of the country.

In recent years, ZnO nanostructure thin films have been used extensively by researchers in dye-sensitized solar cells (DSSCs) application due to its unique photovoltaic properties. The effects of the concentrations of Ni metal dopants on ZnO thin film DSSCs were investigated. ZnO–Ni nanocomposites were synthesized via sol-gel method. In this paper, the structural, morphological, and chemical properties of ZnO–Ni nanocomposite thin films were reported. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microcopy (AFM) and mapping analyses have found out that the crystallite and grain sizes of ZnO-Ni is increasing when Ni percentage is increased. The optical study from UV-Vis spectroscopy indicates that the band gap energy for ZnO–Ni photoanodes is in the range 3.5–3.7 eV. Energy dispersion X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) have identified the elements and chemical bonding that are related to ZnO and Ni. The photovoltaic performances were analyzed using photocurrent-voltage (J–V) measurement and electrochemical impedance spectroscopy (EIS). As the result, ZnO–Ni photoanode based DSSC with 60% of Ni concentration shows the highest power conversion efficiency (0.421%) with J_sc, V_oc and FF of 1 mA/cm², 0.95 V and 0.443.

Photo-supercapacitors (PSCs) are independent energy sources serving the cause of simultaneous photoelectric conversion and energy storage. Insights on the working of PSCs are inevitable to realize higher efficiencies in these integrated systems and so theoretical analyses are highly required. A theoretical study on PSC comprising a CdS/CdTe thin film solar cell with a supercapacitor is carried out. The device physics of the solar cell is characterized by Sah-Noyce-Shockley (SNS) theory and the Electrical Circuit Model is used to model the working of supercapacitor. The temporal evolution of the PSC charging is theoretically simulated by the differential equation of the integrated circuit, solved using numerical methods. The effect of solar cell factors on the PSC charging is studied. With the optimized solar cell parameters, the maximum value of Energy Conversion and Storage Efficiency (ECSE_max %) of about 8.8% can be achieved with the proposed PSC.

Accurate detection of faults in grid connected solar PV systems is important to ensure the reliability of power systems with distributed generation. Considering the aforesaid fact, here, a smoothed pseudo-Wigner-Ville distribution (SPWVD) and stacked sparse autoencoder (SSA) based automated feature extraction technique is proposed for accurate detection of faults in grid connected solar PV systems. To this end, three phase current data of normal as well as different fault scenarios obtained from point of common coupling (PCC) were converted into direct (d) and quadrature (q) axis using extended Park’s vector approach. Then, the obtained d-axis (I_d) and q-axis (I_q) currents were converted to 2D time-frequency images using SPWVD. The converted time-frequency spectrum of the normal as well as faulty current data were used as inputs to the proposed SSA model for deep feature extraction. After extraction of deep features using SSA, analysis of variance (ANOVA) test and false discovery rate (FDR) correction was employed to select the most discriminative features. The feature selection was followed by classification using machine learning classifiers. It has been observed that the proposed technique achieved mean fault recognition accuracy of 98.79 and 97.56% for d-axis and q-axis currents respectively, respectively. The present approach can be used for accurate diagnosis of faults in grid connected solar PV systems.