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Highlights: [•] The addition of paper waste increases the thermal performance of bricks. [•] Paper waste additions into brick increase the porosity. [•] Predictive models for simulation and optimization of heat transfer process have been developed. [•] Material conductivity, surface emissivities and mean brick temperature have been considered as input variables. [•] The design of hollows in brick models helps further improve the thermal performance. [Copyright &y& Elsevier]

• Propose a new scale suitable for the photovoltaic construction of urban buildings. • Selection of building complex classification indicators suitable for photovoltaic construction. • The algorithm of K-means + random forest is proposed to complete the classification of building complexes. The large-scale development of urban building photovoltaics (PV) has become an important avenue for cities to achieve building energy conservation, emission reduction, and carbon neutrality. Assessing the solar energy potential of urban buildings plays a crucial role in the installation and overall planning of urban building PV systems. However, due to the vast number and diverse types of urban buildings, individual building calculations can be both labor-intensive and inefficient. Therefore, batch processing of buildings after classification is a feasible approach. Previous assessments of solar energy potential in building clusters mainly focused on typical clusters or standard geometric areas, but all urban building types were covered. Based on this, this paper proposes a method for defining Building Complexes with a Single Land Use Nature (BCSLUN) by combining geographical distribution and urban land use characteristics. Furthermore, population density, building density, compactness, and land use characteristics are selected as features, and a method that combines K-means clustering and random forest classification is proposed to complete the classification of building complexes. Taking the central urban area of Xi'an, China as an example, 5,804 building complexes are classified into four building types. The cross-validation classification accuracy is 0.99, and the Kappa coefficient is 0.94. Based on Rhino modeling, the global solar radiation on the surface of each building complex was calculated. The annual surface global radiation of the four building types is 11,442.73 MWh, 2,734.71 MWh, 13,923.81 MWh, and 67,215 MWh. The violin-box plot shows a significant classification effect, which proves the rationality of the proposed classification method. Finally, a potential map based on solar radiation from urban building surfaces is generated. Building complex classification can quickly and accurately estimate the solar energy potential of urban buildings, providing decision-making support for the large-scale construction of urban building PV. Moreover, this method can be easily applied to other cities. [ABSTRACT FROM AUTHOR]

Analysis of solar radiation on buildings at the urban or individual scale has an important share in the formation of a sustainable environment. The accuracy of solar radiation analysis in buildings depends on the holistic analysis of the buildings and the efficiency of the model. Traditional solar radiation analysis approaches use some technologies such as LIDAR, ALS, aerial photographs, satellite images, and MLS. These technologies are expensive and not suitable for non-existing structures. In this paper, a novel approach is presented to evaluate the potential direct and diffuse solar radiation aggregated on 3D structures which can be either in planning stage or completed at the urban or individual scale. During the study, Angstrom–Prescot model is validated for the target region, and it is used for estimating the global solar radiation potential at specific points. Dynamical changes of shadow areas on building surfaces affect solar energy estimations, different algorithms are required for precise radiation analyzes on 3D buildings. In the proposed approach, finite element method, back-face detection and ray-tracing algorithms are utilized to obtain more precise results. Thus, real-time shadow analysis and analysis of the desired sensitivity and time scale can be obtained using the proposed approach. In the last phase of the study, a nearby site with various building layout scenarios is designated as test bed. Each scenario is analyzed separately using the proposed approach and the results are presented in the paper. The proposed work-model creates an ideal tool for urban planners, architects, civil engineers and energy investors. [ABSTRACT FROM AUTHOR]

This paper presents a method to evaluate the thermal impact of complex fenestration systems on the energy balance of a building zone based on directional solar heat gain coefficients (DSHGC) and bi-directional scattering distribution functions (BSDF). The proposed methodology is presented as an alternative to layer-by-layer heat transfer models. An example of a layer-by-layer heat transfer model is the ISO15099 as implemented in the EnergyPlus building simulation program. The ISO15099 model relies on a number of assumptions that are not justified in the case of three-dimensional structures, air-permeable layers and deviations from ideal geometries, which are common features in commercial daylighting and solar-control systems. In this paper, the proposed methodology is implemented in the Fener simulation engine and compared with EnergyPlus for systems for which the assumptions of the ISO15099 model are valid. Then, the Fener program is used to simulate the thermal behaviour of a zone with a fenestration system that contains sawtooth-shaped retro-reflecting interior blinds, which cannot be directly modelled with the ISO15099 model. The impact of different control strategies on the thermal performance of the zone is demonstrated for this case study. [ABSTRACT FROM AUTHOR]

• The design and performance comparison of a novel use of the concentrator to achieve the multifunction of the electricity generation and daylighting;. • The prototype of the concentrators are manufactured and the outdoor overall concentrating photovoltaic/daylighting experiment system was built;. • Optical performance of the concentrator was analyzed through the ray-tracing simulation and indoor experiment under the solar simulator;. • The actual transmittance of the system was investigated through the outdoor experiment under different sky conditions. This paper aims to validate an efficient way to use the low-concentration ratio concentrator for the building integrated concentrating photovoltaic/daylighting system, which is able to collect maximum solar energy for the renewable electricity generation and provide the function of daylighting. A 2-D static concentrator has been designed by leaving the lower portion of the outer parabolas near the base area uncoated to form the "daylighting window", which is named as CPVD (indicating that the concentrator is for the concentrating photovoltaic/daylighting system), while the concentrator with the same structure but can only achieve the onefold function of the electricity generation is named as CPV. In order to address the interaction effects between the concentrating PV performance and daylighting performance, the overall detail comparison is made for the CPVD module and CPV module through the ray-tracing simulation and experimental characterization. It's found that CPVD and CPV have similar optical performance (indicated by concentrating PV performance, optical efficiency, opto-electric gain and flux distribution on the receiver etc.) at various incidence angles, which validates that setting the "daylighting window" have no native effects on the optical performance of the concentrator. At last, in order to quantify the beneficial harvest for the daylighting, the conducive lighting transmittance through the "daylighting window" under two different sky conditions: clear and overcast sky conditions are investigated through the outdoor experiments. The outdoor concentrating photovoltaic/daylighting experiment test rig is built and the transmittance of the CPVD is measured under two different sky conditions. Under the clear sky condition, the daily average transmittance of the CPVD is measured to be 8.73% which is pretty much consistent with the ray-tracing simulation results. Under the overcast sky condition, the transmittance value is lower, the daily average value of which is 7.11%. [ABSTRACT FROM AUTHOR]

• Thermal, luminous and energy efficiency of single-glass with solar films is assessed. • Experimental data was used to calibrate a simulation model in EnergyPlus program. • Films with internal and external application on the side of the glass were analyzed. • Cooling, heating and lighting energy savings assessed for several solar orientations. • A decision-making framework based on performance criteria is provided. This paper examines the thermal and luminous performance of single-glazed windows with and without solar control films (SCFs) and a venetian blind in actual working conditions. SCF is a passive solution to modify the solar-optical properties of glazing systems, in order to reduce the solar gains and the energy use and to increase the indoor comfort conditions. An experimental campaign was carried out simultaneously in both cooling and heating seasons in two similar office rooms, one with a SCF applied on the internal surface of the glass and the other without any SCF. The experimental data was used to calibrate a model in EnergyPlus and to assess the energy performance of several SCFs with different thermal and optical characteristics for different orientations of the façade. A decision-making framework was applied to identify the potential use of SFCs as retrofitting solutions for single-glazed windows based on energy performance criteria. The results show that SCFs have a real impact in reducing the cooling energy use for South, East and West solar orientations (SCFs with low solar transmittance coefficients show reductions of the cooling energy use up to 86%) due to the reduction of solar gains, while there is an increase in the heating and lighting energy use. [ABSTRACT FROM AUTHOR]

• Development of a new model was developed to estimate the technical potential for net zero energy buildings. • It considers different locations, climates and building types and vintages. • It combines methods for bottom-up energy modeling and geospatial analysis. • Results show a significant energy savings in all regions and building types. With the Paris Agreement coming into force, global efforts will need to maximize opportunities through energy efficiency and renewable energy generation. Zero energy/carbon initiatives are mushrooming worldwide, but it has not been fully understood which building types in which climates and under which conditions can potentially be built to net zero energy standards. In order to inform these efforts, a new model was developed to estimate the technical potential for building—integrated solar energy (BISE, the name of the model) generation in a high resolution regional, climate and building typology breakdown., The BISE model also evaluates the opportunities for potential net zero energy buildings based on the BISE findigns, combining these with the findings of two global low-energy building models. The BISE model has a very high resolution in terms of geographic regions, climate types, building types and vintages. Moreover, the model combines methods for bottom-up energy modeling and geospatial analysis. The thermal building energy demand estimation is based on the 3CSEP-HEB model and the plug load scenarios are based on the BUENAS model. Results are wide, due to intrinsic limitationso of the model detailed in the paper, but it is shown that there is a substantial potential for building-integrated solar energy generation in all world regions, and that the Deep Efficiency Scenario allows significantly more building types to meet net zero energy levels by 2050 in contrast to a scenario when only moderate energy efficiency improvements are implemented. [ABSTRACT FROM AUTHOR]

• A practical PV/T (Photovoltaic/Thermal) solar panel was developed. • The panel can supply 40–60 °C water by controlling the flow rate. • The panel converts 73.5 % of solar energy at about 40 °C hot-water supply. • The panel surface temperature was about 50 °C even at about 60 °C hot water supply. • The panel's efficiency is compared to other PV/T panels with heat pipes/thermosyphons. The practical efficiencies of existing commercial m-Si and CIS PV modules measured in reality by our group were less than 15 % because of the higher temperatures of the PV modules, and the rest of more than about 85 % of solar energy would be the exhaust heat to the environment. It was already reported in 2020 that the principle of an environmentally-friendly PV/T (Photovoltaic/Thermal) solar panel using an m-Si PV module to utilize 71.3 % solar energy for electricity and 40 °C hot water, as well as suppress heat radiation from the panel. The panel was designed to confirm the principle, i.e., it was an experimental PV/T solar panel. In this paper, a new practical environmentally-friendly PV/T solar panel is proposed for aiming the application to BIPVT (Building-integrated Photovoltaic/Thermal) systems. The new panel uses a CIS PV module, and all the functions, including a heat exchanger using flat aluminum tubes, are placed in the panel box, which is almost the same size as a simple CIS PV panel. The proposed PV/T solar panel converts 73.5 % of solar energy with 13.0 % power generation efficiency and 60.5 % heat collection efficiency at a 40 °C hot water supply in Yokohama, Japan. The efficiency is higher than the previous experimental panel. The proposed panel also can suppress heat radiation at about 50 °C even in the case of 60 °C hot water supply. The proposed PV/T solar panel can supply all residential heat demands, such as domestic hot water (DHW) and space heating or cooling, using solar heat with a lower environmental thermal load. [ABSTRACT FROM AUTHOR]

Trigeneration systems based on renewable energies are useful solutions to provide heat, cooling and electricity in buildings and industries. According to the International Energy Agency, more than 30% of the world population has a profile demand requiring heating and cooling and this percentage is above 70% in many developed countries. This paper experimentally evaluates the energy performance of a trigeneration system based on a solar PVT-assisted heat pump installed in an industrial building. The heat pump is a vapor compression air-to-water type, with a nominal capacity of 16 and 10.5 kW in heating and cooling respectively. The PVT solar field consists of unglazed PVT collectors with a total area of 13.6 m2. Results indicate that this type of system is effective to provide heat, cooling and electricity, using mainly solar energy. The PVT solar thermal fraction is significant to provide domestic hot water, but it is less representative in heating production. On the other hand, solar electrical production gets high representative contributions to feed the heat pump compressor. Different performance indicators were calculated to evaluate the system performance. Besides, a comparison with a reference system, that uses a PV instead of a PVT technology, was also evaluated. [ABSTRACT FROM AUTHOR]

A novel solar cooling system, i.e., the solar absorption-subcooled compression hybrid cooling system (SASCHCS), is a better solution for large-scale buildings with many floors, but the thermodynamic characteristics of the system are not adequately realized. The thermodynamic model of the hybrid system is absent, and the design of the nominal cooling capacity of the absorption subsystem and the volume of the storage tank are not known. Consequently, this paper primarily examined the thermodynamics of SASCHCS. A thermodynamic model of the hybrid system was developed, and the working process and performance of the hybrid system for different nominal cooling capacities of the absorption subsystem and the volumes of storage tanks were analysed in detail. The influence of selected parameters on the performance was discussed. It was found that the performance of the system first increases and subsequently decreases gradually with improvement in the nominal cooling capacity of the absorption subsystem. The appropriate ratio of the nominal cooling capacity of the absorption subsystem to the area of the collector should be 0.148 kW/m 2 to 0.222 kW/m 2 . Additionally, the performance of the hybrid system increases first but subsequently decreases gradually with the decrease in volume of the storage tank. An appropriate decrease in the volume of the storage tank is recommended. This paper contributes to a deeper understanding of SASCHCS. [ABSTRACT FROM AUTHOR]

This paper aims to provide the current state of the art of solar sorption systems. Through comprehensive literature review of solar sorption systems, it was concluded that these technologies have several limitations and drawbacks. The low performance and the high cost are the main disadvantages of these technologies. However, solar cooling is considered attractive because solar radiation is in phase with the demand for cooling. Due to its attractiveness, the research is still going and focusing on solving the technical, economical, environmental problems, to achieve high performance and low cost of solar sorption systems. Improvements through investigating geometrical, system configurations, physical parameters, and operational modes on the performance of solar thermal sorption cooling systems are presented. A survey of the new configurations, novel additions, new techniques, new methodologies are also presented in this paper. Several cases studies in different climatic conditions are summarized. Economic feasibility for absorption and adsorption systems is discussed. It can be concluded that cost and energy effective solar sorption systems can be developed if suitable combinations of system components with operating conditions are selected. Finally, there is still the need for more research on solar sorption systems to make them both cost and energy competitive with the conventional cooling technologies. [ABSTRACT FROM AUTHOR]

Highlights • The urban energy budget can be reduced by retro-reflective (RR) directional cool materials. • The effect of ageing on RR tiles and paints performance is investigated. • The aged samples are characterized by spectrophotometric, directional and colorimetric analysis. • The cooling potential of new and aged RR materials is evaluated by an algorithm simulation. • The aged materials are performant: the urban cooling effect is preserved. Abstract Cool materials have been proposed for building applications given their potentialities in reducing building energy consumption, urban heat island effects, and global warming. Among cool materials, retro-reflective (RR) ones have been recently proposed for their ability to reflect backwards the incidental striking solar energy. This property is useful in densely urbanized areas, in urban canyons patterns, and in urban areas with buildings of different heights, because it avoids that the reflected energy contributes to the overheating of the neighbor buildings and structures. This study aims to predict the long-term performance of some RR tiles and paints intended for building applications. To this purpose, laboratory accelerated aging tests as described in the ASTM G154 were performed to determine the long-term material properties within a much shorter time than with outdoor weather aging. The samples show minimal changes in the reflectivity, directional reflection, and colorimetry. Finally, this paper shows that the RR character of the investigated materials and their urban cooling potential would be preserved. [ABSTRACT FROM AUTHOR]

Glazing energy resulting from solar radiation can be a primary source to vary the thermal field inside of a building. As the glass material is loaded by excessive solar radiation, the drastic increase in the glazing energy yields the greater solar heat transferring indoors and thereby raises the interior temperature. Reducing the glazing energy or temperature resulting from solar radiation can be a solution to decrease the solar effect on the interior thermal field and subsequently advantageous to reduce energy demands. Therefore, this paper provides non-linearly patterned glass technology which incorporates non-linear patterns throughout the exterior surface of glass to reduce the solar effect on the glass material. Based on theoretical and experimental analyses provided in this paper, incorporating non-linear patterns over the glass surface is able to yield the increase in the incident angle as well as the decrease in the solar energy acting on the glass. Therefore, the temperature reduction of the solar-loaded glass material can be acquired as the non-linear pattern is applied. However, the thermal performance of non-linearly patterned glass is dependent on the pattern design. Reducing the dimension of the pattern spacing and/or the radius of curvature of the non-linearly pattern member helps decrease the surface temperature of glass under solar radiation. [ABSTRACT FROM AUTHOR]

In this paper different combinations of solar energy and heat pump systems are compared and investigated through transient system simulations. The focus is on a small capacity heat pump (HP) with a heating capacity rate of 5.36 kW. The building (single family house 140 m 2 ) which are considered in this paper have a space heating demand of about 45 kW h/m 2 a. Based on a conventional air source HP and a parallel solar air source HP system, serial solutions for the combination of solar-HP systems are defined and analysed. For the consideration and evaluation of different systems through transient system simulations, a semi-physical HP-model is used, which offers the possibility to use two evaporators in series. With a combined parallel solar air source HP system the system performance (SPF System = 3.65) can be increased significantly compared to a conventional air source HP system (SPF System = 2.55). Unglazed selectively coated absorbers as source for the HP offer the advantage, that the collector can be used as an air heat exchanger. If solar radiation is available, higher temperatures at the evaporator of the HP can be achieved, compared to a conventional air source HP system. By the integration of unglazed solar absorbers as source for the HP the HP performance can be increased significantly (SPF HP increases from 3.25 up to 3.55 compared to a conventional air source HP). [ABSTRACT FROM AUTHOR]

• The solar louver was proposed to increase direct heat gaining for building. • Effects of blades' angle and characteristics on heat gain of solar louver was quantified. • Indoor temperature was higher and temperature field was more uniform with coupled solar louver. • By comparison with non-coupled solar louver, solar louver in maximum light transmittance mode decreased active heating supply capacity by 33.8%. Promoting solar energy for heating is of great significance for achieving the national goals of "double carbon" goals. Increasing the heat gain of window space could improve the solar energy utilization in congested urban environments. The paper proposed a new heating type for active solar house by solar louver. Thermal effects validation on solar louver were studied by field-test and simulation analysis. A solar louver model was established on the platform of MATLAB and TRNSYS. The simulated results showing that heat gain of solar louver reached the largest when blades' angle was about 10°. Solar louver with high reflectivity and low thermal emissivity could capture more heat gain. The in-situ experiments of active solar house coupling solar louver were carried out in Ordos. From 24th to 29th Jan. 2022, all-day comparative experiments of thermal effects in actual winter-weather were conducted. The experimental results indicating that solar louver in maximum light transmission mode was preferred in active solar house. Compared with the condition of solar louver in overlapped light transmittance mode, maximum light transmission mode could obtain 17.7% higher heat gain. Indoor temperature was more higher and temperature field was more uniform. Moreover, by comparison with the non-coupled solar louver, solar louver in maximum light transmittance mode decreased active heating supply capacity by 33.8%, which could reduce energy consumption of building. The main work here provided a theoretical basis for performance optimization of active solar house. [ABSTRACT FROM AUTHOR]

Latent heat storage technology plays an important role in the effective utilization of clean energy such as solar energy in building heating, but the low thermal conductivity of heat storage medium (phase change material) affects its large-scale application. As a new heat storage enhancement technology, rotation mechanism has a good application prospect. In this paper, the solidification performance of a triplex-tube latent heat thermal energy storage unit at constant speed (0.5 rpm) is studied numerically. Different optimization design methods (Taguchi method and response surface method) are used for deep analysis. The influences of fin position, number, and material on solidification properties are explored by the Taguchi method. Then, the unit structure (fin angle, fin length, and fin width) is optimized by the response surface method. Compared with the original structure, the average heat release rate of 8 copper fins with all outer tubes is increased by 108.93%, and the solidification time is reduced by 52.06%. The optimal structure can further shorten the solidification time by 29.14% and increase the average heat release rate by 40.5%. Additionally, the study of wall temperature shows that increasing temperature difference makes solidification speed faster and heat energy release faster. This effect effectively eliminates the adverse effects of slow solidification during the later stages of the process on the system. [ABSTRACT FROM AUTHOR]

The rise of clean energy such as solar energy provides a new idea to optimize the energy structure, and Photovoltaic thermal (PVT) heat pump system is one of the mainstream development at present. The wrong sensor data will have a great impact on the control and efficiency of the whole PVT heat pump system. In order to deal with this situation, Virtual in-situ calibration (VIC) based on Bayesian inference and Markov chain Monte Carlo (MCMC) is applied to PVT system. This paper presents a generic sensor fault diagnosis and calibration method for building energy systems using a PVT heat pump system as an example. Firstly, the data generated based on the mathematical model of PVT system is used to test the feasibility of VIC in this system. The results show that VIC can well reduce the systematic error and random error of the sensor. However, with the further study, it is found that in the actual system, it is impossible to establish a mathematical model which can reflect the relationship between the sensors with high accuracy. The VIC may fail or even have worse calibration results. Therefore, in order to solve the above problems, this study suggests using sparse autoencoder model instead of mathematical model. The model proved to be more accurate and to reflect the interconnectedness of the sensors, which helped the implementation of the VIC. The calibration method based on sparse autoencoder (SAE) can calibrate not only a single sensor in the PVT heat pump system, but also multiple sensors in a local area. After sparse autoencoder Virtual in-situ calibration (SAE-VIC) calibration, systematic and random errors of all sensors can be effectively reduced, and the accuracy of sensor calibration can reach more than 90 %. [ABSTRACT FROM AUTHOR]

• A retractable roof module with three slopes of the same length is implemented. • One slope of the roof with a PV panel follows the Sun. • The movement of the mechanism links reflects the movement of the roof. • The percentage of open space of the roof is 58% for the open space under the roof. • The roof with a PV panel delivers 16% more energy than the system without tracking. The use of building-integrated photovoltaic (PV) systems in the form of retractable roofs is an alternative option to existing installations without tracking systems (NT) or horizontal single-axis tracking systems (HSAT). This paper presents a retractable roofing module intended for the installation of PV panels. The main objective of this study is to identify modern solutions for these systems in terms of geometry and kinematics, which would allow the displacement of the roof slopes to follow the trajectory of the Sun during the day. This study is based on the parametric modelling and virtual prototyping of engineering objects. A moveable roof module is obtained, which, in addition to its function of shading and protection from rainfall, serves as a small movable solar power plant. The structure of the roof module is based on the construction of a mechanism comprising three revolute kinematic pairs and one prismatic kinematic pair, whose movement is strictly defined. The roof comprised three moving slopes of the same length. One of the slopes is designed for the installation of a PV panel; it moves according to the Sun to obtain maximum energy gains. For an adopted PV panel length of 1.0 a , the maximum roof covering space is 2.69 a. An analysis of the natural lighting for the panel following the Sun was performed, and the angle of inclination with respect to the horizontal plane was determined. The inclination of the panel ranges from +80º to –75º. In the case analysed, the HSAT delivers approximately 16% more energy than the NT system. The adaptation of retractable roofs with PV panels enables the optimal use of space around buildings, which are occupied by fixed or moveable installations with PV panels. [ABSTRACT FROM AUTHOR]

• Detailed optical, electrical and thermal coupled model of a novel LCPV/T-PCM module has established. • The performance of the module was evaluated through the first and second law of thermodynamics. • The calculation method of electrical performance is provided. • The module is optimized using response surface method methodology. This paper presents a simulation and optimization study of a nanoparticle-enhanced phase change material (PCM) assisted low-concentration photovoltaic/thermal (LCPV/T) module. An optical, electrical, and thermal model coupling finite element simulation is developed, with the thickness of the PCM, the mass fraction of nanoparticles in the heat transfer fluid and PCM, and the velocity of the heat transfer fluid as optimization parameters. To improve the efficiency of the optimization process, a response surface methodology is used to investigate the polynomial relationship between the parameters and module performance. The significance level and average error of each polynomial are found to be lower than 0.05 and 2.5%, respectively, indicating their statistical significance and accurate prediction of module performance. The fitting polynomials are used to optimize and analyze the module, and the results show maximum values of output thermal energy, output thermal exergy, output electrical energy/exergy, total output energy, and total output exergy of 573.11 W, 13.05 W, 110.40 W, 869.93 W, and 121.08 W, respectively. Comparison with the previously designed module revealed that the newly designed module demonstrated better electrical output performance, providing valuable guidance for the energy supply of zero-carbon buildings. [ABSTRACT FROM AUTHOR]

[Display omitted] • A state-of-the art review and discussion is presented for the ADBEIPCM. • Experiment studies were needed to show the long-term performance of the ADBEIPCM. • Organic PCMs and the macro-encapsulated methods were most used. • Intelligent control methods determine the performances of the ADBEIPCM. • Outlooks and recommendations for ADBEIPCM can facilitate its further development. the research of PCMs in the field of building energy efficiency has developed rapidly over the past decade. The static PCM-built envelopes cannot flexibly adjust their heat storage and release according to the changes in weather conditions and occupants' demands, resulting in low heat storage and release efficiency. The application of the adaptive dynamic building envelope integrated with PCM (ADBEIPCM) addresses this problem. This paper systematically reviewed the ADBEIPCMs for the first time, including their system configuration, working principles, control strategies, and system performance. The research methods and the PCM properties were also well summarized. The results show that the ADBEIPCM can store solar energy and release heat in time to reduce building load and improve comfort mainly by rotating, moving, flipping, and controlling the state of vents. This review divided the ADBEIPCMs into two categories: opaque envelopes and transparent envelopes. The experiment studies and simulation studies accounted for 15.28% and 84.62% of the research on opaque envelopes, and each accounted for 50% of the research on transparent envelopes. But onsite monitoring studies on transparent envelopes only accounted for 25%. In the design of ADBEIPCM, the main encapsulation method of PCM was macro-encapsulation, and the type of PCM was mainly organic. This review analyzed the shortcomings of existing studies and gave recommendations for engineers, architects, and scholars. Future research should focus on the development of novel PCMs with high strength and stability, the development of artificial intelligence-based short-term control strategies, and the development of ADBEIPCM based on bionic technology and powered by renewable energies. [ABSTRACT FROM AUTHOR]

In a privatized global marketplace, innovation is a key driver of sustainable development and national competitiveness. Here we report on an innovative new fully building-integrated thermal solar panel concept that is patented and currently being readied for commercialization. The paper outlines the French regulatory landscape governing the deployment of thermal solar panels in France, and thus the need for countries like France to develop new building-integrated solar power meeting “building-envelope” integration requirements for protected areas. We go on to introduce the new as-developed system, its physical modelling via a finite element analysis model constructed using an electric circuit analogy, and the results achieved on a detached home retrofitted with this system and trialled for a 12-month period. This paper leads out of COST – European Cooperation Science and Technology – framework action TU 1205 “Building Integration of Solar Thermal Systems”. [ABSTRACT FROM AUTHOR]

The paper describes procedures for the direct calorimetric measurement of the solar heat gain coefficient g in detail. g is also called SHGC, solar factor, g -value or total solar energy transmittance TSET. All these terms are used synonymously in this document although there are some differences in the details of the definitions of these properties (e.g. different reference wind conditions or reference solar spectra). The document aims to summarize more than 25 years of experience in g -value testing at Fraunhofer ISE, Freiburg, Germany, which includes many different transparent and translucent building materials ranging from transparent insulation materials to daylighting and solar control systems and active solar energy harvesting facade components like building-integrated PV systems (BIPV) or building-integrated solar thermal collectors (BIST). The document focuses on methods for the calorimetric measurement of g under steady-state laboratory conditions. Transient outdoor measurements are beyond the scope of this paper. It also describes the corresponding error analysis and methods to correct experimentally determined values g exp to reference conditions, if it is not possible to reproduce the reference boundary conditions exactly in the laboratory. [ABSTRACT FROM AUTHOR]

The successful deployment of distributed photovoltaic (PV) systems requires assessment of the potential of possible installations. This depends mainly on their exposure to solar radiation, which can vary substantially with location, especially in the urban landscape. This paper seeks to estimate the potential for electricity generation by building-integrated PV in typical residential building types in dense urban locations, accounting for shading by adjacent structures. 3D modeling of the shadows cast by buildings is carried out with a new R package, developed as part of the study. The algorithm can assess the shadows cast on vertical surfaces (typically walls) or horizontal ones (typically roofs), given a database of obstacles representing buildings in the form of extruded polygons, and the sun's position at any desired time interval. The methodology is demonstrated for a case-study neighborhood in Rishon LeZion, Israel, with diverse building typologies. The simulation shows which building typologies offer the greatest solar potential, calculated per dwelling, building plot area or for the entire neighborhood. The results show that although roofs are less affected by mutual shading than vertical facades, some facades (mainly south and east oriented) can still make a substantial contribution to the overall solar potential of urban buildings. [ABSTRACT FROM AUTHOR]

External fixed shading devices are generally used to adjust solar influx radiation and save energy in summer. However, they could block the beneficial solar radiation in winter. In this paper, a photovoltaic thermal-compound thermoelectric ventilator (PVT–TEV) system is proposed and investigated. The PVT–TEV system not only could prevent direct solar radiation from going into buildings in summer, but also could heat fresh air by the air-type PVT coupled with a thermoelectric ventilator system in winter. A PVT–TEV system was built in a room for testing the system. Results demonstrate that the performance of the PVT–TEV system is mainly affected by solar radiation when the system works in the sunny days of winter. The stronger the solar radiation is, the more the heat of PVT–TEV system gains and the higher the fresh air temperature is. The average electrical efficiency of PVT is 10%, the average thermal efficiency of PVT–TEV is 26.7% and the average COP h of PVT–TEV is 6.4. In the rainy day, the outdoor fresh air is heated when it flows through heat pipe exchangers of the thermoelectric ventilator. The higher the working voltage is, the more the heat TEV system gains and the lower the COP h of the TEV system is. The average COP h of PVT–TEV system is 1.73 when the operating voltage is 24 V. The PVT–TEV system provides an active and green method for building exterior shading device and supplying fresh air. [ABSTRACT FROM AUTHOR]

Actual national and international energy strategies generally encourage the use of renewable energy sources. Thermal energy storage (TES) offers various opportunities in the design of renewable energy systems. Thermochemical heat storage has gained popularity among researches because of higher energy density and lower heat loss compared to sensible and latent heat storage. On the other side solar energy has been recognized as one of the renewable energy sources with the most potential. This paper reviews thermochemical heat storage technologies and systems with emphasis on systems involving solar energy utilization in buildings. The studies are reviewed based on used storage materials, system configuration as well as models to predict and optimize system performance. [ABSTRACT FROM AUTHOR]

To conduct a more complete analysis of low-energy and net-zero energy buildings that considers both the operating and embodied energy/emissions, members of the building community look to life-cycle assessment (LCA) methods This paper examines differences in the relative impacts of cost-optimal energy efficiency measure combinations depicting residential buildings up to and beyond net-zero energy consumption on operating and embodied flows using data from the Building Industry Reporting and design for Sustainability (BIRDS) Low-Energy Residential Database. Results indicate that net-zero performance leads to a large increase in embodied flows (over 40%) that offsets some of the reductions in operational flows, but overall life-cycle flows are still reduced by over 60% relative to the state energy code. Overall, building designs beyond net-zero performance can partially offset embodied flows with negative operational flows by replacing traditional electricity generation with solar production, but would require an additional 8.34 kW (18.54 kW in total) of due south facing solar PV to reach net-zero total life-cycle flows. Such a system would meet over 239% of operational consumption of the most energy efficient design considered in this study and over 116% of a state code-compliant building design in its initial year of operation. [ABSTRACT FROM AUTHOR]

Building integrated Photovoltaics (BIPV) receives growing attentions from both architectural and energy saving perspectives. Large commercial building envelopes can be utilized due to their great potential of reducing building energy consumption and increasing PV integration impact, especially in climate zones with rich solar resources. Most current studies have been focused on predicting electricity generation of BIPV systems with existing envelope geometries, while few studies have discussed the generation of proper envelope shapes for PV integration due to the challenge of integrating architecture and engineering. This paper introduces a novel optimization method for BIPV shape development based on the shape grammar theory. The method reforms given building shapes/envelopes to produce a set of better BIPV shape alternatives, as well as determines the best placement and matching BIPV systems for the optimized envelopes. The main set of criteria considered during the generation and optimization process include PV power generation, PV economic impact and building energy consumption. Architectural preferences are included in generating preferred design alternatives, such as view consideration and shape direction. Commercial buildings in Egypt are used to demonstrate and validate the applications of the developed method and tool. The method and tool can help designers in achieving an optimal design of building envelope that is most suitable for maximizing PV integration. [ABSTRACT FROM AUTHOR]

A new photovoltaic loop heat pipe/solar assisted heat pump (PV-LHP/SAHP) water heating system was introduced in this paper. With the combination of solar energy, LHP and heat pump technology, the composite system could operate in the PV-LHP mode, the solar/air source heat pump (SASHP) mode and the air source heat pump (ASHP) mode. The mathematical model of the system was constructed to simulate operating performances in typical working conditions and in long-term run. The influence of main structure and operating parameters were also analyzed. To validate the accuracy of the built model, an outdoor test rig of the PV-LHP mode was established in Qinhuangdao City. Investigation results showed that the overall photothermal efficiency of the system is comparable to traditional photovoltaic/thermal (PV/T) water heating systems. The monthly average power consumption per liter hot water is 0.009 kW h/L, and the monthly average COP of heat pump modes is about 3.10. Besides, the annual solar heating ratio of the system is up to 57.8%. Compared with the traditional ASHP system, the life cycle cost of the PV-LHP/SAHP system could be reduced by 29.6%. [ABSTRACT FROM AUTHOR]

In the case of highly efficient buildings the solar and internal gains have a higher impact on the energy balance than on classical constructions, with lower insulation. In this context, a model was developed which considers the three dimensional heat transfers through the walls. It simulates the transient behavior of rooms with the use of a refined spatial and temporal discretization and considers the projection of solar radiation through a window onto interior walls, referred to as sun patch. Validation of the model was carried out using experimental data from a low energy cell operating in a natural climate. Shorter sampling steps seem necessary to consider accurately the fluctuations of the weather data and the short dynamics of the systems such as the regulated heaters. In this paper, simulations with weather data at different time steps (1 min, 10 min and 1 h) are going to be analyzed. The impact of the contribution regarding the adaptive and variable time step of the differential equation solver will also be shown. Finally, the impact of the different time steps on the accuracy of the low energy cell’s temperatures and heating loads will be discussed. [ABSTRACT FROM AUTHOR]

The popular operation mode of following thermal load often causes power surplus and efficiency decrease in CCHP (combined cooling, heating and power) systems at part load. CAES (compressed air energy storage) is thus one of the appropriate technologies to improve CCHP part-load efficiency through peak load shifting. However，the output power of CAES is possibly not high due to low temperature of the compressed air entering air turbine. In view of these problems, this paper proposed a gas turbine based CCHP combined with solar thermal energy and compressed air energy storage (S-CAES). The off-design models of gas turbine based CCHP and S-CAES were built. The merits and flaws of two different control strategies of S-CAES were analyzed. The characteristics of the proposed system indicate that the energy efficiency and exergy efficiency are both higher than those of the CCHP system without S-CAES. The performances of S-CAES are mainly influenced by the designed parameters, load distribution of demand side and the capacity of gas turbine. A case study of the proposed CCHP with S-CAES system in an 180000m 2 hotel building located in South China shows that the optimal power capacity of S-CAES comes to 435 kW; and energy efficiency increment gains 1.015% in comparison with a corresponding optimized CCHP system without S-CAES. [ABSTRACT FROM AUTHOR]

Ubiquitous modernization of building energy and management systems brings tendencies for an effective integration of renewables in buildings. This article shows how solar energy can be in charge of energy savings within a building by integration of solar systems with Trombe wall. Numerical calculations of Trombe wall thermal resistance and its performances in comparison with a common wall are considered. Additionally, energy-efficiency gaining by a combination of PV modules and Trombe wall, using simulations by SAM (System Advisor Model) software is discussed. PV module parameters and their impact on its electricity production are observed and analyzed. The PV module parameters, analyzed in the paper are: the tilt angle α of PV modules, incident angle β of direct sunrays on PV modules, normal beam irradiation N and PV cells operating temperature. With bigger incident angle β of direct sunlight on PV modules, the normal beam irradiation is smaller, which brings less electricity production. The impact of PV module operating temperature can be neglected in comparison with the impact of tilt angle on PV module electricity production. The optimal tilt angle of PV modules for generating maximum annual electricity is around latitude angle. It varies with normal beam irradiation to achieve the maximum monthly electricity production. [ABSTRACT FROM AUTHOR]

The temporal fluctuation of solar energy resources often require the utilization of thermal energy storage to increase the level of solar energy. Solar energy systems that are used to meet the heating demands of buildings can be implemented in a variety of system configurations, ranging from energy production and storage at the building-level, to centrally located production and storage components coupled with a district-heating network. In this paper, quasi-steady state simulation models are used to evaluate the impact that different design configurations of decentralized and centralized solar thermal systems (with short- and long-term storage) have on the overall economic cost of the energy provision and the degree of solar energy utilization. A suburban neighbourhood in Switzerland consisting of 11 buildings is selected as a case study. Simulation results suggest that building-level long-term storage configurations out perform all other system configurations in terms of solar fraction and system efficiencies for the given case study. Furthermore, the results demonstrate that the location of the thermal storage and the separation of short- and long-term storage are crucial issues that affect the performance of building-level renewable energy sources, and thus merit further investigation. [ABSTRACT FROM AUTHOR]

In this paper, it has been attempted to present a temperature control method for the building and, simultaneously, reduce costs of providing energy in hybrid heating systems. In the present work, a building in Tehran city has been investigated as a sample during a single day and applying intelligent control methods in the presence of two gas and solar heat sources. Furthermore, the influence of each of these methods has been studied on reducing costs as well as regulating indoor temperature. In the next step, the utilized controllers have been redesigned for the laboratory model and their capability has been evaluated through experimental tests. Based on the acquired results, it is deduced that, compared to other methods, utilizing a PID controller optimized by genetic algorithm not only reduces 50% of energy providing costs, but also regulates the inner temperature of the Lab model with an error lower than 1%. This method is faster than the others in regulating the model temperature. However, in the real building modeling case, the efficiency of this method has been reduced relative to the laboratory model, mostly because of variable conditions such as variable solar emission intensity during different hours of the day. Yet, acceptable results have been acquired by performing MPC and correct modeling. These results show that, as the variable parameters increase, the MPC presents higher capability compared to other methods In this case, the MPC has similar costs to the genetic algorithm while it regulates the temperature faster and with lower error. [ABSTRACT FROM AUTHOR]

The Solar Decathlon is a competition for universities from all over the world which focuses on designing, building and operating experimental, solar-powered houses. Participating in the project offers universities a unique and interdisciplinary platform for teaching, learning and research which combines practical experience with research. In 2022, the European edition was held in Germany for the first time. The event took place with a new urban profile to increase both the relevance of the competition and the learning experience. Its main topic was the further development of the European city, and specifically focused on the existing stock of residential apartment buildings. A total of 18 teams from 11 countries with over 500 students took part, with 16 teams ultimately building their houses on a shared solar campus. Demonstrating a balanced or a positive energy balance in practice was one of the essential goals of the competition. This was achieved by 13 of 15 projects in the energy contest. The prerequisites for this were a high level of energy efficiency and the consistent use of solar energy. Both strategies were embedded in convincing architectural concepts. These ranged from the minimised visibility of standard systems on rooftops, through to custom-built systems with full architectural integration in façades. Hybrid solar systems also became a focus, with the goal of making optimum use of the surfaces on the building envelope. This paper focuses on the energy engineering and technical and architectural integration of the solar systems. It also includes the results achieved in the competition linked to the learning experience. [ABSTRACT FROM AUTHOR]

Solar energy utilizations in buildings are contingent on efficient shading models. This paper presents a new trigonometric model that was simple in application and robust in handling diverse site environments. The developed model was experimentally validated and compared to existing shading techniques such as pixel counting and polygon clipping. Additional analyses were performed to examine building façades ranging from flat to free-form surfaces in both linear and non-linear urban forms. This study integrated two submodels into the shading model to estimate the reduction in cooling demand and the energy production from solar applications. On annual basis, elliptical urban grids provided less normal beam radiation by a mean of 4.7 % or 22.8 W/m2 than the linear grids tangent to the curvilinear ones. South-facing façades gained more radiation by a factor ranging from 1.26 to 1.55 due to wider street grid conditions. Shade-less protrusions of the free-form façades allowed the incidence factor to reach up to 0.91 compared to 0.35 in flat façades. Although the developed model had an average error of 5.2 %, the computational time was reduced by more than 40 %. [ABSTRACT FROM AUTHOR]

• This paper conducts assessment of hybrid renewable systems for urban buildings. • A new demand model for heterogeneous building types is developed. • Time series forecast of electricity market is proposed. • Novel renewable supply and balance scenarios are developed. • Techno-economic assessment of hybrid renewable systems shows feasibility. This research conducts a technical and economic feasibility study of multi-energy hybrid systems (MEHS) combining different renewables for a northern climate city of Finland to address issues of replacing fossil energy by renewable energy sources (RES) to achieve zero carbon emissions. The renewable energy systems MEHS include geothermal, biomass and solar energy. The selected city-study site is the Olympic Training Center occupied by heterogeneous buildings which presents a good representative urban city for the assessment of the energy supply and demand. A generic and integrated modeling framework grounded in a combination of novel forecasting models for the heterogeneous building energy demands, the splitting of space heating and hot water use, the coupled renewable energy generation, and the time series electricity market is developed to investigate optimal MEHS configurations based on the technical and financial analysis. Innovative scenarios of MEHS are developed. The analysis results show that MEHS can flexibly meet the energy demand for the heterogeneous buildings and the optimal configurations can be realised by an innovative integration of geothermal and solar sources as well as electricity as complementary energy. Model uncertainty and its impacts on the analysis are also considered and discussed. [ABSTRACT FROM AUTHOR]

Abstract: With the development of urbanization in China, more and more high-rise residential buildings are constructed, mostly with 10–15 stories. Solar water heating system has been widely used in low-rise residential buildings in China, while its application in high-rise apartment is still in the initial stage. In this paper, the current application situation of solar water heating system in urban residential buildings of China is investigated. Additionally, demonstration projects of high-rise residential building are introduced, in which the application feasibility and limitation of solar water heating system are emphasized and some appropriate planning types of that are discussed. Finally, this paper analyzes the applicability of solar water heating systems integrated design in typical high-rise apartments from various aspects (such as architectural elevation, architectural plane and detailed construction) in the planning and designing phase. [Copyright &y& Elsevier]

This paper deals with a numerical and experimental study of energy performance as well as an economic study of a solar under floor heating system for a traditional bathroom (Hammam). Prior to this, the solar under floor heating system was designed via a parametric study conducted by means of dynamic simulations for the solar collectors area and inclination, the storage tank, the piping materials, the pumps mass flow rates, the temperature regulation and the thickness of the active slab. Moreover, two configurations with or without thermal storage were compared. The Hammam was monitored via air temperature and humidity measurements as well as IR thermography. Good agreement between simulation and experimental results was found with 94% of the discrepancies less than 1 °C. Numerical results show that the system without thermal storage allows the Hammam's operative temperature to reach the desired one. The latter ranges between 30 °C and 37 °C for sunny days in winter, while the system with thermal storage leads to at least 10 °C operative temperature lower compared to system without thermal storage. In addition, the thermal storage system allows having quasi-constant floor temperature that depends on the storage volume, as it avoids large day/night temperature fluctuations thanks to its thermal inertia. Nevertheless, the solar floor heating system configuration with storage tank does not achieve the desired floor surface temperature of the Hammam. Furthermore, it was stated that the best configuration, which leads to an operative temperature of around 35 °C inside the Hammam, is that with cross-linked polyethylene serpentine tubes (PEX) inserted in a concrete slab of 5 cm thickness, 4 m 2 water solar collectors with 80 kg h −1 mass flow rate and temperature regulation difference of 5 °C. On the other hand, the studied solar floor heating system exhibits high to excellent energy performance depending on the use of the Hammam and auxiliary heating is almost not needed for a rational use. Furthermore, the economic feasibility of the solar floor heating system of the Hammam indicates that the annual heating energy consumption is reduced by at least 72%. Moreover, the annual energy savings are about 950 MAD (around 97 USD) and 690 MAD (around 70 USD) respectively compared to the electric and gas heating systems. The payback period of the solar system is then around 6 and 8 years respectively. Over the lifetime of the solar system, which is assumed to be 15 years, its cumulative reduction of the CO 2 emissions is up to 10 tons. [ABSTRACT FROM AUTHOR]

ETFE (ethylene tetrafluoroethylene) cushion integrated flexible photovoltaics (PV) is an extension of building integrated photovoltaics into membrane structures, which could be near zero-energy, sustainable and environmental-friendly buildings. This paper focused on a two-layer ETFE cushion integrated flexible photovoltaics with experimental study and theoretical analysis. Field experiments on a prototype were carried out to investigate temperature distribution and characteristics. It is found that temperature distribution was the result of solar irradiance, incident angle and surface curvature of ETFE cushion and that solar irradiance had an essential effect on temperature distribution. The theoretical thermal model was developed based on energy balance equation and the corresponding differential equation was solved by the Runge-Kutta method. Maximum temperature difference of 3.3 K between experimental and numerical results demonstrated that this thermal model could predict PV temperature appropriately. Furthermore, a modified equation to determine heat transfer coefficients was proposed and average heat transfer coefficients of PV and ETFE foil were 4.89 W/(m 2 K) and 4.39 W/(m 2 K). In general, this study could provide basic values and observations for investigating thermal performance of ETFE cushion integrated flexible photovoltaics. [ABSTRACT FROM AUTHOR]

Solar energy is clean and renewable energy; phase change material (PCM), used in buildings, can store the surplus heat and release when needed to save energy in winter. This paper establishes a new model of PCM floor coupled with solar water heating system (PFCSS). A module of PFCSS building was established in TRNSYS. The module was validated by a full-scale experiment. Two experiment buildings, a reference building and a PFCSS building, were set in Ninghe County of Tianjin, China. The experiment lasted for 15 days in February. Two mathematical methods, MRE (mean relative error) and Bland-Altman consistency analysis, are used to evaluate the accuracy of the model. In the comparison of the experiment data and simulation data of PFCSS building, MRE is 0.6% and the result of Bland-Altman consistency analysis is 95.1% (95% confidence interval −1.94–1.46). A model of the control building with ordinary radiant floor was set up to compare the differences in its temperature performance in relation to that of the PFCSS building. PFCSS building’s temperature fluctuation is smaller and the heating process is longer than control building. If the indoor temperature is maintained at 20 °C, the PFCSS building can save 5.87% on the energy consumption, when compared with the control building. Based on these two existing models, the influences of PCM’s thermal physical parameters on the indoor air temperature were analyzed by simulation. [ABSTRACT FROM AUTHOR]

Pitched-roof buildings make up a considerable proportion of architectural roof styles. Precise estimation of solar energy potential on pitched roofs is thus crucial to the sustainable development and renewable energy consumption of human habitats. Conventional solar radiation measurements usually adopt Light Detection and Ranging (LiDAR) data, which can only be extracted from existing buildings. There has been relatively little research assessing solar radiation on pitched roofs. This paper develops a pixel-based approach to estimation of solar energy potentials over pitched roofs based on the pretext of architectural design drawings. A typical Australian house with nine roofs is then chosen for implementation through a case study. The solar radiation on a certain cell of a shadow map is mathematically formulated for each pixel unit. Its yields over a certain time period are calculated by considering multiple instantaneous solar irradiances and visually presented through image processing. The resulting solar radiation maps, especially a coloured 3D map, reveal the roofs’ radiation distribution including effects from objects on the roofs such as chimneys. Radiation contour lines are mapped to obtain installation ranges for solar devices. This study will benefit commercial energy investors, residents and urban planners in the efficient use of renewable energy sources through accurate prediction of solar radiation potential and identification of areas receiving high radiation over sloping roofs. [ABSTRACT FROM AUTHOR]

This paper discusses the performance of a solar assisted ground source heat pump (SAGSHP) system used for storage of solar energy in day time and space heating at night. Experiments were conducted to estimate the effectiveness of solar energy storage under the ground using a U-tube ground heat exchanger by absorbing solar energy from 9 A.M. to 5 P.M. and utilize the stored energy during space heating in the night time from 7 P.M. to 3 A.M.. Using the experimental data, heat absorbed by the solar collector, heat injected into the ground, heat extracted from the ground and COP of the system have been computed. Results indicate that heat absorption by the solar collector varied from 2.07 to 2.56 kW with increase in mass flow rate. Due to heat losses, only 1.991–2.414 kW of solar heat could be injected into the ground in the day time. Increase in mass flow rate of heat transfer fluid in the collector and ground heat exchanger has resulted in 21% increase in heat injection into the ground. Due to charging of ground, thermal energy of 2.8–3.2 times the work input to the solar collector could be extracted additionally from the ground in the night time for space heating. Charging of ground has resulted in 23% increase in the COP of the system for space heating in the night time. [ABSTRACT FROM AUTHOR]

While power crises persist in Africa with many heads of governments placing priority on power generation, the need for energy conservation through efficient lighting can be a short-term solution. This paper compiles the power supply and consumption pattern from lighting of six cities and towns in North Central Nigeria. A total of 1637 residential households were surveyed. Each compound had 2 to 4 houses. Most of the households surveyed had a combination of modern and local buildings such as huts. The work revealed that the predominant form of electricity consumption is in lighting. Electricity supply is found to last for an average of 5 days a week and 9.8 h a day. The major electric lighting source is the 60 W and 100 W incandescent bulbs, but a significant population uses both incandescent and energy efficient lamps (e.g. compact fluorescent lamps, CFLs) for their lighting needs. In the absence of public power supply, kerosene and low power generators are used as alternative sources for lighting. The number of kerosene lamps in a residential compound was found to be 3 or more. About 70 per cent of power generated in Nigeria can be saved if efficient lighting sources such as CFLs and solid state lighting are urgently adapted. Also, an estimated 796.4 billion naira (US$4.98 billion) will be saved annually from fuel to power electric generators if they are replaced by solar- based lighting. [ABSTRACT FROM AUTHOR]

Precise estimation of solar energy on building roofs plays a critical role in sustainable development and renewable energy consumption of high-density human habitats. Conventional solar radiation models based on costly Light Detection and Ranging (LiDAR) data are only adequate for existing buildings, not for future construction areas. In this paper, a pixel-based methodology is constructed for estimating solar energy potential over roofs. Buildings with flat roofs in a newly planned construction area are chosen as a case study. The solar radiation at a certain cell is mathematically formulated in the pixel unit, and its yields over a certain time period are calculated by considering multiple instantaneous solar irradiances and are visually presented by image processing. Significant spatial and temporal variations in solar radiation are measured. Within the study area, the maximum and minimum annual radiation yields are estimated at 4717.72 MJ/m 2 /year and 342.58 MJ/m 2 /year respectively. Radiation contour lines are then mapped for outlining installation ranges of various solar devices. For each apartment building, around 20% of roof areas can obtain 4500 MJ/m 2 /year or more solar radiation yields. This study will benefit energy investors and urban planners in accurately predicting solar radiation potential and identifying regions with high radiation over building roofs. The results can be utilised in government policies and urban planning to raise awareness of the use of renewable energy sources. [ABSTRACT FROM AUTHOR]

In this study, a solar based Rankine cycle and geothermal based system for multigeneration is designed and developed. It consists of a Rankine cycle with reheating for power generation, an absorption chiller cycle for cooling, a drying process to dry wet products, useful heat from the condenser of the Rankine cycle, and other useful heat out from heat exchangers. The overall energy and exergy efficiencies of the single generation and multigeneration systems are studied, and it is observed that the energy efficiency of the multigeneration system is higher than the single generation system. The energy efficiency of the single and multigeneration systems are 7% and 37%, respectively. Similarly, the overall exergy efficiencies for the single generation and multigeneration systems are also studied and presented in this paper. In addition to this, parametric studies are performed to observe the effects of different substantial parameters, namely inlet pressure and temperature of the turbine, and reference environment temperature in order to investigate the variations in the system performance in terms of the energy and exergy efficiencies. [ABSTRACT FROM AUTHOR]

This paper is a full review on the development of solar photovoltaic technology for building integration and design. It highlights the classification of Solar PV cell and BIPV product for building design purpose. BIPV poses an opportunity to play an essential part in a new era of distributed power generation. Building integrated photovoltaic systems is powerful and versatile tool for achieving the ever increasing demand for zero energy building of the coming years. While some critical policy challenges exist, the value of generating power directly where it is used, aesthetic designs and flexible thin film module form factors is just starting to be understood, which may help to mitigate the barriers posed for current BIPV applications. [ABSTRACT FROM AUTHOR]

Nowadays, it is well recognized at the international level that the building sector is one of the biggest energy consumers, which made the intervention in this sector the greatest potential for energy consumption reduction and greenhouse emissions mitigation. In Algeria, building sector is responsible of more than 40% of the final energy consumption. Solar energy systems integrated in buildings can be an important solution to this dual problem. The aim of this paper is to estimate the energy performance of a typical single-family bioclimatic house equipped with a solar heating system located in the north Algeria (Algiers) and to investigate its conversion into a zero energy house by installing a grid connected PV system. To achieve this goal, a numerical model of the bioclimatic house coupled with the solar heating system is developed and validated with experimental data. Then, the validated model is used to optimize the adequate size of the solar heating system and to determine its contribution in the production of thermal energy for both DHW preparation and space heating of the house. Finally, a PV system is sized to supply, in parallel with the utility grid, the house with electricity for lighting, appliance and auxiliary electric heater. Furthermore, an economic analysis is made to show the profitability of integration of grid connected PV and solar thermal systems in building. Results show that the conversion of a bioclimatic house into a ZEH using a grid connected PV system, in the north of Algeria weather conditions, present high level of feasibility. However, the return on investment is very high due mainly to the high cost of solar energy components and the very low costs of conventional energy in Algeria. [ABSTRACT FROM AUTHOR]

The rate of glazed area to floor area and to sun-exposed wall area of a room is one of the main relationships in energetically optimized architecture. This paper shows the results of the hygrothermal and lighting behaviour on autumn period, of a Primary School which was monitored for a year. It was selected from a universe of 60 school prototypes located in Resistencia, a hot-humid mid-latitude city in the Northeast of Argentina. The measurements were compared with simulations through Simedif, Ecotect and its Radiance interface, in real occupation conditions. A root mean square error of 0.6 °C was obtained. Then the thermal behaviour of the building with an optimized envelope by regulating its glazed areas was simulated for the same period of autumn. Better hygrothermal comfort conditions were verified with the optimization proposal, as well as higher levels of illuminance and uniformity in the spatial distribution of natural light, which would be reflected in an electrical consumption saving for lighting. Consequently, this study will contribute to determining criteria for sizing suitably glazed areas to achieve wellness conditions, which are not covered in full in the current Planning and Building Codes, for school buildings in Resistencia. [ABSTRACT FROM AUTHOR]

Solar energy has been widely introduced in the building market to provide electricity, heating and domestic hot water for a sustainable development. However, the low-density and the mismatch between energy supply and demand make appropriate its combination with thermal energy storage (TES) systems. The integration of these technologies (solar thermal and TES) in the building design is a key aspect to reduce energy consumption. Latent heat storage using phase change materials (PCM) presents an advantage in comparison to conventional sensible heat storage systems due to the required volume. In this context, an innovative system that integrates PCM inside the structural horizontal building component is presented in this paper. The slab consisted of a prefabricated concrete element with 14 channels filled with macro-encapsulated PCM which is used as a storage unit and a heating supply. In order to melt the PCM the system is coupled to a solar air collector. The prototype is tested in an experimental facility located in Puigverd de Lleida (Spain) where its thermal performance is evaluated under real weather conditions. This study demonstrates the high potential of the concrete slab on reducing the energy consumption compared to a conventional heating system. [ABSTRACT FROM AUTHOR]

Abstract: Building-Integrated Photovoltaics (BIPV) are one of the best ways to harness solar power, which is the most abundant, inexhaustible and clean of all the available energy resources. This paper discusses issues concerning BIPV in architectural design in China, including how to choose between BIPV and building-attached photovoltaics (BAPV), whether it is necessary for photovoltaic components to last as long as buildings and how to design BIPV structures. The paper shows that we should consider the function, cost, technology and aesthetics of BIPV, rather than solely the high integrations. According to developments in technology and markets, photovoltaic structures and design should be focused on the maintenance and replacement of photovoltaic cell modules, rather than simply prolonging their lives. To solve problems associated with the existing photovoltaic structures in China, we design a building photovoltaic structure that allows convenient maintenance and replacement of photovoltaic components. [Copyright &y& Elsevier]