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[Display omitted] • A new solar-based multigeneration with a thermosyphon-assisted cooling is proposed. • Thermodynamic and exergoeconomic analyses are performed using Aspen HYSYS and EES. • The system energy and exergy efficiencies are 61.34% and 58.08%, respectively. • Dryer unit has the best thermodynamic performance among other subsystems. • Heat exchanger of the PEM owns the highest cost destruction rate. Nowadays, due to the global energy crisis, limited reservoirs of fossil fuels, and their negative environmental effects, the use of renewable energy sources and multigeneration systems have become good alternatives for conventional thermodynamic systems. One of these resources, whose technology has developed rapidly in recent years, is the use of solar energy for the simultaneous generation of various products. Therefore, in this research, a multigeneration system with several subsystems is introduced. The proposed system includes a solar energy collector to receive thermal energy, two thermal energy storage tanks, an organic Rankine cycle, and a Kalina cycle to generate electricity, a multi-effect distillation unit to produce fresh water, an electrolyzer to produce hydrogen, as well as heat recovery for hot water and hot air generation. In this multigeneration system, the cooling unit is designed with the help of a thermosyphon. The performance of the proposed system is studied from energy, exergy, environmental, and exergoeconomic viewpoints using Aspen HYSYS and EES software. The obtained results show that due to the addition of the thermosyphon unit to the refrigeration system, the exergy efficiency increases from 55.62% to 70.26%. As a result of this combination, the performance of the whole system is improved and the amount of costs are reduced. In addition, the parabolic collector system has the highest exergy destruction ratio, 39%, among the subsystems. Furthermore, the results of the exergoeconomic analysis indicate that the PEM water heater with 33.3% and the ejector with 22.7% own the highest cost destruction rates. [ABSTRACT FROM AUTHOR]

• Business models: new growth drivers for increasing renewable energy adoption by the C&I segment. • Key new trends that are being explored in the Indian market. • Adoption of large-format modules. • Cost analysis of onsite/rooftop solar installation models in India. • Risks and challenges: existing buildings, design standards and codes, lack of manufacturers. Commercial and industrial (C&I) applications have been the most active in india's onsite solar market. These applications account for almost three-quarters of the rooftop solar market in India. As a result of the COVID pandemic that began in 2020, solar installation slowed. The C&I market segment, on the other hand, is likely to recover and see a rise in solar installations. The C&I market has been forced to optimize its costs in light of the pandemic. In addition to helping companies accomplish these goals, rooftop solar systems with battery storage can also contribute to their social responsibility efforts. Rooftop solar systems with battery storage are also expected to grow in popularity. Battery prices are expected to reach $100 per kWh in roughly two years (by 2023), propelling the rooftop solar and battery storage sectors forward. Rooftop solar and Battery Energy Storage System (BESS) are ideal alternatives for behind-the-meter (BTM) applications in India due to their 90 GW of capacity. An Indian case study breaks down the costs of PV installation. This study examines the emerging technology trends in India's Commercial & Industrial Rooftop Solar market, as well as general advice for consumers and investors contemplating solar PV installations. [ABSTRACT FROM AUTHOR]

Solar photovoltaic (PV) systems, are effective measures to reduce the greenhouse gas emissions related to the generation of power. However, the large exploitation of solar PV modules, leads to undesirable waste accumulation, impacting the environment. Solar PV waste management research is an emerging field which has received more attention recently, affected by the increase volume of solar PV disposal. However, only a few studies have reviewed the current trends in solar photovoltaic waste management. This study reviewed the emerging trends in solar photovoltaic waste management research from 1974 to 2019 using the scientometric review techniques. A total record of 4683 articles were retrieved from the Web of Science database on solar PV waste. The co-word, co-citation and co-author analysis of the retrieved articles were conducted to determine the emerging trends in the PV waste management research. The results revealed that, with a gradual growth in the PV waste management research, performance and efficiency of polymer solar cells have been the centre of recent research due to its light weight, flexibility, environmentally harmless materials and lower cost over the silicon based solar cells. However, it will be years before they are ready for commercialization for specific applications. Thus, the silicon-based modules are the most installed to date and will be coming to their end-of-life very soon. The results also show that, little attention was given to areas like recycling, recovery, policies and regulations on solar PV module waste management. Future research should focus on assessing the recycling potential and emissions from current solar PV modules and the easy remanufacture, recovery and reuse of future solar PV modules. [ABSTRACT FROM AUTHOR]

This study evaluates the performance of graded refractive index (GRIN) anti-reflective (AR) structures on photovoltaic (PV) modules across twenty global locations and compares them with conventional thin film AR coatings and bare glass. Optimized glass nanocones were chosen to represent the GRIN structures. Electrodynamic simulations were conducted to assess reflection properties at multiple angles of incidence. GRIN AR structures dramatically reduce total solar-integrated reflection to 0.2% at normal incidence, compared to 3.8% for bare glass and 0.8% for optimized thin film AR coatings, and maintained low reflection across a range of incident angles, demonstrating only 0.7% reflection at 60 degrees compared to significantly higher values for other surfaces. Detailed hourly simulations for twenty global locations revealed that GRIN AR coatings substantially reduce annual reflection loss to just 0. 86 ± 0. 19 % and increase expected annual energy output by up to 11. 15 ± 1. 00 % compared to bare glass at optimal tilt angles. The benefits of GRIN AR coatings are more substantial at sub-optimal panel orientations such as horizontal or vertical due to its broad angle AR properties. These findings highlight the potential of GRIN AR technology to approach the theoretical limit where front surface reflection loss is completely eliminated and enhance solar power conversion efficiencies. Additionally, a generalized model to approximate annual reflection loss for various materials is presented. This research encourages further exploration into GRIN AR coatings to optimize power conversion efficiencies and reduce reflection in PV modules. • GRIN AR coatings reduce solar reflection to 0.2% vs. 3.8% for bare glass. • Reduces annual reflection loss to 0.86%, boosting energy output by 11.15%. • More effective at sub-optimal panel orientations due to broad angle AR properties. • GRIN AR approaches theoretical limit with 0 reflection loss. • Global model that estimates annual reflection loss. [ABSTRACT FROM AUTHOR]

• Design of solar air cavity-receiver with RPC absorbers is presented. • 5 kW prototype was experimentally tested under concentrated thermal radiation. • Parameters: RPC material, pore size, concentration ratio and air mass flow rate. • SiSiC 10 PPI achieved peak efficiency of 0.69 at 1133 °C air outlet temperature. Concentrated solar energy can be used as the source of high-temperature heat for industrial processes, but the challenge is to design a solar receiver that can effect such a thermal conversion efficiently. This study reports on the engineering design and experimental testing of a 5 kW solar cavity-receiver containing a reticulated porous ceramic (RPC) structure that can absorb high-flux radiation volumetrically and heat up, by convection, an air flow serving as the heat transfer fluid. The thermal performance, characterized by the thermal efficiency and the air outlet temperature, was determined experimentally for four parameters, namely: RPC material (silicon-infused silicon carbide or SiSiC, alumina, and ceria), mean pore size (range 0.8–2.5 mm, corresponding to 10–30 pores per inch or PPI, at 0.90 porosity), solar concentration ratio (range 1965–3900 suns over a 4 cm-diameter cavity aperture, supplied by a high-flux solar simulator), and air mass flow rate (range 2–10 kg/h). Thermal efficiencies between 0.22 and 0.69 were obtained at steady-state air outlet temperatures ranging from 1160 to 450 °C. Larger pores enhance heat transfer while variable porosity across the RPC can reduce temperature gradients and potentially contribute to the design optimization. The highest efficiency of 0.69 was achieved by the SiSiC 10 PPI cavity at an air outlet temperature of 1133 °C and air mass flow rate of 9.9 kg/h. The solar receiver design proved to deliver a high-temperature air flow (>1000 °C) with a reasonably high thermal efficiency (>0.65). [ABSTRACT FROM AUTHOR]

• Many Local governments may negotiate franchise agreements with their utilities. • Over 400 jurisdictions have included clean energy commitments in these agreements. • This article provides lessons learned from five cities that have used this option. • Communities can achieve varied clean energy objectives via this pathway. A growing list of the more than 20,000 municipalities in the United States are considering pathways to achieve renewable energy goals. One emerging trend is for municipalities to incorporate energy objectives into their franchise agreements with an electric service provider. Franchise agreements are contracts between municipalities and utilities that grant the utility authority to serve customers in the municipality. In some cases, municipalities have negotiated renewable energy objectives into these agreements. It is still unclear how many municipalities have exercised this authority and to what effect. From a national dataset of 3500 franchise agreements, we selected five cities that adopted renewable energy or energy efficiency objectives into or alongside their franchise agreements for deeper analysis: Chicago, Illinois; Denver, Colorado; Sarasota, Florida; Minneapolis, Minnesota; and Salt Lake City, Utah. We generated seven key takeaways for other cities considering this pathway to achieve their energy objectives. In summary, municipalities can leverage franchise negotiations to pursue both modest and ambitious clean energy goals (i.e. 100% renewable electricity). This analysis provides municipalities with critical insight on how they can use this potentially formidable tool to achieve their own energy objectives. [ABSTRACT FROM AUTHOR]

• A thermocline TES tank is studied through experimental and theoretical methods. • The TES tank use cheap ore as FSM, which provide good thermal characteristics. • The thermocline layer exists during work of TES tank, inducing good TES performance. • The TES tank is further applied in the CSP system, simulated in the four seasons. • The CSP performance during 24 h in four seasons is studied, proving its stability. The dynamic processes of coworking between thermocline thermal storage single (TES) tank and solar collector is studied for their application in solar concentrated power (CSP) plant. The TES tank uses packed-bed ore as heat storage material. Both experimental and numeric methods are conducted to build its theoretical model, which is used in the simulation of the whole CSP system. The theoretical model of the CSP system mainly composes of three parts: solar radiation, solar collector, and TES tank. It is simulated in the location of city Nanjing, China, to study its dynamic performance in the corresponding solar radiation environment in 4 seasons. The result of simulation shows that the CSP system with TES has stable performance while the solar radiation input varies with hour and season. According to the local solar environmental parameters, (the solar radiation energy density within one day of about 28 MJ/m2, and daytime of about 12 h), the solar system with solar collector and thermocline TES tank of proper capacity is designed. In the absence of sunshine during night, the system could supply heat of 225 kW for 12 h continuously, with an efficiency around 51%. With the similar research methods, it is feasible to assess the performance of thermocline TES single tank in CSP system. [ABSTRACT FROM AUTHOR]

• Modeling of chalcopyrite thin film solar cells and modules electrical behavior with respect to temperature and irradiance. • Validation of a multiple linear regression model for estimation maximum power point of solar modules. • Multiple linear regression model for solar module output calculation and prediction. • Temperature coefficient of copper indium gallium diselenide solar modules and their irradiance dependency. • Irradiance-temperature dependent Voc, Isc, MPP, Impp of CIGS modules. This work presents the validation of a heuristic model, which predicts the electrical characteristics of CIGSSe thin film solar modules. This model is based on four-coefficient equations, used to determine electrical parameters from photovoltaic devices such as open circuit voltage, short circuit current, current at maximum power point and maximum power point. The coefficients are obtained numerically by fitting these equations to measured datasets related to various irradiances and module temperatures. These four coefficients or predictors per parameter can then be used to calculate a parameter at different conditions. The datasets employed in this work were obtained from thin film CIGSSe modules, measured under both controlled laboratory and operating outdoor conditions. The validation of the model is performed by comparing the presented approach to well-known established models and methods for module power rating including the international standards IEC and SAPM. The comparison is performed using statistical analysis, comparing the deviation between the predicted and the measured output power. Furthermore, the possibility of evaluating the temperature coefficients through this model is also explored. The proposed model has been applied and validated yielding high correlation coefficients for CIGSSe modules for energy rating, power output forecasting and temperature coefficient calculation. [ABSTRACT FROM AUTHOR]

• On-sun testing of beam splitting silicon PV retrofit to CSP using RP-3 mirrors. • Modeling and experiments confirmed concentration ratio on PV receiver >20. • Measured PV efficiency on average of 12% based on measure flux to modules. • Improvements in tracking and PV module quality would yield significant improvements. Conversion of sunlight into electricity is the fastest growing commercial means of deploying renewable energy at utility scale. The two primary methods for conversion are photovoltaics and concentrating solar thermal power. The complimentary advantages of these two methods motivates interest in hybridizing the two. Here, a spectral beam splitting approach is designed and tested for application as a retrofit in existing parabolic trough concentrating solar power facilities, the first large scale test using such an approach with low-cost silicon photovoltaic cells. Such an approach leverages the existing capital cost of the plant with the potential to boost plant output. The novel on-sun testing here focused on the electrical performance of a silicon photovoltaic module integrated into the most common parabolic trough geometry with a net aperture area of 1.7 m2. The spectral beam splitter has a solar weighted reflectance of 71.2%, and delivered an average flux to the cells of 17,828 W/m2 representing a concentration ratio of 25×, within 10% of the prediction of the optical ray tracing model. The two photovoltaic modules achieved an average efficiency - based upon measured irradiance delivered to the cells - of 12.4% (or 3% if normalized to the total aperture of the area of the mirror). A corresponding decrease in thermal performance was observed when the retrofit was added. Overall the design is capable of providing a path to retrofit existing parabolic trough powerplants to provide a 13% increase in power output using commercially available photovoltaic technology. [ABSTRACT FROM AUTHOR]

• Deep Neural Networks applied to estimate solar panel size, tilt and azimuth. • Solar panel size estimate with mean percentage error of 3.98%. • Tilt and azimuth estimated with absolute error of 2.55 and 4.71 degrees respectively. • Net load data resolution does not heavily impact accuracy. • Proposed approach is robust to mislabeled training data. There is an ever-growing number of photovoltaic (PV) installations in the US and worldwide. Many utilities do not have complete or up-to-date information of the PVs present within their grids. This research presents a deep neural network approach for estimating PV size, tilt, and azimuth using only behind-the-meter data. It is found that the proposed deep neural network (DNN) method can estimate PV size with an error of 2.09% in a data set with fixed tilt and azimuth values and 3.98% in a data set with varying tilt and azimuths. This is a lower error than the benchmark linear regression approach. A net load data resolution of 1 min provides the lowest error when estimating the PV size. The proposed DNN is also reasonably robust to erroneous training data. When applied to estimate PV tilt and azimuth, the proposed method achieves a mean absolute percentage error of 10.1% and 2.8% respectively. These error metrics are 2.0 × and 3.7 × lower, respectively, than the benchmark linear regression achieves. It was observed that a higher data resolution (1 min) does not provide significant gains in accuracy. It is recommended that a data resolution of 60 min is used to reduce the effects of phenomena such as cloud enhancements. The proposed deep neural network approach is also highly robust, maintaining reasonable accuracy with high levels of mislabeled training data. [ABSTRACT FROM AUTHOR]

• Specific Yields (SY) of 26 different PV modules were measured in a desert environment for one year. • SY differences did not correlate with nameplate Power Temperature Coefficient (PTC). • Explained by differences between nominal and field-measured values of Wp and PTC. • Nameplate PTC alone is not a strong predictor of modules' yields in desert conditions. PV modules which are less sensitive to temperature (i.e. have lower power temperature coefficient, PTC) are expected to produce more energy in hot environments. Yet a year-long study of 26 PV technologies in Doha, Qatar, found that their daily Specific Yield (Wh/day/W p) only weakly correlated with their PTC. To investigate possible explanations, we examined in detail the field data from one multi-Si and one CdTe string, and calculated their energy losses attributable to module temperature, low-light conditions, and "W p discrepancy" (difference in W p between manufacturers' flash tests and field measurements). We found that although the CdTe system had lower PTC than multi-Si, it had larger W p discrepancy, which largely accounted for its lower Specific Yield. Further, PTC values derived from field measurements were significantly different from the modules' nameplate values, for both the multi-Si and CdTe systems. The results indicate that modules' nameplate PTC values did not strongly predict their relative Specific Yields in desert climates, largely because of discrepancy between nominal and field values of PTC and W p. [ABSTRACT FROM AUTHOR]

• Complete energy, exergy and economic analyses in a specified PTC. • Calculation of the key parameters of a PTC. • Comparison of the results for different basefluids (water and thermal oil VP-I) and metal oxide nanoparticles (Al 2 O 3 and CuO). • Energy and exergy efficiencies of PTC with water as a base fluid are 10.81% and 9.44% and for oil are 10.64% and 9.07, respectively. • PTC heat rate gain costs are 0.05 and 0.06 $/kWh for water and oil, respectively. • Adding 5% volumetric ratio of Al 2 O 3 and CuO to water increases annual average energy efficiency. In this paper, energy, exergy and economic analyses of a parabolic trough solar collector (PTC) are carried out in Tehran (Capital of Iran). Two basefluids (water and thermal oil VP-1) with different volumetric ratios (1%, 3%, and 5%) of CuO and Al 2 O 3 nanoparticles are investigated. For this purpose, 1-D mathematical model is developed using MATLAB software to simulate the energy and exergy efficiencies of the PTC. The numerical model is first validated with experimental data from literature and a good agreement was obtained. Numerical results show that using water as basefluid has better energy and exergy efficiencies than oil. Annual average energy and exergy efficiencies (10.81% and 9.44%) of PTC using water as a basefluid are higher than those (10.64% and 9.07%) of PTC using oil as a basefluid. Also in general, adding nanoparticles has non-considerable effects on system performance (both basefluids). For example, adding Al 2 O 3 and CuO with 5% volumetric ratio to water as a basefluid increases annual average energy efficiency 0.03% and 0.09%. But exergy efficiency increases by 1.98% and 0.93%, respectively. Cost of heat rate gain by a PTC is 0.05 and 0.06 $/kWh for water and oil, respectively. Also adding nanoparticles to the basefluid does not have a major effect on this cost. [ABSTRACT FROM AUTHOR]

• Dust and pollutants accumulated on PV in six cities located north of Oman was investigated. • The chemical components of accumulated dust were studied and analysed. • The influence of wind velocity and relative humidity on the collected dust type on the PV cells was examined. • Sodium solutions more effective for PV cells cleaning near industrial area due to high percentage of PM. • Dust physical properties dependent on environmental conditions and geographical area. The Sultanate of Oman, similar to other GCC countries, is affected by the fluctuation of oil prices, which led the decision-makers in this country to move towards renewable energy and particularly the establishment of photovoltaic (PV) solar power plants. This step requires a thorough study before spending millions of dollars to build such power plants. Since dust is one of the main problems of PV in the GCC countries, this study investigates the influence of certain weather factors such as wind speed, relative humidity on dust accumulation and the effect of the cleaning method applied to each city separately. After a full year of observation and data collection on climatic conditions and the output of the six systems installed and used in this study, it is found that the cities of Liwa and Sohar, followed by Muscat, exhibit the highest percentage of dust and contaminants. The most prominent pollutants are the particulate matters (PM) from the chimneys of the power plants, and smelters in the industrial city of Sohar. Also, the movement of a considerable number of vehicles in Muscat caused a rise in the concentration of PM deposited on PV cells. For the other three cities (Al-Khabourh, Suwaiq, and Shinas), they are far from any industrial zone, and because of reduced traffic, the percentage of accumulation of dust and pollution of PV cells was limited. Nine available methods have been used to clean the PV cells after the dust accumulated for one month. From these methods, it is found that the use of water is sufficient to wash the PV cells in the cities of Al-Khaburah, Shinas, and Al-Suwaiq, but the effect of cleaning is more reduced on Sohar, Liwa, and Muscat. Because of PM and many chemical compounds, the use of a sodium solution was the best option in cleaning the PV cells of these three cities. It was noted that the loss of solar cell productivity decreases during the rainy season, which acts as a natural cleaner for the PV. The study also found that dew in the cities studied before sunrise causes the interaction of some salts of sodium, magnesium, and calcium and builds a layer of cohesive salts, which are difficult to clean. [ABSTRACT FROM AUTHOR]

• Proposed an MILP model for integration of heating sides and cooling sides. • Optimal combination of heating and cooling equipment as well as the network. • Investigation of the effect of cold and hot thermal energy storage on cost and emission. • A comparison among conventional, heat-driven, solar-driven, and hybrid generations. • Analysis of cooling distribution network, electrical network, and grid interaction. An optimal design and well-scheduled district cooling system is crucial for the success of the implementation of such systems especially when the cooling plant(s) are intended to be connected to a group of newly-built consumers. In order to supply such customers the required cooling load, a huge capital and operation investment in district cooling network is a necessity if the cooling network is separated from the heating production units. One solution scheme is to take advantage of the heating generation units, which are off during summer to drive the cooling equipment. However, among various design parameters, the most important one is the desirable configuration of the district of interest: best selection and combination of the heating and cooling generation equipment. A least-annualized-cost mathematical approach based on the mixed integer linear programming (MILP) is described in this paper to determine the optimal integration as well as the optimal control of the flow and the storage. The test case study showed that the methodology was effective to give a huge savings in both total annual cost and emission for a wide range of designs. More than 67% of CO 2 emission reduction is achieved through the hybrid heat and solar-driven arrangement. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Aqueous Enterococcus (Gram +) & Proteus mirabilis (Gram −) bacteria are photodegrded. • ZnO nanoparticles partly inactivate both aqueous bacteria in the dark. • With solar simulated light ZnO catalyzes complete inactivation of bacteria in 30 min. • Bacterial mineralization is photocatalyzed by ZnO in 4 h leaving no organics. Abstract ZnO nanoparticles have been effectively used in water disinfection from two common types of gram-positive (Enterococcus faecium) and gram–negative (Proteus mirabilis) bacteria under simulated solar radiations by inactivation. Complete mineralization of organic contents that leach out of inactivated bacteria has also been achieved leaving no soluble organic matter in water. Bacterial inactivation and complete mineralization have been confirmed by plate counting, high performance liquid chromatography and total organic content measurement. Effects of different reaction parameters (pH, temperature, bacterial concentration, reaction time and ZnO catalyst loading) have all been studied. Control experiments with Cut-off filters confirm the role of the UV tail in solar simulated light in the photocatalytic process. The results highlight the feasibility of using ZnO photocatalyst in complete disinfection of water from both hazardous Enterococcus and Proteus mirabilis bacteria, leaving no organic matters after degradation. [ABSTRACT FROM AUTHOR]

Highlights • Automated thermostat system controlled pavement heating and solar thermal collection. • In clear sky conditions, the HP-ETCs collected an average daily power of 2.7 kW. • Average solar heating operation raised stored fluid temperature 11.3 °C in 7 h. • SWHS provided adequate energy to maintain above freezing slab surface temperature. Abstract In this paper, a solar water heating system (SWHS) with heat-pipe evacuated tube collectors (HP-ETC) is experimentally evaluated as a hydronic heated pavement system heat source. Outdoor testing in Fayetteville, Arkansas was performed over the 2017–2018 winter season. The data collected in this study were used to evaluate pavement heating and snow-melting performance. A dual automated thermostat heating system was incorporated to (1) control pavement heating operation to maintain an anti-icing surface temperature (2 °C), and (2) control direct fluid heat transfer from the HP-ETC to the storage tank. Results showed that the SWHS with HP-ETC provided adequate thermal energy to maintain two 3.05 m × 1.22 m × 0.13 m concrete slab surfaces above freezing temperature. During a 6 h man-made snowfall test, the pavement maintained a snow-free surface. The maximum storage tank fluid temperature recorded was 74.0 °C during the test period. In clear sky conditions, the HP-ETC collected an average daily power of 2.7 kW. [ABSTRACT FROM AUTHOR]

This paper introduces an enhanced version of Concentrating Photovoltaic Glazing (CoPVG) device. The original CoPVG system was designed as a seasonal glazing, that concentrates sunlight onto the focus of the lens during summer. Whilst, in winter, the system transmits light for indoor daylighting purposes. The newly developed version, entitled Concentrating Photovoltaic/Thermal Evacuated Glazing (CoPVTEG), is capable of simultaneously harvesting thermal energy and electricity while vacuum glazing (VG) has been integrated into the device. A finite element method was employed to simulate the glazing computationally. The developed model was validated by conducting experiments verifying that the model predicts the glazing performance reliably. Two different configurations were considered: placing the VG facing either outside, called disposition A, or inside, called disposition B. These dispositions were analysed computationally to determine the thermal and electrical output powers of the device in Belfast, UK. It was found that locating the VG inside potentially doubled the output electrical power ranging from 63.32 W/m 2 to 92.56 W/m 2 and from 36.03 W/m 2 to 43.88 W/m 2 at noon throughout the year for disposition B and A, respectively. However, the thermal harvesting potential of disposition A is higher than disposition B. In this case, the device potentially generates from 216.46 W/m 2 to 406.20 W/m 2 thermal power at noon. While the potential will be reduced from 163.54 W/m 2 to 396.11 W/m 2 in disposition B. Disposition A is more advantageous for cold-dominant climate zones while disposition B is the suggestion for temperate climate zone like the studied case. • This study presents Concentrating Photovoltaic/Thermal Evacuated Glazing, a semi-transparent and energy-efficient building façade. • The device serves multiple functions by not only passively managing energy, but also generating clean electricity and heat. • An experiment campaign was conducted to characterize the concept and validate a FEM model. • This research investigates the interaction of vacuum glazing and its placement within the device. [ABSTRACT FROM AUTHOR]

Highlights • An experimental and numerical investigation was achieved on a triangular storage collector. • The hourly system performance parameters were investigated systematically for all test conditions. • In the triangular collector, the day-long collection efficiency of the triangular collector under no load condition in winter was found to be 48.7%. • At continuous loading of the triangular collector, the collection efficiency was 55.7% in winter, and 65.1% in summer. • The performance of the triangular solar collectors was, similar to the performance of the conventional thermosyphon flat plate solar water heaters. Abstract In this study, an experimental and numerical investigation was conducted for a new solar collector design suitable for domestic utilization. The study was carried out to evaluate the performance of triangular collectors that were fabricated by cutting a cubic tank at different cutting planes. Experiments were done at different conditions including during summer and winter with and without the removal of hot water outlet. A systematic investigation on the hourly performance parameters of the system was conducted in all test conditions, which included mean storage temperature, velocity distribution, total stored energy and the best location for inlet and outlet water flows. The results revealed that the triangular collector day-long collection efficiency under no load condition was found to be 48.7% during winter with 40.5 °C maximum mean storage temperature and 65 °C maximum temperature for the hot water from the collector tip. During summer, the day-long collection efficiency was found to be 62.2% with 57 °C maximum mean storage temperature and 70 °C maximum temperature for the hot water from the collector tip. At continuous loading of the triangular collector, the collection efficiency was 55.7% during winter and 65.1% during summer. At continuous loading condition test, the maximum temperature difference between the collector outlet and inlet water was found to be 12 °C at 2 PM and 9 °C at the end of the winter day. To verify the experimental test results, a numerical study was conducted using Fluent software. The numerical results showed a good agreement with the experimental data obtained from this study. [ABSTRACT FROM AUTHOR]

The design, fabrication, and on-sun characterization of a solar dish concentrating system for performing the two-step thermochemical redox splitting of H 2 O and CO 2 is presented. It comprises a primary sun-tracking 4.4 m-dia. solar dish concentrator coupled to a secondary planar rotating reflector. This optical arrangement enables the operation of two (or more) solar reactors side-by-side for performing both redox reactions simultaneously by alternating the solar input between them while making continuous and uninterrupted use of the incoming concentrated sunlight. On-sun characterization of the complete concentrating system revealed a peak solar concentration ratio of 5010 suns and an average of 2710 suns measured over the 30 mm-radius aperture of the solar reactor. A detailed optical analysis elucidates measures to increase the optical efficiency and concentration ratio. [ABSTRACT FROM AUTHOR]

The concept of an evacuated flat plate collector was proposed over 40 years ago but, despite its professed advantages, very few manufacturers have developed commercial versions. This paper demonstrates the reduction in heat loss coefficient and increase in efficiency resulting from evacuating a flat plate collector: it is hoped that these results will stimulate interest in the concept. Evacuated tubes are now mass-produced in large numbers; evacuated flat plate collectors could in principle replace these tubes if the technical difficulties in creating extended metal-glass seals can be overcome. The experimental experiences described here should indicate targets for future research. Two different designs of evacuated flat plate solar thermal collector, each with a 0.5 × 0.5 m flooded panel black chrome plated absorber, were tested under a solar simulator. The cover glasses were supported by an array of 6 mm diameter pillars. Inlet and outlet temperatures were monitored via PT100 RTDs and glass temperatures were measured using thermocouples. Inlet temperature was controlled by a fluid circulator connected to a header tank with a Coriolis mass flow meter to measure fluid flow rate. Testing was conducted indoors with and without the use of a fan to cool the top cover glass. The test conditions spanned the range 200 < G < 1000 W/m 2 , 0 ⩽ T M ⩽ 52 ° C . Evacuating the enclosure reduced the measured heat loss coefficient by 3.7 W/m 2  K: this was a close match to predictions and corresponds to an increase in aperture efficiency from 0.3 to 0.6 at T M / G = 0.06 m 2 K / W . The poor efficiency under non-evacuated conditions was due to the black chrome absorber coating being less selective than commercial panel coatings. The solder seals were developed from experience with vacuum glazing but the increased gap led to reliability issues. A vacuum pump maintained the enclosures under a high vacuum (<0.1 Pa) during testing. The enclosure based on a thin rear metal tray proved to be more effectively sealed than the more rigid enclosure with glass on both sides: the latter developed leaks as the front to rear temperature difference increased. The biggest challenge in the manufacture of evacuated flat plate collectors is to ensure a long-term hermetic seal such that no pumping is required. [ABSTRACT FROM AUTHOR]

The combination of high thermal stability and fast reduction/oxidation kinetics has drawn attention to CeO 2 for use in solar-driven, two-step thermochemical cycles for water and/or carbon dioxide splitting. In accordance with this renewed interest in CeO 2 , there is a need to better understand the gas splitting chemistry on the reduced oxide. In this study, we measured the H 2 production rates over ceria powder, thermally reduced by laser irradiation, during oxidation by H 2 O and CO 2 gases in a stagnation flow reactor. The reaction kinetics was extracted using a model-based analytical approach to account for the effects of mixing and dispersion in the reactor. We find the rigor of this approach necessary in order to identify the rate controlling mechanism and assign parameters to the kinetic model, and to successfully model the production of H 2 and CO production over the entire envelope of the fuel curve. The water splitting reaction, in the range of 750–950 °C and 20–40 vol% H 2 O, can best be described by a first-order kinetic model with low apparent activation energy (29 kJ/mol); while the carbon dioxide splitting reaction, in the range of 650–875 °C and 10–40 vol% CO 2 , is a more complex surface-mediated phenomena. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on refrigerant evaluation and performance comparison of a novel solar-powered hybrid ejection-compression cycle for space cooling or refrigeration. By reducing heat consumption and solar collector area, the novel ejection-compression cycle can have better practicality and performance than conventional hybrid ejection-compression cycle. A model for the novel hybrid cycle is proposed including a validated 1-D ejector model. Five refrigerants are selected from a series of candidate refrigerants and are further evaluated based on cycle performance. Finally, R152a is recommended for its good characteristics and performance. With R152a, the novel cycle is compared with conventional cycle. The results show that the novel cycle has both higher electric efficiency (COP ele ) and thermal efficiency (COP th ), when rationally low solar heat is provided. At low heat region and T g  = 90 °C, the novel cycle only consumes 66.6 kW heat to increase COP ele from 3.01 to 3.76, while the traditional cycle consumes 3 times the solar heat to achieve the same COP ele . When more heat is consumed, the COP ele of conventional cycle increases. However, the increasing installation space and capital cost of increasing collector greatly reduce the practicality of conventional cycle. Therefore, the novel cycle has better feasibility and good energy performance. [ABSTRACT FROM AUTHOR]

This paper describes and assesses two strategies to control distributed solar collector fields, especially during days with partial radiation due to the passage of clouds. The main objective of these control strategies is to maximize the electrical power generated during different situations in which different parts of the solar field receive different degrees of solar radiation. Simulations were carried out using two connected models, one for the solar field (taking into account all of its loops), that includes the passage of clouds, and another one for the power cycle. The solar field simulated is a pilot plant, in which it is assumed that all the loops have the same characteristics; and the nominal power range of the Rankine cycle is 800–2330 kW. Finally, the improvement in electrical power achieved by both strategies is compared with a typical control strategy that tries to keep constant the outlet oil temperature of the field. This improvement varies between 4% for clear days and 5.7% for cloudy days. [ABSTRACT FROM AUTHOR]

This paper shows the relationship between the incident solar radiation and the optimum outlet temperature of a solar field to produce the highest amount of electrical power. Various simulations were made for different values of incident solar radiation, calculating for each one the optimum temperature which produces the maximum electrical power and demonstrating that to operate the field at the highest allowable temperature is not the optimal operating point from certain values of solar radiation; a situation which takes special relevance during cloudy days. These simulations were carried out using two connected models, one for the solar field and another one for the power cycle. [ABSTRACT FROM AUTHOR]

In this paper we present an experimentally validated process for the design of high flux solar simulators based on metal halide arc lamps, which are suitable for research applications including high temperature materials evaluation, concentrating solar power generation, and solar thermochemistry. The objective of our work is to facilitate the design of solar simulator hardware from commercially available components, with an emphasis on accurately predicting hardware performance in the design stage. The inputs to the design process include reflector geometry and surface properties, rated lamp power, and lamp dimensions. These inputs are incorporated in a ray tracing analysis along with a semi-empirical model of a metal halide arc source that accounts for arc shape and the spatial variation of emitted power within the arc volume. This lamp-specific optical model is then further generalized to be applicable to a range of commercially available metal halide lamps. The experimental validation of the design process is accomplished using a single simulator module, and a combination of optical flux mapping and calorimetry to compare the distribution of radiant power delivered by the module to design predictions. Our validation process includes data from four different metal halide lamps, spanning a power range from 1.5 kW e to 4.0 kW e . Design predictions for the generalized optical model agree with experimental data to within ±20% for peak flux and ±9% for total power delivered to a 6 cm diameter target. [ABSTRACT FROM AUTHOR]

High-flux optical systems (HFOSs) are optical concentrators used to increase the radiative flux of the natural terrestrial solar irradiation. High radiative flux concentration leads to high energy density in solar receivers which allows to obtain high temperatures. In solar thermochemical applications, the high-temperature heat drives endothermic thermochemical reactions. HFOSs have been deployed for research and development of solar thermochemical devices and systems, from solar reacting media to solar reactors. Here, we review the designs and characteristics of HFOSs as well as challenges and opportunities in the area of high-flux optical systems for solar thermochemical applications. [ABSTRACT FROM AUTHOR]

Solar thermochemical (STC) redox cycles have made substantial advances in recent years, in large part due to the utilization of nonstoichiometric ceria over other iron oxide and zinc oxide based materials that undergo crystallographic or solid-to-gas phase changes. These changes render their utilization in a cyclic nature to be challenging because of the ever-changing physical properties over time and difficulty in preventing reverse reactions when cooling, for example Zn(g) + 0.5O 2 (g) → ZnO(s). However, such phase changes also have the distinct benefit of being accompanied by large changes in entropy which is typically favorable from a thermodynamic perspective. As a result, the theoretical solar-to-fuel energy conversion efficiencies of ceria-based cycles are usually predicted to be lower than their volatile and nonvolatile stoichiometric counterparts; however, in actuality their measured performance is superior. For this technology to become commercially viable, there is a need to develop new materials that can outperform ceria in terms of solar-to-fuel energy conversion efficiency and operate at more benign conditions. This has been a large focus in the thermochemical community over the last 5–6 years and, to date, most of the effort has been centered on reducing the relatively high operating temperatures that are required while maintaining ceria’s desirable characteristics such as favorable oxidation thermodynamics, rapid reaction kinetics, and crystallographic stability. This effort resulted in many perovskite related materials that operate several hundred degrees lower (e.g. 1473 K). Unfortunately, however, their entropy change is usually lower than that of ceria and the results are consistently a compromise in the thermodynamic driving force for oxidation that results in less efficient materials overall. This work focuses on the thermodynamic, experimental, and computational aspects related to the discovery and characterization of new and better performing redox materials and the attributes necessary of them in order to drive the next generation of efficient STC redox materials. [ABSTRACT FROM AUTHOR]

Fresnel reflection on a water surface is highly variable throughout the year and can have a significant influence on building-integrated vertical PV panels, yet is generally disregarded in yield calculations. We analyze beam irradiances of two horizontal pyranometers situated next to a lake, one facing upwards and one facing downwards, to estimate the contribution of Fresnel reflection to the beam irradiance on a vertical surface. We show that in general the observed beam irradiance on the downward facing instrument matches the calculated Fresnel reflection. In contrast to other studies investigating water albedo, we also found that the reflection percentage decreases consistently with higher wind speeds and lower solar zenith angle. Fresnel reflection has the highest contribution for vertical surfaces in winter, with varying contributions between <1% and >30% of monthly global irradiance over the course of one year for different latitudes, and should thus be included in yield estimates for building integrated PV installations situated next to bodies of water. [ABSTRACT FROM AUTHOR]

The variable geometry ejector (VGE) used in solar-powered ejector refrigeration systems enables performance regulation with unstable heat input, which is important in solar energy utilization; however, the ejector performance is significantly affected by the nozzle configuration. To study the effects of the nozzle configuration on the VGE and to optimize the VGE configuration, experimental investigations are conducted on a supersonic nozzle and a subsonic nozzle used in the VGE under a variety of operating conditions. The experimental results show a close relationship between the driving flow behavior and the ejector performance. The driving flow behavior is influenced by the occurrence of Mach waves, which is significantly influenced by the nozzle configuration. Numerical simulations are conducted that further explain the Mach wave behavior as well as the driving flow development inside the VGE. The results are significant for the optimization and application of the variable geometry ejector in solar-powered ejector refrigeration systems. [ABSTRACT FROM AUTHOR]

PVT collectors aim to solar co-generation of electricity and heat. An new concept raises thermal efficiency by concentrating sunlight with CPC reflectors, in order to access a higher number of solar thermal applications. Losses in PV efficiency due to a higher operating temperature are accepted with regard to a higher overall collector efficiency. As a side effect, the concentration lowers the material usage of PV and enables a high efficient thermal coupling of the PV cell to the heat carrying fluid. The work focuses on the construction, as well as on the angle dependent electrical and thermal measurement of the real-size CPC PVT collector prototype ( 1460 mm × 600 mm × 150 mm ). In previous publications, calculations and experiments studied the influence of the CPC reflectors on the PV efficiency. Further, the thermal coupling between PV cell and heat carrier fluid has been measured in a lab experiment. These results, together with transient annual simulations, were considered in the design process of the CPC PVT prototype with an angular acceptance range of ± 25 ° . The experiments were conducted on the outdoor solar test facility at ZAE Bayern in Garching, Germany. The thermal and PV efficiency has been measured with MPP tracking, as well as for open circuit voltage for fluid temperatures up to 107 ° C . It could be shown, that the thermal efficiency while MPP tracking is elevated to 34 % compared to a glazed flat plate PVT with 17 % for collector temperatures 60 K over ambiance. At the same time, the electrical efficiency drops from 15 % cell efficiency to an overall collector efficiency of 9 % , due to the optical setup, temperature effects and a non-uniform flux distribution caused by the reflectors. [ABSTRACT FROM AUTHOR]

In the present work, a prototype molten salt solar gasification reactor was demonstrated at the 2.2 kW scale using simulated concentrated solar radiation. The molten alkali carbonate salt offers the benefits of improved heat transfer, catalysis of gasification, reduced production of tars, and thermal stability for transient solar input. Utilizing cellulose as feedstock and carbon dioxide as oxidizer, the reactor achieved a solar efficiency of 30% and converted 47% of the carbon in a continuous process at 1218 K. Based on an energy balance on the reactor, we project efficiencies approaching 55% with future improvements to the reactor. [ABSTRACT FROM AUTHOR]

A novel rotating fluidised bed solar reactor for the gasification of carbonaceous materials is presented. A simplified single particle model, in which the particle gasification is coupled with three dimensional equations of motion, is developed and used to study the particle residence time and gasification conversion within the proposed reactor, together with their sensitivity to changes in key operating parameters, namely reactor rotational speed, initial feedstock particle radius, radiation intensity, and particle release position. The proposed reactor is shown to offer potential for increased particle residence time and conversion relative to conventional fluidised beds through adjustments of the operating parameters other than the particle release position. The results presented assist in developing an understanding of the operation of the proposed reactor and optimising its performance. [ABSTRACT FROM AUTHOR]

Hybrid solar-biomass thermal power generation systems are important for continuous power generation installations which supplement each other seasonally in India. In this paper, several aspects associated with hybrid biomass-solar power generation installations such as state wise availability of biomass resources, solar direct normal irradiance (DNI) has been discussed. Month wise daily average DNI is considered as 20%, 40%, 60%, and 80% and remaining heat is taken from biomass resource in the proposed hybrid plant. The thermodynamic evaluation (i.e. Energy and Exergy) of hybrid solar-biomass power plant have also been investigated. The total input energy of the proposed hybrid system is taken from the heat transfer fluid through parabolic trough collector (PTC) as per availability of solar resource and remaining from biomass to maintain the steam at superheated state of 500 °C and 60 bar and supplied to turbine at steam mass flow rate of 5 kg/s. The energy and exergy analyses of 5 MW hybrid system with series mode was carried out to identify the effects of various operating parameters like DNI, condenser pressure, turbine inlet temperatures, boiler pressure on net power output energy and exergy efficiencies. [ABSTRACT FROM AUTHOR]

Nowadays, large area CuIn x Ga 1− x Se 2 (CIGS) thin film solar cells still face difficulties and challenges of the uniformity of composition and structure. This study illustrates how Se concentration affects the crystal growth and the defect formation of CIGS from low cost electrodeposited stacked Cu/In/Cu/Ga/Cu layers selenized in the rapid thermal process. Various crystal growth modes were observed in the film selenized with different Se concentrations. It was found that the crystal growth was strongly dependent on the Se concentration in the early stage of selenization between 250 and 350 °C, which can lead to variations of film composition and structure including a phase separation of CuGaSe 2 from CuInSe 2 and formation of defect holes in a CIGS film at a higher selenization temperature. [ABSTRACT FROM AUTHOR]

A 20 kW p Solar Photovoltaic (SPV) system was set up on the library roof-top in Indian Institute of Science, Bangalore, India. This roof-top photovoltaic (RTPV) system partly powers the Central Office of IISc. The main objective of setting up this SPV system was to study the performance of solar plants under different seasons and climatic conditions of Bangalore. The system has been producing an average daily yield of approximately 80 kWh for the past two years which translates to an annual yield of 28.9 MWh. The overall yield of the system up to 14 th September 2015 is 70 MWh. This work focuses on the evaluation of the performance of SPV systems using the popular grading systems, namely Capacity Utilization Factor (CUF) and Performance Ratio (PR). The CUF of the SPV system is 16.5%, which lies within the range of CUF of well-performing solar plants located in India. Average Performance Ratio (PR) of the SPV system is around 85%, which indicates that the performance of the SPV system is satisfactory. PR of the SPV system is correlated with the behaviour of SPV modules in different seasons, with module temperature ( T mod ) as the key factor of comparison. In summer, the SPV modules attain maximum efficiency ( η max ) at T mod of 45 °C, but in winter, it is at 55 °C. In summer, for T mod > 45 °C, module efficiency ( η ) reduces by 0.08% per degree rise in temperature. In monsoon, for T mod > 35 °C, η reduces by 0.04% per degree rise in temperature. In post-monsoon period, for T mod > 38 °C, η reduces by 0.06% per degree rise temperature. However, in winters, the modules attain η max at T mod of 55 °C, without much drop in efficiency. This is mainly because of intermittent natural cooling that takes places at the surface of the modules, due to cool breeze and lower ambient temperatures. [ABSTRACT FROM AUTHOR]

In this study, we investigate the ability of porous tubes to maintain thermal stratification in a water storage tank in comparison to a top-mounted inlet pipe. Transient distributions of temperature and velocity are presented for operating conditions and a tank geometry representative of solar domestic hot water systems using a transient two-dimensional computational fluid dynamic model. The stratification in the tank is quantified by a dimensionless exergy efficiency. The results demonstrate the importance of selection of the permeability of the manifold on performance. A porous manifold improves thermal stratification for intermediate charging, regardless of the choice of permeability. Over a large range of Richardson number, the manifold is most effective for a dimensionless permeability, defined by the ratio of the pressure drop across the porous wall to the axial pressure gradient, equal to 0.02. Such a manifold will deliver the fluid to the tank in a narrow band at the vertical position of neutral buoyancy and will prevent suction of warmer fluid stored at the top of the tank into the manifold. For top charging the porous manifold is comparable in performance to a well-designed inlet pipe. Recommendations of selection of porous material based on dimensionless permeability are provided. [ABSTRACT FROM AUTHOR]

This paper examines the potential of sodium receivers to increase the overall solar-to-electricity efficiency of central receiver solar power plants, also known as solar tower systems. It re-visits some of the key outcomes and conclusions from past sodium receiver experiments, in particular those at Sandia National Laboratories and Plataforma Solar de Almeria in the 1980s, and discusses some current development activities in the area. It also discusses research in sodium receivers with a liquid–vapour phase change (heat pipes and pool boilers), to explore whether technologies developed for dish-Stirling systems have applicability for solar tower systems. Lessons learnt from experience in the nuclear industry with liquid sodium systems are discussed in the context of safety risks. [ABSTRACT FROM AUTHOR]

Measuring the spatial distribution of irradiance on surfaces has extensive applications in various fields of heat transfer such as concentrating solar energy. In this paper, we have introduced a close range radiometry measurement method for flat surfaces employing camera calibration to extract illumination distribution data with high accuracy and resolution. The equations for quantifying the illumination profile on the target using the measured geometrical parameters have been introduced. The method developed in this work was experimentally demonstrated to have an accuracy of ± 10 % with additional improvement opportunities identified and discussed. [ABSTRACT FROM AUTHOR]

In India, continuous production of electricity and sweet/potable water from Solar power and desalination plant plays a major role in the industries. Particularly in Carbon black industry, Solar power adopts Solar field collector combined with thermal storage system and steam Boiler, Turbine & Generator (BTG) for electricity production and desalination plant adopts Reverse osmosis (RO) for sweet/potable water production which cannot be used for long hours of power generation and consistency of energy supply for industrial processes and power generation cannot be ensured. This paper presents an overview of enhanced technology for Solar power and Desalination plant for Carbon black industry making it continuous production of electricity and sweet/potable water. The conventional technology can be replaced with this proposed technique in the existing and upcoming industries. [ABSTRACT FROM AUTHOR]

Based on finite volume method, the steady-state thermal performances of the flat-plate solar collector are studied by taking account of absorber plate thickness, collector tube spacing, collector tube length, collector tube diameter and insulating layer thickness. A physical model of gilled flat-plate solar collector is built, then the numerical simulation of the model is carried out and the numerical simulation results are compared and analyzed with experimental results. The results show that: Either increasing the absorber plate thickness or reducing the collector tube spacing can significantly improve the instantaneous efficiency of the collector. Setting the solar radiation intensity of 700 W/m 2 and the environmental speed of 4 m/s, when the absorber plate thickness increases from 0.1 mm to 2.1 mm, the collector instantaneous efficiency increases from 46.57% to 64.03%. When the collector tube spacing decreases from 170 mm to 50 mm, the collector instantaneous efficiency increases from 52.81% to 66.01%. Reducing the collector tube length and increasing collector tube diameter are both conducive to improve the instantaneous efficiency of the collector. When the collector tube length decreases from 2800 mm to 1200 mm, the collector instantaneous efficiency increases from 57.50% to 60.12%. When the collector tube diameters increases from 8 mm to 20 mm, the collector instantaneous efficiency increases from 56.18% to 63.97%. When the thickness of insulating layer is 30 mm or more, increasing its thickness has no significant effect on improving the instantaneous efficiency of the collector. The research results are helpful to optimize the design parameters of the flat-plate solar collector. [ABSTRACT FROM AUTHOR]

The crystalline silicon type cell is at present the most commonly used photovoltaic device on the market. These solid state devices are only capable of converting a portion of the solar spectrum into electricity. Disregarding reflection losses, the remaining portion is absorbed by the cell thus elevating its operating temperature. It has been shown in a number of previous studies that the overall electrical performance of these cells will deteriorate with temperature, with power output dropping linearly with temperature. In this study, we examine this issue in closer detail by investigating how temperature affects each of the five characterisation parameters required to characterise their electrical behaviour using the single diode five parameter model. Collecting current–voltage data from a mono-crystalline silicon cell at constant irradiance but at temperatures varied within the range of 25 and 70 °C (the typical range experienced in the field), we calculated the five modelling parameters using a unique numerical approach which takes into consideration several points taken from the experimental current–voltage data. It was found that all five modelling parameters were influenced by temperature, with the reverse saturation current followed by the series and shunt resistances being affected most significantly, in that order. Photovoltaic device modelling will be enhanced by taking into account the influence of temperature on each of these characterisation parameters. [ABSTRACT FROM AUTHOR]

A new integrated system, which combines three renewable energy sources and generates five different commodities as useful outputs, is proposed and analyzed energetically and exergetically. The mass, energy, entropy and exergy balance equations for the major components of the integrated system are written and analyzed. The energy and exergy efficiencies for the integrated system and its subsystems are defined and calculated. Parametric studies are conducted by varying dead state properties and operating conditions to investigate their effects on the system performance. Some meteorological and system data from various previous studies are used in the analyses and assessments. The results show that the energy and exergy efficiencies of the integrated system become 36.67% and 25.075% respectively. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fabricated 2μm-thick Si1−xGe x based solar cells with x =0, 0.25, 0.41 and 0.56. [•] Novel strained-Si layer grown on Si1−xGe x improves the solar cell performance. [•] J sc increases from ∼14mA/cm2 for Si cells to 21mA/cm2 for the Si0.44Ge0.56. [•] Improved spectral response for Si1−xGe x solar cells compared to Si demonstrated. [Copyright &y& Elsevier]

Highlights: [•] Development of CZTS solar cells using elemental metal sputtering. [•] Reported efficiency of 5.75%. [•] 112-Oriented CZTS films with well-defined morphology obtained. [•] 550°C found to be optimum temperature for CZTS growth. [•] CZTS films exhibit near-optimum bandgap ∼1.5eV. [ABSTRACT FROM AUTHOR]

Highlights: [•] Analysis of key components for a thermochemical cycle for solar hydrogen production. [•] Process analysis of this two-step thermo chemical cycle with an exergy analysis. [•] Development, simulation and optimization of the secondary concentrator shape. [•] Reactor design with thermal balancing of the reactor. [Copyright &y& Elsevier]

Highlights: [•] A fluid-less description of an inverse thermodynamic cycle is provided. [•] On this ground, a steady state model for solar assisted heat pumps is derived. [•] The model results able to describe the averaged behavior of the considered system. [•] The proposed approach appears suitable in view of design and regulation purposes. [ABSTRACT FROM AUTHOR]

Abstract: Previous computer simulations and bench-scale experiments showed that the heat pipe assisted solar wall had the potential for significantly improved performance relative to conventional passive space heating systems. To further test this potential, a full-scale prototype of the heat pipe system was designed, built and installed in a classroom on the University of Louisville campus in Louisville, KY. During the spring heating season of 2010 (January–April), maximum daily peak thermal efficiency was 83.7% and average daily peak thermal efficiency was 61.4%. The maximum hourly average room gain achieved during the season was 163W/m2. On days with good solar insolation, the thermal storage was heated to temperatures sufficient to provide significant energy to the classroom – even during the coldest days of the season. During the longest period (4 days) of low insolation during the season, average hourly heat delivery to the room from storage remained positive, and was never less than 16.6W/m2. During good insolation days following a period of consecutive low insolation days, thermal storage temperature was quickly restored to levels comparable to those obtained during consecutive good insolation days. Estimated heat removal factor * transmittance absorptance product F R(τα) and heat removal factor * overall loss coefficient F R U L values for the system were comparable to those for glazed liquid active collectors. [Copyright &y& Elsevier]

Abstract: Australia has an abundant solar energy resource that is likely to be used for energy generation on a large scale. Variable sources of electricity generation require knowledge of the nature of their variability at all time scales. This study examines the effect that El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) have on solar radiation in Australia, in order to establish the role for seasonal forecasting of solar power. Calendar years are classified into their ENSO state using a sea surface temperature index. The ERA-Interim and NCEP reanalysis products are then used to estimate the effect of ENSO on global horizontal solar irradiance over the continent. A bootstrap technique is used to obtain confidence regions for the effect in both winter and summer. The main impact of ENSO occurs during winter over a large part of eastern Australia. Little impact was observed over the continent during summer. A similar analysis is conducted for the Indian Ocean Dipole (IOD) to ensure that the observed ENSO effect is not a manifestation of the IOD. This study indicates that the ENSO phenomenon may account for solar energy changes of more than 10% in some locations on a seasonal basis. We show that the solar radiation analysis is directly applicable to solar energy yield. Knowledge of this variability may influence the location of large solar generation plants. Also, there is a potential to predict solar energy a few months ahead by means of seasonal forecasting systems, which would help to assist with planning for electricity grid. [Copyright &y& Elsevier]

Abstract: This paper presents the modeling and optimization of a solar assisted heat pump using ice slurry. Solar collectors are used as the primary source of thermal energy, with two distinct loops allowing the collectors to operate in series with an ice tank, or a warm water tank. Thermal energy stored in the ice tank is transferred to a warm water distribution tank via a heat pump. First, a new mathematical model of an ice slurry storage tank is presented. Validation of the model with experimental data confirms its ability to predict the ice mass and tank fluid temperatures during the charging and discharging modes of operation. The developed ice tank model is combined with the TRNSYS energy simulation program to formulate a complete model of the proposed heat pump system. This computer model then serves as a base for a mathematical optimization with the objective to minimize the energy use for heating and DHW over a single heating season. Simulated results demonstrate the potential of the optimized system in reducing the heating operating energy use of a high performance home in Montreal, QC. [Copyright &y& Elsevier]