Search

Abstract: An experimental system was developed and tested in order to investigate the exergetic performance of a solar photovoltaic system (PV) assisted earth-to-air heat exchanger (under ground air tunnel) that is used for greenhouse cooling at the Solar Energy Institute, Ege University, Izmir, Turkey. This system was under operational conditions successfully during the 2010 summer cooling season. This paper provides the experimental results obtained between 18th of August and 26th of August of in 2010. Exergy destruction in the system was calculated and presented in this paper using a reference temperature of 15°C. Results are discussed and interpreted in the paper for various performance metrics, such as the effect of climatic conditions and operating conditions on the system performance. Results show that the system may be satisfactorily used for greenhouse cooling in the Mediterranean and Aegean regions of Turkey. [Copyright &y& Elsevier]

Abstract: Zero energy balance (ZEB) is an essential and paramount topic in building design. The paper addresses this important research area with special regard to the Mediterranean climate. To deal with ZEB in architecture, a final design proposal for a new housing development in the peri-urban context of Tricase – a town located in the south of Italy – is presented and used for energy investigation. With reference to this pilot case study, the paper highlights that high performing and zero energy balance buildings cannot be reached by technology alone, but by the search for an integrated design combining passive tools (high thermal mass brick wall structures – as an evolution of the traditional stone construction of the region, high reflective materials, solar shading devices, ventilation strategies, etc.) with solar and wind energy micro-generation. Results show that zero energy balance and zero local CO2 emission houses in the Mediterranean climate present high levels of feasibility, which can be simply achieved by energy-efficient solutions using local materials and traditional construction processes, thus resulting into high quality performing buildings within recognisable urban environments. [Copyright &y& Elsevier]

Abstract: This paper describes a new general method for building simulation programs which is intended to be used for the modelling of complex facades. The term ‘complex facades’ is used to designate facades with venetian blinds, prismatic layers, light re-directing surfaces, etc. In all these cases, the facade properties have a complex angular dependence. In addition to this, such facades very often have non-airtight layers and/or imperfect components (e.g. non-ideal sharp edges, non-flat surfaces, …). Therefore building planners often had to neglect some of the innovative features and to use ‘work-arounds’ in order to approximate the properties of complex facades in building simulation programs. A well-defined methodology for these cases was missing. This paper presents such a general methodology. The main advantage of the new method is that it only uses measureable quantities of the transparent or translucent part of the facade as a whole. This is the main difference in comparison with state of the art modelling based on the characteristics of the individual subcomponents, which is often impossible due to non-existing heat- and/or light-transfer models within the complex facade. It is shown that the new method can significantly increase the accuracy of heating/cooling loads and room temperatures. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a simplified mathematical model develops to study round the year effectiveness of photovoltaic/thermal (PV/T) and earth air heat exchanger (EAHE) integrated with a greenhouse, located at IIT Delhi, India. The solar energy application through photovoltaic system and earth air heat exchanger (EAHE) for heating and cooling of a greenhouse is studied with the help of this simplified mathematical model. Calculations are done for four types of weather conditions (a, b, c and d types) in New Delhi, India. The paper compares greenhouse air temperatures when it is operated with photovoltaic/thermal (PV/T) during daytime coupled with earth air heat exchanger (EAHE) at night, with air temperatures when it is operated exclusively with photovoltaic/thermal system (PV/T) and earth air heat exchanger (EAHE), for 24h. The results reveal that air temperature inside the greenhouse can be increased by around 7–8°C during winter season, when the system is operated with photovoltaic (PV/T), coupled with earth air heat exchanger (EAHE) at night. From the results, it is seen that the hourly useful thermal energy generated, during daytime and night, when the system is operated with photovoltaic (PV/T) coupled with earth air heat exchanger (EAHE), is 33MJ and 24.5MJ, respectively. The yearly thermal energy generated by the system has been calculated to be 24728.8kWh, while the net electrical energy savings for the year is 805.9kWh and the annual thermal exergy energy generated is 1006.2kWh. [Copyright &y& Elsevier]

The paper focuses on the experience with research of combined building-energy systems such as energy roofs, ground heat storage and active thermal protection. The EB2020 experimental house was largely designed in accordance with the patented ISOMAX system (SK 284 751, author: Dipl.-Ing., Phys. Edmond D. KRECKÉ), which represents a high potential for the use of renewable energy sources. When designing the experimental house EB2020, we eliminated the problem of this system by designing top heat sources, whose heat sources are exclusively solar and geothermic energy. The investigated building is designed with the following heat sources and energy systems: energy roof, low-temperature gas boiler, fireplace with hot water exchanger, ground heat storage, storage water heat storage with electric reheating, active thermal protection, large-area radiant low-temperature heating / high-temperature cooling, liquid cooling circuit in the ground outside the building, recuperative air handling unit and air ground heat exchanger. In this paper we describe the theoretical procedure for calculating the efficiency of the energy roof, comparison with a classic solar collector, experimental measurements of the energy roof during one season and evaluation of the measured data. The application of an energy roof requires lower investment costs than conventional solar collectors, but experimental measurements have shown that the energy gain and the achieved temperatures of the working substance at the outlet are significantly lower. For higher efficiency energy roof, it is worth considering installing a dark roofing and installing more circuits with a suitable orientation according to cardinal directions. This may be the subject of further research. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the performance analysis on a hybrid air-conditioning system according to the hybrid building energy system of the green building demonstration project in Shanghai, in which a 150m2 solar collector is used to power two 10kW adsorption chillers, a vapor compression heat pump is used to cool air in the evaporating end while the condensing heating at about 80°C is fully used to regenerate a liquid desiccant dehumidification system. In the hybrid system, the sensible cooling to the air is treated mainly by solar adsorption cooling and vapor compression cooling, whereas the latent heat is treated by the liquid desiccant dehumidification system with regeneration from the condensing heat of the heat pump. The results show that the performance of this system is 44.5% higher than conventional vapor compression system at a latent load of 30% and this improving can be achieved by 73.8% at a 42% latent load. The optimal ratio of adsorption refrigerating power to total cooling load for this kind of hybrid systems is also studied in this paper. [Copyright &y& Elsevier]

[Display omitted] • The motivations to implement pre-cooling are discussed. • Recent pre-cooling and solar pre-cooling studies are reviewed. • Pre-cooling simulation methods are briefly introduced. • Method, aims, and findings of each study are summarized. • Current gaps in the field are identified and future works are suggested. Ever increasing numbers of air-conditioners and, in many places, more extreme weather and urban overheating are placing additional stresses on electricity networks globally, reflecting not only their high power draw but also highly correlated operation driven by weather conditions. The resulting peak demands can be considerably greater than average network flows requiring additional electricity generation and network capabilities for what might only be infrequent periods. Energy users must of course pay for this additional investment, including potentially via peak demand and time-of-use charges. Pre-cooling of buildings to spread air conditioning demand is one approach to reduce these peaks. Its potential contribution depends on the thermal performance of the building stock, particularly how long it can retain pre-cooled air, and patterns of weather on warm days. The use of solar energy, including particularly rooftop solar photovoltaics presents another possible option. Photovoltaics generates during daylight hours, which is well-matched with higher temperatures. However, photovoltaics generation may often be declining while heat loads in buildings and hence air conditioning are still climbing in the late afternoon. This suggests the potential of solar pre-cooling when solar photovoltaic electricity is used to run air conditioners in the pre-cooling phase. Literature reviews to date have tended to focus on only aspects of pre-cooling and solar pre-cooling, for example, the effect of thermal mass on the energy performance of buildings but not specifically on peak demand shifting and cost reduction. There is a particular gap with review papers that investigate pre-cooling and solar pre-cooling together with detailed characterization of their potential in different circumstances. The review presented here covers a wide range of state-of-the-art studies in the field of pre-cooling and solar pre-cooling covering the period 2014 to 2021. It also presents, for the first time, the necessary steps to design and implement pre-cooling and solar pre-cooling strategies. It is intended to support the growing research studies and practical implementations of pre-cooling and solar pre-cooling within the electricity sector. [ABSTRACT FROM AUTHOR]

In Japan, a feed-in tariff scheme has been implemented to promote the use of photovoltaic power generators in combination with electric batteries. Although many researchers have assessed the operation of grid-connected photovoltaic systems with electric batteries, little attention has been paid to the impact of the electric batteries’ degradation characteristics. This paper evaluates the operation of a grid-connected photovoltaic/electric-battery system in a house in terms of cost savings and energy savings. We constructed a long-term operational optimization model considering the degradation characteristics of the electric battery. This model contains two objective functions: energy savings and operating costs. We create a scenario of power rates and photovoltaic/battery system configurations. To reveal the optimal operational strategy for the photovoltaic/battery system, the multi-objective optimization problem was solved. As a result, Pareto-optimal solutions were obtained, and trade-off relationships between cost and energy savings are presented. In this study, the utilization of a grid-connected photovoltaic system with an electric battery was expected to be most effective in energy-saving priority operation. [ABSTRACT FROM AUTHOR]

In this paper a thermodynamic analysis of a concept approach based on a possible form of load management for photovoltaic energy is presented. By using the surplus electricity for driving a compression chiller it is possible to load a low temperature thermal storage. This cold storage can be used to cover the cooling demand of domestic refrigerator and freezers. A parameter study was performed to evaluate the energetic efficiency for this system in a single family home. A short economic evaluation compares the concept to a system without storage and to a system with battery storage. [ABSTRACT FROM AUTHOR]

This paper investigates the Demand Side Management (DSM) in a commercial building microgrid with solar generation, stationary Battery Energy Management System (BESS) and gridable (V2G) Electric Vehicle (EV) integration. Taking into consideration of a comprehensive pricing model, we first formulate a deterministic DSM as a mixed integer linear programming problem, assuming perfect knowledge of the uncertainties in the system. A two-stage stochastic DSM is further developed that addresses the stochastic nature in solar generation, loads, EV availabilities and EV energy demands. The proposed DSMs are validated with real solar generation, loads, BESS and EV data using sample average approximation. Detailed case studies show that the stochastic DSM outperforms its deterministic counterpart for cost saving for a wide range of prices, though at the expense of higher computational time. Computational results also demonstrate that moderate number of EVs helps to cut down the overall operation cost, which sheds light on the benefit of future large scale EV integration to smart buildings. [ABSTRACT FROM AUTHOR]

This paper describes a methodology developed for determining the solar energy potential of large scale urban areas based on building typology. As a result of the method, the solar yield at the roof can be determined, taking into account shading obstructions and assembly distances. In the model the utilized as well as the collected energy is calculated, taking into account the energy losses by unused energy, energy delivery and energy storage. A main pillar of the method is the building typology that classifies buildings according to roof characteristics and other geometric factors influencing the domestic hot water demand. For each building type the following outputs are calculated: the solar yield, the maximum potential energy that can be produced by roof-integrated photovoltaic panels, the maximum potential energy that can be covered by solar thermal collectors and the realistic energy produced by solar thermal collectors taking into account economical considerations. Based on the model, urban-level solar potential estimations can be carried out with the use of digital cartography at low costs. Such an estimation is presented in a case study for Debrecen, Hungary, but the model can be adapted to any settlement with different building types or climatic conditions. [ABSTRACT FROM AUTHOR]

In this paper, a new and efficient hybrid AC/DC solar powered Homegrid model is proposed based on the load characteristics of a typical set of home appliances working on a 220 V, 50 Hz system. The load characteristics of home appliances are represented by a static ZIP (constant impedance ( Z ), constant current ( I ) and constant power ( P )) coefficient model, a useful load model in power flow studies. A Homegrid system is formed by analysing the distortion produced by modern household equipment, and a K -factor with a significant role in the overheating of residential/distribution transformers is determined. Further, the ZIP load model is validated by a simulation and the results are compared with experimental data. To improve the efficiency and quality of the traditional Homegrid system, a solar powered hybrid AC/DC supply network model is proposed. This system eliminates redundant power conversion stages and mitigates the loss due to the harmonics by a shift of harmonic intensive loads to the Direct Current (DC) network side. Its effectiveness has been investigated with a simulation in MATLAB as well as with hardware implementation. This proposed energy efficient Homegrid model could be quite helpful in fulfilling the idea of net zero or surplus energy buildings. [ABSTRACT FROM AUTHOR]

The outside surfaces of south and west outer walls can absorb a large amount of solar energy in winter, which is very difficult to be directly used for space heating due to larger thermal resistance of the wall. The wall implanted with heat pipes (WIHP), as a new type of passive solar utilization technology, can make good use of the heat absorbed by the outside surface of wall. In this paper, the applicability of the WIHP in winter was studied by calculating and analyzing the working hours and heat transfer capacity of the south and west WIHPs in different districts, and the working temperature in Beijing was calculated to analyze the heat transfer performance at different time. The results show that the south WIHP is with more working hours, larger heat transfer capacity and higher energy saving rate, which can be used in the 93.63% of heating areas. The working time of the west WIHP is postponed compared with the south WIHP, so the west WIHP can only be used in specific districts. Moreover, combining the west and south WIHPs can suggest better performances, which can be popularized in engineering applications. [ABSTRACT FROM AUTHOR]

This paper presents an effort to estimate the impact of dust accumulation on exterior building roof absorptivity and total radiative heat gain. A new model is introduced to calculate a building solar absorptivity as a function of dust accumulation rate. Hourly dust deposition is modeled using the Non-hydrostatic Multi-scale Model (NMMB) to predict monthly averaged dust accumulation over time. The correlation sensitivities to its input parameters and the impact of dust accumulation on building annual loads are also studied. Results show that dust accumulation increases the roof solar absorptivity from its initial value up to dust absorptivity based on the site climatic condition and roof characteristics. The predicted monthly averaged accumulated dust for all studied sites varies between 1.3 and 73.8 g/m 2 /month. The new model has resulted in an annual cooling space increase of 44.7–181.1 kWh/m 2 /year, for the selected hot-dry sites with moderate to extreme dust storm conditions. Heating reductions were found to be 0.5–13.1 kWh/m 2 /year which are not significant in comparison to the increase in annual cooling load. The results of this work were attempted to improve the predictive capability of current building simulation models. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of a new designed Trombe wall in combination with solar chimney and water spraying system in a test room under Yazd (Iran) desert climate. The Trombe wall area is 50% of that of the southern wall of the building that occupies less space and reduces the implementation costs. The new design of the channel has caused the absorber to receive the solar radiation from three directions. Based on the results, the optimum mass flow rate and the nozzle diameter of the water spraying system has been obtained 10 l/h and 30 μm, respectively. The results indicate that the water spraying system decreases indoor temperature and increases indoor relative humidity by about 8 °C and 17%, respectively. The most effect of outdoor relative humidity variation is on indoor relative humidity, rather than indoor temperature. When outdoor temperature increases, both indoor relative humidity and the difference between indoor and outdoor relative humidity decreases. The results also showed that the stored energy of the Trombe wall plays important role in the air ventilation during non-sunny periods. Lastly, the water spraying system enhances thermal efficiency by approximately 30%. [ABSTRACT FROM AUTHOR]

Outdoor air is a common heat source for heat pumps, whose limits are well known. However the use of different sources requires additional investment costs. It is then interesting, starting from a given additional investment, on one side to evaluate different compositions for a set of sources and on the other to choose the most favourable source from time to time, according to the building energy demand and the thermal level of each available source. This paper presents a study conducted on the base of a heating system based on multi-source heat pumps. By means of dynamic simulations in TRNSYS, several scenarios were assessed with respect to primary energy consumption in order to define, given an additional budget for the heat pump system, whether it is a good option to invest in ground source or in solar source for the heating systems. The analysis reveals that the most energy efficient solution both for absorption and compression heat pump based systems is to adopt a multi-source system; the ground exchangers should then be sized to allow a minimum ground inlet temperature of −2 °C, and the saving in investment cost should be directed to buy solar collectors. [ABSTRACT FROM AUTHOR]

Energy crisis and global warming have become more and more serious with the social development. Since buildings account for a significant proportion of the total energy consumption and carbon emissions, it is very necessary and urgent to decrease building energy consumption. Minimizing the need for energy use in buildings through energy-efficient measures and adopting renewable energy are the basic strategies. Zero energy buildings, which only consume solar energy and other renewable energies, have been considered as one solution and have drawn more and more attention in recent years. Solar thermoelectric cooling technologies can be powered directly by a photovoltaic (PV) and cause no harm to the environment, which fully fulfill the demand of ZEBs. This paper reviews solar thermoelectric cooling technologies and proposes a technical route of solar thermoelectric cooling technologies for use in zero energy buildings. It can be seen that solar thermoelectric cooling systems can minimize the energy demands, increase energy effectiveness and reduce fossil energy consumption in buildings. With the thermoelectric and PV industry's development along with the advent of new materials, the solar thermoelectric cooling technologies for use in zero energy buildings are promising. [ABSTRACT FROM AUTHOR]

This paper introduces a multi-stage heat storage system using phase change materials with different melting points into the heat pump solar absorption refrigeration system which proposed by our earlier research work. Using meteorological data for the city of Nanjing, the performance of the novel system with a cooling capacity of 10 kW is quantitatively analyzed: (1) More than 91 m 2 of solar collection area is required for the single flat-plate collector to satisfy the daily need of cooling. (2) Four different types of collectors, including single flat-plate collector, all-glass vacuum tube collector, heat pipe evacuated tube collector, and compound parabolic vacuum tube collector are compared. The results of solar collection areas show that the difference among them is not significant. Considering the building adaptability and production cost in the application designs, single flat-plate collector is preferred. (3) The coefficient of performance for the system with multi-stage heat storage system is approximately 1.3–2.4 times to that with the corresponding single-stage heat storage system at the given conditions. (4) The coefficient of performance of the novel system increases with the melting points of the phase change materials in the heat storage system when the solar radiation intensity is high (0.8 kW/m 2 ), and behaves the opposite when the solar radiation intensity is low (0.3k W/m 2 ). [ABSTRACT FROM AUTHOR]

This paper deals with the methodology of sizing a sustainable heating–cooling system, which consists of a heat pump, thermo-solar collectors and underground water tank, as a seasonal thermal energy storage. The methodology is based on successive and coupled energy balancing of all system elements for time intervals of 1 h, during one representative calendar year. The starting assumption for the calculation contains the size of the underground storage tank, its burial depth, the size of building that is heated or cooled, and the temperature of air in the building. To make the calculation, it is necessary to know the so-called dynamic boundary conditions during a calendar year, comprising the following: hourly outdoor air temperature, hourly insolation (received solar radiation energy) and hourly temperature of the ground surface. The calculation result is the size of the thermal–solar collectors surface, which will ensure the sustainability of the system, i.e. it will ensure that after one year of operation this system is restored to the original conditions, without disturbing natural environment in which it is used. For the purpose of presenting the methodology and checking the influence of individual parameters of the system's operation, a numerical simulation was performed and required surfaces of thermo-solar collectors were determined for one of the system models. Analyses of the influence of the underground tank burial depth, tank size and the initial water temperature in the tank on the required size of thermal–solar collectors were also performed. [ABSTRACT FROM AUTHOR]

EN ISO 13790 is the international standard used for the calculation of the thermal energy requirement of buildings. The evaluation of solar gains through the glazed surfaces is done with a simplified procedure that determines the transmitted solar energy through the transparent surfaces as the product of the normal incidence solar gain coefficient g gl,n and a correction factor F W , that considers the directional aspects of the beam solar radiation. In the absence of adequate national guidelines, the correction coefficient F W in EN ISO 13790 for non-scattering glazing is set constant and equal to 0.90. In this paper, the results obtained by the TRNSYS computer code demonstrate that a generalized use of a constant value of F W = 0.90 provides significant deviations. Therefore, a correlation to evaluate a variable F W coefficient, in function of the incidence angle of solar radiation and of the number of glass panes, is reported. The accuracy of the obtained results was verified comparing the calculated values with those provided by the TRNSYS software. Finally, with reference to two buildings located in two localities with different weather data, the thermal energy needs by applying the EN ISO 13790 procedure with F W = 0.90 and with variable F W have been compared. [ABSTRACT FROM AUTHOR]

Cooling by solar energy is one of the key solutions to the global energy and environmental degradation issues. Solar liquid desiccant based on evaporative cooling is proposed as an eco-friendly alternative to the conventional vapour compression systems due to its huge untapped energy savings potential. In this paper, the recent works on solar assisted liquid desiccant cooling and its various applications combined with evaporative air-conditioning under different climates are reviewed and advantages the system may offer in terms of energy savings are underscored. A basic description of the principles of hybrid solar liquid desiccant with direct and indirect evaporative cooling is provided. Finally, solar regeneration methods and recent developments for the liquid desiccant air-conditioning system are presented. [ABSTRACT FROM AUTHOR]

Currently, there is no methodical procedure for selecting solar-optical properties of roller shades, which affect the energy and indoor environmental performance of perimeter building zones. This paper presents a new systematic methodology for identifying the range of shading properties (openness factor and visible transmittance) that can significantly reduce the risk of glare. A model that calculates angular beam–beam and beam–diffuse shading optical properties using minimum inputs is used within a hybrid ray-tracing and radiosity daylighting model, validated with full-scale experiments. The temporal variation of beam and total vertical illuminance is used to define the annual visual discomfort frequency and establish a process for selecting the range of acceptable shading properties for each set of external parameters (location, orientation, glazing visible transmittance, and buffer zone). The combined impact of visible transmittance and openness factor on discomfort frequency and daylight metrics is non-linear and complex. Recommendations for openness factors and visible transmittance values are made for different scenarios. Selecting the upper limits of suggested ranges can provide more daylight into the space and reduce the probability of high contrast. These guidelines may be used for selection of shading products, followed by considerations about energy savings and provision of outside view. [ABSTRACT FROM AUTHOR]

Solar-ground source heat pump system (SGSHPS) is a new type of high efficiency, energy saving and environmental protection air-conditioning technology. In this paper, experimental studies and numerical simulation on the performance of a SGSHPS operated in different heating modes were carried out. The experimental system was installed in Nanjing of China and solar collectors were coupled with ground heat exchangers (GHE) through an insulated water tank. Four operation modes including ground source heat pump (GSHP), combined operation mode, day and night alternate operation mode and solar U-tube feeding heat alternate operation mode were investigated during winter season. The heat pump performance, solar collecting performance and borehole wall temperature variations were analyzed and compared for various modes. The experimental results indicate that for the combined operation mode, the system operation efficiency during day can be improved by the assistance of solar energy, and the excess solar energy collected during day can be stored in ground by the GHE to improve the operation performance of GSHP during night. The proportions of heat source burdened by solar and geothermal energy are 43.3% and 50.2% respectively. For the alternate operation modes, the temperature resumption of ground surrounding the GHE can be well achieved due to the intermittent heat extraction of GHE or feeding solar heat into ground and thus the overall utilization efficiency of solar and geothermal energy can be improved greatly. During the whole experimental period, the average COPs are 2.37 and 2.72 for GSHP and SAHP operation mode respectively, and the corresponding parameters are 2.69, 2.65 and 2.56 for the combined operation mode, day and night alternate operation mode and solar U-tube feeding heat alternate operation mode, respectively. The average solar collecting efficiency are 43.6%, 47.3% and 38.8% for the combined operation mode, SAHP operation mode and solar U-tube feeding heat operation mode, respectively. Based on the unit modeling, a dynamic simulation program was constructed to investigate the seasonal performance of the SGSHPS operated in different heating modes, the simulation results show that the seasonal average COP are 3.67, 3.64, 3.52 and 3.48 for the combined operation, day and night alternate operation, solar U-tube feeding heat and GSHP mode, respectively. From the view of improving the overall efficiency and increasing heat source fraction of solar energy, the combined operation mode is the best. [ABSTRACT FROM AUTHOR]

Nowadays absorption chillers are of more interest due to considerable saving in energy consumption and using thermal energy sources. In this paper, a sensitivity analysis is accomplished on a double-effect absorption chiller with 100 t of cooling capacity to study the effect of different parameters on auxiliary energy. The input parameters taken into account in the sensitivity analysis are the volume of storage tank, area of evacuated tube collector, and mass flow rates of water passing through the collector and generator. It is also supposed that the evacuated tube collector is mounted at the monthly optimum angle to get as much solar radiation as possible. Two objective functions are considered for the genetic algorithm namely the auxiliary energy and the net profit obtained from the solar system. An economical analysis is required to calculate the optimum area of collector. The computer code is developed to minimize the auxiliary energy, and maximize the profit. Since the auxiliary energy costs money, it is advantageous to use the same system with minimum auxiliary energy. However, the results show that the optimum mass flow rates of hot water passing through the generator and collector have an important role on reducing the auxiliary energy. [ABSTRACT FROM AUTHOR]

Obtained as a research result of conducted project, this paper presents an innovative, energy efficient multipurpose system for a sustainable globally cost-effective building's solar energy use and developed methodology for its dynamic analysis and optimization. The initial research and development goal was to create a cost-effective technical solution for replacing fossil fuel and electricity with solar energy for water heating for different purposes (for pools, sanitary water, washing) in one SPA. After successful realization of the initial goal, the study was proceeded and as a result, the created advanced system has been enriched with AC performance. The study success was based on understanding and combined measurements and by BPS made predictions of AC loads and solar radiation dynamics as well as on the determination of the synergetic relations between all relevant quantities. Further, by the performed BPS dynamic simulations for geographically spread buildings locations, it has been shown that the final result of the conducted scientific engineering R&D work has been the created system of confirmed prestigious to the sustainability relevant performance – globally cost-effective building integrated photovoltaic powered heat pump (HP), assisted by waste water heat recovery, for solar AC, water heating and saving. [ABSTRACT FROM AUTHOR]

The heat transfer performance on the wall has a great influence on the energy conservation and the indoor thermal comfort. Once it can be adjustable according to the requirement, the wall can effectively regulate the indoor temperature, thereby directly reducing the building energy consumption. In this paper, a new type of passive solar energy utilization technology, the wall implanted with heat pipes (WIHP), was proposed, and its heat transfer performance and energy-saving characteristic were investigated theoretically and experimentally with the typical meteorological data of Jinan. The results indicate that the theoretical results agree well with experimental ones. The heat transfer performance of the WIHP is adjustable and controllable, which can reduce the heating load and improve thermal environment. During the winter in a typical year, the heat loss of the south external wall is reduced by 14.47%. Therefore, such a type of wall can apparently improve the indoor thermal environment, which can be popularized in engineering applications. [ABSTRACT FROM AUTHOR]

Artificial neural network (ANN) is a useful tool that using estimates behavior of the most of engineering applications. In the present study, ANN model has been used to estimate the temperature, efficiency and power of the Photovoltaic module according to outlet air temperature and solar radiation. An experimental system consisted photovoltaic module, heating and cooling sub systems, proportional integral derivative (PID) control unit was designed and built. Tests were realized at the outdoors for the constant ambient air temperatures of photovoltaic module. To preserve ambient air temperature at the determined constant values as 10, 20, 30 and 40 °C, cooling and heating subsystems which connected PID control unit were used in the test apparatus. Ambient air temperature, solar radiation, back surface of the photovoltaic module temperature was measured in the experiments. Obtained data were used to estimate the photovoltaic module temperature, efficiency and power with using ANN approach for all 7 region of the Turkey. The study dealing with this paper not only will beneficial for the limited region but also in all region of Turkey which will be thought established of photovoltaic panels by the manufacturer, researchers and etc. [ABSTRACT FROM AUTHOR]

Traditional air conditioning and heating systems in buildings are fossil fuel based energy systems, which take the main responsible for the carbon emissions. In contrast, using solar energy for air conditioning becomes one of the promising approaches to reduce energy consumptions and negative environmental impacts from buildings. University of California, Merced built a test facility to investigate the technology: solar cooling. The solar system has 54 m 2 external compound parabolic concentrator (XCPC) solar collectors to drive a 23 kW double-effect absorption chiller. This paper first provides the detailed energy performance analysis of the experiments conducted in August, 2012. The data collected from the experiments shows that the system could provide adequate cooling for a test facility between 11AM to 5PM in both sunny and cloudy days. The daily average collector efficiency is at the range of 36% to 39%. The average coefficient of performance (COP) of the LiBr absorption chiller is between 0.91 and 1.02 with an average of 1.0, and the daily solar COP is approximately at 0.374. In addition to the experimental investigation, a detailed life cycle economic and environmental assessment was also performed by comparing the solar systems to the conventional systems in two types of office buildings at three locations at California. Two different solar cooling system configurations were considered: (i) configuration 1 sizes the area of solar collectors and absorption chiller to meet the peak cooling demand, and uses natural gas as the only backup energy source; (ii) configuration 2 sizes the area of solar collectors and absorption chiller to meet half of the peak cooling demand, and uses natural gas as the backup energy source for the absorption chiller, while incorporates an electrical vapor compression chiller to meet the rest half of peak cooling demand. The annual performance predicts that the systems can achieve the annual solar fraction around 55–68%. And the configuration 2 achieves better life cycle economic and environmental performance than the configuration 1. Specifically, the configuration 2 can achieve lower present worth cost during the entire life span than the conventional systems. And both configuration 1 and 2 can reduce the life time carbon footprint by 35–70%. [ABSTRACT FROM AUTHOR]

Traditional windows, as the major source of daylight, have a common problem which is uneven distribution of daylight in the room. Several innovative daylighting systems such as light shelves, fixed and movable reflective louvres, reflective sills, prismatic glazing, light pipes, etc., have been developed to address this problem. This paper reports on a research programme that investigates retrofitted solutions to uneven distribution of daylight in deep-plan office buildings. The work presented here follows initial investigations into the design and applicability of an automated retrofitted panel thermal shutters which can also act as a sunshade and daylighting system. The system has a patented function which allows each shutter/louvre to be controlled and placed separately from other louvres. This study evaluates the effectiveness of the system when acting as a sunshade, light shelf, reflective louvre, and reflective sill under clear, overcast, and sunny sky conditions. According to the results, the system significantly improved daylight distribution and reduced the need for artificial lighting by 60%. [ABSTRACT FROM AUTHOR]

This paper details the dynamic simulation of a small, super insulated Passivhaus residential structure, namely The Ohio State University's entry into the 2011 Solar Decathlon competition. This study explores the use of a conventional vapor compression conditioning system as well as the effects of occupant behavior on the parameters affecting comfort within the structure. It adds to the current literature on the subject by presenting a simulation of a Passivhaus and its HVAC system in a mixed climate where cooling and dehumidification are traditionally required. Furthermore it adopts a simulation tool which acts on time scales significantly less than 1 h. It is concluded that the house, while energy efficient, has difficultly controlling moisture levels. In the summer season it is too humid, and in the winter it is too dry. The study concludes that conventional HVAC equipment cannot fully address the moisture and indoor air quality issues that are a result of new building techniques with stringent air infiltration and insulation standards. [ABSTRACT FROM AUTHOR]

Recently, a rapid growth in various applications of ejector refrigeration systems has been observed in numerous sectors. With the applications based on solar or waste energy, designed to supply the motive energy have becoming widespread, a real alternative to compression devices in air-conditioning technologies has become a fact. Furthermore, it has been shown that ejector systems may effectively compete with absorption systems under temperature of the motive heat source lower than 80 °C. This paper presents experimental investigations carried out on a specially constructed prototype/stand for the ejector air-conditioning, operating with isobutane as a working fluid under motive vapour temperature below 75 °C. The effects of operation parameters have been thoroughly analysed. The ejector cycle performance coefficient was presented and discussed. The loss coefficient for the ejector was determined as well. It has been shown that loss coefficient in the investigated set-up is higher than 0.75. [ABSTRACT FROM AUTHOR]

• An experiment of SGHP system and the detail description of combi-storage are presented. • Five daily operation modes are identified using the contributions of the energy inputs. • The dynamic thermal behaviors of the combi-storage are investigated and analyzed. Experimental investigations on thermal behavior of a combined solar and ground source heat pump (SGHP) system for a single-family house are presented. The SGHP system was installed at the Lyngby campus of Technical University of Denmark. Detailed experiments were carried out on the system in 2019 under real weather conditions covering domestic hot water (DHW) consumption and space heating (SH) demand. Depending on the contributions of the energy inputs to the combi-storage, five typical daily operation modes are classified. The focus of the investigations is on the dynamic thermal behaviors of the heat storage under different operating conditions. When the combi-storage was primarily heated by solar energy, the inlet stratifier in the storage performed well, ensuring thermal stratification and a good utilization of solar energy. Water temperature in the storage reached up to about 68℃ at the end of the solar heating process. When the combi-storage was primarily heated by the ground heat, the water temperature near the outlet for SH was kept at a temperature range from 26℃ to 31℃ in the heating process to ensure the outlet temperature level of SH, and the water temperature near the outlet for DHW was in the temperature range 47℃∼51℃ in DHW volume. When there was no heat input to the combi-storage, the pre-stored heat can meet the daily heating demand, and the number of days on this mode was up to 9.4% of the total experimental days. The paper gives valuable inputs for researchers and engineers who plan to integrate the combi-storage in a renewable heating system with solar collectors and ground source heat pumps. [ABSTRACT FROM AUTHOR]

[Display omitted] • Review on application of PCM in trombe wall was performed. • Incorporation of PCMs results in minimizing energy consumption of buildings. • The optimum PCM location into buildings depends on the climate. • Immersion and direct incorporation causes leakage due to heat cycles. • The encapsulation techniques have successfully overcome all of drawbacks. Energy crises and environmental pollution are two of the cardinal obstacles that affect human life today. As part of the efforts to address the excessive energy demands in the last few decades is using renewable energy like solar. As the building sector continues to grow with the growing population, correspondingly, the demand for energy consumption required to heat and cool buildings for thermal comfort augments. To tackle this problem, techniques such as designing green buildings for sustainable architecture have been employed. One of these technologies is the Trombe wall which has been utilized as an avenue for heating buildings using renewable solar energy. Meanwhile, the practice of latent heat storage systems with phase change materials (PCM) is an efficient method to store energy. Substantial research has been carried out to assess the contribution of incorporation of latent heat storage and Trombe walls in buildings on their thermal energy performance. The present review paper communicates a summary of the recent advancements in this topic. The various designs of Trombe walls and different phase change materials types are presented. Research concerning the incorporation of PCM incorporation techniques is scrutinized. Finally, hitherto published literature regarding the applications of PCM in the Trombe wall is underscored and discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] New concept of a solar-biomass hybrid cooling system was presented. [•] This paper presents the design of a solar-biomass hybrid system. [•] 3-Possible configurations were considered, to get the most suitable for the design. [•] Design was to satisfy a cooling load of 4.5kW, and solar to biomass ratio of 0.7. [Copyright &y& Elsevier]

Abstract: Liquid desiccant air-conditioning system is a novel air-conditioner with good energy saving potential. For the liquid desiccant air-conditioning system, the energy consumption mainly relies on the regeneration process of desiccant solution. As the regeneration process of the liquid desiccant air-conditioning system only needs low-grade energy, solar energy (a kind of renewable energy) can be used to regenerate the desiccant solution and the solar desiccant regeneration system has attracted many attentions. In this paper, recent theoretical and experimental works on solar thermal regeneration method and solar electrodialysis regeneration method of the liquid desiccant air-conditioning system are extensively reviewed. Moreover, the comparison of solar TH regeneration method and solar electrodialysis regeneration method is discussed. The results showed that compared to the solar thermal regeneration system, the solar electrodialysis regeneration system is more energy-efficient but expensive. [Copyright &y& Elsevier]

• Community-led solar energy projects in India are analyzed using the grassroots innovation literature. • The status of community energy projects in the US, Europe and India and presented. • Three case studies, namely DURGA, Barefoot College and Rampura solar project, are reviewed. • Case studies are consistent with social justice concerns, such as participation, equitable distribution of benefits and recognition of marginal communities. Sustainable technologies for social mobilization and community empowerment are contemporary phenomena of grassroots innovation movements. The origins of the grassroots innovations appear in the appropriate technology movement of the 1970s, the People's Science Movement of the 1980s, and more recently, the Social Movement Organization as seen in the cases of the Honey Bee Network in India and the Social Technology Network in Brazil. This paper articulates the community energy movement in India in the framework of 'grassroots innovations for sustainability'. The paper presents three fine case studies of off-grid community energy initiatives namely, the Dungarpur Renewable Energy Technologies Private Limited, (DURGA), the Barefoot College and the Rampura Community Solar Power Plant (CSPP). The case studies represent three different kind of business models of community energy projects – a private limited company, a market-based model and a village energy committee (VEC) model. Therefore, they are representative of different grassroots innovations in off-grid energy projects. The case studies exemplify how off-grid community energy projects may manifest an embedded character of the grassroots innovations and address energy poverty and social justice concerns, such as community participation, equitable distribution of benefits, representation of marginalized communities. The case studies also demonstrate that the grassroots innovations in off-grid energy projects may enhance social mobilization, community empowerment and sustainability. To conclude, the findings of this research show that grassroots innovations in technology and sustainable development are consistent with each other. [ABSTRACT FROM AUTHOR]

• A new interlayer ventilated PCM component was proposed and developed. • A new PCM component model was established in TRNSYS. • The interlayer ventilated PCM component can increase the minimum temperature of the room by more than 2℃ at night. The application of solar energy for heating in buildings has the problem of heat supply and demand time mismatch. In this paper, an interlayer ventilated phase change material (PCM) component (IVPC) that can be coupled with solar air collector was proposed. The thermal performance of IVPC was tested through experiments. The results show that if IVPC completes latent heat storage, the optimal air supply temperature of solar hot air is 35 ∼ 45℃ and the air supply speed is 3 ∼ 4 m/s. The latent heat release time can be maintained for 5 h. To build an IVPC coupled with solar air collector system (IVPSS) in TRNSYS, to simulate the improvement effect of IVPC on heating temperature fluctuations, a rural building in cold regions of China was selected. IVPSS can maintain the indoor temperature of the building in the range of 8 ∼ 16℃. Compared with buildings without IVPSS, the room temperature throughout the day can be increased by 5 ∼ 8℃. IVPC can effectively use solar energy to peak load shifting, reduce room temperature fluctuations, improve indoor thermal comfort, and provide solutions for farmhouses in cold regions to use clean energy for heating. [ABSTRACT FROM AUTHOR]

• Develope a new type of solar thermal collector for both heat and cold collection. • It has the tested heating power of 505 ± 7.8 W/m2. • It also has the tested cooling power of 321 ± 5.0 W/m2. • The cooling capacity is higher than conventional collectors. A Flat Plate Solar Collector (FPSC) is a commonly used device to harvest solar energy. An FPSC is typically covered on top with a single-pane glass, known as a glazed FPSC. A conventional glazed FPSC is generally used only for heat collection. The purpose of this paper is to describe an innovative design of a dual purpose solar thermal collector that is able to utilize sustainable energy, i.e., solar heat and night sky cooling, to accomplish heat and cold collection. In this proposed collector, a double-pane "window" was used on the top of an FPSC to replace the conventional single-pane glass cover, which allows water or other liquid flowing in the space between the two panes to lose its heat to carry out cold collection through both long-wave radiation and convection. The measurement results obtained from a real-world experiment on a prototype collector indicate that the developed collector is not only able to retain the functionality of a conventional glazed FPSC for heat collection with the tested heating power of 505 ± 7.8 W/m2, but also to have an additional ability for cold collection with enhanced cooling power (321 ± 5.0 W/m2) and cost-effectiveness compared with conventional unglazed FPSCs, photovoltaic-thermal (PVT) collectors, or the devices using daytime radiative cooling materials. [ABSTRACT FROM AUTHOR]

Abstract: There are many immediate adverse effects on the environment such as large amount of greenhouse gases and pollutants emissions from the burning of fossil fuels for electricity generation. Photovoltaic (PV) systems are promising solar energy applications to generate electricity without emitting pollutants and requiring no fuel. In modern urban cities, most buildings are high-rise with limited spaces for PV system installation, the concept of building integrated photovoltaic (BIPV) would be an appropriate alternative form of the application. This paper studies a medium size grid-connected BIPV system mounted in an institutional building. Technical data including solar radiation and energy output were analyzed. The operational performance and electricity benefits of the BIPV system were examined in terms of cost, energy and environmental aspects. The monetary, embodied energy and greenhouse gas payback periods were estimated and reported. To shorten the payback periods, the BIPV system should incorporate with more passive energy-efficient architecture designs. This on-site measurement contributes the most accurate method of obtaining reliable data for determining the performance of various designs under the actual operating environments for evaluation. [Copyright &y& Elsevier]

Abstract: In this paper a ray-tracing method is developed to describe the global solar transmittance of louver shading devices. The method is integrated in the dynamic building energy simulation program TRNSYS to assess the cooling demand and required peak cooling power in a south oriented office room. The proposed integrated approach allows calculating the solar transmittance for each time step. As the method is quite complex and requires an important computational effort, this research contrasts the results against the performance of simplified modeling and implementation approaches to assess the performance of louver shading devices. The use of view factor models not accounting for reflections in the shading device underestimates the cooling demand and the peak cooling power. It is shown that representing the shading device as a fixed reduction factor, independent of orientation and shading typology is an unacceptable simplification. However, the use of a simplified implementation of shading factors based on ray-tracing calculations is possible within acceptable margins of error. Best results are achieved by implementing solar radiation weighted monthly averages allowing to estimate the cooling demand and peak cooling power within 3%. [Copyright &y& Elsevier]

Abstract: A new system of solar air-conditioning, which adds the heat pump into the original solar air-conditioning, is proposed in order to improve the solar energy application grade. The new type of solar air-conditioning system is analyzed and compared with the original system. Calculations show that: (1) when the sun radiation intensity is high (0.8kW/m2), the cooling capacity of the new system is 1.7 times the original system under the given conditions of this paper. When the sun radiation intensity is low (0.2kW/m2), the cooling capacity of the new system is decreased by 70% compared to high radiation intensity conditions, and the original system could not provide refrigeration. (2) In a certain solar radiation intensity, new type solar air-conditioning system reduces the requirement of a high efficiency solar collection system (SCS). At a certain collector efficiency, it can operate stably by adjusting the water mass flow rate of SCS under different solar radiation intensities. (3) For the heat pump system (HPS) of the new type solar system, under the same rage of evaporation temperature and condensation temperature, R600a HPS has higher COP and less power consumption than R134a HPS under obtaining same cooling capacity condition. [Copyright &y& Elsevier]

Abstract: This paper presents the first and second law analyses of the developed solar-desiccant air-conditioning system (SDACS). The results of the analyses show that the solar collector is the main contributor to both energy loss and exergy destruction of the system at 35.56% and 55.30%. The water pipe network contributed to 13.45% and 1.65% of energy loss and exergy loss. Electric heater contributed to 0.66% and 7.94% of the energy loss and exergy destruction. Storage tank contributed to 5.80% and 6.70% of energy loss and exergy destruction. Desiccant wheel contributed to 3.25% and 0.58% of energy loss and exergy destruction. Air fans contributed to 0.44% and 1.51% of energy loss and exergy destruction. At present, the thermal energy system (TES) has energy and exergy performances based on electric consumption of 2.428 and 0.199. The desiccant cooling system (DCS) has energy and exergy performances based on thermal consumption of 0.403 and 0.093. The desiccant cooling system has in terms of energy and exergy performances based on electric consumption of 1.627 and 0.029. The whole system (SDACS) energy and exergy performance based on electric consumption are 1.238 and 0.084. [Copyright &y& Elsevier]

Abstract: In order to eliminate the influence of thermal resistance between the absorber tube and the copper fin of the conventional evacuated solar collector, which would decrease the thermal performance of the evacuated tube collector, a filled-typed evacuated tube with single U-tube (SUFET) was presented in our previous work, in which the filled layer was used to transfer energy absorbed by the working fluid flowing in the U-tube. In this paper an improved filled-type evacuated tube with double U-tubes (DUFET) was presented by means of theoretical analysis and experimental study to increase the heat transfer area and then improve the heat transfer efficiency of collectors. The structure of filled-type evacuated tube with double U-tubes was given first, and then the thermal performance of filled-type evacuated tube with double U-tubes was studied in both theory and experiment. The experimental results showed the feasibility and validity of this design. Finally, a comparative study between SUFET and DUFET was given at the same working conditions. [Copyright &y& Elsevier]

Abstract: The sensitivity of low energy and passive solar buildings to their climatic context creates a requirement for accurate local climate data. This situation takes on increasing importance in the context of modelling Passivhaus buildings where the absence of conventional oversized heating and cooling systems implies a greater reliance upon fabric and system optimisation. Conversely, future climatic changes may also pose serious implications for super insulated buildings with inadequate solar shading. Currently, many widely used building performance simulation (BPS) tools still rely on very limited sources of climate data. The following research examines the need for regional and, in some cases, micro-regional climatic data when designing ultra-low energy Passivhaus buildings in the UK. The paper proposes a new methodology for generating this data in PHPP format. The data generated is compared to alternative sources, and the implications discussed in the context of three case studies examining a certified Passivhaus dwelling in a mountainous region of Wales as well as two locations, in close proximity, within London. If correctly implemented the use of such data should provide a more robust basis for future cost and performance optimisation in low energy and passive building design. [Copyright &y& Elsevier]

Abstract: In Brazil, a low-latitude country characterized by its high availability and uniformity of solar radiation, the use of PV solar energy integrated in buildings is still incipient. However, at the moment there are several initiatives which give some hints that lead to think that there will be a change shortly. In countries where this technology is already a daily reality, such as Germany, Japan or Spain, the recommendations and basic criteria to avoid losses due to orientation and tilt are widespread. Extrapolating those measures used in high latitudes to all regions, without a previous deeper analysis, is standard practice. They do not always correspond to reality, what frequently leads to false assumptions and may become an obstacle in a country which is taking the first step in this area. In this paper, the solar potential yield for different surfaces in Brazilian cities (located at latitudes between 0° and 30°S) are analyzed with the aim of providing the necessary tools to evaluate the suitability of the buildings’ envelopes for photovoltaic use. [Copyright &y& Elsevier]

Abstract: A triple-state LiCl–H2O absorption system with a power of 10kW that is fully driven by solar thermal energy has been designed and installed in a detached house in Spain. The system dissipates heat through a swimming pool, avoiding the need for a cooling tower. The system is fed using a solar thermal system with an area of 35.54m2. The behavior of the system was monitored for a full year. The design and the calculations for the thermal requirements are presented, and the values of the coefficient of performance (COP) and the expected temperatures are compared with those obtained experimentally. This paper demonstrates that the actual values are slightly lower than the simulated values. The experiment has validated the possibility of using a swimming pool as a sink for heat dissipation. The economic analysis shows that the internal rate of return (IRR) reaches 12.45% while achieving a 68% reduction in greenhouse gasses GHG emissions. The results show that this approach can add great value to solar thermal energy systems while avoiding problems due to high temperatures during the summer months. [Copyright &y& Elsevier]

Abstract: A building integrated cooling facade is proposed in this paper. It is a fan-assisted system that consists of two vertical plenums. The first plenum was made of black aluminium transpired plate and a sandtile wall, while the second plenum is formed by the sandtile wall and the building wall. The aluminium plate served as a solar collector and the sandtile wall was an evaporative pad. The reverse side of the sandtile wall that contacted with the air in the second plenum was coated with a water-resistant layer, hence the air was cooled without adding any moisture into it. The facade cooling performance under various operating conditions is investigated through experiment and theoretical analyses. It is found that inlet water temperature is the key factor affecting the cooling performance. In terms of cooling efficiency, the energy consumption to generate 1kW of cooling that cooling the air to 293K is only 0.52W, which is similar to the amount of energy required by some of the solar indirect evaporative cooling and desiccant cooling systems. [Copyright &y& Elsevier]

Abstract: In this paper, design and experimental analysis of glaze photovoltaic thermal (PVT) tile air collector has been discussed. Fabricated glazed PVT tile consists of a single solar cell, duct and fan for extraction of heat associated with the bottom of solar cell. Observations taken at glazed hybrid PVT tile 1 and tile 2 have been considered as case-I and case-II, respectively. Experimental validation has also been performed and it has been observed that that there is a good agreement between theoretical and experimental results with correlation coefficient and root mean square percentage deviation of 0.96 and 7.9, respectively. The performance evaluation in terms of electrical efficiency, overall thermal energy and exergy gain of both the cases has been carried out in indoor conditions at various intensities. It has been found that the electrical efficiency is higher in case-I as compared to case-II. On the contrary the thermal output of case-II is higher than case-I on same intensity and mass flow rate. It has been found that the average electrical and thermal efficiency of newly designed and fabricated glaze PVT tile is 12.4% and 35.7%, respectively. This economical solar simulator can be used by manufactures for testing of different type of photovoltaic tiles as well as photovoltaic modules. [Copyright &y& Elsevier]

Abstract: While a great reduction of the energy demand for the environmental control of civil buildings has been reached in recent years, still a great potential of energy savings lies in other sectors like the one of agricultural production. The scope of this paper is to investigate the energy performance of some of the recent envelope and systems technologies that best can contribute to a great reduction of the energy demand for the climatic control of a greenhouse for intensive crop production. This article concentrates on three aspects: the use of polycarbonate hollow sheets to reduce the thermal transmittance of the glazing, the application of polypropylene sheets as a basal heating system and the solar energy capture by means of low cost plastic solar collectors. A tunnel greenhouse for basil production of 40m of length and 10m of width was considered as a case study and modelled within the EnergyPlus simulation software. The climate locations that were considered refer to the north-west of Italy. The results show that savings of the order of 30% can be achieved by using more insulated transparent materials. On the contrary, the application of the solar collectors still remains problematic because of the large land use and lower global efficiencies. [Copyright &y& Elsevier]

Abstract: Photovoltaic-electrodialysis (PV-ED) regeneration is a novel method for liquid desiccant cooling system (LDCS), which has a higher performance than the conventional thermal regeneration method by using solar photovoltaic components to drive an electrodialysis regeneration process. However, there are many defects in the previous proposed single-stage PV-ED system. In this paper, a new double-stage photovoltaic/thermal ED regeneration system is presented. Analysis of the performances of the single-stage and double-stage regeneration system is made and the influential factors are investigated. It reveals that the double-stage PVT-ED regeneration system is more applicable than the single-stage PV-ED regeneration system for liquid desiccant cooling system. Moreover, comparisons between the single-stage system and the double-stage system show that the double-stage system is more energy efficient than the single-stage system under the optimized working conditions. [Copyright &y& Elsevier]