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This paper reviews applied single and hybrid solar energy-saving techniques with emphasis on solar chimney, Trombe wall, and photovoltaics for building energy consumption and thermal comfort. Solar energy techniques can be broadly classified into passive and active. Passive strategies refer to collecting, storing, and distributing solar energy without relying on electrical or mechanical components. In contrast, active techniques rely on mechanical and electrical components. The discussed passive devices include solar chimney and Trombe wall. Different design configurations have been reported to influence various buildings' thermal and electrical performances. On the other hand, active solar strategies in buildings including photovoltaic technologies, are discussed. Moreover, applied the hybrid system of these techniques in building is discussed. The review paper critically analyzes these systems' energy and thermal performances to demonstrate their significance in building applications. The significant findings of these studies demonstrate the capability of these systems to provide thermal comfort and considerable energy savings. The review studies indicated that passive architecture could improve thermal (as high as 20%) and visual comfort and reduce electricity consumption by 46%. Besides, several highlights on BIPV and BIPV/T systems are discussed, showcasing their status, recent research, development, and applications toward achieving building energy efficiency. Throughout the review, it is seen that solar technologies applied in buildings have undergone a remarkable revolution, demonstrated significant energy-saving potentials and opening the road for application in net-zero energy buildings. Further research is required on some of the technologies to assess the techno-economic feasibility of these systems in the building sector. [ABSTRACT FROM AUTHOR]

• This study proposes an hour-ahead demand response (DR) for PV-based smart homes utilizing the AI method in digital twin while taking into account customer energy consumption and discomfort; • This study adopts a MARL approach for ensuring optimum and decentralized decision-making among several devices; • This study presents a steady cost prediction method utilizing ANN for overcoming the uncertainties in upcoming costs; • This study also compares the energy prices under 2 various scenarios including and excluding AI-enabled DR. Energy management (EM) systems need to have the flexibility to take the optimum real-time decision in the face of constantly varying market factors. Demand response (DR) has become the newest method of improving the performance and reliability of the electrical system. Here, an hour-ahead DR algorithm is proposed for EM at home. This paper presents an artificial neural network approach that uses stable cost predictions as a method for dealing with upcoming price uncertainties. For making optimum and decentralized decisions for various household devices, multi-agent reinforcement learning has been used along with predicted upcoming costs. This paper conducts the simulation with shiftable, non-shiftable, and controllable loads to determine the effectiveness of this suggested EM strategy. Based on the outcomes of the experiments, this suggested DR algorithm has capable of handling EM for a number of devices, minimizing consumer electricity expenses and discomfort prices, and helping the consumer considerably reduce its energy expenses in comparison to a benchmark using no DR. [ABSTRACT FROM AUTHOR]

• Examines resources allocation issue for minimizing the solar power usage in fog computing-enabled wireless IoTs using NOMA. • A typical case is considered to support several IoT devices for offloading computations together to the similar FN. • As a way of achieving an optimal efficiency-complexity balance, a whale optimization algorithm (WOA) is introduced. • The suggested layout is more efficient than current methods in terms of throughput, latency, blackout likelihood, and power usage. Fog computing is used to handle applications that require a lot of calculations at the network's edges for wireless Internet of Things (IoT) networks that have source-limited equipment. In addition to reducing computational time and fronthaul traffic information, fog computing still poses challenges in allocating the existing computing and communication sources, while maintaining the strict quality of service (QoS) standards. The current study examines the issue regarding task management and heterogeneous resource allocation among equipment for wireless IoT networks. As a means of transferring the information to the fog computing nodes (FNs), IoT devices collecting large amounts of information require appropriate offloading decisions. This paper investigates how non-orthogonal multiple access (NOMA) can be deployed for IoT networks in order to enable many devices for transmitting information of the load and the market to a similar FN simultaneously, in a similar frequency range, and in the same code domain. Several IoT devices are optimized together based on their resource allocation and transmission power in this paper while meeting the QoS standards. Additionally, the optimization problem can be expressed in the form of a mixed-integer nonlinear programming problem with the goal of minimizing the system's power usage. The problem would be NP-hard so a whale optimization algorithm (WOA) has been proposed for solving. According to simulation outcomes, the suggested architecture performs well in terms of throughput, delays, blackout likelihood, and power usage. [ABSTRACT FROM AUTHOR]

• Introducing an energy management in renewable based MGs with DRP considering tidal and solar units in real-time digital twin case. • Developing a GWOA to find the optimal economic operating point in a nonlinear constraint multi-objective framework. • Proposing an intelligent deep GAN based model to predict the output power of tidal and solar units. • Critical and technical analysis of different algorithms in the microgrid operation and management. In this research study, a novel demand response program (DRP) has been proposed for renewable-based microgrids (MGs) which takes into account the high penetration of tidal units and solar energy as important, prevalent renewable resources in the power systems. To this end, multi-objective problem (MOP) structure is a promising solution to reduce the whole operating costs of the scheduling problem as well as decrease the high risk of failure in electrical power transmission because of component increasing failure rates and extended repair time. The complexities and nonlinearity of the problem necessitate an innovative heuristic solution which is derived from the Grey Wolf optimization algorithm to help for resolving the problem without making any assumptions or compromising precision. This paper also proposes the dynamic 3-phase correction (DPC) formulation to boost the layout convergence ability by increasing the global search features. Through such a modification, the diversity of the members in the algorithm population increases which would result in low computational burden and low possibility of trapping in local optima. Moreover, it is necessary to have a clear and accurate estimation of the output power of renewable sources in the system. Considering that solar irradiance is hard to anticipate, this paper develops a deep learning layout that uses generative adversarial networks (GAN) to forecast the hourly power generation of the tidal and solar agents. GAN model consists of two competing networks which help to enhance the training process by increasing the accuracy of distinguishing real data from fake data. At the end, IEEE standard test system is used to evaluate the efficiency and effectiveness of the suggested multi-layer problem. The simulation results display that the suggested deep model outperforms other well-known algorithms in smart microgrids. [ABSTRACT FROM AUTHOR]

[Display omitted] Two significant manifestations of the passive effect of building photovoltaic (PV) systems include the enhancement of the thermal performance of the envelope and the reduction of building energy consumption through the installation of PV systems on the building envelope's surface. This paper presents a review of the passive impact of PV roof systems, PV wall systems, and PV window systems, as well as the effects of the external environment, building ontology conditions, and PV system configuration on the passive effects. The study concludes that in regions with a hot climate, the shading effect of PV roof and PV wall systems during the summer can reduce the building's cooling load by 20% to 70%. In frigid climate regions, heating energy consumption during the winter can be reduced by 10% to 20% through the PV wall system's ability to recycle hot air in the cavity. Indoor thermal comfort can be improved while reducing lighting energy consumption by 3% to 14% with PV windows. A comprehensive analysis of the existing literature on the influencing factors reveals that the influencing factors of the passive effect have complex uncertainties and non-linear coupling characteristics under various conditions. To provide a theoretical foundation for the scientific popularization of photovoltaic systems, this paper identifies current research problems and prospective research directions for building photovoltaic systems based on the current status of research in the literature. [ABSTRACT FROM AUTHOR]

This paper presents dynamic air-based models of a hybrid photovoltaic-thermal (PVT) collector. The models are developed with the aim of estimating the temperature of the collector components and therefore of estimating the annual generation of electrical energy and thermal energy outputs, by using actual climate data of six different cities based on Köppen-Geiger-Photovoltaic (KGPV) climate zones. The results show that the unglazed type collector has the best PV cooling while the dual channel collector has the best air heating among air-based PVT collectors. The results also indicate that the use of additional fluid enhances both electrical and thermal performance. The dynamic models are validated by comparison with results found in the literature. The paper also discusses a novel bi-fluid PVT system combined with a storage tank and an H-infinity based robust controller that can handle uncertainties. The results of the bi-fluid system show that the fraction of energy demand covered by the system is highly dependent on climate conditions and the collector's surface area. It was found that for a small-scale house (standard for four people), the proposed system can cover more than 70% annual domestic hot water demand for cities with high solar irradiance and 32% for a city with low solar irradiance. • Estimating annual generation of electrical and thermal energy outputs of PVTs for various climate zones. • A new design of a bi-fluid PVT system which incorporates a storage tank as well as a robust controller. • Consistency of the dynamic models has been validated by comparison to results found in literature. [ABSTRACT FROM AUTHOR]

• A grid-connected solar PV-based multigeneration energy system is presented. • Economic, energy, environmental assessment for the proposed system is carried out. • Single objective/multi-objective optimization scenarios are analyzed and compared. • Sensitivity analysis is conducted to point out the effect on system performances. Solar photovoltaic-based multigeneration energy systems (SPVMES) which can use the excess energy of photovoltaic (PV) systems for heating and hydrogen production to improve the self-consumption of solar PV, have gained wide attention as a promising solution for clean and efficient production. To reliably meet diverse energy demands, gird system is integrated into a SPVMES as a backup energy source. In this paper, a grid-connected SPVMES is established to meet the electricity, heating and hydrogen loads, including PV, electrolysis, solid oxide fuel cell, electric heater for small-scale centralized heating and energy storage devices for electricity, heating and hydrogen storage, respectively. The emphasis to focus on when designing and dispatching the SPVMES lies in system performance evaluation. The innovation of this paper is to design and dispatch such a grid-connected SPVMES in a preliminary design stage through economic, energy and environmental assessment by considering cost of energy (COE), energy rate (ER) and renewable fraction (RF). Simultaneously, to explore which single objective/multi-objective optimization has better performance in comprehensive system evaluation, four different scenarios named COE optimization, RF optimization, ER optimization and multi-objective optimization are analyzed and compared. The specific application processes of component sizing and system dispatching with different optimization objectives are presented in detail. The results show that the proposed system has the COE of 0.0343$ in COE optimization scenario, the ER of 0.9128 in ER optimization scenario and the RF of 0.8811 in RF optimization scenario, which shows its significant potential in economic, energy efficiency and environmental performance. By comprehensively scoring the four optimization scenarios, it can be found that the multi-objective optimization scenario has better performance in system performance evaluation compared to the other three single objective optimization scenarios. Additionally, the multi-objective optimization could balance the tradeoff of COE, RF and ER and compromise the results of the single objective optimization scenarios. Potentially, sensitivity analysis is conducted to point out the effect of discharging depth of battery, PV subsidy, linear increasement of loads and seasonality effect on system performances. [ABSTRACT FROM AUTHOR]

• This paper analysed the thermal, spectral and colour characteristics of PDLC glazing in warm and humid climates using a test cell of 0.3*0.4 m size. • This paper also analysed the Visual characteristics, including daylight glare and circadian entrainment, in a test room with a PDLC sheet on a west-oriented window of 1.3 m * 1.3 m. • This study provides references for installing PDLC glazing in a warm and humid climate. This paper detailed the experimental investigation of the Polymer Dispersed Liquid Crystal (PDLC) glazing over visual comfort, thermal performance, circadian entrainment, and energy consumption of an office room in a warm and humid climate. In addition, an elaborated study was carried out on the PDLC glazing's spectral, visual, thermal, and circadian characteristics. The thermal evaluation was carried out with a test cell of size 0.3*0.4 m. It was observed that the internal glass surface temperature was comparatively higher than the external glass temperature. It indicates the high solar gain of PDLC glazing. Under opaque and transparent states, the Correlated Colour Temperature (CCT) and a Colour Rendering Index (CRI, R a) were almost identical. For an ultraviolet (UV) lamp source, PDLC film reflects most of the radiation under an opaque condition. Circadian Stimulus is 10–20 % more under clear states than the opaque state. A real-time experiment was performed in a test room at Manipal, where the PDLC sheet was pasted on the west-oriented window. Colour rendering and circadian effectiveness were satisfactory. CS was always above 0.3, the minimum requirement for circadian entrainment. Due to the milky appearance of the opaque state, a low solar elevation angle induces more reflection on the workspace, and hence more daylight comes into the interior. Under these conditions, uniformity is less. It is observed that PDLC is most suitable in the south and the north orientation windows for the southern tropical climate. The energy consumption was observed as 0.5 kWh /day. [ABSTRACT FROM AUTHOR]

A 50 kW p photovoltaic (PV) power plant installed in a hospital had its efficiencies analyzed in this work. Two emergency services of the hospital have been chosen to be fed with produced energy. In the present paper, easy sizing up means were used. The PV system is synchronized to the electrical grid to ensure the solar energy production and the batteries charging in priority. In case of electric grid perturbation, the batteries provide with the stored energy. For the studied system, the month of May is the better energy production month among the eight studied months with almost perfect efficiency in terms of meeting the needs of the two connected services. However, this month is one of the heat wave months in the sahelian strip. The batteries energy is very requested to ensure the energy supply in the two emergency services of the hospital. The best operation month is May. However to find the optimum operation, it well be better to install off-grid system. The temperature and local dust are also degradation factors to take into account. This paper shows that the PV off-grid can be used to improve the resilient of the population in areas with high security challenges. The failure of the PV plant is estimated at 0%. Indeed, once the SONABEL grid is desynchronized, the grid inverters use the energy in batteries to continue the injection. The environmental constraints such as low illumination, high temperature, dust, etc. must be added in the perturbation factors of the solar energy production. • New way to improve the population resilience in areas with high security challenges. • In the Sahel the optimum operation of PV power plant is found in the month of May. • The PV plant failure is brought near 0%. • The environmental constraints are the degradation factors to take into account. [ABSTRACT FROM AUTHOR]

• Novel FADSS is fabricated for the water production from thin air. • It incorporates a small blower to facilitate airflow through the system. • Condenser is used for the condensation of desorbed vapour from silica gel. • Bed design study is performed for effective solar energy utilization. • Honeycomb bed, with an airflow rate of 30 LPM, is found as optimal. This paper presents an innovative approach addressing the problem of clean and drinking water scarcity by developing and optimizing a flow-assisted desiccant solar still (FADSS) that harnesses atmospheric moisture using solar energy. It is an extension of the conventional desiccant solar still incorporating a small blower to facilitate airflow through the system, and operates in a two-cycle process. During the night (adsorption process), ambient air is blown continuously through the bed, enabling the silica bed to adsorb moisture. During the daytime (desorption process), solar energy heats the silica bed, releasing the adsorbed water vapour to the circulating air, which carries it to the condenser. The water vapour condenses in the condenser, and the air returns to the bed. The paper focuses on optimizing the FADSS by studying the airflow rate, a critical parameter for maximum water production. It varies from 20 to 60 L per minute (LPM). Further, the paper also investigates the four different bed design configurations for maximum water production. The FADSS thermal efficiency is calculated to analyze its performance. The highest water production of 694 ml/day was achieved using a 0.25 m2 glazing area in the honeycomb bed design. This output was obtained by employing an airflow rate of 30 LPM and a 3 cm thickness of silica gel. Interestingly, The honeycomb bed effectively utilized ∼38 % of solar energy for water production in the FADSS, while about 9 % was lost due to sensible cooling of the air in the condenser. The findings suggest that the honeycomb bed, with an airflow rate of 30 LPM, represents the optimal operational parameters for this system. [ABSTRACT FROM AUTHOR]

With the increasing adoption of solar photovoltaics (PVs) in the power grid, the grid authorities are faced with significant challenges in managing PV intermittency, variability and uncertainty. The inherent ramping behaviour of the PVs results in short-term PV power fluctuations which in-turn affects the grid voltage regulation. This has resulted in implementation of new grid codes to limit the ramp-rate (RR) behaviour of PVs allowing the grid resources to curb the power fluctuations. Energy storage system (ESS) is one such fast acting resource that helps in limiting and smoothing PV power fluctuations when coordinated by RR control algorithms. This paper proposes an ESS-based RR control strategy to smoothen and limit PV power fluctuations in the power grid. The proposed RR control strategy has been implemented for two types of smoothing namely, aggregated smoothing that considers the overall PV output, and individual node-level smoothing that considers the individual PV output. The technical feasibility of this RR control strategy to limit the PV power fluctuations is analysed using a standard IEEE test network with both centralized and distributed ESS placements at various PV penetration levels. The effectiveness of the proposed RR control strategy in reducing voltage fluctuations in the power network is also studied. Moreover, cost optimization is carried out with various PV penetration levels to ensure optimal ESS operation at the lowest possible cost while adhering to the optimization and network constraints. The paper further provides detailed techno-economic analysis for various case scenarios. • Ramp-rate control of solar PV is implemented using energy storage system. • Different types of smoothing techniques are used in ramp-rate control strategy. • Impacts of both centralized and distributed energy storage systems are analysed. • Techno-economic analysis is conducted for optimal operation of energy storage. [ABSTRACT FROM AUTHOR]

• An active hybrid solar-electrical dryer is considered. • Identification modeling method of the dryer is established. • Fuzzy control approach to control the temperature inside the dryer is used. • Numerical simulation and experimental tests were carried out. • Electrical energy consumption is elaborated. In this paper, an indirect hybrid solar-electric dryer was used to be able to dry a wide range of agriproducts and to ensure a continuous drying operation. The hybrid dryer is a multivariable system made up of a solar collector, a drying chamber, a fan in the outlet duct, and electrical resistance heaters. To preserve the product quality, the temperature should be kept within a restricted temperature range during the drying process. Temperature control is also required to optimize the conventional energy demand and to achieve better use of the available solar energy. This paper presents the thermal behavior study and the control of the temperature inside a hybrid solar dryer. To predict the temperature evolution in a fairly short time, a state-space model based on the nonlinear least square method was developed. Based on the temperature prediction model, Fuzzy Logic Controller (FLC) was developed and its performances were compared with a Proportional Integral (PI) temperature controller. The experimental tests were carried out under an air mass flow rate of 0.025 kg/s and the temperature was controlled at 60 °C and 80 °C. By using this combination, the static temperature inside the drying chamber remains under 0.8 °C and the relative error remains under 1.04%. The developed fuzzy controller could almost recover the dryer performances in less than 8 min after temperature disturbance. Moreover, for continuous use covering day and night, the temperature controller allows reducing the conventional energy consumption by 11.3%. [ABSTRACT FROM AUTHOR]

• Prevalent quality assessment of drying materials with solar energy was reviewed. • The potential application of solar drying for high-quality dried products was introduced. • The physical and chemical mechanisms of quality transformation during drying process were clarified. Solar energy is a green and renewable clean energy. Using this as main or auxiliary energy to dry agricultural materials could reduce energy consumption and improve product quality. In the drying process of agricultural materials, not only drying technologies but also drying parameters would affect the quality of materials. This paper provides a guided technological tour on solar drying through a literature research. An overview about the drying technologies to evaluate the drying quality, such as traditional sun drying, solar tunnel drying, solar greenhouse drying, solar-assisted drying system, is presented to demonstrate advances and application potential of solar drying. Finally, variable temperature drying is preliminarily proposed and tested to verify its superiority of energy saving and drying quality improvement. The literature research in this paper gives a reference on the effective application of solar drying through specifying the mechanisms of quality transformation. [ABSTRACT FROM AUTHOR]

Drying of materials is an important and essential mechanism during the production process in industries. Drying fruits and vegetables is an ancient method used for food preservation. Apart from the agricultural sector, there are many industries such as automobile, rubber, paper and pulp, sugarcane, wastewater treatment, lignite/coal, etc. require heat energy for drying during production processes. Conventional energy sources such as coal, natural gas, and electricity are used for the heat energy required for drying. Due to the increase in cost and pollution involved in conventional sources, solar energy-based drying systems can be encouraged. This review work provides a detailed analysis of solar-based dryers used in various industries namely agricultural, marine, tea, sugarcane, automobile, rubber, pulp, and paper industries. In addition, the utilization of solar energy for sewage drying, industrial waste drying, and lignite coal drying for power generation are reviewed. Different types of dryers presently available in the market are also discussed in the review work. Various parameters used for the performance of the dryers such as drying rate, amount of energy required for drying, collector efficiency, drying efficiency, specific energy consumption have been discussed. Economic, environmental, and social aspects of solar dryers are also presented, and recommendations are given in the paper. [ABSTRACT FROM AUTHOR]

• The solar potential in different residential blocks is simulated. • The influences of block morphological parameters on solar potential are varified. • Four parameters that impact on the block solar potential more than 70% are verified. • The facade PV capacity in high-rise and hybrid residential blocks is more than 66%. • The average PV installation rate of roof, south and west facade is 96%, 32% and 39%. Block-scale application of photovoltaic technology in city is becoming a viable solution for renewable energy utilization. Rapid urbanization process has made urban buildings have huge development potential for solar energy in China, especially in residential areas that occupy large parts of the city. However, the residential blocks in China show differences in the morphological layout and parameters, which means they have diverse potential for solar energy development. This paper studies the effect of quantified morphological parameters on solar potential for residential blocks in Wuhan, China. The distribution characteristics of solar potential in different block environments are discussed. Various strategies are evaluated in terms of the installation position and height of PV modules. The results showed that floor area ratio, building density, average building height and building interval have significant impact on solar potential for residential block, and their correlation can reach 75%, 71%, 78% and 72% respectively. The average PV installation ratio of roof, south facade and west facade can reach 96%, 32% and 39% respectively. The results of this paper not only provide a reference to the block-scale application of PV technology in urban environment, but also stimulate the implementation of photovoltaic policies on various residential blocks in China. [ABSTRACT FROM AUTHOR]

[Display omitted] • Difference in working principle of Solar Thermoelectric Generators (STEGs) and PV-TEG Hybrid Generators is discussed. • Design parameter optimization of TEG only system is not same as that for STEG and PV-TEG hybrid system. • Enhancement in the concentration ratio improves TEGs efficiency, leading to increased conversion efficiency of the hybrid system. • Micro-channel heat pipe significantly reduces the number of TEG used, thus, reducing the overall cost of the system. With the continuously increasing demand for energy, reduction in greenhouse gas emission for daily energy usage is a challenging task. Solar energy based technologies possess the potential to address this challenge since sun is a renewable and abundant source that does not produce any emissions. It would be additional benefit if in the process of using such technologies, wasted heat energy is also converted into electrical energy. Thus, integration of thermoelectric and photovoltaic hybrid systems offers the flexibility to exploit solar spectrum across full wavelength. Thermoelectric Generator (TEG) when integrated with solar electricity conversion technologies result in fabrication of (i) solar thermoelectric generators (STEGs) and (ii) photovoltaic-thermoelectric (PV-TEG) hybrid devices with enhanced efficiency. Improvements in the conversion efficiencies of these technologies would aid in making solar energy at par with conventional forms of energy generation. This paper reviews the prospect of integrating TEG with solar electricity conversion technologies by examining the recent efforts in the field. In particular, the difference in the working of these two type of devices have been focussed on. This review presents in-depth analysis of the state-of-the-art methods used to achieve optimum performance. Moreover, various applications are stated and PV efficiency and losses are discussed along with possible resolutions. Furthermore, recent advancements in these device technologies have been compiled and cost and commercialization aspects have been focussed on. The review aids as a guide to select appropriate procedure of optimizing the performance in these devices as per requirements and specific application. [ABSTRACT FROM AUTHOR]

• BIM is used as a thinking tool for the conceptual design process. • The model is intended for the neutralization of energy consumption, estimating the amount of photovoltaic panels needed to achieve a NZEH. • A new, original methodology is used, with a built BIM prototype to measure energy consumption. • This tool for enriching the world with a new sustainable dimension is implemented in the BIM app as part of the software. • The originality of this paper is to create an embedded simplification tool for evaluating the electrical energy consumption (energy system) inside BIM. BIM is not simply a drafting tool or advanced CAD. BIM is a collaboratively generated and maintained data-rich information source, especially when it comes to the energy-calculation process and beyond. Due to growing awareness around energy conservation, numerous projects and initiatives have occurred to promote the development of low- and net-zero-energy homes. The widespread adoption of photovoltaic rooftop systems has shown that solar homes can be a effective solution to that energy demand; nowadays, the idea that BIM is not just software has been decided upon. In this paper, a new approach was used to calculate energy consumption using a BIM template designed for this purpose. The greatest value derived from BIM was in the template designed to neutralize energy consumption by calculating the number of photovoltaic panels needed to achieve a net-zero-energy house. The BIM prototype developed is considered a useful tool, intended to be used by everyday, non-specialist users to aid and disseminate energy knowledge in order to achieve a zero-energy home, as well as to be used as a decision-support tool, incorporating energy simulation into the early design process of zero-energy buildings in architectural practice. Finally, the tool was tested on a group of users in order to fine-tune and develop the design parameters of the template. [ABSTRACT FROM AUTHOR]

• Detailed thermal design of a silica gel/water adsorption chiller is presented. • Adsorption chiller can be stably operated at 2.2 ∼ 3.6 kW cooling output. • COP and SCP can reach 0.485 and 140.3 W·kg−1, respectively. • Cooling/chilled water temperatures have greater influence on SCP. Silica gel/water adsorption refrigeration is regarded as a suitable solution for scalable solar cooling application in current stage but it needs necessary improvements in system design and performance. In this paper, authors present detailed thermal design of a small-scale silica gel-water adsorption chiller with heat and mass recovery scheme. Besides, the adsorption system is built for performance test under typical medium solar hot water temperature (70 °C). The results show the adsorption chiller can be stably and reliably operated while cooling power ranges from 2.2 to 3.6 kW. COP and SCP can reach 0.485 and 140.3 W·kg−1, respectively, at 70/30/25 °C hot/cooling/chilled water inlet temperatures. The increase of cooling water inlet temperature from 26 °C to 32 °C causes 11.2 % and 28.9 % declines of COP and SCP, respectively. However, the increase of chilled water inlet temperature from 12 °C to 25 °C contributes to 61.1 % and 114.1 % increments of COP and SCP, respectively. In addition, inlet temperatures of both cooling and chilled water have greater influence on SCP than COP. Through this study, better understanding of adsorption chiller thermal design and its performance under medium solar hot water temperature is obtained. [ABSTRACT FROM AUTHOR]

• TDDs require smaller roof opening, provide light deeper than conventional skylights. • Evaluation of light delivery and visual comfort performance of TDDs under real sky. • Studied influence of TDD dome, diffuser, diameter and other factors. • Prismatic domes provide more rounded daily illuminance profile. • No visual discomfort detected. Tubular daylight devices (TDDs) require a much smaller roof opening than conventional skylights and, because of their highly reflective tube, they can deliver daylight farther away from the building envelope. This can provide lighting energy savings, increasing resilience in new and existing buildings. Different types and configurations are available amongst commercially available TDDs, including domes/diffusers with varying optical properties and the diameter of the TDD. This paper presents a comprehensive experimental evaluation of the lighting and visual comfort performance of multiple configurations of commercially available TDDs, varying dome type (prismatic and clear), diffuser type (Fresnel and prismatic), and diameter (53 and 35 cm), under a range of environmental conditions (different times of day/year, sky cover). Based on illuminance measurements, estimated lighting energy use is also presented. Results indicate that, for clear sky, light levels increase and energy use decreases with solar altitude (e.g., 16 Wh/m2 daily energy use intensity on a high maximum daily solar altitude (MDSA) day and 34 Wh/m2 on a low MDSA day) and TDD diameter (e.g., 34 Wh/m2 and 69 Wh/m2 for 53 cm and 35 cm TDDs, respectively, for low MDSA). The daily illuminance profile is more rounded for prismatic domes and has higher peaks for clear domes; this translates into a somewhat higher average daily useful daylight illuminance (DUDI) for prismatic domes (86 %) when compared to clear domes (80 %). No clear impact of diffuser type was apparent. Measurements indicated no discomfort glare for any of the conditions tested. [ABSTRACT FROM AUTHOR]

• Accurately modeling the blockchain system based on the miners' energy consumption during the data transactions process. • Offering a two-stage structure of energy consumption management of miners through an IPS-based placement algorithm. • Developing a distributed energy architecture among blockchain miners and the electrical grid and renewable energy resources located on the grid inspired by the PDMM concept. Addressing the blockchain technology (BCT) challenges, such as the high energy consumption is unavoidable in smart power systems to take maximum advantage. As an antithetical point, there is a structural duality between using BCT in the electrical grid due to its advantages and energy consumption. To this end, this research work is an inclination toward controlling the miner's energy consumption based on a realistic and efficacious two-stage energy mechanism toward the distributed energy concept and optimal placement of data mining devices. In this circumstance, such a new structure allows miners to mainly sustain their hash rates as a prominent index for security achievement and optimally decrease their cost. This paper suggests a novel distributed model for miners coincided with the smart electrical grid getting inspired by the Prima-Dual Method of Multipliers (PDMM) based distributed approach to settle down the needed power bartering between miners and energy supply resources. In addition, for a similar purpose, it seems to reach the ideal resolution needs to perform the modified reaffirmation of miners (the mining pool) within the secured grid. To execute this task, this research recommends the Intelligent Priority Selection (IPS) techniques as well. When all is said and done, the result of this approach can aid researchers with performing in the field of improving social advantages by the usage of the suggested method. [ABSTRACT FROM AUTHOR]

• A multi-parametric analysis study has been conducted for 96 building scenarios. • The impact of building construction on the energy and temperature performance is studied. • The effect of different phase change materials on temperature regulation is investigated. • Several configurations have been recommended for both building constructions. This paper presents a comparative study that will evaluate and optimize 96 building cases in a multi-parametric manner. This study is conducted by using the EnergyPlus simulation software with the integrated PCM hysteresis model. The studied building designs were carefully selected to have equivalent air volume, while taking into consideration the outer wall shape of the building to increase or decrease the outside sun and wind exposed surface as well as increasing the PCM area inside the buildings. Three different building forms were evaluated, the square form, the octagonal form which is considered as the building design with a reduced surface, and finally the innovative zigzag form which has a higher wall surface compared to the square form. Additionally, these three building forms, were evaluated at two different constructions (light-weight and heavy-weight), four different PCM types and four different HVAC scenarios. The main purpose of this study is to assess indoor air temperature fluctuation reduction, energy efficiency, and PCM activation. The results reveal an energy saving up to 13.1 % and a maximum total yearly temperature fluctuation reduction of 653 °C. The recommended building configuration was able to reach a maximum PCM activation of 26.63 %. [ABSTRACT FROM AUTHOR]

• The study makes the following main contributions: • 1) A mathematical layout is developed to include renewable resources for load scheduling in digital twin-based microgrids. • 2) Uncertainty modelling of PV production employing Beta PDF for load scheduling is utilized in digital twin environment. • 3) The load scheduling algorithm employing RL for minimizing the energy bills regarding a renewable resource is developed. Utility companies recognize the importance and necessity of demand response (DR) programs for reducing the increased production costs associated with rising energy demand. The advent of smart information and communication systems has made DR programs on the basis of cost a viable option to control load in smart microgrids. Small domestic consumers are rapidly using stochastic renewable energy resources such as photovoltaic (PV). The study examines an integrated layout for residential load scheduling or load commitment problems (LCP) with renewable energy resources no matter what kind of tariff is applied. Uncertainty-based decision-making problems are effectively solved using reinforcement learning (RL). The paper proposes an RL-enabled solution to the LCP in smart microgrids. An innovative aspect of the study is the development of an integrated layout containing an implementable solution that takes into account user satisfaction, stochastic renewable power, and tariffs. In simulation tests, the suggested layout is tested for its effectiveness and flexibility. An analysis of the algorithm's efficiency using a household user with schedule-able and non-schedulable devices, together with a PV resource, has been presented. [ABSTRACT FROM AUTHOR]

• Experiences from SWH systems mandatory installation in China were summarized. • The interaction of seven stakeholders in SWH building application was analyzed. • Three key factors for the successful mandatory installation of SWH were summarized. • Recommendations were given for using the mandatory installation policy effectively. • The government should regularly evaluate the effectiveness of policy implementation. The paper summarizes the implementation experiences and lessons learned from the solar water heating (SWH) system mandatory installation policy in China. In-depth interviews, questionnaire surveys and field investigation were conducted to understand the prevailing attitudes of the stakeholders associated with the application of SWH in buildings. Scenario analysis was used to analyze the effect of expanding the coverage of mandatory installation policies. The results show that due to the strong market externalities of SWH building applications, the government must provide inducements to stakeholders through mandatory policies or fiscal incentives to create an impetus for them to use SWH extensively. For China, it is necessary to strengthen and support the utilization of renewable energy policies and extend the mandatory installation policy of SWH systems to taller buildings to fulfill the national renewable energy application goals. The most reasonable technical route, full process control, and attention to system operation and maintenance are the three key factors for the successful implementation of a mandatory installation policy for SWH systems. The policy recommendations presented in this paper can not only be applied to China but also other developing countries as well. [ABSTRACT FROM AUTHOR]

• Optimal Window-to-Wall Ratios were recommended for various building orientation. • Integrated models with different glazing area and orientation combinations were proposed. • Daylight factor, air temperature and air velocity were computed for each test scenario. • Three optimal intervals of Window-to-Wall Ratio were determined respectively. • Intersection interval of the three subsets is the optimal interval of Window-to-Wall Ratio. Since the ratio of glazing and opaque areas on building facade has significant impact on the indoor visual and thermal comforts as well as energy consumption, the optimal Window-to-Wall Ratio is necessary to be explored for the rural residences with a large quantity in China. Due to the traditional dwellings has been representative of housing samples among rural residences, Sizhai traditional dwellings situated in Zhejiang Province were chosen as the study buildings in this paper. The building model is rotated to 20° increments clockwise to create 18 building orientation intervals. Furthermore, the Window-to-Wall Ratio of front facade for the building model was divided into 8 intervals at increments of 0.1, from [0.1–0.2] to [0.8–0.9]. Through indoor environment simulation, the daylight factor, air temperature and air velocity were computed for the test scenarios with different building orientation and Window-to-Wall Ratio combinations. Three optimal intervals of Window-to-Wall Ratios at a series of building orientations corresponding to the daylight factor, mean maximum indoor temperature and mean indoor air velocity are determined respectively, based on the criteria of national codes and thermal comfort ranges. The intersection interval of the three subsets is the optimal interval of Window-to-Wall Ratio for the study building. In addition, for verifying the accuracy of research results, two validation techniques (i.e., comparison of experimental measurement data, and comparison of computational results from other simulation tools) were adopted in this paper. [ABSTRACT FROM AUTHOR]

• The use of GB techniques based on 106 projects was examined for future upgrading. • Water-saving and site planning categories exhibited the highest achievement. • This study identifies four main barriers limiting GB quality upgrading. • This study presents recommendations in four aspects for GB quality upgrading. • Upgrading GB projects for urban heat mitigation and urban flooding management. Building sector is one of the primary culprits of environmental deterioration and energy consumption. Green building (GB) can be an effective solution to these challenges and has been prioritised by many nations, while the quality of most GBs was still low. Therefore, this paper aims to examine the application of GB techniques. In specific, an empirical study was conducted among 106 GBs in China. Results indicate that both water-saving and site planning categories received the highest achievements, followed by indoor environmental quality and energy-saving, and the material-saving and innovation categories were the most difficult to achieve. The items in site planning, energy-saving and indoor environmental quality clusters that depended more on design techniques could be realised evenly, while the water-saving and material-saving clusters that relied more on materials and equipment witnessed two extremes: one approaching to 100% and one close to zero. There could be an increase in technique achievement from low-quality GBs to high-quality GBs. Nevertheless, the achievements of many items were extremely in both one-star, and two- and three-star groups. Some even witnessed the reduction from the low-quality GBs to the high-quality GBs. A further investigation indicated that the unavailability of GB technique checklist, the impact of economic cost, low technological operability and the unavailability of GB products constrained the GB technique application. The combining impacts of them could further lower the GB technique application. To unlock these barriers, efforts should be made from the perspective of (1) revision and localisation of GB standard, (2) extensive technical support, (3) government regulations and support, and (4) the co-benefits: integration with other programmes. Overall, this paper is of value to improve GB technique application and facilitate the transitions towards higher quality GB agenda. [ABSTRACT FROM AUTHOR]

• This paper describes a community level approach to achieve zero energy objectives. • An agent-based model is developed to study renewable energy adoption by consumers. • Multiple renewable energy options are modeled simultaneously to study adoption. • The results highlight the importance of community solar to increase adoption. • Social interactions among consumers significantly affect their adoption decisions. As zero energy buildings take on an increasingly prominent role in overall efforts to reduce energy consumption, it is necessary to identify effective policies for their design and implementation. However, current zero energy building (ZEB) policies focus mainly on new buildings, primarily through on-site renewable energy generation, such as rooftop photovoltaic (PV) systems. Having a few high performing buildings will have limited impact if the community as a whole is not net zero. A more practical approach to achieve zero energy goals is to extend the zero energy boundaries beyond an individual building and have a group of buildings evaluated together as a community, such that the community in itself becomes a zero-energy community (ZEC). Successful ZEC implementation requires that community members actively participate in renewable energy and energy efficiency programs and collectively support the goal of zero energy. Hence, a consumer-oriented analysis is needed to support effective ZEC design decisions and promotion efforts. This paper describes a conceptual agent-based model for an urban neighborhood in Des Moines, Iowa, to predict household level renewable energy adoption behaviors in presence of multiple options. Specifically, the level of consumer participation before and after introducing a community solar option for the neighborhood is evaluated via experimentation with the model. Simulation results demonstrate that introducing a community solar program increases household level adoption as well as the proportion of community level electricity consumption met through renewable sources. The amount of increase in adoption, however, depends on the choice of design parameters, such as premium that households must pay to participate. The results also show that timeliness of achieving ZEC goals depends upon the frequency of social interactions in the neighborhood, indicating the importance of community events in the successful creation of a ZEC. [ABSTRACT FROM AUTHOR]

• A novel application mode of CSP with HEHP technology is proposed. • The flexible operation benefits of CSP with HEHP technology in the IES are analysed and quantified. • The carbon emission trajectory of the IES containing CSP with an HEHP device is depicted. • CSP with HEHP technology increases the utilization of solar energy. • A rational combination of the hydrogen and thermal energy storage capacities are necessary. The efficient integration of renewable energy with hydrogen storage is an important means for China to achieve carbon neutrality. Concentrated solar power (CSP) is an emerging technology for solar energy utilization that combines the advantages of power generation and energy storage. However, CSP has not been fully exploited because of the high generation cost and an incomplete market mechanism in China. The heat collected by CSP can be utilized for high-temperature electrolytic hydrogen production (HEHP), which is an efficient technology for hydrogen production and storage, and reducing carbon emission. Thus, a low-carbon operating mode for an integrated energy system (IES) consisting of wind, solar and hydrogen energy is proposed in this paper. First, an optimal operation model of electricity-heat-hydrogen coupling for an IES containing CSP and HEHP is established. Second, the effect of CSP with HEHP on the total operation performance of the system is evaluated from the aspects of the system economy, renewable energy utilization, and carbon emission. Finally, the model is validated by a case study of an island IES, and an optimal sizing for hydrogen energy storage and thermal energy storage of CSP is determined. The results show that CSP with HEHP can effectively improve the utilization rate of solar energy and reduce the carbon emissions of the system, offering an approach for carbon reduction planning and the operation of CSP in electric-hydrogen energy systems. [ABSTRACT FROM AUTHOR]

• Assessing solar power technical potential in China with high-resolution data. • Quantifying the gap between actual generation and technical potential at plant level. • Actual solar power generation is only 30% of the technical potential. • Technology, construction, and management factors cause the underperformance. Improving the power output of solar photovoltaic (PV) farms is critical to maximize the potential of PV power and reduce extensive land use in the context of large-scale deployment of renewable energy. In this paper we developed an integrated solar power potential assessment framework to quantify the gap between technical potential and actual generation of solar PV farms on national, provincial, and plant scales, and identify the key factors that cause the underperformance of PV farms. Specifically, to assess technical potential, hourly meteorological reanalysis data is adopted and the power generation-related parameters are calculated (i.e. optimal panel tilt, array spacing, packing factor etc.) with consideration of their spatial variability. For actual power generation, a detailed plant-level dataset is first established by this study which integrates technical, operational, and geospatial information from 145 solar farms across seven provinces in China. Our results show that the actual PV power generation per square meter is only 1/3 of the estimated technical potential. Technological factor is the primary factor, accounting for 48.43% of the underperformance, followed by engineering and management factors, accounting for 38.55% and 13.02%, respectively. The novelty of our study is revealing the underperformance level of solar farms in reality, identifying the causing factors, and highlighting the importance of integrating land-use efficiency indicators into solar power planning and development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Conducting optimization in the MED desalination plants. • Transforming the process into a solar-powered one. • Making determination of cost-effectiveness by utilizing sensitivity analysis. • Parametric optimization of the multiple effect distillation process utilizing fossil fuels. • Identifying the most suitable solar collector and HTF from economic standpoint. The utilization of multi-effect distillation (MED) in thermal desalination processes is more widespread owing to lower energy consumption. The focus of this paper is to optimize the performance of MED through process optimization. It aims to identify the optimal operating conditions that result in maximum water and power production. Additionally, it investigates the potential of using solar renewable energy as a substitute for the current fossil energy source. Subsequently, a switch to solar energy was made with a focus on an economically viable approach. The research explored the best-suited collector and fluid for heat transfer among the 8 types of molten salt for use in the collector. Subsequently, an economic and sensitivity analysis was conducted using this procedure. The outcomes indicated that by enhancing the stated procedure, it was found that 27.93 Megawatt (MW) of heat would be required when 6938 ton/h of natural gas are burned. Additionally, the 4-effect MED process produced 6.123 MW of electricity and 116.5 cubic meters per hour (m3/h) of freshwater. The gain output ratio (GOR) of the process saw an uptick from 2.75 to 3.328, whereas MED efficiency showed progress from 13.76 to 49.218 %. The parabolic trough collector (PTC) collector outperforms the linear Fresnel collector (LFC) and solar dish (SD) collector in terms of efficiency among other results. To store heat for the rest of the day and night and supply thermal energy for the entire process, 155,542 square meters (m2) of this collector are necessary. Additionally, in regards to the thermal fluid of the PTC collector, coastal chemical registered heat transfer salt (HITEC salt), a commercial mixture of solar salt, has exhibited superior performance over other molten salts (for a total expenditure of 50 million dollars over two decades). In addition, the economic analysis has indicated a return rate of 32.46 % for the investment and a capital recovery period of 3.08 years for the process. The implementation of the mentioned process in renewable mode results in the avoidance of 18.5 tons per hour (ton/h) of carbon dioxide (CO2) emissions. [ABSTRACT FROM AUTHOR]

• The paper discusses challenges in integrating solar power in Norway, limited to 36% of feasible capacity. • Seasonal variations in solar energy production emphasize the need for year-round energy management. • A critical threshold of 36% feasible solar power integration highlights the importance of balancing production and consumption. • Effective energy management is crucial for aligning solar production with consumption patterns. This research study delves into the solar energy potential and capacity in Norway, aiming to assess the viability of solar power integration in the country's urban landscape. Through a comprehensive analysis, historical data, and PVsyst simulations, the study reveals that solar photovoltaic (PV) systems offer significant promise in contributing to Norway's renewable energy goals. The study uncovers a seasonal variation in solar energy production, with peak generation during the summer months due to extended daylight hours and more intense sunlight. However, winter months experience lower solar energy production due to limited daylight hours and weaker solar radiation. To fully exploit solar energy potential, effective energy management strategies such as energy storage, smart grid technologies, and demand response mechanisms are crucial. Moreover, the research highlights the relationship between energy consumption and solar energy production, emphasizing the importance of efficient energy management and capacity planning. Bridging the gap between supply and demand requires optimized solar energy utilization aligned with consumption patterns. A key finding of this study is the identification of a pivotal threshold: up to 36% of the feasible solar power, equivalent to 31 GWp, can be integrated into the grid to match daily production and consumption. However, exceeding this threshold leads to challenges in peak production times, necessitating exports or additional strategies to accommodate the excess energy. In conclusion, this study underscores the promising prospects of solar energy integration in Norway. By leveraging solar power's potential, implementing effective energy management measures, and addressing challenges, Norway can work towards a more sustainable and resilient energy future, reducing reliance on fossil fuels and making significant strides in combating climate change. [ABSTRACT FROM AUTHOR]

• The energy and cost benefits of dynamic PV-integrated shading devices are assessed. • Both energy efficiency and on-site energy generation benefits are considered. • Optimal design and operation of PV-integrated shading systems are determined. • PV-integrated overhangs can allow office spaces to achieve net zero energy operation. • For Australian office buildings, PV-integrated shading systems are highly cost-effective. The paper summarizes a comprehensive analysis to determine the energy and cost benefits of static and dynamic photovoltaic (PV)-integrated shading devices when applied to windows of office spaces located in different climate zones across Australia. The evaluated dynamic shading systems consist of rotating overhangs placed above the windows and operated to minimize the annual energy demands of office spaces. For the first time, the study determines through optimization-based controls the best angle settings for the rotating overhangs on hourly, daily, or monthly basis to minimize the energy consumption of office spaces in Australia. The analysis results indicate that both optimally designed static and optimally operated dynamic PV-integrated overhangs have substantial potential to reduce the annual energy needs of office spaces for all Australian climates with annual energy savings ranging from 45% to over 100% depending on the building orientation, window size, glazing type, and overhang depth. This high energy benefits are attributed to the multi-function capability of the PV-integrated shading systems to minimize cooling and space thermal loads while maximizing on-site electricity generation. Unlike the case of static shading devices, it is found that dynamic PV-integrated overhangs allow office spaces to reach net-zero energy operation for certain climate zones in Australia. [ABSTRACT FROM AUTHOR]

• Study feasibility of a Grid-Connected PV power supply system in data center's cooling system. • With storage batteries, utilization of PV power increased by up to 27.64 % in the discussed days. • Optimized number of battery groups and PV panels were given to reduce carbon emission. • Find threshold of battery's unit price for the adoption of it to maximize economy performance. • Provide guidance for design and operation of such system with q IT between 500 and 1100 W/m2. The cooling system of a data center accounts for a significant part of its energy consumption, and the adoption of solar energy can reduce its power demand from the grid. This paper investigated the optimal configuration of a grid-connected PV power supply system to a data center's centralized water-cooling system. Firstly, mathematical models for photovoltaic panels and storage batteries were established. Then, two operating strategies were proposed, respectively, for two systems with and without storage batteries, and the supply–demand matching performances were studied. With storage batteries, mismatch problem between electricity generated by photovoltaic panels and electricity consumed by the water-cooling system can be significantly improved. Utilization ratio of electricity generated by photovoltaic panels was increased by up to 27.64 % in the discussed typical days. Annual utilization of electricity generated by photovoltaic panels can also be significantly increased, especially when heat dissipation density is small. Lastly, the optimal configurations were discussed. To reduce carbon emission, number of battery groups were recommended for different heat dissipation density and number of photovoltaic panels. Full life-cycle carbon reduction ranged from 1.77 to 3.71 tCO 2 /m2 and carbon emissions reduced from 14.23 to 62.14 % as compared with the traditional system. As for the economic performance, the recommended number of photovoltaic panels are 798, 1330 and 1589 for heat dissipation density being 500, 800 and 1100 W/m2, respectively. While the recommended number of batteries was 0 if unit price of batteries is higher than 11.1 ten thousand yuan/group. [ABSTRACT FROM AUTHOR]

• Bibliometrics overview of ZEB publications. • Draw of the collaboration networks from ZEB research publications. • Brought out thematic trend of the development ZEB over the time. • Discussions of the main challenges and solutions for ZEB studies. Zero Energy Building (ZEB) is gaining more attention as a solution to significantly mitigate the environment concerns. However, a bibliometric analysis of the topic, a very useful method to analyze the database of published publications and reviews, is lacking. Especially, to provide when and how this concept has been brought out, insights into the state-of-art technology, the findings of the collaboration networks and the challenges of ZEB. To address this gap, in this paper, ZEB studies have been reviewed using multiple perspectives and analytical tools, such as VOSviewer and Biblioshiny to analyze the collaboration networks and the thematic trends of ZEB publications. The original data was retrieved in Scopus, a total of 1051 documents including research articles and reviews published from 1976 to 2020. The analysis of the number of publications over the years shows that the development of Zero energy building research has gone through three stages: a slow development period from 1076 to 1999, followed by a development from 2000 to 2010 and finally a rapid development from 2011 to 2020. The study also reveals different rankings, including the most widely collaborated scholars, the most cited scholars, the most published countries, etc. Therein, the United State, United Kingdom and China have the most research on ZEB. Based on the analysis of co-occurrence network and evolution of thematic keywords, it is found that energy efficiency and life cycle assessment (LCA) are the main challenges for the achievement of ZEB target. Finally, these challenges have been discussed and solutions provided. [ABSTRACT FROM AUTHOR]

Engineering the thermal and optical properties of windows is a key to reducing building energy demand, which constitutes a major portion of worldwide electricity consumption. Depositing thin-film photovoltaic coating that simultaneously generates power and allows visible light can be a viable route towards nearly zero energy building (nZEB). Such windows with Semi-Transparent Photovoltaics (STPV) have unique physical properties that require comprehensive modeling to properly estimate the performance. In this paper, we adopt an integrated approach to unify device simulation – yielding electrical, optical and thermal parameters – with building energy simulation using E n e r g y P l u s and a Matlab based power generation platform. The power generation code contains models for shadow from nearby buildings, geography and climate dependent solar insolation and ambient temperature variation to predict efficiency accurately. We also develop a thermal model to find the U-value of a glass coated with STPV. We find that such coating dramatically improves insulation by reflecting infra-red radiation. Our results show that – contrary to roof-top solar panels – STPV modules, when put on all four vertical surfaces, produces significant output in the presence of both shadow and cloud. The net energy footprint of a building with a perovskite based STPV is found to be in the range of 45–80 KWh/m 2 -yr, well below the source energy use intensity goals set by different countries. • Integrated approach combining device simulation, solar insolation and building simulation to estimate energy footprint. • Model for U-value for semi-transparent photovoltaic coating on glass. • Vertical surfaces receive substantial insolation even under cloud due to strong diffused irradiance. • 25%–60% saving in energy and 40%–70% saving in lighting load in the presence of both shadow and average cloud. [ABSTRACT FROM AUTHOR]

• Experimental demonstration of shade-tolerant MPPT with efficiency optimization. • Voltage doubler-quadrupler rectifier enables optimal shade-tolerant MPPT. • This rectifier optimizes efficiency of solar energy harvesting by microconverters. • Demonstration of up to 8% efficiency improvement at PV module voltages down to 8 V. This paper presents a performance enhancement method for the high-gain isolated dc-dc converters intended for module level photovoltaic applications. DC voltage gain of a microconverter should change in a wide range, which requires use of undesirably high or low values of the switch duty cycle that result in high losses in the front-end stage. A reconfigurable rectifier at the output stage of the photovoltaic microconverter enables dc gain control and, consequently, limits variation of the duty cycle to more favourable range. This work proposes use of a reconfigurable rectifier capable of reconfiguring its topology from a voltage doubler to a voltage quadrupler. The paper explains the derivation, operation and the control principle of a reconfigurable rectifier. A single-switch quasi-Z-source front-end stage was used as an application example of the wide input voltage range photovoltaic microconverter in the experimental study. It is demonstrated that by the application of the proposed approach the lower boundary of the input voltage could be shifted from 20 V down to 8 V, which has enabled for the microconverter a unique possibility of shade-tolerant operation with the implementation of a global MPPT. [ABSTRACT FROM AUTHOR]

Highlights • Currently, the air channel of SAH were mostly used serpentine flux paths composed of spoilers. • The sharp turn of 180° could create eddy current in the flow path and form "dead zone" during the flow process. • It reduces the ability of heat convection between the absorber plate and air in solar air heaters. • Therefore, the spiral solar air heaters (SAAH) is proposed in this paper, in which there is only a 90° turn of the channel. • Based on this design, pressure and power consumption of fans can be reduced and heat convection can be enhanced in SSAH. Abstract A new type of solar air heaters was proposed by using the spiral shape of spoilers instead of the serpentine shape. The function of the spiral solar air heaters (SSAH), including heat collection efficiency, temperature differences between inlet and outlet, irradiance, and air volume were experimentally studied in this paper. According to the testing, the difference of temperature between inlet and outlet is related linearly to irradiation, and heat collection efficiency is related the quadratic function relationship to irradiation with a constant flux. Finally, the heat loss coefficient of the SSAH is determined by the normalized temperature to be 5.69 W m−2 K−1. Compared with the conventional and serpentine SAH, this kind of solar air heaters had a higher heat collection efficiency. [ABSTRACT FROM AUTHOR]

Highlights • An innovative solar cooker using Fresnel lens for cooking outdoors is designed. • Optical, thermal and cooking performance of the cooker with 2 D tracking is reported. • Light receiving rate of the cooker is over 0.9 in 2.2° tracking accuracy. • The average temperature without load reaches 361 °C under direct irradiance I = 712 W/m2. • The maximum energy efficiency of the system is 22.6%. Abstract Solar cookers use clean and accessible solar energy to heat food. They provide a new choice for outdoor cooking for users. However, currently available solar cookers now have some weaknesses such as being too big to carry, low heating temperature and overlong cooking time. To overcome these problems, this paper designs a novel portable solar cooker using a curved Fresnel lens as the concentrator. This novel solar cooker can focus sunlight onto an evacuated tube collector to heat the food here. It has a high concentration ratio and allows tracking the sun in both zenith and azimuth angles manually, therefore it is possible to get higher cooking temperature and shorten the cooking time. In this paper, the structure and working principle of the device are introduced. The optical performance of the system is simulated by a software and the heat transfer model of the system is established and presented. Experimental studies have been carried out, and the variation of maximum temperature of the system during the day under no-load condition has been obtained. Moreover, to test the system performance, the theoretical maximum temperatures of the system with no-load condition under different irradiances have been calculated. Results indicate that when direct irradiance is I = 712 W/m2 the obtained highest average temperature of the system without load can reach at about 361 °C. Besides, the performance of the solar cooker has been tested on four kinds of 0.5 kg representative foods, namely, sweet potato, pork (all lean), yam and radish. Results show that cooking time of pork is the shortest (only 34 min), and radish is the longest (64 min). All cooked food reaches the edible standard. [ABSTRACT FROM AUTHOR]

Parabolic trough collectors are widely used to generate thermal and/or electrical energy from direct solar irradiation. These collectors use parabolic mirrors to precisely focus sunlight onto so-called absorber tubes. The optimal design and geometric alignment of all necessary components is essential in order to achieve a high degree of efficiency and a high energy yield. However, this optical fine-tuning process can be quite challenging and is in many cases avoided by using absorber tubes with larger diameters, which in turn cause greater thermal losses and a higher material effort. This paper describes a simple, yet reliable and quantifiable way to measure the optical performance of a parabolic trough collector using a commercial multi-junction solar cell (CPV). The presented measurement system allows for convenient adjustment of the parabolic mirror and the effective optimization of the overall collector design. The theoretical background is discussed and the test setup is described in detail. Measurement results are presented, ranging from the determination of the actual optical concentration ratio, the optimal centering and height adjustment of the absorber tube to the measurement of the contribution of the individual mirror segments, revealing that the investigated industrial parabolic trough collector can be improved in terms of optical accuracy. Finally, an optical surveillance of the mirror using a line laser was performed to validate the results. • New way to measure the optical performance of a parabolic trough collector. • Multi-junction solar cell (CPV) are used as a light sensor. • Theoretical background and various measurement setups and results are presented. • Optical concentration ratio of 128 x was measured with a parabolic trough collector. [ABSTRACT FROM AUTHOR]

• Shape interpolations between four common front shape extrema of the Energy-saving Chinese Solar Greenhouse (ECSG) were studied. • Two kinds of optimal ECSG shapes were identified in this study. • PCA analysis were conducted to determine the optimal greenhouse construction parameters. • The proposed model framework allows the investigation of the effects of different shape variations of solar greenhouses for any arbitrary latitude. Determining the optimal shape for greenhouses that is suitable for cold northern regions is essential for non-seasonal fruit production. In the present study, a structural model was developed for energy-saving Chinese solar greenhouses (ECSG), which combines a greenhouse energy balance model with a detailed shape analysis. All possible greenhouse shape interpolations within four common front shape extrema were systematically analysed to determine an optimal ECSG shape with a maximal energy performance for use during winter. The analysis revealed a direct relationship between the interception of solar radiation in the greenhouse and the height of the ridge. Our results indicated that the flatter the curve of the front cover, the more radiation is intercepted by the ground and north wall of the greenhouse. As a result, compared to the commonly used greenhouse type, two types of optimal ECSG shapes were identified, each attaining an increase of 2°C in the minimum night temperature. The general model framework developed in this study allows the investigation of the effects of different variations in the many small detailed interpolation shapes of ECSGs for any arbitrary latitude which can be used directly to provide guidance for the construction of a new generation of energy-efficient solar greenhouses. Also, with the interpolation method proposed in this paper, large-scale shape statistical analysis now can be performed to help qualified decision-making during the process of greenhouse construction. [ABSTRACT FROM AUTHOR]

Many countries have adopted schemes to promote investments into renewable energy sources resulting, among others, in a high penetration of solar PV energy. The system integration of the increasing amount of variable electricity generation is therefore a highly important task. This paper focuses on a residential quarter with PV systems and explores how heat pumps and thermal and electrical storages can help to integrate the PV generation through self-consumption. However, self-consumption and PV integration are not only affected by technologies but also by pricing mechanisms. This paper therefore analyses the impact of different tariffs on the investment and operation decisions in a residential quarter and its interaction with the external grid. The considered tariffs include a standard fixed per-kilowatt-hour price, a dynamic pricing scheme and a capacity pricing scheme. To account for the interdependent uncertainties of energy supply, demand and electricity prices, we use a module-based framework including a Markov process and a two-stage stochastic mixed-integer program. Analysing a residential quarter in Southern Germany as a case study, we find that the integration of a PV system is economically advantageous for all considered tariffs. The self-consumption rate varies between 58 and 75%. The largest PV system is built when dynamic prices are applied. However, the peak load from the external grid increases by a factor of two under this tariff without any incentive for reduction. In contrast, capacity pricing results in a reduction of the peak load by up to 35%. [ABSTRACT FROM AUTHOR]

• The potential of rooftop solar photovoltaic (PV) in the context of the political, economic, social, technical and environmental (PESTLE) framework in Africa. • The prospect of dual use of building integrated photovoltaic (BIPV) in Africa. • Implementing appropriate energy policy and financing schemes in African cities. • Promoting a sustainable path for cost effective recycling and reuse of end-of-life PV in African cities. Power outage is a regular occurrence in most African cities due to increasing energy demand from population growth and commercial activities outstripping the grid capacity. This results in disruption to normal life putting stress on businesses and affecting development across the continent. This review paper investigates the potential of solar photovoltaic (PV) in African cities from three perspectives. Firstly, the potential of rooftop PV in the context of the political, economic, social, technical, legal and environmental aspects (PESTLE) is evaluated. Thereafter, sustainable waste management of solar PV panels is reviewed in anticipation for the upcoming wave of end-of life solar panels. Finally, the prospect of dual use building integrated photovoltaic (BIPV) as power generators and building components is investigated from case studies in Africa. Most studies highlight the strong potential of rooftop PV and BIPV due to the availability of high radiance in the continent. However, our review shows that affordability and lack of investment acts as a significant barrier to mass adoption of this technology which could be remedied by implementing appropriate energy policy and financing schemes. Alternative financing of PV products and service solutions such as leasing, pay monthly, pay-as-you-go, and subscriptions are emerging as popular options, and these approaches seem to act as drivers to market expansion. The review also emphasizes on the need for effective and sustainable waste management of solar PV products through implementing appropriately designed recycling schemes. This will need to be adopted now to ensure success and to prevent a waste management crisis in the future for the African continent. [ABSTRACT FROM AUTHOR]

• Proposal of a method to construct typical generic block models using local datasets. • Urban form influences strategy of solar technology in low-carbon scenario. • Solar cooling contributes to carbon reduction in subtropical areas. • Technology and morphology design can overcome the high-density constraints. The use of solar energy in an urban context is essential for low-carbon urban development and global climate change mitigation. In this paper, the application of multiple solar energy techniques, namely, photovoltaic (PV), photothermal (PT), and photothermal-driven cooling (PC) techniques, in tropical Macau was investigated. Based on the typological method, sixty generic block typologies were formulated. A parametric workflow was constructed to facilitate block modelling and simulate energy consumption and solar radiation. The optimal technique strategy for each typology was identified under a low-carbon scenario. The energy and environmental performance levels of the blocks were evaluated by calculating and comparing the solar potentials, load matching conditions, primary energy consumption levels, and carbon dioxide emissions. The results indicated that the PT technique should be preferred for blocks with high floor area ratio (FAR) values, while the PV technique should be prioritized for blocks with low FAR values under the low-carbon scenario. Moreover, the PC technique is necessary in subtropical areas to reduce carbon emissions. In addition, it is suggested that solar energy should be adopted in blocks with high site coverage ratio (SC) and low surface area-to-volume ratio (SAV) values, as well as blocks with low FAR values. Regarding blocks constrained by high-density urban development, appropriate decisions on technology and morphological design could help to overcome constraints and realize low-carbon community targets. This study could provide suggestions for urban planners and building designers in the application of the urban solar potential at the early stages of urban design or urban regeneration. [ABSTRACT FROM AUTHOR]

• The vertical temperature gradient were analyzed in offices. • An evaluation index for air-conditioning energy consumption was proposed. • The energy-efficiency advice on air-conditioning for offices is given. Installing curtains on windows prevents direct sunlight from entering the indoor working space. It also alters the direction of solar heat radiation and the spatial distribution characteristics of indoor heat gain. This paper analyzes the relationship between the change of heat gain in the working and non-working spaces of the room under the effect of curtains. Meanwhile, it proposes an index of The Useless Cooling Capacity Ratio (UCCR) of the room to analyze its useless cooling capacity. In the hot summer and cold winter region, this study employs experimental and simulation methods to investigate the influence of solar radiation intensity, curtain thermal characteristics, and other factors on the vertical temperature gradient and heat flux indoor during the summer. The results showed that installing curtains on the windows reduced the vertical temperature gradient of the working space and improved the thermal comfort. The vertical temperature gradients in the working and non-working zones under the experimental conditions were 0.24 °C/m and 0.66 °C/m for the room with curtains and 0.62 °C/m and 0.57 °C/m for the room without curtains, respectively. Curtains can regulate the spatial distribution of heat loads and UCCR in a room and make the room more energy efficient. The UCCR for rooms with and without curtains were 24 % and 18 %, respectively, with curtains adding 120 kJ of useless cooling capacity to the work area. [ABSTRACT FROM AUTHOR]

• Long-term operational monitoring of a Zero Emission Building (ZEB) in Beijing. • An existing building being retrofitted into a Zero Emission Building (ZEB). • Key Building Mounted Photovoltaic (BMPV) technologies are practically utilized and their effects are estimated. • The ZEB realized its own net-zero carbon emission and net energy production. • The ZEB could be a comprehensive experimental platform. Building mounted photovoltaic (BMPV) technology is a promised way to achieve carbon peak in building sector. Focused on the influence of heat from PV modules on building envelope's heat transfer and energy saving performance, and the power generation, the coupling mechanism of power generation and heat transfer of integrated photovoltaic technology on building façades has been investigated. The synergy of solar energy generation and building energy consumption have been studied in this paper. The installation method of building PV system was proposed, with which can achieve the maximum energy saving. Furthermore, the achievements have been applied in Zero Emission Building (ZEB) of China Academy of Building Research (CABR), demonstrating way to realize zero carbon building by integration of photovoltaic technology. Total of 236.1 kWp PV systems were installed in ZEB. Monitoring data shows that the annual power generation of ZEB could reach 212,382 kWh, and the power generation per building area is 73.79 kWh/m2, which could meet all the energy demands. In addition, it can supply extra power to surrounding buildings. The ZEB can provide experience and practice data supporting carbon peak in building sector. [ABSTRACT FROM AUTHOR]

• This paper presents an experiment on solar-powered air conditioning. • The study compares two scenarios: on-grid and off-grid, offering insights into their respective performances. • Evaluation metrics include solar fraction, energy consumption, and operational time fraction. • The solar-powered air conditioning system exhibits superior performance under higher demand and elevated temperatures. • The economic viability of the system is attractive, enhancing its appeal and potential for widespread adoption. Air conditioning is vital in maintaining indoor comfort and improving air quality, particularly in regions with high temperatures and humidity. However, the increasing demand for air conditioning has significant implications for energy consumption and the environment. Solar air conditioning can play a vital role in mitigating such impacts. This study presents an experimental setup that utilizes a solar photovoltaic system to power an air conditioning unit. The system is installed in a 36 m2-research lab at The University of Jordan, equipped with PV panels with a capacity of 2.67 kWp, a battery pack, a charge controller, an inverter charger, and an air conditioning unit. Two testing scenarios are conducted: an on-grid system connected to the electrical grid and an off-grid system operating independently. A clear sky day and a partially cloudy day were selected for each scenario in testing. The results were evaluated based on the solar fraction, energy consumption, and operational time fraction (OTF). The solar fraction was found to be higher during periods of higher demand and ambient temperature, and the average OTF was 70 % for all trials. In off-grid trials, the system had maintained operation solely on PV power during the studied load profile in the clear sky day. In contrast, limitations in charging power caused system shutdown in the partially cloudy trial. An economic analysis for the local payback period (PBP) was conducted based on the Hourly Analysis Program and PVsyst software simulation, which shows an attractive simple local PBP for on-grid and off-grid systems of 6.91 and 6.4 years, respectively. [ABSTRACT FROM AUTHOR]

• Vacuum glazing application in water flow window. • Experimental testing and numerical analysis. • Reduced thermal transmission through the window. • Improved thermal comfort sensation. • Increased water heat gain in cooling season. Thermal transmission through translucent façades is the primary source of energy consumption in buildings. A vacuum-glazing insulated water-flow window (VWFW) offers improved thermal insulation and enhanced solar water preheating performance. This paper explored the effectiveness of vacuum-glazing (VG) insulation in a water-flow window (WFW) and the energy-saving performance of a VWFW compared to a common double-glazing water flow window (DWFW). This comparison was conducted based on experimental and numerical analyses. The results revealed that with VG insulation, the annual heat gain of a room through the window was reduced by 50.3% compared to that measured with a DWFW. Moreover, the interior glazing surface temperature of the VWFW was more stable and closer to the room temperature set-point. Monthly average water heating efficiencies of 40% and 34% were obtained for the VWFW and DWFW, respectively. WFWs can be applied as energy producers in building. The advantages of VWFWs include improved electricity savings and reduced carbon emissions. These values were found to be 78.34 kWh/m2 and 69.8 kg CO2-eq/m2, respectively, for the VWFW, while those of the DWFW were 33.67 kWh/m2 and 30 kg CO2-eq/m2. The use of VWFW is thus meaningful for further reducing building-related energy consumption and reaching carbon neutrality. [ABSTRACT FROM AUTHOR]

• Investigated strategies that can deliver NZE performance for high-rise residential buildings in Australia. • It was challenging for tropical, subtropical and cold temperate climates to meet the NZE targets. • Design and optimisation of the envelope was effective in overcoming the challenges imposed by the more demanding climates. • The impacts of shading from neighbouring buildings presented the largest obstacle to energy production through the façade. • Study demonstrated a need to include density factors in the design consideration for NZE high-rise residential designs. Net-Zero Energy (NZE) buildings are gaining popularity globally as a solution to reduce operational energy usage and limit greenhouse gas emissions in the building industry. Their deployment is occurring rapidly as many countries are planning to make it mandatory for new developments. Despite the advancements in research in the various aspects of NZE, significant barriers do exist to its successful adoption and implementation, particularly with respect to high-rise residential buildings which are becoming a major portion of the housing supply in Australia. One of the challenges attributed to the achievement of NZEB performance is the uncertainty involved in selecting appropriate solution strategies that could deliver quality performances. This paper investigated strategies that can deliver NZE performance for high-rise residential buildings in Australia. A calibrated model of 26 storey high-rise apartment building with 396 units was prepared for detailed analysis of NZE strategies using building simulation. The impact of various interventions was evaluated across cities in five climate zones in Australia and a guideline for solution sets that can deliver the goal for each climate zone is presented. The findings show that NZE performance for high-rise residential buildings can be realised in Australia, albeit with some limitations. While the tropical, subtropical and cold temperate climates appear to be more challenging, proper design and optimisation of the envelope proved to be effective in overcoming the challenges imposed by the more demanding climates. The impacts of shading from neighbouring buildings and objects presented the largest impediment to energy production through the façade. [ABSTRACT FROM AUTHOR]

• A simplified model based on two indicators: sky view factor and sun coverage factor. • A model between the two indicators with simulated solar energy yield was established. • A validation study showed that the average relative error of the model was 6.6%. • The model reduced the computation time while preserving accuracy. The evaluation of rooftop solar energy potential in cities has a fundamental role in the development and utilization of solar energy. The irradiance-based approach of evaluation is a repetitive calculation process combined with the complex geometry of urban forms. This research paper proposes a framework that utilizes urban streetscapes to quickly estimate the urban solar energy potential using a simplified solar energy yield model based on two indicators: sky view factor (SVF) and sun coverage factor (SCF). First, 327 Google Street View images were converted into fisheye images, which were semantically segmented based on the deep-learning Full Convolutional Network (FCN). Then, the SVF and SCF were calculated based on the method of pixel statistics. Finally, a model with the simulated solar energy yield was established. Furthermore, a validation study was conducted using rooftop solar production data, which showed that the maximum estimation error of the proposed model was less than 8% and the average relative error was 6.6%. Generally, the proposed model reduced the required computation time while preserving a satisfactory degree of accuracy. [ABSTRACT FROM AUTHOR]

• A comprehensive review of the recent nano-based PV cooling systems is conducted. • Separate nano-enhanced PCMs, separate nanofluid-based, and hybrid PV cooling units are discussed. • Governing equations of materials' properties and PV performance are derived. • Detailed systems' description and major results are illustrated. • Research trend is analyzed via VOSviewer software based on Scopus database, and Future prospects are suggested. The environmental pollution and growing energy demand necessitate the development of power generation using renewable energy systems, especially solar photovoltaic (PV) panels. Despite being an eco-friendly and durable power generation technology, PVs demerit for low conversion efficiency (15–20%). In other meaning, a very low amount of the incident irradiance is converted into electricity, whereas the major is absorbed as heat, uplifting the PVs' surface temperature and declining their efficiency and reliability. Therefore, it is crucial to find a proper cooling technique for upgrading PVs' performance. Recently, along with the nanotechnology development, nano-based PV cooling units have been proposed and investigated as the inclusion of nanoparticles enhances the thermal properties of base materials. Herein, in this paper, the conducted efforts to improve the PVs' performance using nano-based cooing systems were reviewed and discussed. The surveyed PVs' cooling methodologies were classified into separate and hybrid systems: nano-enhanced PCMs, nanofluid-based, and hybrid nano-based cooling units. All relevant equations of materials' properties and PV performance were presented. In addition, the research trend of this field was analyzed by conducting a comprehensive bibliometric analysis using VOSviewer software and based on the Scopus database in the period (2006–2020). Besides, comprehensive discussions of proposed and designed systems were conducted, and major findings were summarized. Based on the literature, using hybrid nano-based cooling systems, the surface temperature reduction can reach 16 °C with enhancement in electrical efficiency up to 50% compared to conventional uncooled PV panels. Furthermore, some future work suggestions were given. [ABSTRACT FROM AUTHOR]