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Metal–organic frameworks (MOFs) are promising for indoor humidity regulation due to steep stepwise water uptake and moderate regeneration temperature. Current approaches for performance improvement of MOFs such as impregnating hygroscopic salts and grafting functional groups face the challenge of corrosion and instability. Herein, a template‐guided tuning strategy is proposed to synthesize binary nanocomposite. Highly ordered mesoporous channels of MCM‐41 provide uniform nucleation sites for MOF growth, enabling a 21.5% promotion of specific surface area (3188.14 m2 g−1) and 23.4% improvement of water uptake (1.53 g g−1 at 20°C/90% relative humidity) for the nanocomposite compared with parent MIL‐101(Cr). The fast kinetics and superior stability together guarantee its practical application. Further, a paradigm of continuous indoor humidity regulation driven by sunlight is demonstrated, which realizes smart regulation of the indoor humidity to the human comfort zone (40–60%) with near‐zero energy input. [ABSTRACT FROM AUTHOR]

Winemaking is a global industry that needs to advance with the times taking into consideration the developing drinking needs, tastes of human beings and the growing demand on the world's renewable energy sources. Climate changes have brought nowadays challenges of energy requirements, subsequent emissions and the detrimental effects facing the winemaking industry and mankind. Given its energy requirements, concomitant emissions and the pernicious effects, winemaking industry should bear the brunt of improving energy utilization efficiency and promoting the development and adoption of renewable energy utilization technologies. Various kinds of renewable energy are being used in winemaking industry worldwide, especially solar energy in the form of solar thermal and solar photovoltaic, which offer a clean solution to fossil fuels shortage and pollutant emissions caused by or involved in winemaking processes. The objective of this paper to present challenges facing solar energy utilization in winemaking by summarizing the status of solar energy utilization in wineries worldwide, by outlining the current solar energy profile of these wineries and by stressing the existing and potential application aspects of solar energy in winemaking. Considering the more rapid development of PV industry, PV chain and economic feasibility are analyzed. By taking China as an example, the comparison and asymmetry between PV production and active solar-related winemaking are stressed aimed at appealing to winemakers and policymakers to turn more to renewable energy like solar energy. Based on that, essential suggestions are provided, which are expected to extend solar energy systems for subsequent contributions to energy conversation, environmental protection and reduction of land occupation. [ABSTRACT FROM AUTHOR]

In this paper, a solar hybrid desiccant air conditioning system, which combines the technologies of two-stage desiccant cooling system and geothermal heat pump together, has been configured and theoretically analyzed. The hybrid system mainly includes a two-stage desiccant cooling system with design cooling capacity of 80 kW, a geothermal heat pump for fresh air handling with 75 kW in nominal cooling capacity, a geothermal heat pump for capillary radiation terminal with cooling capacity of 244 kW, an evacuated tubular solar collector array of 530 m 2 , a hot water storage tank and a cooling tower. Performance model of the system has been created in TRNSYS simulation studio. The aim of this paper is to evaluate the performance of the solar hybrid air conditioning system, thereby providing useful data for practical application in the demonstration project. Simulation results show that, under typical weather condition, the solar driven desiccant cooling unit can achieve an average cooling capacity of 70 kW, which contributes 31.4% of the cooling capacity provided by the hybrid system. Corresponding average thermal COP is about0.83 under Shanghai weather conditions. [ABSTRACT FROM AUTHOR]

Solar energy refrigeration is very attractive for low-temperature grain storage because the cooling load of low-temperature grain storage is roughly in phase with solar energy availability. In this study, a solar-powered adsorption chiller was developed with aim of developing an alternative refrigeration device for low-temperature grain storage. The solar-powered adsorption chiller was put into experimental operation during summer and autumn. Test results show that the solar-powered adsorption chiller can produce a cooling capacity about 66–90 W per m2collector area. Its daily solar-cooling COP (coefficient of performance) is about 0.1–0.13 under the climatic conditions of daily solar radiation being about 16–21 MJ/m2·day. With appropriate ventilation appliance, this kind of solar-powered adsorption chiller could be considered as an alternative for low-temperature grain storage in most areas of China. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper, a solar hybrid desiccant air conditioning system, which combines the technologies of two-stage desiccant cooling (TSDC) and air-source vapor compression air-conditioning (VAC) together, has been configured, experimentally investigated and theoretically analyzed. The system mainly includes a TSDC unit with design cooling capacity for 10kW, an air-source VAC unit with 20kW in nominal cooling capacity, a flat plate solar collector array for 90m2, a hot water storage tank and a cooling tower. Performance model of the system has been created in TRNSYS simulation studio. The objective of this paper is to report the test result of the solar hybrid air conditioning system and evaluate the energy saving potential, thereby providing useful data for practical application. Experimental results show that, under typical weather condition, the solar driven desiccant cooling unit can achieve an average cooling capacity of 10.9kW, which contributes 35.7% of the cooling capacity provided by the hybrid system. Corresponding average thermal COP is over 1.0, electric COP is up to 11.48. Under Beijing (temperate), Shanghai (humid) and Hong Kong (extreme humid) weather conditions, the solar TSDC unit can remove about 57%, 69% and 55% of the seasonal moisture load, thereby reducing electric power consumption by about 31%, 34% and 22%, respectively. These suggest that the solar hybrid system is feasible for a wide range of operating conditions. [Copyright &y& Elsevier]

• The efficiency factor of direct expansion PVT module is derived and validated. • Proposed a novel design method for PVT module employing roll-bond evaporator. • Parameter analysis is conducted to evaluate the thermal performance of four different channel patterns. • Hexagon and rectangle types have better temperature uniformity while grid and linear types have lower pressure loss. Direct expansion solar assisted PVT (photovoltaic/thermal) heat pump is a combination of PVT technology and heat pump technology, which can improve the comprehensive conversion efficiency of solar energy, and it is suitable for solar heating applications. In this paper, the efficiency factor of direct expansion PVT module employing roll-bond panel has been theoretically derived, modified, and validated by experimental results. Moreover, the efficiency factor could be used to design, evaluate, and optimize the thermal performance of direct expansion solar assisted heat pump systems. In addition, parameter analysis of four evaporator unit types has been conducted, and the recommendation values of each parameter have also been presented. The simulation results show that the roll-bond evaporator (fluid channel width: 10 mm) with hexagon and rectangle patterns have better temperature distribution uniformity than grid and linear types, and their temperature differences are both 0.038 °C while their dimensionless pressure losses are 0.109 and 0.230, respectively. To specifically design different kinds of PVT collector/evaporator or direct expansion evaporators, a novel design method for roll-bond evaporator is proposed, and a combination of hexagon and grid types is recommended for PVT module. Moreover, the recommendation fluid channel width of the roll-bond panel is 8 mm to 13 mm while the scaling ratio is 0.8 to 1.2. The modified efficiency factors are 0.521, 0.564, 0.549, and 0.342 of hexagon, grid, rectangle, and linear types when the fluid channel width is 10 mm, respectively. [ABSTRACT FROM AUTHOR]

• A solar-driven GAX-based ammonia-water absorption heat pump was proposed. • Experimental and theoretical analysis on the system was carried out. • Thermal efficiency of the heat pump was optimized. • Effects of different operation parameters on system performance were analyzed. This research involves a GAX-based ammonia-water absorption heat pump, which utilizes solar energy and natural gas as heat source. The experiments of parabolic tough collector and GAX absorption heat pump were carried out separately. GAX absorption heat pump is operated when the ambient temperature is 4.31–11.07 °C, COP approaches 1.44–1.66. Thermal efficiency of the PTC varies from 0.50 to 0.60. A mathematical model of the coupled solar absorption heat pump is built. The effect of each heat exchanger size on the GAX cycle performance is investigated, results show that the heat exchanger size of solution cooled absorber has the greatest impact on the cycle. Both Solar driven mode and Solar-NG driven mode were studied. Solar driven mode is strict with solar energy, if the direct normal irradiance is below 560 W/m2 the system cannot work. Solar-NG driven mode could work under any solar radiation condition. In this mode, generation temperature could be controlled by changing the flow rate of natural gas. The optimal generation temperature is found to be around 180 °C when T amb = 7 °C, DNI = 800 W/m2, T wout = 45 °C. Besides, system analysis reveals that the heat pump could perform competitive in low ambient temperature if the solar radiation is abundant, which makes Lhasa a perfect site for the system. Economic analysis in Lhasa show that the addition of solar collector could reduce the operating cost by more than 25%. [ABSTRACT FROM AUTHOR]

• A solar PV/T heat pump is proposed for residential heating in high latitude area. • Design of build-in PCM heat storage unit is proposed and simulated. • The overall efficiency of this solar PV/T heat pump system can reach above 75%. PV/T (photovoltaic/thermal) technology is a combination of PV module (photovoltaic utilization) and collector (photothermal utilization), which can improve the comprehensive utilization efficiency of solar energy and has a broad application prospect. In this paper, PV/T module is coupled with heat pump evaporator to form a direct-expansion solar PV/T heat pump which is suitable for heat application in high latitude area. To achieve stable residential heating, a solar PV/T heat pump system coupled with build-in PCM (phase change material) heat storage is therefore proposed and simulated. Meanwhile, the mathematical model of solar PV/T heat pump coupled with build-in PCM heat storage system is established and verified. The simulation results show that the temperature of underfloor heating which using build-in PCM heat storage can reach 22–31 °C after 39 h when the circulating water is 40 °C. Moreover, the heating COP (Coefficient of Performance) increases with the increase of solar radiation, ambient temperature and area of PV/T collector, and decrease of wind speed, respectively. A 20 m2 PV/T panel module can output 21.4% of the electricity to power grid when the solar radiation intensity is 600 W/m2 and meet the heat demand of a 100 m2 room while maintain the operation of the system. Meanwhile, the heating COP can reach 5.79 which is 70% higher than the conventional air conditioning system and the electrical, thermal, overall efficiencies are 17.77%, 55.76% and 75.49%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • The energy and economic impacts of solar photovoltaic soiling were modelled. • Relative net-present value change was defined to assess optimal cleaning intervals. • We compared the soiling-induced efficiency and economic losses in seven cities. • The efficiency loss is the lowest (<0.04) for Tokyo and highest (>0.8) for Doha. • The optimal intervals are 23–70 days (manual) and 17–49 days (machine). Abstract This work developed a framework to predict the energy and economic impacts of solar photovoltaic soiling. This framework includes the effects of relative humidity, precipitation and tilt angle on solar photovoltaic soiling. A concept of relative net-present value change was introduced to determine the optimal cleaning interval. The uncertainties in the economic analysis were accounted for using a Monte Carlo simulation method. The framework was used to study the soiling-induced efficiency and economic losses of solar photovoltaic modules in seven cities (i.e. Taichung, Tokyo, Hami, Malibu, Sanlucar la Mayor, Doha, and Walkaway). Overall, the efficiency loss (in ascending order) for Tokyo/Walkaway < Taichung < Sanlucar la Mayor < Malibu/Hami < Doha for a one-year study period. Doha experiences an efficiency loss over 80% for a 140-day exposure, while Tokyo has an efficiency loss less than 4% for a one-year exposure. Malibu has longest optimal cleaning intervals (70 days for manual cleaning and 49 days for machine-assisted cleaning) that leads to the relative net-present value changes of 1.7% and 1.1%. Doha has the shortest optimal cleaning intervals (23 days for manual cleaning and 17 days for machine-assisted cleaning) that leads to the relative net-present value changes of 21% and 19%. The work serves as an effective tool for designing optimal cleaning protocols for solar photovoltaic systems. [ABSTRACT FROM AUTHOR]

• Quantifies hourly generation potential of building-integrated PV (BIPV) for Tokyo. • Shading effects and morphological characteristics of building stock are considered. • PV potential equivalent to 15%–48% of the annual energy demand in the year 2050. • Changes in hourly net electricity load and potential impacts are evaluated. The installation of photovoltaic (PV) modules is one of the most effective measures for decarbonizing urban building stock. The considerable potential of the process has been demonstrated using building-integrated PV (BIPV) modules. Earlier studies have provided significant knowledge about the PV potential of buildings, but a detailed investigation of the large-scale installation of BIPV modules on building façades has not been undertaken. In the present study, a model for estimating the hourly PV potential of building surfaces on a regional scale was developed and applied to commercial building stock in Tokyo, Japan. Analytical results showed that the generated PV power would be capable of satisfying 15%–48% of the annual electricity demand of the building stock in 2050, based on the extent to which the PV potential of building surfaces, especially façades, was exploited. This demonstrates the usefulness of BIPV for achieving a decarbonized society. Additionally, hourly estimation results showed that, if a higher economic efficiency is pursued, the use of large-scale installation of BIPV together with rooftop-mounted PV could increase the PV power generation without altering the hourly PV power fluctuation. However, electricity demand and generation analyses revealed the negative impacts of the larger-scale BIPV installation on the power system: The reduction in asset utilization and the increase in the need for flexibility. The findings of this study promise to be useful to policymakers in formulating guidelines for the use of BIPV modules. [ABSTRACT FROM AUTHOR]

• Solar photovoltaic-assisted ground-source heat pumps are studied in Nordic climate. • Ground regeneration with solar thermal energy improves long-term performance. • Designs are compared in terms of energy efficiency, cost, and ground heat transfer. • Photovoltaic-thermal leads to lower investment costs by reducing the borehole size. Ground source heat pumps (GSHP), as a renewable energy technology, are highly efficient systems suitable for meeting the heating needs of buildings, particularly in heating-dominated regions like Scandinavia. This study aims to better define the scope of application and sizing of GSHP combined with photovoltaic-thermal (PVT) collectors in Nordic conditions. The study compares seasonal performance factors (SPF), average ground temperatures, and investment costs for heating different numbers of apartment blocks in two distinct Nordic climates: Baltic climate and cold continental climate. To assess the long-term effects on the energy performance of GSHP + PVT systems, dynamic simulations using the TRNSYS software are conducted over a period of 50 years. The results demonstrate that PVT improves the long-term system performance, particularly in large and compact borehole (BH) fields, while in smaller BH fields, natural regeneration keeps playing a substantial role. For instance, PVT added to a GSHP system with large BH field can limit the ground temperature reduction after 50 years by 33 % compared to the configurations without PVT. In contrast, this reduction is only 13 % for systems with small BH fields. Moreover, the results show that GSHP + PVT can lead to a reduction of up to 95 % in the required area for installing the BH field while maintaining (almost) the same energy performance compared to a conventional GSHP. Notably, this study shows that the utilization of GSHP + PVT leads to a substantial reduction in BH length (up to 50 %) while maintaining a similar system SPF. It leads to a decrease in investment costs of up to 9.32 % and 22.92 % for the scenarios located in Norway and Sweden, respectively, compared to the case with PV instead of PVT. These findings suggest that PVT integration holds promise for advancing the GSHP adoption in high-latitude regions, especially in larger installations and colder climates, by mitigating investment costs while preserving the system SPF and ground temperature stability. [ABSTRACT FROM AUTHOR]

In this study, a distributed aerobic composting system was proposed and simulated assisted by a solar photovoltaic thermal (PV/T) heat pump. The PV/T heat pump was adopted to provide the electrical energy and heat energy required by the aerobic composting system. In addition, the area of solar photovoltaic panels required for compost fermenter at different volumes was calculated, and the effects of ambient temperatures, wind speeds and solar radiation intensities on the performance exhibited by the hybrid system were investigated. As indicated from the result, when the temperature of the composting tank was maintained at 60 °C, the C/N ratio can be reduced to 11.5:1 and the GI can reach 101.7%, satisfied the compost maturity standard. Moreover, as the ambient temperature decreased, the heat loss of the composting system and the energy consumption of the hybrid system increased. The wind speed did not significantly impact the comprehensive performance exhibited by the system. Under the average solar radiation of 600 W/m2, a maximum of 10 m2 PV/T panels could be installed on the top of a standard container, and a maximum of 6000L of aerobic composting system could be installed within the container. Accordingly, the 6000L composting system coupling with PV/T heat pump could generate 85.64 kWh electricity in one period (10 days) without consuming energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Theoretical and run-test evaluation of the 50 MW beam-down power plant is conducted. • The variation in heliostat efficiency, flux density, and power generation is analyzed. • The average outlet temperature of the molten salt was up to 559℃ for 50 min. • The flux density of hyperboloid mirror on four typical days is 10.2/11.2/10.9/9 kW/m2. • The flux density of receiver on four typical days is 353.6/399.1/381.7/314.2 kW/m2. The beam-down concentrating solar power plant has the advantages of high concentrating ratio, low installation and maintenance requirements, and low pump consumption. To conduct further theoretical and run-test evaluations of the optical and thermal performance of the beam-down concentrating solar power system, the Yumen Xinneng 50 MW beam-down power plant is analyzed in this research. The variation of the heliostat field efficiency, hyperboloid mirror flux density, receiver flux density, and annual power generation under various operating parameters is discussed. The run-test results from June 12th indicated an average outlet temperature of molten salt reached 559°C between 13:07 and 13:56 under an average direct normal irradiation of 739.7 W/m2. The corresponding inlet temperature increased from 302.3°C to 307.6°C due to the rewarming effect caused by the increase in hot molten salt. Regarding the simulation results, the recommended design parameters for the vertex ratio of the hyperboloid mirror are between 0.775 and 0.8 to mitigate the contradiction between initial investment and optical efficiency. The maximum values of cosine efficiency, shading and blocking efficiency, shading efficiency of the hyperboloid mirror, and attenuation efficiency for the heliostat field are 85.56%, 99.96%, 99.35%, and 97.46% on June 1st for the maximum solar elevation angle of 70.72°. Consequently, the maximum values of the average hyperboloid mirror flux density and receiver flux density are 11.2 kW/m2 and 399.1 kW/m2 on June 1st. The maximum power generation for a 7-day period is 4674.22 MWe in June with a duration time of 100 hours. This paper can further expand research on the comprehensive performance of beam-down power plants. [ABSTRACT FROM AUTHOR]

Abstract: A solar-powered adsorption chiller with heat and mass recovery cycle was designed and constructed. It consists of a solar water heating unit, a silica gel-water adsorption chiller, a cooling tower and a fan coil unit. The adsorption chiller includes two identical adsorption units and a second stage evaporator with methanol working fluid. The effects of operation parameter on system performance were tested successfully. Test results indicated that the COP (coefficient of performance) and cooling power of the solar-powered adsorption chiller could be improved greatly by optimizing the key operation parameters, such as solar hot water temperature, heating/cooling time, mass recovery time, and chilled water temperature. Under the climatic conditions of daily solar radiation being about 16–21MJ/m2, this solar-powered adsorption chiller can produce a cooling capacity about 66–90W per m2 collector area, its daily solar cooling COP is about 0.1–0.13. [Copyright &y& Elsevier]

[Display omitted] • A novel solar-driven biomass chemical looping gasification system is studied. • The system achieves a carbon-gas yield of 0.69 and an energy upgrade factor of 0.71. • The fuel reactor produced CH 4 , CO, CO 2 and H 2 at 0.63, 11.86, 8.85, and 18.53 mmol/g. • High-purity H 2 is produced at 7.17 mmol/g in a separated stream. • Fayalite is found as a byproduct due to the interaction between reactants. A novel solar-driven biomass chemical looping gasification (SBCLG) system was proposed and experimentally demonstrated for the co-production of pure hydrogen and syngas from biomass wastes using high-flux solar irradiation. In this system, a steam reactor and a solar fuel reactor were adopted to replace the air and fuel reactors in a typical biomass chemical looping gasification (BCLG) system, respectively. The SBCLG exhibits two advantages over BCLG: (1) the syngas yield is raised as the high-temperature process heat is provided by solar radiation rather than biomass combustion, and (2) a pure hydrogen stream is generated in addition to the syngas stream, which allows a flexible adjustment of the carbon-to-hydrogen ratio for downstream chemical processes. This study marked the first demonstration of a complete cycle of SBCLG in a cavity-type packed-bed solar reactor under simulated high-flux solar irradiation. Magnetite (Fe 3 O 4) was circulated between the steam reactor and the solar fuel reactor as the oxygen carrier (OC). The optimal operational parameters, the reaction temperature and solid contact pattern, were first determined in preliminary experiments in an electric furnace. Then, the effect of biomass to oxygen carrier mass ratio (m RH : m OC) on the key performance indicators was also investigated in a solar reactor. When m RH : m OC = 1:2, the highest values of the average carbon-gas yield of 0.69 ± 0.05 and energy upgrade factor of 0.71 ± 0.04 were achieved. The solar fuel reactor produced CH 4 , CO, CO 2 and H 2 at 0.63, 11.86, 8.85, and 18.53 mmol/g biomass, respectively, with the steam reactor yielding high-purity H 2 at 7.17 mmol/g biomass. The results indicated that the SBCLG is a viable method for co-production of pure hydrogen and syngas in separate streams. [ABSTRACT FROM AUTHOR]

Borehole heat exchanger (BHE) is a promising method for extracting heat from the deep geothermal energy which has been widely used for residential heating in high latitude areas. The solar assisted photovoltaic/thermal (PV/T) heat pump could convert solar energy into useful heat efficiently, and could be further used to heat water from the BHE to a higher temperature level. In this paper, a residential heating system using BHE coupled with solar assisted PV/T heat pump is therefore proposed with further performance analysis. The simulation results show that a larger mass flow rate could increase the BHE's heat extract capacity but also increase the flow resistance and pump power under nominal conditions. The circulating water would not extract heat from rock-soil if the inlet temperature exceeds 48.5 °C when mass flow rate is 12 kg/s. Furthermore, the maximum water temperature from this hybrid system could reach 40.8 °C while the solar fraction is 67.5% when the area of PV/T module is 1000 m2, solar irradiation is 600 W/m2 and depth of the BHE is 2500 m. In the meantime, the heating COP of this hybrid system could reach 7.4 and the system could operate independently without power input from electrical grid. • A hybrid residential heating system using borehole heat exchanger coupled with solar assisted PV/T heat pump is proposed. • The structure and operating parameters of this hybrid system have been analyzed. • The heating COP of this hybrid system could reach 7.4, while the solar fraction is 67.5%. • The maximum thermal effect radius of a 2500 m borehole heat exchanger is within 8 m. • Higher mass flow rate and inlet temperature lead to lower heating COP and temperature difference between outlet and inlet. [ABSTRACT FROM AUTHOR]

In this study, we presented a detailed experimental investigation of an air source liquefied petroleum gas (LPG)-solar driven absorption heat pump (LSAHP) using Generator Absorber heat eXchanger (GAX). The GAX absorption heat pump with a nominal heating capacity of 55 kW uses ammonia-water as working pairs and is powered by hybrid energy sources: a 45 m 2 parabolic trough solar collector (PTC) and a direct-fired liquefied petrol gas (LPG) burner. The thermal performance of the PTC was characterized with selected on-sun conditions. Results showed that solar thermal efficiency can reach up to 53.55% with direct normal insolation of 450 W/m 2 and inlet thermal oil temperature of 191 °C. Three operation modes were identified based on the driven energy sources: ( i ) LPG-Solar hybrid mode, ( ii ) Solar only mode, and ( iii ) LPG only mode. Under the average ambient temperature of 17.52 °C, 20.0 °C, 8.77 °C the averaged COPs of three modes are 1.54 (mode i ), 1.63 (mode ii ) and 1.20 (mode iii ) respectively. Solar energy contributions reached 40.2% and 55.10% in mode i and mode ii separately which demonstrated the feasibility of the coupling of PTC and GAX heat pump to reduce the dependence on fossil fuel. The impact of operation conditions (ambient temperature, inlet hot water temperature, and LP gas flow rate) on the heating capacity and system performance were investigated under steady-state conditions. Results indicated that higher ambient temperature, higher gas flow rate, and lower inlet hot water temperature benefit the heat pump performance, among which the influence of ambient temperature is the greatest. COP reaches 1.47 with 19 °C ambient temperature and 35 °C inlet hot water temperature. It’s worth noting that COP’ achieves 1.82 under the same condition if we exclude the heat loss of flue gas. [ABSTRACT FROM AUTHOR]

The solar/autothermal hybrid gasifier (SAHG) is an attractive approach to provide continuous production of the syngas via coupling autothermal and solar gasification together, where the SAHG mainly includes fully solar, hybrid, and fully autothermal modes. An ICE CCHP system driven by the SAHG with an indirectly irradiative two-cavity reactor introduced conceptually and investigated thermodynamically. Considering the effects of solar flux inputs and various reactant ratios, a zero-dimensional steady-state model of the SAHG was established by using Gibbs free energy minimization, and was validated with the reported data. The optimal steam-to-feedstock and oxygen-to-feedstock ratios has been achieved based on the restrictions of temperature over 1000 K and minimization of steam input. The results of two consecutive days indicate mole flow rates of H 2 and CO were increased by over 38.8% and 11.8%, respectively, leading to an increment in LHV s by 51.7%. An increment in primary energy ratio by 11.5% can be achieved by using the SAHG-CCHP system. The yearly assessment of the SAHG-CCHP system shows that the yearly average increments in heat, power, and cooling for the SAHG system were reached by 19.5%, 23.8%, and 4.5%, respectively. A yearly average increment of 14.2% in primary energy ratio can be obtained under the solar radiation condition of Singapore. [ABSTRACT FROM AUTHOR]

Combining renewable energy with building energy supply is an effective way to pivot the building sector to carbon–neutral. This paper proposes a novel solar-assisted energy supply system which is applied in residential buildings for heating, cooling and domestic hot water. The heating/cooling output of the proposed system is mainly contributed by a vapor compression system to address the supply–demand mismatch of solar energy supply system, and the other part is assumed by a solar driven absorption system that is operating with lower generation temperature and higher evaporation temperature to assist the vapor compression system. Therefore, a solar-assisted absorption-compression system (SAACS) exploits the full potential of solar heat for annual energy supply by improving the contribution of per unit solar collection area, with considerable electricity-saving compared to air-source heat pumps. A thermodynamic model is established and validated by the results of the built experimental prototype which is testing. Solar-assisted heating mode and solar-assisted cooling mode are compared in comprehensive evaluation criteria to illustrate the performance differences caused by the assisted solar energy. The results indicate that solar heat at 60 °C is feasible for heating and cooling, revealing the great potential for efficient conversion from solar energy for heating and cooling. Due to the introduction of solar energy, the cooling and heating COP ele increases by 10.3 % ∼ 17.6 % and 32.3 % ∼ 56.3 %, respectively. Despite the lower increase in COP ele , electricity-saving ratio shows greater value at low hot water temperatures, varying from 24.3 % to 19.6 % for cooling and from 44.1 % to 39.7 % for heating as hot water temperature increases from 60 °C to 85 °C. The maximum SCOP is 0.63 for cooling, and 1.14 for heating. Yearly investigation shows that the SAACS combined with 20 m2 CPC collector has an annual average solar fraction of domestic hot water of 0.85 and a discounted payback period of 3.12 years. These results demonstrate the feasibility and flexibility of the SAACS applied to residential buildings toward decarbonization. • Flexible modulation of solar energy enable application for residential buildings. • Thermodynamic model and experimental prototype are implemented. • Both heating and cooling supply make use of solar energy. • Heat driven temperature is as low as 60 °C. • Discounted payback period is 3.12 years. [ABSTRACT FROM AUTHOR]

[Display omitted] • An all-day freshwater harvester is constructed and tested practically on an island. • Continuous water harvester yields 0.67 g water g sorbent -1 h−1 at 31 °C and 66–93% RH. • Feasibility of air-cooled condensation for large-scale air water harvester. • Matching of condensation and desorption is vital to practical water generation. • Low grade heat source can be applied for regeneration, like solar energy. Recent researches have demonstrated sorption-based atmospheric water harvesting (SAWH) as a sustainable, energy-efficient, and low-cost strategy to alleviate the water crisis. But the low daily water productivity of devices (L/kg day−1) remains a bottleneck to achieve efficient water production as they are merely allowed for intermittent operation. This limitation makes it rather challenging to deploy discontinuous SAWH systems for practical water production at large scales. Herein, we fabricated an active continuous SAWH (AC-SAWH) device with optimized sorbent bed structure. By configuring two sorbent beds and using nano-porous adsorbent by confining lithium chloride in silica sol modified activated carbon fiber felt (ASLI) as atmospheric water adsorbents, such a novel design enables water production in a continuous mode, delivering a water productivity of 8.3 kg day−1 or 0.67 kg h−1 at a regeneration temperature of 90 °C, with a thermal efficiency of 32.6%. This is the first exploration in continuous water production with a large-scale SAWH device, meeting personal drinking water demand of 5 L day−1 and demonstrating a promising water productivity for personal/household utilization in islands. With its excellent all-day freshwater harvesting performance and a scalable process, this continuous SAWH system is potential to make a contribution to the global water-energy-climate nexus. [ABSTRACT FROM AUTHOR]

• A clapboard-type internally circulating fluidized-bed solar reactor was introduced. • The gas flow rate had a significant effect on the particle circulating rate. • Solar-to-thermal conversion efficiencies of SiC, alumina, and sand were reported. • The bed mass had an apparent effect on the solar-to-thermal conversion efficiency. • SiC presented the highest solar-to-thermal conversion efficiency of 10.7 ± 0.4%. Fluidized-bed based solar reactors for the gasification of biomass have been widely recognized as a promising approach to produce high-quality syngas due to the merits, e.g. continuous operation and superior heat and mass transport. In this work, a novel high-temperature solar reactor with a clapboard-type internally circulating configuration that can efficiently mitigate the overheating of the bed wall affected by non-uniform solar radiation, is designed, constructed, and experimentally investigated under Singapore's first 28 kW e high-flux solar simulator. To investigate the flow dynamics in the high-temperature solar reactor, a transient 3D computational fluid dynamics multi-phase model is developed accordingly and validated by the experimental data. The simulated results can well clarify the flow and thermal behaviours in experiments. The effects of the gas flow rate and bed mass on the thermal performances of different Group-B particle materials are studied through experiments and simulation. The results indicate that increasing the bed mass in the solar reactor is capable of mitigating the overheating of the absorber surface caused by hot spots. The gas flow rate is dependent on the particle thermo-physical properties and shape as well as the clapboard geometric parameters. The highest solar-to-thermal conversion efficiency (defined as the ratio of the accumulated sensible heat of the particles to the solar power input) of 10.7 ± 0.4% is achieved by SiC due to its superior thermal conductivity. [ABSTRACT FROM AUTHOR]

Adsorption-based, atmospheric water harvesting is a promising method for addressing water scarcity, which is a common issue in island areas, which often contain a large amount of fresh water in the air. Most existing adsorption-based atmospheric water harvesting systems usually require an additional cooling source, e.g., water-cooling, to cool the released humid high-temperature air below its dew point to harvest liquid water. To date, large-scale atmospheric water harvesting devices that use air cooling in such conditions have not yet been developed. Herein, we report a forced air-cooled proof-of-concept device for harvesting water from island air. Fabricated using 21 kg activated carbon fibre felt (ACFF)–silica sol–LiCl30, this device generated up to 7.7 kg of water (adsorption at 31 °C with 63% relative humidity) per day-and-night cycle, with a thermal efficiency (ratio of thermal energy to water conversion) of 0.37, using air cooling alone in laboratory-simulated island conditions. This study verifies the possibility of using air cooling to condense released humid air. It provides a flexible water generation solution for island regions with limited supplies of fresh water and power. • A large-scale air-cooled atmosphere water generator was constructed and tested. • The device delivered 7.7 kg water and achieved a thermal efficiency of 0.37. • Equilibria and dynamic properties of the composite adsorbents were characterized. • Heat energy can be provided by solar energy or other renewable energy sources. • Adsorption–desorption cycle could help space heating and sustainable agriculture. [ABSTRACT FROM AUTHOR]