Search

Abstract This study explores the integration of nanotechnology and Long Short-Term Memory (LSTM) machine learning algorithms to enhance the understanding and optimization of fuel spray dynamics in compression ignition (CI) engines with varying bowl geometries. The incorporation of nanotechnology, through the addition of nanoparticles to conventional fuels, improves fuel atomization, combustion efficiency, and emission control. Simultaneously, LSTM models are employed to analyze and predict the complex spray behavior under diverse operational and geometric conditions. Key parameters, including spray penetration, droplet size distribution, and evaporation rates, are modeled and validated against experimental data. The findings reveal that nanoparticle-enhanced fuels, coupled with LSTM-based predictive analytics, lead to superior combustion performance and lower pollutant formation. This interdisciplinary approach provides a robust framework for designing next-generation CI engines with improved efficiency and sustainability. Diesel engine performance and emissions were found to be influenced by variations in combustion chamber geometry, underwent validation through simulation using Diesel-RK. Re-entrant bowl profile in quaternary blend is found to exhibit 31.3% higher BTE and 8.65% lowered BSFC than the conventional HCC bowl at full load condition. Emission wise, re-entrant bowl induced 90.16% lowered CO, 59.95% lowered HC and 15.48% lowered smoke owing to improved spray penetration and faster burning of soot precursors. However, the NOx emissions of DBOPN-TRCC were found to be higher. The simulation outcomes, derived from Diesel-RK, were subsequently compared with empirical data obtained from real-world experiments. These experiments were systematically carried out under identical operating conditions, employing different piston bowl geometries.

Different direct solar harvesting systems for daylighting are being explored to achieve high uniform illumination deep within buildings at minimal cost. A promising solution to make these systems cost-effective is the use of plastic optical fibers (POFs). However, heat-related issues with low-cost POFs need to be addressed for the widespread adoption of efficient daylighting technologies. Previous studies have explored solutions for this overheating problem, but their effectiveness remains uncertain. This study proposes a low-cost fiber optic daylighting system integrated with a newly patented mechanical component designed to secure the fiber optic bundle at the focal point, providing three levels of heat filtration while ensuring uniform illumination. Our methodology involves selecting a small area, installing the setup, and measuring both heat and light readings, followed by validation through software simulations. The operational principle of this technology is explained, and experimental tests using lux meters and infrared thermometers were conducted to investigate the system’s characteristics. The three-level heat filtration device reduces temperature by approximately 35 °C at the surface of the optical fiber, and the average illumination of the room is around 400 lux. These results were further verified using RELUX simulation software. The findings demonstrate the promising potential of this new device in solar heat filtration and achieving uniform illumination. Recommendations for mitigating overheating damage and exploring heat filtering possibilities in new parabolic solar daylighting systems for further research are also provided.

The increasing occurrence of severe vulnerabilities, such as natural catastrophes and man-made attacks, has resulted in a corresponding rise in power outages on a global scale. Given the growing recognition of such exceptional occurrences, there is a pressing need to examine the matters pertaining to resilience and the mitigation of risks. This study presents a comprehensive overview of the current state-of-the-art in power system resiliency, as well as an exploration of the measures required to ensure a sustainable environment.These instances of measures include resilience by enabling localized generation and distribution of electricity,diversification of energy resources, withstanding of severe weather conditions, cyberattacks and enabling communities to proactively address the consequences of power outages. There are multiple approaches to bolstering resiliency, which aim to facilitate recovery from unforeseen circumstances and promote stability in the face of uncertain events. These measures also serve to mitigate the impact of unexpected incidents such as power outages. Integrating unpredictable renewable energy sources like solar and wind power into energy networks is difficult, especially in terms of resilience. Renewable energy output fluctuates owing to weather and time of day, requiring sophisticated grid management, energy storage, and demand-response mechanisms to maintain system balance and resilience. This study elucidates the enhanced principles of power system dependability and resilience, in addition to several ways for establishing a sustainable power ecosystem. It examines the complex dynamics of risk assessment, including equipment failures, natural disasters, and human errors, to determine their likelihood and implications. Moreover, the study thoroughly examines the critical moments that occur after accidents, emphasizing the need of prompt reaction and recovery measures in reducing downtime and restoring regular operations to impacted power networks. This involves determining the fundamental reasons behind the incidents, such as whether they arise from equipment malfunctions, human mistakes, external influences like natural calamities, or cyber assaults. In addition, the report examines the efficacy of current response protocols and emergency procedures in reducing the impact of accidents and restoring regular operations to impacted electrical systems.

Abstract In recent years, there has been a lot of research and debate on how solar energy can be used instead of conventional sources of heating to power residential heating. In this study, the Trombe wall (TW) technique, based on natural convection and energy storage, was examined to predict mass flow rate, temperature field, and velocity field for the TW system under steady conditions. A numerical simulation model was investigated for further validation using k‐ε turbulence and discrete ordinates (DO) radiation models. Independent grid studies were conducted to ensure that there were no changes after varying the grid numbers. The effect of the air gap was carried out to enhance TW thermal performance. CFD simulation shows good agreement with published data in the literature, and the optimum air gap was set at 0.1 m. The results pave the way for future studies to improve passive solar heating systems, which will eventually help move towards more sustainable residential heating solutions.

Abstract Perovskite solar cells (PSCs) hold potential for low-cost, high-efficiency solar energy, but their sensitivity to moisture limits practical application. Current fabrication requires controlled environments, limiting mass production. Researchers aim to develop stable PSCs with longer lifetimes under ambient conditions. In this research work, we investigated the stability of perovskite films and solar cells fabricated and annealed in natural air using four different anti-solvents: toluene, ethyl acetate, diethyl ether, and chlorobenzene. Films (about 300 nm thick) were deposited via single-step spin-coating and subjected to ambient air-atmosphere for up to 30 days. We monitored changes in crystallinity, electrical properties, and optics over time. Results showed a gradual degradation in the films’ crystallinity, morphology, and electro-optical properties. Notably, films made with ethyl acetate exhibited superior stability compared to other solvents. These findings contribute to advancing stable and high-performance PSCs manufactured under normal ambient conditions. In addition, we also discuss the possible machine learning (ML) approach to our future work direction to optimize the materials structures, and synthesis process parameters for future high-efficient perovskite solar cells fabrication.

This research comprehensively examines the influence of the V-shaped rib angle of attack on the thermal and hydraulic efficacy of microchannel heat sinks (MCHS), employing Computational Fluid Dynamics (CFD) simulations over Reynolds numbers ranging from 100 to 900. The primary innovation of this investigation resides in the methodical analysis of the impacts of varying rib angles, specifically from 35° to 90°, on both heat transfer and flow resistance within the MCHS framework. The findings indicate that a reduced angle of attack, notably 35°, markedly improves thermal performance, as evidenced by the Nusselt number (Nu) achieving a value of 13.81 at a Reynolds number of 300, in contrast to a mere 8.12 at 90°. This enhancement in thermal transfer is ascribed to the more effective turbulence produced at lower angles, which optimizes convective heat transfer while minimizing excessive resistance. Importantly, this study also underscores the dual effect of rib angle on flow dynamics, as diminished angles elevate friction factor (f), necessitating increased energy input for fluid movement—friction factor at a Reynolds number of 300 were recorded at 0.0465 for 35° and 0.0288 for 90°, thereby validating the compromise between heat transfer and flow resistance. This research offers a novel perspective that while elevated rib angles (approaching 90°) mitigate hydraulic resistance, they concurrently reduce the enhancement of heat transfer, thereby accentuating the necessity for an optimized rib angle to achieve equilibrium between thermal and hydraulic performance.

Food security has become a major concern for most countries. This is due to: 1) the growth of the world population, 2) the decline of natural resources, 3) the loss of agricultural land, and 4) the increase of unforeseen environmental conditions (storms, fires, and other natural hazards). The fire outbreak, in general, has developed into a serious concern. In the coming years, the rate of fire outbreaks could rise exponentially, requiring immediate attention to avoid loss of property and life. To resolve such an issue, a shift from the agricultural industry to smart agriculture via applications of 1) the Internet of Things (IoT), 2) embedded systems, and 3) sensors for fire prevention are required to improve operational efficiency and productivity. A fire detection and anti-fire security (FDAS) system in smart agriculture using the IoT and embedded system is proposed. The proposed system has four technology levels: 1) the edge network layer, 2) the fog network layer, 3) the cloud computing layer, and 4) the data representation layer. The proposed system uses an embedded system like a Raspberry Pi device and sensors to measure the amount of fire smoke in the air and the proportion of fire in the area. The data obtained from the sensors are sent over the internet to the ThingSpeak platform using the machine-to-machine-based Message Queuing Telemetry Transport (MQTT) protocol for further display and analysis. Data available is then 1) stored, 2) processed, and 3) visualized through the ThingSpeak platform in real-time. An e-mail alert is sent to the farm owner if a fire is detected on the farm using the Simple Mail Transfer Protocol (SMTP). When a fire is detected, the anti-fire system is activated. It further filters and analyzes the data using the MATLAB application. Python programming language is also used to develop the program source code. The performance results of the proposed scheme show an accurate fire detection and anti-fire system performance for improving food security and sustainability in agriculture.

Solar energy systems operate directly connected to the sun. Solar chimney power plants are privileged systems that can provide power output even in cloudy weather and during hours when there is no sun. The design and sizing of this system, which researchers focused on after its first application in the 1980s, is very effective on its performance. In this study, the collector slope and chimney slope that give maximum power output for the Manzanares pilot plant are investigated with a 3D CFD model. Simulations made using the RNG k-e turbulence model and the DO (discrete ordinates) solar ray tracing algorithm provide results that are in high compatibility with experimental data and literature. It is understood that the system provides maximum power at 0.6° collector slope and 1.5° chimney divergence angle. It is seen that the system, which gives a power output of approximately 46 kW in the reference case, exceeds the power output by 4.5 times and reaches 216.853 kW in the design that includes the collector and chimney slope. The effects of the main elements of the system on the performance are also included by changing the collector radius and chimney height while preserving these inclination angles. More than the power output in the reference case, 49.233 kW, can be achieved with the inclined design, with a collector radius of 73.2 m and a chimney height of 155.68 m. Although the effect of increasing the chimney height on power output continues after 1.2 floors, its effect decreases. In the study, it is seen that increasing the chimney height and changing the collector radius provide a greater increase in power output. Furthermore, the scope extends to the incorporation of an Artificial Neural Network (ANN) model, presenting a novel approach to predicting SCPP system performance. The findings ascertain the utilisation of 9 neurons in the hidden layer of the ANN, demonstrating a precise alignment with the study data.

Energy consumption data reveals that buildings account for 40 % of overall energy usage. Without urgent intervention, this figure is poised to escalate alongside population growth, exacerbating the dependence on fossil fuels for energy production. Addressing this pressing issue demands effective measures to curtail energy consumption in buildings, a realm where research on bamboo's thermal performance still needs to be improved. This study fills a critical gap by investigating the integration of bamboo fibre in the briquettes, known for their high heat transfer coefficient (U-value). Leveraging the innovative coheating test method, the research pioneers an unexplored avenue to evaluate thermal performance. This novel approach distinguishes the study as a unique and original endeavour in the field. The findings demonstrate significant thermal enhancements by substituting bamboo fibre: 2 %, 4 %, and 6 % bamboo additions yield U-values of 4.698 W/m2K, 3.94 W/m2K, and 2.77 W/m2K, respectively. Notably, the 6 % bamboo-reinforced briquette showcases a remarkable 49.9 % improvement in thermal resistance compared to conventional counterparts. This study marks a pioneering effort towards achieving energy efficiency through sustainable materials in designing low/zero carbon buildings. By showcasing the potential of bamboo as a thermal insulator, the research illuminates a promising path for future construction practices. Embracing such innovations is paramount in mitigating the environmental impact and securing a sustainable future.

Concrete is an essential component of the construction industry, valued for its high compressive strength (CS) and durability. However, when exposed to extreme conditions like fire without protective structural elements, its physical integrity deteriorates rapidly, leading to significant alterations in its mechanical properties. This research aims to provide a potential solution to this issue by assessing the fire resistance of various concrete samples, including unplastered (UNP), roughly plastered (RP), and those with contemporary insulation plaster (CIP) substitutions, at different thicknesses. These samples are subjected to varying temperatures and exposure times within an oven, followed by CS testing. These temperature levels and time intervals correspond to 300 °C, 450 °C, and 600 °C, with the time range is restricted to 60, 90, and 120-min, respectively. The results indicate that an increase in sample thickness correlates with a reduction in concrete degradation at high temperatures. Moreover, the findings reveal that after 120-min of exposure at 600 °C, UNP, RP, and CIP-reinforced samples achieve CSs of 27.435 MPa, 27.74 MPa, and 30.28 MPa, respectively. Notably, the 3 cm CIP-reinforced sample exhibits a CS exceeding 30 MPa under the most extreme conditions. The research incorporates regression and computational fluid dynamics (CFD) analyses to complement the experimental investigation. The regression analysis suggests that CIP-reinforced samples can withstand temperatures up to 600 °C for approximately 173-min, while the study implies that they could endure temperatures as high as 861 °C during a 120-min exposure.

Solar energy is an effective means of reducing global greenhouse gas emissions. This review provides an overview of building-integrated photovoltaic thermal (BIPVT) systems, highlighting their potential advantages and challenges. The goal is to evaluate how BIPVT systems can improve energy efficiency, cost-effectiveness, and sustainability. This article provides a comprehensive study of various BIPVT systems and spectral splitting techniques and discusses the performance and efficiency of different BIPVT applications. Additionally, this review analyzes the factors that influence the design, installation, and maintenance of BIPVT systems, as well as the economics, feasibility, and market potential of BIPVT systems. The results show that BIPVT systems have significant promise in improving photovoltaic (PV) module electrical efficiency, system thermal efficiency and reducing energy consumption, thus contributing to climate change mitigation. However, its high initial installation cost compared to traditional heating and cooling systems or stand-alone solar systems remains a major barrier to widespread adoption. To enhance market dynamism, further research and development work is required to improve performance and efficiency, reduce installation costs and overcome existing technical challenges.

In green energy buildings, air conditioning charges can be lowered through careful planning of the building’s envelope. This article investigates several strategically designed phase change material (PCM) roof envelopes for savings on air conditioning prices, CO2 emission abatement, and payback timeframes in hot–arid and warm-temperate climates, taking into account unsteady heat transfer characteristics, cooling, and heating degree–hours. This is accomplished by using six different PCMs–RCC (reinforced cement concrete) roof envelope cases (RCC roof with PCM layer on the outer side, RCC roof with PCM layer on the center (middle), RCC roof with PCM layer on the inside, RCC roof with PCM layers placed on the outside and center, RCC roof with PCM layers placed on the center and inside, and RCC roof with PCM layers placed on the outer side and inside) with three PCMs (FS29 (form stable mixture), HS29 (hydrated salt), and OM29 (organic mixture)). PCM thermophysical characteristics are experimentally measured. The analytical results are experimentally validated. In hot–arid and warm-temperate regions, the layer of PCM installed on the outside of the RCC with HS29 saved the most on air conditioning expenses, at 6.29 and 6.61 $/m2, respectively. They also reported the greatest carbon mitigation of 300.55 kg of CO2/year and 281.58 kg of CO2/year with the faster payback periods. PCM roof envelopes are the most energy-efficient option for green buildings.

In this study, the design, manufacture and thermal performance analysis of a Fresnel lens driven hot water/steam generator are presented. The designed system is suitable for domestic and industrial hot water/steam usage and can be easily scaled up to meet different capacity needs. In the first step of the research, thermal behaviour of the cast plate heat exchanger driven by a Fresnel lens with a concentration ratio of 100 is investigated at different working fluid velocities (0.6, 0.8, 1.0, 1.5 and 2.0 m/s) and at different absorber surface temperatures (700, 800, 900 and 1000 °C). Outlet temperature of working fluid from the cast plate heat exchanger is determined through a 3D CFD model for each case. The capacity of the steam generator for different operating times (h = 1, 2 and 3 hours) is also evaluated. The highest working fluid temperature at the outlet of heat exchanger is 914.8 °C for T_cp= 1000 °C and V_wf = 0.6 m/s. On the other hand, the lowest temperature is observed as 424.7 °C for T_cp = 700 °C and V_wf = 2.0 m/s. The steam capacity of the system for h = 3 hours is determined as 1696.5 and 508.9 kg in the best (V_wf = 2.0 m/s) and worst cases (V_wf = 0.6 m/s), respectively.

Thermal insulation plasters have become the focus of attention in the building sector. Among the most important reasons for this is the high thermal energy losses of the buildings. Since conventional briquettes used in buildings allow high heat transfer, the construction industries are looking for alternative insulation ways with low cost and high thermal efficiency. The use of insulation plasters is becoming popular due to the high cost and installation of insulation materials such as Expanded Polystyrene (EPS), which is among the alternative ways. Therefore, in this study, the novel insulation plaster (NIP) developed in contrast to traditional insulation plasters is tested on conventional briquettes in different thicknesses. On considering the total heat transfer coefficient (U-value), it is understood that whilst the conventional briquette has the highest value with approximately 5.5 W/m2K, the briquette with 2-2 NIP thickness has the lowest value with a value of almost 2.86 W/m2K. As a result of the tests, the total heat transfer coefficient of the briquette with 1-1 NIP thickness is observed to have an improvement of nearly 22.5% compared to conventional briquettes, while a progress of approximately 36.4% is seen in briquettes with 2-1 NIP thickness. In addition, it is revealed that the best mitigation in the overall heat transfer coefficient is about 47.9% in briquettes with 2-2 NIP thickness. It is also figured out that NIP has additional thermal durability thanks to the dead air pores and boron minerals in its internal structure.

Photovoltaic (PV) systems are capable of meeting the urgent demand for power production for both domestic and commercial purposes. PV systems possess serious drawbacks as their performance is heavily influenced by environmental variables like wind, radiation, shadow, dust, and soil accumulation. The current work examines the performance of solar PV panels in the presence of soil and dust at various tilt angles. A solar PV simulator was used, and experiments were conducted for a hot-dry climate location (Vellore, Tamil Nadu, India, 12.91° N, 79.1325° E), to evaluate the performance of solar PV panels under varying dust deposition. A total of seven different samples, such as black soil, desert soil, red soil, alluvial soil, laterite soil, coal dust, and bird droppings, were selected and dispersed over the surface of the PV panel at various weights of 10, 20, 30, 40, and 50 g. The physical characteristics of the dust samples have been emphasized as being essential in determining how effectively the PV panel functioned. Bird droppings were shown to have the greatest influence on PV panel efficiency because of their tendency to stick to the panel surface due to moisture content, but coal dust, independent of tilt angle, was found to have the least effect. Coal dust was determined to have the least impact of all soil types since it is quickly blown away and does not stick to the surface. Bird droppings accounted for about 46.42 %–89.18% of the efficiency loss, which was determined to be high, whereas coal dust accounted for less than 13% of the efficiency loss. Furthermore, it was revealed that considered tilt angles (0O and 12.91O) have a minor influence on the PV's overall performance.

The construction sector, including in developed countries, plays a notable part in the overall energy consumption worldwide, being responsible for 40% of it. In addition to this, heating, ventilating and air-conditioning (HVAC) systems constitute the largest share in this sector, accounting for 40% of energy usage in construction and 16% globally. To address this, stringent rules and performance measures are essential to reduce energy consumption. This study focuses on mathematical optimisation modelling to enhance the performance of indirect-contact evaporative cooling systems (ICESs), a topic with a significant gap in the literature. This modelling is highly comprehensive, covering various aspects: (1) analysing the impact of the water-spraying unit (WSU) size, working air (WA) velocity and hydraulic diameter (Dh) on the evaporated water vapour (EWV) amount; (2) evaluating temperature and humidity distribution for a range of temperatures without considering humidity at the outlet of the WSU, (3) presenting theoretical calculations of outdoor temperature (Tout) and humidity with a constant WSU size and air mass flow rate (MFR), (4) examining the combined effect of the WA MFR and relative humidity (ϕ) on Tout and (5) investigating how Tout influences the indoor environment’s humidity. The study incorporates an extensive optimisation analysis. The findings indicate that the model could contribute to the development of future low-carbon houses, considering factors such as the impact of Tout on indoor ϕ, the importance of low air velocity for achieving a low air temperature, the positive effects of Dh on outdoor air and the necessity of a WSU with a size of at least 8 m for adiabatic saturation.

COVID-19 or novel coronavirus is not only an international emergency for public health but also has significant consequences on energy, economy, and environment. Although much of the World’s attention is understandably focused on COVID-19’s human toll, the outbreak’s economic toll also potentially has catastrophic implications and has disrupted all the leading economies. Consequently, the energy market has plunged, leading to an oil supply surplus and a decline in the price. Policymakers also examine the impacts of COVID-19 on the energy market and its relation to the ongoing transition to renewable energy. Against this backdrop, this paper helps in summarising the impact of COVID-19 on economy, energy and environment. Besides, it provides some critical recommendations and policy measures for the energy sector to overcome the challenges from the impact of COVID-19.

Solar energy is one of the most promising forms of alternative energy because it has no adverse effects on the environment and is entirely free. Converting solar energy into thermal energy is the most common and straightforward method; the efficiency of solar thermal conversion is approximately 70 percent. The intermittent nature of solar energy availability affects the performance of solar water heaters (SWH), which lowers the usefulness of solar energy in residential and commercial settings, particularly for water heating. Even at low temperatures, the performance of a collector can be improved by using low-density polyethylene (LDPE) glazing instead of traditional glass because it is less expensive and lighter than glass. Using a comprehensive experimental-simulative study, the Glass Solar water heater (glass SWH) and the low-density polyethylene solar water heater (LDPE SWH) are analyzed, examined, and compared in this work. These solar water heaters have galvanized iron (GI) as their absorber material. The SWHs were operated in a closed loop at a constant mass flow rate of 0.013 kg/s, and a 4E analysis (which stands for energy, exergy, economics, and efficiency recovery ratio) was carried out. This analysis included a look at the dynamic time, uncertainty, weight reduction, carbon footprint, and series connection. An LDPE SWH has an energy efficiency that is 5.57% and an exergy efficiency that is 3.2% higher than a glass SWH. The weight of the LDPE SWH is 32.56% lower than that of the glass SWH. Compared to the price of a conventional geyser, installing our SWH results in a cost savings of 40.9%, and monthly energy costs are reduced by an average of 25.5%. Compared to October, September has the quickest dynamic time to reach the desired temperature, while October has the most significant dynamic time. The efficiency recovery ratio (ERR) of a glass SWH is 0.0239% lower than that of an LDPE SWH. LDPE SWHs had a carbon credit worth INR 294.44 more than glass SWHs. The findings of these tests demonstrate that the LDPE SWH is a practical replacement for traditional means of heating water, such as SWHs and geysers.

Bu çalışmada toplayıcı eğiminin sisteme etkisi Manzanares prototipi esas alınarak geliştirilen 3 boyutlu CFD modeli ile analiz edilmektedir. Nümerik modelde güneş yükü için DO (discrete ordinates) ışınım modeli ve sistem içerisindeki hava hareketi için RNG k-ε türbülans modeli birleştirilerek uygulanmaktadır. 1000 W/m2 güneş ışınımında sistemdeki maksimum hız 14.3 m/s olarak bulunurken bu değer deneysel veri olan 15 m/s ile uyum içerisindedir. Manzanares prototipinde toplayıcı giriş yüksekliği 1.85 m olarak verilmektedir. Bu çalışma kapsamında toplayıcı giriş yüksekliği sabit tutularak, toplayıcı çıkış yüksekliği sırası ile 2.91, 3.97, 5.04, 6.12 ve 7.17 m olarak tasarlanmakta ve bu sayede toplayıcı eğiminin 0.5, 1, 1.5, 2 ve 2.5° olduğu durumlarda sistemin performansındaki değişim değerlendirilmektedir. Elde edilen sonuçlar toplayıcı eğimindeki artışın sistemdeki hava hareketinin kütlesel debisini arttırdığını ve bu artışın sistemin güç çıkışını iyileştirdiğini göstermektedir. Referans durumu temsil eden eğimsiz toplayıcı için toplayıcı verimi %38.7 iken toplayıcı eğimi 1° olduğunda verimin %41.5’e iyileştiği gözlenmektedir. Sistemin çıkış gücü referans durumda 54.5 kW iken toplayıcı eğimi 2.5° olduğunda 57.1 kW olarak belirlenmektedir.

In this study, a new procedure for drying of cashew kernels is proposed. The new methodology involves the use of solar air dryers to remove the dark sticky coating called testa on the surface of the cashew kernel to get the final product. There are several challenges in the new procedures, especially with respect to the moisture level to be retained in the cashew kernel post drying for facilitating the optimal peeling activity. In this regard, thermal performance is carried out through a set of experimental and computational trials. The experiments have revealed that the natural and forced convection solar dryers with drying speeds of 1.0 kg/h and 1.66 kg/h, respectively, showed drying efficiencies of 51.7% and 50.9%, which is within the permissible acceptable limit, thus ascertaining a moisture reduction of 40 to 42% in each of case and keeping the moisture content within the band of approximately 5%, required for effective peeling of the testa from the cashew kernel to obtain the final product. This new method has resulted in batch drying of cashew kernels of up to 30 kg capacity in a time span of 360 minutes of solar irradiation with an average consumption of 255 kJ. The results of the experiments are also validated from the artificial neural network (ANN) and response surface methodology (RSM) modelling, resulting in better prediction and optimization of the performance parameters. The error between the actual and experimental values is well within the permissible limit of +/-5%, thereby correlating the experimental and statistical values for deriving an ANN model for predicting the results for different time duration and solar irradiation. In this way, the thermal analysis of the solar dryers for drying cashew kernels has resulted in findings, which shall be utilized to improve the overall performance efficiency and the methodology adopted for maximum yield.

To limit the adverse impact of fossil fuel-generated power, energy generation from solar photovoltaic (PV) power is gaining importance. A lot of utility-scale PV power plants are being installed in tropical regions owing to the increased sunshine hours especially during the summer season. The influence of rain on the performance of PV power plants during monsoon seasons in a tropical climate is not studied in detail. This paper analyses the operational performance of a 2 MWp photovoltaic plant commissioned at the Kuzhalmannam site, Palakkad district, Kerala State, South India. The methodology includes the analysis of standard performance metrics of the plant utilizing two-year measured data and comparison with other climates. The PV plant's average performance ratio (PR) is 73.39, with an average of 15.41% capacity utilization factor (CUF) over the study period. The most deficit generation for the PV plant is observed in the months from June to August, which are part of the Southwest monsoon season. It is observed that the monsoon seasons prevailing in the region have a more substantial influence leading to a 35% reduction in energy generation from the annual average generation. Further, a comparison with other climates revealed that the specific yield obtained in rain-dominated monsoon tropical climates is lesser than dry and temperate climates.

Bu çalışmada enerji verimli düşük/sıfır karbon binalar için geliştirilen sürdürülebilir ve çevre dostu pencere ve cam teknolojilerinin kapsamlı bir analizi sunulmaktadır. Ortalama ısı transfer katsayısı (Uvalue), güneş ısı kazanç katsayısı, görünür ışık geçirgenlik katsayısı, UV ve IR ışık bloklama kapasitesi, termal konfor, maliyet ve ticarileşebilme potansiyeli gibi temel performans kriterleri üzerinden söz konusu yeni nesil pencere ve cam teknolojileri incelenmekte ve konvansiyonel ürünlerle karşılaştırılmaktadır. Pencereler bina kabuğundan gerçekleşen toplam ısı kayıplarının yaklaşık %60’ından sorumlu olduğu için, çalışmalar çoğunlukla ısıl direnci yüksek ürün geliştirme üzerine yoğunlaşmaktadır. Bu manada vakum cam teknolojisi oldukça iyimser sonuçlar ortaya koymaktadır. Vakum camlar 0.50 W/m2 K’in altında U değerlerine sahiptir. Bu değer hava ya da argon dolgulu çok katmanlı klasik pencere teknolojilerinde 2.00-2.70 W/m2 K aralığındadır. Isıl dirençli fotovoltaik cam uygulamaları (TRPVG) yaklaşık 1.19 W/m2 K’lik bir U değeri ile hem çift katmanlı camlara göre iki kat daha iyi ısıl yalıtım ortaya koymakta hem de birim m2 ’den yaklaşık 100 W elektrik üretimine imkân tanımaktadır. Low-e camlar sert iklim koşullarında pencere orijinli ısıl kayıpların etkin minimizasyonunda anahtar rol oynamaktadır. Aerogel camlar görsel kaliteyi etkilese de sınırlı bir et kalınlığında ortaya koyduğu benzersiz ısıl direnç açısından farkındalık oluşturmaktadır

Thermally resistive PV glazing (TRPVG), which is a recently developed technology for low/zero carbon buildings, is in the centre of interest worldwide as a consequence of multifunctional benefits of this novel product such as remarkably better thermal insulation performance compared to conventional PV and other fenestration technologies in market, clean energy generation, self-cleaning, sound insulation, UV and IR absorption, etc. In this study, thermal insulation performance of TRPVG is numerically optimised through a well-known CFD software ANSYS FLUENT. Optimisation is based on determining the optimum inert gas (argon) thickness (τ) behind the amorphous silicon (a-Si) PV module which yields to minimum overall heat transfer coefficient (U-value) for the entire structure. For a typical case (τ=16mm), CFD results are compared with the experimental data derived from the standardised co-heating tests, and a good accordance is achieved. CFD results are also compared with the findings of thermal resistance approach, which assumes heat conduction takes place in the inert gas medium only. The results reveal that natural convection effects become notable for the values of τ over 10 mm. In other words, τ stands as a parameter that needs to be optimised for its values greater than 10 mm. For the typical TRPVG sample with τ=16mm, the overall U-value from the CFD research is determined to be 1.19 W/m2K, which is in good agreement with the experimental data. The optimised value of τ for the TRPVG structure introduced is determined to be 20 mm, which guarantees the minimum total heat transfer rate (Q) across the glazing and maximum temperature difference between internal and external glazing surfaces. Keywords: Windows, PV glazing, U-value, Thermal insulation, CFD, Co-heating test

The heat storage and release performance of cascade phase change units are investigated numerically for users in Inner Mongolia’s severe cold region. Three schemes of phase change material combinations are thoroughly tested. We obtained a better material combination scheme S3 (palmitic acid + polyethylene glycol), which has higher heat storage capacity per unit mass, higher average heat flux, and better unit synchronisation performance, so that it is more suitable for solar heating and cascade heat storage units in cold regions of Inner Mongolia. This study takes into account the irradiation variation of typical days during the winter heating season. The results show that the palmitic acid and polyethylene glycol combination scheme has the highest total heat storage per unit mass. This scheme also performs well in the synchronisation of two-stage storage units. When compared to the other two schemes, the average heat flux is increased by 25.5% for the first stage unit and 16.8% for the second stage unit.

Geometric parameters in solar chimney power plants are numerically optimised for the purpose of better power output figures. Several parameters have been investigated in the pilot plant such as chimney height and diameter, collector diameter and slope, and slenderness. However, ground slope has not been studied to date despite its perspicuous impact on turbulent flow. In this study, the impacts of the different slope angles of the ground, where the solar radiation is absorbed through the collector, on the main performance parameters of the system are numerically analysed through a reliable CFD software ANSYS FLUENT. By considering the actual geometric figures of the pilot plant, a 3D model is constructed through DO (discrete ordinates) solar ray tracing algorithm and RNG k-ε turbulence model. For the solar intensity of 1000 W/m2, the maximum velocity inside the system is found to be 14.2 m/s, which is in good accordance with the experimental data of 15.0 m/s. Starting from 5 m inside the collector, the chimney inlet heights are reconfigured 0.209, 0.419, 0.625, 0.838, and 1.04 m, respectively, and when the ground slope is 0.1, 0.2, 0.3, 0.4, and 0.5°, the changes in the performance output of the system are investigated. For the reference case which refers to the horizontal ground, the maximum air velocity is determined to be 14.2 m/s and the power output is 54.3 kW. However, when the ground slope is made 0.5°, it is observed that the maximum velocity increases by 37% to 19.51 m/s, and the power output is enhanced to 63.95 kW with a rise of 17.7%. Sloping ground is found a key solution to improve the turbulent effects inside the plant, thus to enhance the electrical power output.

Solar chimney power plants (SCPPs) are promising systems for clean energy generation. SCPPs are ideal for the large-scale harnessing of solar energy. They operate efficiently without auxiliary energy and do not cause any environmental pollution. There are several theoretical, numerical and experimental attempts to date for performance assessment of SCPPs, however, there are still contradictions in the findings, and a thorough performance evaluation is still missing. Therefore, in this study, a novel three-dimensional axisymmetric computational fluid dynamics (CFD) approach is proposed by considering the pioneer plant in Manzanares region. For a realistic approach, actual geometric parameters of the pilot plant are utilised in the CFD model, and the performance assessments are done regardless of time. Pressure, temperature and velocity distributions within the SCPP from collector inlet to chimney outlet are numerically modelled with respect to changes in solar radiation and atmospheric temperature. For model validation, the numerical findings are compared with the typical experimental findings performed in pilot plant, and a good agreement is obtained. For a certain value of solar radiation (1000 ​W/m2), maximum air velocity in the pilot plant is found to be 14.24 ​m/s, which is compatible with the experimental data of 15.00 ​m/s. Static pressure is found to sharply decrease from chimney ground to turbine inlet, and then steadily rises to the chimney outlet. Minimum static pressure is observed to be −100.18 ​Pa ​at 21.92 ​m from the ground. Output power of SCPP linearly increases with the solar intensity whereas it steadily reduces with ambient temperature. Available power is determined to be 49059 ​W for the case of 1000 ​W/m2, and the atmospheric temperature of 293 ​K.

Solar PV plants are being installed in many airports around the globe. Reflection from the solar PV arrays is a big concern for airport stakeholders. This paper aims to assess the glare occurrence and its impact from the proposed solar PV plant installed in an airport. The prediction of glare is carried out with the help of computational software for a randomly selected area within the boundary of Kuantan airport, Malaysia. The selected zone is not suitable for solar installations as per FAA's glare policy. In the selected area (Apv), the duration of glare on ATCT from solar modules installed is 6778 min (green and yellow glare). Also, the flight path is free from any kind of glare occurrence. Glare occurs between March to mid-October, mostly from 7.00 a.m. to 8.00 a.m. Green and Yellow glare last up to 10 min and 30 min respectively in a year. In this regard, remedial steps for mitigating possible glare are discussed. Glare prediction helps in the early adoption of suitable remedial measures against glare hazard. Keywords: Airport, Glare, Malaysia, Reflectivity, Solar PV

The world’s demand for electricity will double by 2050. Despite its high potential as an eco-friendly technology for generating electricity, solar energy only covers a small percentage of the global demand. One of the challenges is associated with the sustainable use of land resources. Floating PV (FPV) plants on water bodies such as a dam, reservoir, canal, etc. are being increasingly developed worldwide as an alternative choice. In this background, the purpose of this research is to provide an outline of the hybrid floating solar system, which can be used to generate renewable energy. The hybrid technologies discussed include: FPV + hydro systems, FPV + pumped hydro, FPV + wave energy converter, FPV + solar tree, FPV + tracking, FPV + conventional power, FPV + hydrogen. The review also summarizes the key benefits and constraints of floating solar PV (FPV) in hybrid operation. Among the various hybrid FPV technologies, with solar input and hydro energy were among the most promising methods that could be potentially used for efficient power generation. The valuable concepts presented in this work provide a better understanding and may ignite sustainable hybrid floating installations for socio-economic growth with less environmental impact.