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<jats:p>The main objective of the work was to use solar energy for desalination of water. A solar chimney desalination system, which includes the solar chimney, solar collector, evaporation system, and passive condenser, was designed and built. The air enters into collector and gets heated and released at the bottom of chimney. Due to draught effect dry air goes upward. The air is humidified by spraying salt water into the hot air stream using a mistifier at the middle of chimney. Then, the partial vapours contained in the air are condensed to give desalinated water. The performance of the integrated system including power and potable water production was estimated and the results were discussed. With a 3.4 m height setup, experimental test rig was capable of evaporating 3.77 L water daily condensing 2.3 L water. It is compact in nature as it is easy to assemble and dissemble. It can be used for purifying rain water in summer under rain water harvesting. Because of using country wood, recycled Al cans, and GI sheet in fabrication, it is lower in cost.</jats:p>

<jats:p>Household cooking is a major energy intensive activity in most of the Ethiopian households. Replacing the existing inefficient cooking stoves and the polluting energy source with a renewable source of energy plays a paramount role in conserving the environment and reducing the indoor pollution. In this study an energy storage phase change material is proposed to store solar thermal energy for a potential household cooking application. The selected phase change material has a melting point range which is well fitted to the operating range of temperatures for most of the household cooking activities. The solar energy source is simulated with electrical heating for experimental investigation of the thermal characteristics. Also it is intended to study the thermal characteristics of the mixture using deferential scanning calorimeter to identify at which mass ratio the mixture shows better thermal characteristics. From the laboratory analysis it is found that the 60% NaNO<jats:sub>3</jats:sub> and 40% KNO<jats:sub>3</jats:sub> by mass have shown promising thermal characteristics. For applying the selected salt mixture for cooking application, an experiment was conducted on two Ethiopian local meals, shiro wet and potato meal, to know how much energy is required to cook them and what amount of the PCM is required to store the required energy. The result reveals that 2.38 kWh energy is required for cooking the two meals for five family members for lunch and dinner. To store the energy required 4 kg of the PCM was required. Experiments were conducted to see the charging and discharging time of 60% NaNO<jats:sub>3</jats:sub> and 40% KNO<jats:sub>3</jats:sub> by mass. From the experimental result for 1.4 kg of the PCM, charging time of 50 minutes up to 300°C and a discharging time of 4.5 hours (from 300°C to 100°C) are required.</jats:p>

<jats:p>In this study, the performance of three global solar radiation models and the accuracy of global solar radiation data derived from three sources were compared. Twenty-two years (1984–2005) of surface meteorological data consisting of monthly mean daily sunshine duration, minimum and maximum temperatures, and global solar radiation collected from the Nigerian Meteorological (NIMET) Agency, Oshodi, Lagos, and the National Aeronautics Space Agency (NASA) for three locations in North-Western region of Nigeria were used. A new model incorporating Garcia model into Angstrom-Prescott model was proposed for estimating global radiation in Nigeria. The performances of the models used were determined by using mean bias error (MBE), mean percentage error (MPE), root mean square error (RMSE), and coefficient of determination (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msup><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:mn fontstyle="italic">2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>). Based on the statistical error indices, the proposed model was found to have the best accuracy with the least RMSE values (0.376 for Sokoto, 0.463 for Kaduna, and 0.449 for Kano) and highest coefficient of determination,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:msup><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:mn fontstyle="italic">2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>values of 0.922, 0.938, and 0.961 for Sokoto, Kano, and Kaduna, respectively. Also, the comparative study result indicates that the estimated global radiation from the proposed model has a better error range and fits the ground measured data better than the satellite-derived data.</jats:p>

<jats:p>The use of renewable energies requires a precise and detailed quantification of the resource available. Because of the cost of solar stations or limited availability of skilled human resources, in most emerging countries, this assessment is made only on a few points scattered over large areas. We report here a simple and inexpensive method to evaluate the photovoltaic (PV) potential for a specific geographic region and a given PV capture technology. The system allows for a direct evaluation of the energy actually obtainable by scaling the measurement array of photovoltaic cells. The proposed measurement system can be installed as a stand-alone unit, or as part of a measurement network, connected to a more sophisticated central hub. The measurement station consists of said PV array (or similar PV array), a resistor, and a portable data logger. The system is calibrated with a device composed of a small array of PV cells, a resistor load bank, and two multimeters. Due to its low cost, this system can be replicated as many times as required with minimal investment. This would make it possible to evaluate the available photovoltaic potential of large regions with accurate and detailed data. Measurements carried out in Buenos Aires and in Antarctica confirm the consistency of the method.</jats:p>

<jats:p>This paper presents an analysis of the effects of ultraviolet (UV) exposure on amorphous silicon (a-Si), bare crystalline silicon (c-Si), and epoxy resin encapsulated c-Si devices. The long-term reliability of photovoltaic (PV) modules is crucial in ensuring the viability of PV as a successful source of energy. Accelerated UV ageing methods are required to quickly evaluate the UV durability of module materials. A UV exposure unit was designed and constructed and provided an average of 45.7 W/m<jats:sup>2</jats:sup> of UV irradiance over the exposure area with a nonuniformity of 14.9%. The a-Si devices lost up to 44% of maximum power (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">a</mml:mi><mml:mi mathvariant="normal">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>) at Standard Test Conditions over 500 hours of exposure to UV, with maximum losses of 11% in short-circuit current (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:msub><mml:mrow><mml:mi>I</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">s</mml:mi><mml:mi mathvariant="normal">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>), 11% in open-circuit voltage (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">o</mml:mi><mml:mi mathvariant="normal">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>), 23% in voltage at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">a</mml:mi><mml:mi mathvariant="normal">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mrow><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">p</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>), and 29% in current at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">a</mml:mi><mml:mi mathvariant="normal">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mrow><mml:msub><mml:mrow><mml:mi>I</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">p</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>). The epoxy resin encapsulated samples lost up to 6.4% in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">a</mml:mi><mml:mi mathvariant="normal">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>, 6% in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M9"><mml:mrow><mml:msub><mml:mrow><mml:mi>I</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">s</mml:mi><mml:mi mathvariant="normal">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>, and 7% in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M10"><mml:mrow><mml:msub><mml:mrow><mml:mi>I</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">p</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> with the changes in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M11"><mml:mrow><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">o</mml:mi><mml:mi mathvariant="normal">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M12"><mml:mrow><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">p</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> being random. The bare cells showed relatively little degradation. UV radiation thus accelerates the degradation of a-Si devices, deteriorates polymeric encapsulates of modules, and possibly affects the antireflective coatings applied on solar cells.</jats:p>

<jats:p>Nowadays in order to meet the increase in power demands and to reduce the global warming, renewable energy sources based system is used. Out of the various renewable energy sources, solar energy is the main alternative. But, compared to other sources, the solar panel system converts only 30–40% of solar irradiation into electrical energy. In order to get maximum output from a PV panel system, an extensive research has been underway for long time so as to access the performance of PV system and to investigate the various issues related to the use of solar PV system effectively. This paper therefore presents different types of PV panel systems, maximum power point tracking control algorithms, power electronic converters usage with control aspects, various controllers, filters to reduce harmonic content, and usage of battery system for PV system. Attempts have been made to highlight the current and future issues involved in the development of PV system with improved performance. A list of 185 research publications on this is appended for reference.</jats:p>

<jats:p>The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the network characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. We discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.</jats:p>

<jats:p>A “Solar Salt” (NaNO<jats:sub>3</jats:sub>–KNO<jats:sub>3</jats:sub>60 : 40 molar mixture) latent heat storage has been charged by direct solar illumination. Solar Salt as a Phase Change Material (PCM) can be an attractive small scale heat storage solution, as the melting temperature of about 220°C can be suitable for cooking purposes. The tests were made with a double-reflector setup. In this setup a secondary reflector positioned above the focal point of the primary reflector directs the rays onto a heat storage positioned below a hole in the primary reflector. The reflectors are tracking the sun, but the storage is stationary. The direct illumination of the absorber top plate during the tracking of the sun melted the salt in the storage through conducting fins. This is a system where portable heat batteries can be charged, during sunshine hours, and then provide heat for cooking during evening times.</jats:p>

<jats:p>Dye sensitized solar cells (DSSCs) are fabricated from porous cadmium sulfide (CdS) nanocrystalline thin films. The porous CdS nanostructured thin films are deposited onto FTO/glass substrates by the chemical bath deposition (CBD) method. The surface morphology, crystalline structure, and optical properties of the prepared nanocrystalline thin films are investigated. Rhodamine B, Malachite green, Eosin methylene blue, and Cresyl violet dyes are used to fabricate the DSSC devices. Comparing the absorption spectra of porous CdS nanocrystalline films, all dyes show an absorption peak in the transparent range of CdS thin films indicating that they are suitable for the preparation of DSSCs with CdS. Current-voltage (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>I</mml:mi><mml:mtext>-</mml:mtext><mml:mi>V</mml:mi></mml:math>) characteristics show that the solar cell that is fabricated using Malachite green dye shows the highest conversion efficiency of 0.83% while using Rhodamine B dye produces a solar cell with lowest efficiency of 0.38%. However, heat treatment of the fabricated solar cells causes significant enhancement in the output of all devices.</jats:p>

<jats:p>Solar energy is an alternative source of nonrenewable energy in Oman. Sultanate of Oman government showed initiation into utilization of solar energy for domestic applications. Conversion of solar radiation into useful heat is the simplest application of solar energy, in which it can be used for late evening cooking. In this context, present work highlighted the design and development of solar cooker for Oman climatic conditions. The current work signifies usage of solar cooker for late evening cooking using stearic acid and acetanilide as phase change materials (PCM). Solar cooker parts are developed in-house and connected to water heating system compounded with evacuated tubes solar collector and storage tank. The circumference of cooker unit is incorporated with spiral stainless steel heat exchanger and annulus area of the pot is filled with PCM material. PCM releases heat at late evening and effective cooking up to 7:30 PM is noticed. The experimental results indicated the cooker efficiency of 30% and collector efficiency of 60–65% during the study. Overall, experiments showed satisfactory performance on the developed cooker.</jats:p>