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Over the past decade, the significance of solar photovoltaic (PV) system has played a major role due to the rapid growth in the solar PV industry. Reliability, efficiency and safety of solar PV systems can be enhanced by continuous monitoring of the system and detecting the faults if any as early as possible. Reduced real time power generation and reduced life span of the solar PV system are the results if the fault in solar PV system is found undetected. Therefore, it is mandatory to identify and locate the type of fault occurring in a solar PV system. The faults occurring in the solar PV system are classified as follows: physical, environmental, and electrical faults that are further classified into different types as described in this paper. Once a fault is located and detected, an appropriate diagnosis method needs to be used to rectify it. In this paper, a comprehensive review of diverse fault diagnosis techniques reported in various literature is listed and described. This paper helps the researchers to get an awareness of the various faults occurring in a solar PV system and enables them to choose a suitable diagnosis technique based on its performance metrics to rectify the fault occurring in solar PV systems.

This study aims to assess the performance of compression ignition (CI) engine powered with various biodiesels. The engine used for this test was a single-cylinder, water-cooled, naturally aspirated, CI engine. The biodiesels used in this study were neem methyl ester (NME), mahua methyl ester (MME), cottonseed methyl ester (CME), tamanu methyl ester (TME) and Albizia saman methyl ester (AME). According to the results, the TME-operated CI engine had 2.69%, 10.53%, 6.31% and 5.49% higher brake thermal efficiency than the MME, NME, CME and AME, respectively, without exhaust gas recirculation (EGR). Tamanu biodiesel outperformed the other test fuels in terms of performance and emissions. As a result, tamanu biodiesel was chosen as the best fuel for further testing. The results showed that tamanu biodiesel emitted more oxides of nitrogen (NOx) emissions than diesel. EGR could be used with the CI engine, resulting in a significant reduction in NOx emission. Compared to tamanu biodiesel without EGR conditions, the percentages of EGR 5%, 10% and 15% used with TME-operated CI engine produced 9.9%, 18% and 21.3% less NOx emission. The combination of EGR and tamanu biodiesel resulted in a slight increase in hydrocarbon, smoke and carbon monoxide emissions but a substantial reduction in NOx emissions. According to the study’s findings, tamanu biodiesel with 10% EGR demonstrated optimal engine characteristics while having a low environmental impact.

Solar energy is at the forefront of renewable energy sources. Depending on the increasing energy need, the use of clean energy sources is inevitable in terms of human health and the environment. The application of solar chimney power plants (SCPPs) is one of the not very old and promising systems. SCPPs are systems that attract attention with their long life and simple working principles. SCPPs have three basic elements: collector, chimney and turbine, and optimizing these elements in terms of design and operational parameters plays a key role in the performance parameters of the system such as power output and efficiency. This study, which references the Manzanares pilot plant, aims at the collector dimensioning of the system to achieve the optimum power output and efficiency from the plant and to assess the upper thermodynamic limits of the Manzanares pilot plant. The most challenging aspect of SCPPs, in general, is their high cost, and large collector areas constitute a notable fraction of this cost. Therefore, for performance and cost optimization, collector dimensioning is of vital importance and reveals the innovative aspect of this study. For this purpose, a 3D 90° computational fluid dynamics model is created with ANSYS engineering software. RNG k-e turbulence model and discrete ordinates solar ray-tracing algorithm are applied to the model. In the study, solutions are taken in the dimensions of the pilot plant with an ambient temperature of 290 K and two different radiation intensities of 800 and 1000 W/m2. The collector radius (Rcoll) is increased up to 2 times the reference size and its effect on the system is evaluated. It is found that the plant, which produces an electrical power of 46.6 kW at 800 W/m2, will generate 138.3 kW of electrical power if the Rcoll is doubled. The optimum collector radius rate (Xcoll) is found to be in the range of 1.00–1.50. For the greater values of Xcoll than 1.50 (183 m), it is observed that the exponential increase in power output stops, and cost-related upper thermodynamic limits are achieved.

Due to the increasing demand for energy worldwide, photovoltaic (PV) cooling systems have become an important field of research in recent years. The most important factor affecting the performance of a solar PV cell is its operating temperature. For harvesting heat from solar PV systems, phase change material (PCM) is regarded as the most effective material. As a result, this study discusses and describes the effect of using PCM and nanoPCM (NPCM) in cooling PV cells. This research reviews the various feasible hybrid photovoltaic thermal (PVT)–PCM and PVT–NPCM methods used for cooling PV. The concept focusing on PV cooling technology is discussed where air, water and nanofluid are used as the working medium in combination with PCM and NPCM. It is observed that when high performance heat transfer and improved cooling rate are needed, active cooling methods are favoured, whereas passive cooling methods rely on themselves and don’t require extra power. It is also found that the effectiveness of applying PCM or NPCM for thermal control is heavily influenced by atmospheric air temperatures as well as the precise PCM or NPCM used. It is envisaged that this review will help new researchers better understand the qualities and capabilities of each cooling strategy. They are offered to help investigators quickly identify the basic science that led to the development of the thermal performance system and also improve the overall performance of the PV system.

Solar farms are becoming a crucial part of the renewable energy mix. Yet, the literature has not reported a generalized approach to its design. In this regard, this paper attempts to provide a detailed plan of a 5-MW grid-connected solar farm. In addition, the procedure to analyze the land footprint of the solar plant is also developed. At first, the main components of the solar farm are selected qualitatively. Then, using an excel spreadsheet, the sizing of photovoltaic (PV) array, inverters, combiner boxes, transformers, cables and protection devices is carried out. Finally, the land footprint analysis of the proposed solar farm was carried out mathematically. The proposed solar PV power plant comprises 13 490 numbers of PV modules with a 365-W rating. Nineteen numbers of PV modules will constitute a string. One hundred forty-two numbers of strings will be connected to an inverter of 1 MW rating. The energy output from five such inverters will be fed to the nearest electric substation using a transformer of 1 MVA capacity. The DC and AC cables having a voltage drop of less than 1% are selected. The inter-row distance and ground coverage ratio (GCR) are estimated as 1 and 0.78 m, respectively. The required number of mounting module structures is found to be 710. The proposed solar farm’s total land use requirement is ~43768.41 m2 (around 3 acres). It was observed that the sizing of solar plant components mainly depends on the electrical parameters of the PV module and inverter selected by the designer. Similarly, the land use requirement is influenced by the inter-row distance and PV site layout. This research is expected to streamline the different approaches of solar farm design, which will be beneficial to energy professionals and policymakers.

This study interprets the effect of using sand or gravel as energy storage unit in solar chimney power plants. The effect of using low-cost materials is evaluated. Based on the Manzanares pilot plant, a 3D CFD model is created. Geometric parameters are kept constant in simulations performed with ANSYS FLUENT engineering commercial software. By simultaneously solving DO (discrete ordinates) solar ray tracing algorithm and RNG k-ε turbulence model, the outputs of the system are examined at 290 and 300 K temperatures. The temperature distribution and power outputs of the use of sand and gravel as soil material at different temperatures and solar radiation are compared. It is understood that the use of both materials does not significantly affect the performance of the system and can be used economically instead of each other. It is seen that the system will give a power output of approximately 41.636 kW with both storage materials at a radiation intensity of 800 W/m2 and an ambient temperature of 300 K. It is seen that the ambient temperature affects the temperature increase in the system, and the temperature increase is higher at 290 K.

A unique nano-coated photovoltaic (PV) glazing technology with superior multifunctional features, thermally resistive PV glazing (TRPVG), is introduced, and for three different configurations of TRPVG (TRPVG-Air12, TRPVG-Ar12, TRPVG-Ar16), UVC/UVA absorption, noise reduction, thermal insulation, electricity generation, visible light and solar radiation control are evaluated through an extensive experimental methodology. Energy production and acoustic tests are conducted in a simulation house, whereas the rest of the experiments are carried out under real operating conditions. The results reveal that each sample is capable of blocking 100% of incoming UVC and UVA light. Visible light control of TRPVG-Ar12 (Glass 1) is found to be 94.4%, whereas it is 88.9% for TRPVG-Air12 (Glass 2) and 93.6% for TRPVG-Ar16 (Glass 3). Solar radiation blockage of Glasses 1–3 is found to be 93.5%, 90.9% and 94.8%, respectively. Average temperature difference between front and rear glazing is determined to be 21.3°C, 19.9°C and 21.7°C for Glasses 1, 2 and 3, respectively. A total of 25 independent acoustic tests are performed for Glass 3, and the sample is observed to reduce 33% of outdoor noise in dBA. Solar simulator tests reveal that Glass 3 can generate 102.6 W of electricity per square metre of PV module area.

Solar energy is deemed as the most abundant, reliable, eco-friendly and totally free resource of energy. There is a wide range of techniques to harness solar energy for different purposes. Among all the available methods, direct conversion of sunlight into electricity through photovoltaic (PV) phenomenon is the most mature and popular process. Progress of PV technology in market is perspicuous; however, it has still some drawbacks such as notable land requirement in cities, energy conversion efficiencies that already reached the theoretical limits and social acceptance issues due to aesthetic details. To overcome the aforesaid challenges, solar PV tree concept has been recently developed, and the simplicity, compact structure and elegance of this novel technology have been in the focus of researchers. Within the scope of this review, the concept of solar PV tree has been extensively investigated in terms of various design aspects and potential applications. Current performance characteristics of solar PV tree systems and power management strategies in real applications have been discussed. Challenges involved with the solar PV tree technology have also been addressed as well as suggestions on the direction of further works.

There are many factors that have a major influence on reducing the energy expenditure in building sector. This research aims at qualitative and quantitative assessment of those factors such as double glazed windows, vertical greenery systems (VGS), integrating of semi-transparent photovoltaic device with architectural design of buildings, energy saving by using heat reflecting coating, passive climate control methods, energy saving by shading, building energy performance enhancement by using optimisation technique, double skin green facade, etc. through a holistic and thematic approach. Among the aforesaid techniques, VGS is found the most reliable, efficient and sustainable solution. Attractive VGS can improve the urban environment, increase biodiversity, mitigate pollution also results economic benefit of the buildings as like as energy savings and decreasing surface temperature. Four fundamental energy saving methods are used in VGS which are considered as passive energy saving mechanism. Firstly, interception of solar radiation due to the shadow risen by the vegetation; secondly, vegetation also provides thermal insulation; thirdly, plants evapotranspiration helps for evaporative cooling of building; finally, building blockage makes a variation of wind effect on building. The peak cooling load of ivy coated green building wall has been reduced by 28%. If a VGS is installed without windows and building facing on west, east, south and north correspondingly, the reduction in the cooling load capacity of the building is observed to be up to 20, 18, 8 and 5% respectively. Very high thermally resistive glazed areas on building envelope can be secured via thin film PV glazing and vacuum glazing products with an average U-value of 1.1 and 0.4 W/m2K, respectively. Energy use policies are also helpful to improve energy consumption scenario of buildings. For developing more energy-efficient, sustainable and eco-friendly buildings, these techniques might be helpful for the building designers and architects.

Influence of area ratio (AR) on main performance parameters of solar chimney power plants (SCPPs) is investigated through a justified 3D axisymmetric CFD model. Geometric characteristics of Manzanares pilot plant (MPP) are taken into consideration for the numerical model. AR is varied from 0.5 to 10 to cover both concave and convex (convergent and divergent) solar chimney designs. Following the accuracy verification of the CFD results and proving mesh-independent solution, main performance oriented parameters are assessed as a function of AR such as velocity, temperature and pressure distribution within MPP, temperature rise of air in collector, mass flow rate of air around the turbine area, dynamic pressure difference across the turbine, minimum static pressure in the entire plant, power output and system efficiency. The results reveal that AR plays a vital role in performance figures of MPP. Mass flow rate of air ($\dot{m}$) is found to be 1122.1 kg/s for the reference geometry (AR = 1), whereas it is 1629.1 kg/s for the optimum AR value of 4. System efficiency (η) is determined to be 0.29% for the reference case; however, it is enhanced to 0.83% for the AR of 4.1. MPP can generate 54.3 kW electrical power in its current design while it is possible to improve this figure to 168.5 kW with the optimal AR value.

Recent studies show that it is possible to reduce heating or cooling demand of a building as using heat recovery systems. Heat recovery technology is basically utilised to mitigate the heat loss, and hence energy consumption due to HVAC. Within the scope of this study, thermal comfort analyses of a test house integrated with a novel polycarbonate heat exchanger are conducted. At pre and post-retrofit case, temperature, relative humidity and CO2 measurements are carried out for a test period of one week. The results indicate that the internal CO2 concentration is not at desirable range due to lack of ventilation in the test house at the pre-retrofit case. However, following the integration of the novel ventilation system into the test house, CO2 concentration is found to be varying notably from 350 to 400 ppm which corresponds to the actual comfort conditions for indoor environments. It is also concluded from the results that the average relative humidity inside the test house at the post-retrofit case is found to be 57%, which is in the desired range whereas it is considerably high before retrofitting. © 2017 Elsevier Ltd

The rate of air leakage related energy loss from glazed areas is unequivocal especially in older and poorly installed windows. Therefore, in this research, a comprehensive experimental investigation is done to analyse the importance of air leakage on overall heat transfer coefficient (U-value) of conventional air filled double glazed windows. The tests are conducted in a typical UK dwelling of Nottingham fitted with traditional air filled double glazed windows. One sash of the test window is sealed internally with a special transparent cover to provide excellent airtightness whereas the second window sash is left as it is to represent the ordinary case. The experiments are conducted in April 2016, and dynamic co-heating test methodology is applied to evaluate the rate of enhancement in the U-value of airtight window sash. The results indicate that the airtight window sash has a notably lower U-value compared to the ordinary window sash due to the impact of airtightness and reverse heat flux during noon time owing to the greenhouse effect between transparent cover and internal glazing. The overall U-value of ordinary window sash is found to be 2.67 W/m(2)K, whereas it is 1.79 W/m(2)K for airtight window sash. It is observed that about 33% of reduction in heat losses can be achieved via airtight windows. (C) 2017 Elsevier B.V. All rights reserved.

Solar box cookers draw attention of many researchers across the globe as a promising renewable energy application for cooking purposes. Compared to other types available in literature, solar box cookers are more in the centre of interest owing to their simple and low-cost design, emerging thermodynamic performance figures, high durability and reliable cooking processes without any risk of burning food. On the other hand, cooking power and overall thermal performance of solar box cookers are still somewhat challenging to compete with the conventional cooking systems for the climatic conditions with low solar radiation potential like the Black Sea Region of Turkey. Within the scope of this research, a novel solar box cooker is devised, fabricated and tested to overcome the said shortcomings of traditional solar box cookers through natural and recycled materials. Double-glazed structure having 16-mm-thick air between two 6-mm-thick thermally resistive clear glasses is considered for aperture glazing with an area of 0.16 m2. The oven area has a depth of 350 mm, and it is entirely painted matte black for maximum solar absorption. The oven body made of stainless steel sheets is encountered by a latent heat storage medium filled by natural beeswax product, waste of propolis. Propolis is a resinous mixture that is used for protection of beehives, from either climatic changes or diseases. Polyphenols rich in balsamic part of the structure is extracted by alcohol than used for many apitherapic purposes. The remaining pulp or waste is not considered. In this study, it is used as green chemistry agents. It is found that water temperature in the cooking pot is kept over 40°C till very late hours as a consequence of latent heat storage. First figure of merit is determined to be 0.08, and the thermal efficiency of the cooker varies from 7.47 to 4.54%.

HISG (heat insulation solar glass) is a recently developed multi-functional glazing technology to mitigate energy consumption of buildings. HISG can generate electricity similar to conventional PV (photovoltaic) glazing products when exposed to sunlight, however it differs from them by having some extraordinary characteristic features such as thermal insulation, which is competitive with Argon filled triple glazed windows, acoustic comfort, remarkable energy saving potential and self-cleaning ability owing to TiO2 nano coating. Within the scope of this research, latest results from laboratory and in-situ testing of HISG are presented in terms of its key role in mitigating heating and cooling demand of buildings as well as clean energy generation. Lighting and thermal comfort related parameters such as shading coefficient, UV, IR and visible light intensity are also investigated through the tests conducted in real operating conditions. It is achieved from the results that instant electricity generation of HISG is 16% higher than that of standard PV glazing owing to its nano layer reflective film. Shading coefficient of HISG is only 0.136, which provides almost 80% reduction in solar heat gain compared to ordinary glazing. Indoor air temperature measured from HISG test house in summer time is very close to the ambient temperature, whereas it is found to be 14.7 °C higher in ordinary glass test house due to greenhouse effect. Annual heating and cooling demand tests indicate that HISG provides 38 and 48% energy saving in heating and cooling season, respectively. © 2016 Elsevier Ltd.

Energy saving and its efficient utilization is of prime interest in today's world due to the limited energy resources and growing significance of environmental issues. Despite the intensive efforts to narrow the gap between conventional energy sources (wood, coal, gas, oil, etc.) and renewables, renewable energy resources currently supply only about 14% of total world energy demand. In this regard, energy management and optimization are considered compulsory as much as the clean energy generation. Recent works indicate that the buildings play a significant role on global energy consumption. They are responsible for about 40% of global energy demand. Among the different building types, domestic buildings have the largest share with 63% and most of energy is utilized for heating, ventilation and air conditioning (HVAC) systems in those buildings. Energy consumption levels of buildings can be notably reduced through waste heat recovery in HVAC systems. There are several attempts in literature addressing the possibility of decreasing energy consumption of buildings via waste heat recovery technologies. The heat recovery technologies are cost effective and user friendly applications. The use of heat recovery systems aims at mitigating the energy consumption for HVAC applications as well as the greenhouse gas emissions, and hence decreasing the adverse effects of global warming on the Earth. It is well-documented in literature that the heat recovery systems are very promising for domestic applications. In this paper, experimental results of a novel heat recovery system developed for low-carbon buildings are presented. The proposed heat recovery system consists of a plate-type heat exchanger, blower fans and ducts. The parallel-flow arrangement is used to run the system. The system is designed as under roof application. The aim of the system is to recover waste heat and to preheat fresh air using stale air. The experiments of the system are carried out in winter season in Kent, UK. The study aims to investigate the coefficient of performance (COP) of the system as well as the heat recovery efficiency. The results show that the heat recovery efficiency of the proposed system is around 89% while the COP is 4.5. The proposed system can be used in both winter and summer conditions without requiring additional work. Its labor cost is extremely low, so it is cost-effective and user friendly. © 2015 Elsevier B.V. All rights reserved.

In recent years, solar cookers have been technologically promoted by most of the national governments as renewable and sustainable cooking system round the globe. In the present article, a solar box cooker (SBC) has been developed for fast response and uninterrupted cooking process. For this purpose, a cylindrical copper tube infused with thermal energy storage (TES) has been designed and tested under a modified SBC. Experimental study has been carried out on three different TES materials such as; grainy carbon powder, paraffin wax and specific mixture of carbon powder and paraffin. Specifically, twelve TES filled tubes have been brought into the use for experimentation at three different configurations. Results indicate that the modified cooker has better performance in terms of efficiency (53.81%), overall heat loss coefficient (5.11 W/m2°C), cooking power (68.81 W) and heat transfer coefficient (56.78 W/m2°C) in comparison with a conventional SBC and other designs using different TES materials. PCM infused tubes are low in cost and flexible to carry with SBC for outdoor cooking. It can easily be carried anywhere along with cooker. This novel configuration enables a fast response cooking with an enhanced efficiency irrespective of climatic conditions. The total cost of SBC is estimated about $39.11.

Primary energy consumption has increased by 49% and CO2 emissions by 43% during the last two decades, and the predictions indicate that the growing trend will continue as a consequence of the notable growth in world population. Nations with developing economies (South America, Middle East, Africa and Southeast Asia) have an average annual energy consumption rate of 3.2%, whereas the rate is 1.1% for most of the developed economies (North America, Japan, Australia and Western Europe). In this paper, overall energy consumption in the UK by sector is evaluated from 1973 oil crisis to the present. The scope is split into four sectors as transport, domestic, industrial and services sector and the results for each are presented in a comparable way. Percentage of total primary energy consumption and final energy consumption by fuel type are presented. Several factors affecting the overall energy consumption are also investigated.

U-value assessment is a significant process to be able to evaluate the thermal insulation performance of building materials notably windows. About 60% of energy losses from building envelope is attributed to windows, hence accurate and reliable thermal resistance evaluation of glazed areas is of vital importance for a sensitive energy demand analysis of buildings. U-value assessment of windows is usually conducted through theoretical and numerical methods in literature. However, dwellers frequently complain about the insufficient thermal insulation performance of commercial glazing products when compared to the reported U-values in datasheets. This inconvenience arises from the lack of comprehensive experimental tests which simulate the actual operating conditions. Therefore, in this research, argon filled double glazed windows, which is one the most common fenestration products in market, is numerically and experimentally analysed in terms of U-value performance. Although computational fluid dynamics (CFD) analyses reveal that the U-value of the reference sample (4 mm pane + 20 mm argon + 4 mm pane) is 0.89 W/m(2)K, which is in good accordance with the theoretical data (0.80 W/m(2)K), it is observed from the environmental chamber tests that the U-value in simulated operating conditions is 1.25, 1.18 and 1.32 W/m(2)K for top, centre and lower positions of the window sample. The tests are repeated for accuracy verification, and the U-value is found to be 1.23, 1.18 and 1.31 W/m(2)K for the said points. In this respect, it is concluded that thermal bridges and edge effects play a key role in actual U-value performance of glazing products. Therefore, experimental performance figures are recommended to be utilised in energy demand analyses of buildings. (C) 2018 Elsevier B.V. All rights reserved.

Heat insulation solar glass (HISG) is a multi-functional glazing technology, which has been developed at the University of Nottingham with an ultimate goal of mitigating energy consumed in buildings. HISG is capable of producing electricity when exposed to sunlight. It also differs from a conventional transparent photovoltaic (PV) module by providing some characteristic features such as thermal insulation, sound insulation, self-cleaning and energy saving as well as power generation. In this respect, HISG is very promising for both energy-efficient retrofitting of existing buildings and new-build applications. Therefore in this paper, an experimental attempt is made to investigate thermal performance characteristics of HISG. A test rig is constructed consisting of four different glazing configurations with the same thickness (air filled double glazed window, air filled double glazed window with low-e, argon filled double glazed window with low-e and HISG) and overall heat transfer coefficient ( U -value) of each sample is determined in an environmental chamber through a standardized co-heating test methodology. The results indicate that HISG is not only a power producer but also a good insulator. U -value of HISG is found to be 1.10 W/m 2 K. Maximum temperature difference between internal and external glazing is also achieved by HISG with 12.70 °C.

Although commercialization is still challenging for superinsulation materials, intensive efforts are being made for cost reduction. They provide superior thermal performance and hence their future potential is notable. Optimizing insulation thickness of superinsulation materials can make a significant contribution to the energy saving in buildings and thus to greenhouse gas abatement. Therefore in this study, optimum thermal insulation thickness of aerogel and its environmental impacts are investigated for the climatic conditions of Nottingham, UK. Insulation thickness dependencies of annual energy cost and energy saving are determined for different energy sources. Degree-day and present worth factor effects on optimum aerogel thickness are investigated. The paper also covers the environmental aspects of aerogel-based retrofitting of buildings by analysing the potential fall in greenhouse gas concentrations. It is concluded from the results that aerogel-based thermal superinsulation provides remarkably slimmer constructions and larger living spaces in buildings compared to the conventional insulation materials. Aerogel insulation is found to be very appropriate as additional internal insulation for the non-insulated cavity walls. The reliability and the feasibility of the theoretical results are also verified by an experimental work carried out in a test house.

In this paper, solar box cookers with ordinary and finned absorber plates are theoretically investigated in terms of thermodynamic performance parameters. For a typical summer and winter day, temperatures of solar cooker components such as glass cover, internal air, absorber plate, cooking vessel and the liquid are determined theoretically versus time. The analysis is carried out for conventional and finned absorber plates, and accuracy of the results is verified by a previously published experimental work. Energy and exergy efficiencies of box-type solar cookers are plotted versus time for various cases. The methodology presented in this paper enables to make a preliminary evaluation of ordinary and modified solar box cookers with respect to changes in main environmental parameters such as temperature and illumination intensity. Some recommendations are also made to enhance the power outputs of the aforementioned solar cookers.

In the present work, a computational fluid dynamics analysis has been carried out for analysing heat transfer from a longitudinal fin with step change. For the aforementioned problem, heat is transferred by conduction through the fin along its length and dissipated from the fin surface via natural convection to the ambient and thermal radiation to the surrounding. For a given volume or mass, the total amount of heat dissipated from the fin surface, fin effectiveness and fin efficiency have been determined for two novel fin profiles and the results have been compared with that of conventional rectangular fin (CRF). Numerical calculations have been carried out for five different cases. It has been concluded that novel fin configurations dissipate more heat and produce higher fin efficiency than the CRF profile. The rectangular fin with single-step change has been found to be the most efficient fin profile in terms of maximum heat loss and fin efficiency. The optimum fin dissipated ∼3.4% more heat and provided 2% higher efficiency than the CRF profile. Some recommendations have been made about the potential application areas of proposed fin configurations.

Homotopy perturbation method is a novel approach that provides an approximate analytical solution to differential equations in the form of an infinite power series. In this work, homotopy perturbation method has been used to evaluate temperature distribution, efficiency and effectiveness of straight fins exposed to convection. The fin efficiency and the fin effectiveness have been obtained as a function of thermogeometric fin parameter. The results have revealed that the homotopy perturbation method is a very effective and practical approach for a rapid assessment of physical systems. The resulting correlation equations can assist thermal design engineers for designing of straight fins with both constant and temperature-dependent thermal conductivity.

This paper presents a novel model to evaluate the electrical performance of a silicon photovoltaic (PV) module with respect to changes in main environmental parameters such as temperature and illumination intensity. A simple one-diode model is proposed to estimate the electrical parameters of PV module considering the series resistance and shunt conductance. Effects of PV module parameters on current–voltage characteristic curve are investigated. The proposed model also makes a thermodynamic assessment concerning the effects of environmental and electrical parameters on efficiency and maximum power output of the PV module. Kyocera KD205GH-2P 205-W high-efficiency multi-crystal PV module is used for model evaluation. Model results are compared with the manufacturer's data report and an excellent agreement is observed. Copyright , Oxford University Press.

In this study, an experimental research concerning the effects of passive cooling on performance parameters of silicon solar cells was presented. An aluminum heat sink was used in order to dissipate waste heat from a photovoltaic (PV) cell. Dimensions of the heat sink were determined considering the results of a steady-state heat transfer analysis. The experiments were carried out for different ambient temperatures and various illumination intensities up to 1 sun under solar simulator. Experimental results indicate that energy, exergy and power conversion efficiency of the PV cell considerably increase with the proposed cooling technique. An increase of ∼20% in power output of the PV cell is achieved at 800 W/m-super-2 radiation condition. Maximum level of cooling is observed for the intensity level of 600 W/m-super-2. Performance of PV cells both with and without fins increases with decreasing ambient temperature. Copyright , Oxford University Press.

In this paper, a thorough review of the available literature on photovoltaic/thermal (PV/T) systems is presented. The review is performed in a thematic way in order to allow an easier comparison, discussion and evaluation of the findings obtained by researchers, especially on parameters affecting the electrical and thermal performance of PV/T systems. The review covers a comprehensive historic overview of PV/T technology, detailed description of conventional flat-plate and concentrating PV/T systems, analysis of PV/T systems using water or air as the working fluid, analytical and numerical models, simulation and experimental studies, thermodynamic assessment of PV and PV/T systems and qualitative evaluation of thermal and electrical outputs. Furthermore, parameters affecting the performance of PV/T systems such as glazed versus unglazed PV/T collectors, optimum mass flow rate, packing factor, configuration design types and absorber plate parameters including tube spacing, tube diameter and fin thickness are extensively analyzed. Based on the thorough review, it can be easily said that the PV/T systems are very promising devices and PV/T technology is expected to become strongly competitive with the conventional power generation in the near future. Copyright , Oxford University Press.

In this research, internal thermal superinsulation in residential buildings is experimentally and statistically evaluated in terms of potential thermal bridging effects. As a consequence of significant deviations in thermal resistance values in buildings at post-retrofit, large amounts of heat losses occur through non-insulated building elements such as separating walls. Therefore, it is of vital importance to determine the level of energy loss due to such thermal bridges through an internal thermal superinsulation retrofit conducted in a typical UK building. 20 mm thick fibre-silica opaque aerogel blanket is implemented internally on the walls of a test bedroom, and the heat flux from the separating wall is measured and compared for the cases of pre and post-retrofit. The results reveal that the average amount of heat loss through the non-insulated separating wall at the post-retrofit is 5.86 W/m2, whereas it is only 0.66 W/m2 at the pre-retrofit. The results are also verified through a statistical model, which is presented for the first time in literature. The novel model is capable of providing information about potential energy loss from non-insulated walls as a function of location. © 2016 Elsevier B.V. All rights reserved.

Heat insulation solar glass (HISG) is a recently developed smart building material to minimize energy consumption of building sector. HISG might be presumed to be a conventional photovoltaic glazing product; however, it is completely unique by having some characteristic features such as superior thermal insulation, which is competitive with triple-glazed windows using argon as inert gas, acoustic and thermal comfort, self-cleaning ability owing to TiO2 nano-coating on module surface and extraordinary energy saving potential in both summer and winter. In our previous works, comprehensive experimental and numerical works have been carried out for power generation and thermal insulation performance of HISG under various climatic conditions. Within the scope of this research, optical- and lighting-related performance parameters of this smart building material are evaluated through extensive laboratory and in situ tests. Shading coefficient, visible light intensity, and UV and IR penetration are investigated via the tests conducted in real operating conditions. It is achieved from the results that the shading coefficient of HISG is only 0.136, which yields almost 80% reduction in solar heat gain compared with ordinary glazing. It is also observed from the in situ tests that HISG has a %100 UV and 99% IR blocking rate, which is of vital importance in terms of human health and thermal comfort conditions. Glaring effects are totally resolved via HISG, which is still a challenge for the buildings with conventional glazing products, especially in summer. © The Author 2016.