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Solar steam generation enabled by bubbly flow nanofluids
摘要： Plasmonic nanofluids are recently explored to promote steam generation, showing great promise of such fluids for solar thermal applications. However, plasmonic nanoparticles are opaque and the nanofluids require high mass concentration to achieve efficient evaporation, which in turn leads to parasitic light absorption for the underlying particles. In this work, we introduce bubbles into dilute plasmonic nanofluids to enhance solar water evaporation. The dynamic bubbles not only act as light scattering centers to extend the incident light pathway and amplify solar flux, but also provide large gas-liquid interfaces for moisture capture as well as kinetic energy from bubble bursting to improve vapor diffusion. The coupling effect between plasmonic heating and bubbly-flow humidification results in a steam generation rate of 0.72 kg m?2 h?1 under two-sun, which is about three-time higher than that of the pure water. A series of experiments under different light intensities, concentration of nanofluids, gas flow rates as well as photothermal materials such as carbon nanotubes (CNTs) and magnetic Fe3O4 nanoparticles are also conducted to verify the concept. It is concluded that all the nanofluids enhance the steam generation process, and the bubbly flow nanofluids can be further improved the performance. This work provides an original insight on the bubbly flow nanofluids for solar vapor generation, and stands for a basis to design scalable solar evaporators from accessible raw materials.
关键词： Solar energy,Bubbly flow,Plasmon heating,Steam generation,Nanofluids
更新于2025-09-11 14:15:04
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Challenges and research needs in life cycle analysis of building-integrated photovoltaic
摘要： Building-integrated photovoltaic (BIPV) is a promising solar energy technology that looks set to grow in popularity in the pursuit of a sustainable future. It has the potential to mitigate some of the main concerns over ground-mounted solar energy systems such as land use. However, there is an apparent gap in our understanding of its life cycle environmental impacts. Very few life cycle analysis (LCA) studies have evaluated BIPV comprehensively in comparison with standalone PV systems and other energy technologies. In this paper, we review the limited existing LCA studies on BIPV and identify the challenges and future research needs. The findings will help researchers, industries and policy makers better understand the environmental sustainability of BIPV to facilitate its development.
关键词： building-integrated photovoltaic,environmental sustainability,life cycle analysis,solar energy
更新于2025-09-11 14:15:04
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[IEEE 2019 4th International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT) - Sao Paulo, Brazil (2019.8.26-2019.8.30)] 2019 4th International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT) - Sensitivity Analysis of Controlled-Temperature Thermoresistive-based Radiometers
摘要： Currently, renewable energy is being explored all to solar radiation, many solutions are currently available on the market and many more are being developed in industry and academy. In this scenario, a thermoresistive-based radiometer would provide information regarding solar radiation to solar energy systems at a very low cost. In this paper, the sensitivity of radiometers based on thermoresistive electrical equivalence are analyzed. It is verified that the change of the temperature of the sensor affects considerably its sensitivity. Another architecture was proposed in which the difference of temperature between the sensor and the environment is made constant. Here, we propose the most efficient difference of temperature in order to provide best sensitivity-wise measurements. Also, architectures employing PTC and NTC type sensors, with analog voltage and pulse width modulated output signals, are analyzed and compared regarding their sensitivity.
关键词： thermoresistive sensors,radiation,solar energy,measurements
更新于2025-09-11 14:15:04
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Performance study of a new type of transmissive concentrating system for solar photovoltaic glass curtain wall
摘要： There are many problems in Building Integrated Photovoltaics (BIPV) system, such as contradiction between daylighting and electricity generation, unable to match the demand of light control, need to constantly adjust angle for tracking, and so on. A new type of transmissive concentrating system for glass curtain wall is proposed which can improve the performance of solar photovoltaic glass curtain wall. The concentrating characteristic was studied by a series of comprehensive simulation and experiment. The optical software is used to simulate the influence of concentrating characteristics in different incident angles. Compared with solid and trapezoidal structure compound parabolic collector, the concentrating performance of hollow with water structure is also simulated. Simulation results shown that the receiving rate of hollow with water compound parabolic collector is changing slowly when incidence angle is increasing between 0 and 20°, and it can achieve 70% when the incidence angle less than 20°, and it is better than other concentrator with different cross section shapes. Based on simulation results, the experimental samples were processed and tested in a typical sunny weather. The experimental results were in good agreement with the simulation results. The system had a minimum transmittance of 28.2% at noon, but before 9:40 AM and after 15:40 PM, the transmittance exceeds 55% and can meet lighting requirements of rooms. It can be proved that the new system has passive light control function, which is expected to replace the double-layer vacuum glass curtain wall that is widely used nowadays.
关键词： Glass curtain wall,Solar energy,Building integrated photovoltaics,Light control,Transmissive concentrating
更新于2025-09-11 14:15:04
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Economic Assessment of Solar Photovoltaics Use in Agricultural Greenhouses in Greece
摘要： Modern greenhouses can utilize renewable energy sources for covering their energy requirements and reducing their carbon footprint. Solar photovoltaics use for power generation is currently a reliable and cost-effective technology which is used in many applications. The purpose of the current work is to investigate the possibility of using solar photovoltaics in agricultural greenhouses in Greece and to assess their profitability compared with the profitability of their use in households. Semi-transparent and opaque photovoltaic cells can be used for electricity generation with the net-metering regulations covering all their annual electricity needs. Existing studies in various countries concerning their use in greenhouses have reported a payback period of the investments of 4-10 years. In Greece the cost of electricity in the agricultural sector is subsidized while economic incentives are offered regarding the use of this technology in greenhouses. Economic assessment of the investment of solar photovoltaics in greenhouses for a period of 25 years in Greece indicates payback periods of 7.2 and 14.4 years, depending on capital subsidies obtained, while positive net present values are achieved. Their use in households in Greece has a payback period of 10.4 years while the net present value is also positive. The current study indicates that the use of solar photovoltaics in modern greenhouses in Greece supported financially by the government according to the net-metering regulations is profitable, offering economic and environmental benefits to the farmers.
关键词： profitability,solar energy,net-metering,agricultural greenhouses,photovoltaics,Greece,pay-back period,net present value
更新于2025-09-11 14:15:04
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Formation of poly-crystalline BaSi2 thin films by pulsed laser deposition for solar cell applications
摘要： A new growth method for BaSi2 thin films by using pulsed laser deposition (PLD) on transparent SiO2 and CaF2 substrates has been developed. X-ray diffraction and Raman spectroscopy revealed the poly-crystalline property of the deposited films. By introducing a thin Si buffer layer on SiO2 substrate, the crystalline quality of BaSi2 thin films were improved. BaSi2 thin films exhibited a Ba/Si ratio very close to 0.5, indicating the good stoichiometry control of PLD growth. The absorption coefficient of the poly-BaSi2 reached 105 cm-1 and its band gap was deduced to be 1.32 eV, which are similar to those grown by molecular beam epitaxy or sputtering. A maximum photoresponsivity of 12.5 mA/W was achieved in the BaSi2 thin film, which implies the potential of PLD-deposited BaSi2 for thin film solar cell applications.
关键词： Thin films,BaSi2,Solar energy materials,Pulsed laser deposition
更新于2025-09-11 14:15:04
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A New Approach to H-Infinity Control for Grid-Connected Inverters in Photovoltaic Generation Systems
摘要： The present study investigates the stability problem of the grid-connected inverters (GCIs) for possible variations in grid impedance. A new type of H1 control method is proposed for the current control loop of inverters, where the third weighting function is determined using the game theory. The proposed method is applied to the GCI in a photovoltaic system and its response to variations in grid impedance is investigated. Computer simulations conducted for comparison of H1 and PI controller indicate the effectiveness of the proposed control algorithm. Simulation results also show that the proposed algorithm significantly outperforms the PI controller under the conditions of varying grid impedance.
关键词： solar energy,photovoltaic power generation,robust control,power electronics,grid-connected inverters,weighting function,game theory,H-in?nity control
更新于2025-09-11 14:15:04
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Solar Energy, dc Distribution, and Microgrids: Ensuring Quality Power in Rural India
摘要： Ensuring quality power in rural India. As the Leisang village in Manipur received electricity in April 2018, the prime minister of India announced that every Indian village is now electrified. A village is considered electrified in India when 10% of its homes receive electricity. However, the number of village homes that have electricity has now reached 84%, with some 41 million households still without power. This village-electrification program has been going on for many years. Until a few years back, there was a large shortage of power with power demand exceeding supply, leading to no/a weak push to extend the grid to the village. Over the last few years, when more coal power plants became operational, the supply strengthened. At the same time, the energy costs for the solar and wind power-attained grid parity, enabling the addition of significant renewable power. Simultaneously, the power grid was strengthened, and India attained a single national grid on 31 December 2013, such that power generated in surplus areas could be transported to deficit regions. All of this helped in surplus power generation because the demand did not pick up much in recent years. The social obligation to extend the electric grid to each village and then to at least 10% of its homes no longer had a fundamental bottleneck. The target-driven approach of the prime minister’s office helped to expedite the effort.
关键词： dc Distribution,Rural Electrification,Solar Energy,India,Microgrids
更新于2025-09-11 14:15:04
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Evaluating the service quality of solar product companies using SERVQUAL model
摘要： Purpose – This study aims to consider a five-factor model to evaluate the service quality of solar product companies in the context of rural Punjab (India) and validate the proposed model. In addition, the study considered the factors which affect the service quality of solar product companies. Design/methodology/approach – A five-factor model of service quality has been tested for reliability and validity by confirmatory factor analysis. For determining satisfaction of the solar product users, SERVQUAL model/gap analysis has been applied. Five dimensions, namely tangibility, reliability, responsiveness, assurance and empathy have been considered to assess the overall satisfaction level. A modified scale of Parasuraman incorporated in 1985 has been used as a survey instrument for research. A sample size of 345 solar submersible pump users was selected. Findings – The study concluded that dimensions such as reliability, responsiveness, assurance and empathy have lesser gap. The major gap has been found in the tangibility dimension which includes variables like modern design of solar energy products, facilities and attractiveness, variety of solar products and performance of solar products, etc. Research limitations/implications – As primary data are concerned, the biasness of the respondents may affect the results of the study. The survey has been conducted in the Punjab region, and a sample size is 345 only which may not reflect the broader picture. Practical implications – Solar energy has huge benefits in the Indian agriculture sector. The erratic state of power supply in India casts important costs on agriculture productivity. One such segment concerns systems, an important input for agriculture production. The study has implications for solar energy product manufacturers, as it makes them aware about customer perception toward services of solar product companies. Social implications – To decrease pollution and to save the environment, solar energy technologies have a good potential energy source and to meet the global energy demand, as it is the most promising and reliable energy source. Originality/value – The existing studies in the context of service quality of solar product companies in Punjab have been majorly confined to proposing key drivers toward adoption of renewable energy sources. By providing an insight into the satisfaction level of farmers for solar submersible pumps, the proposed study attempts to fill the gap. As the study relates to solar product users in rural Punjab, the findings will be of additional value to solar product companies which are manufacturing solar products. Therefore, it is expected that this research will fill the gap in literature by studying empirically the service quality of solar product companies.
关键词： Surveys,Confirmatory factor analysis,Energy sector,Solar energy,Solar energy products,Factor analysis
更新于2025-09-10 09:29:36
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Managing Global Warming || Solar energy
摘要： I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.
关键词： photovoltaic,solar thermal energy,greenhouse gas emissions,renewable energy,solar energy
更新于2025-09-10 09:29:36