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- 摘要
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Environmental Biotechnology: For Sustainable Future || Role of Solar Energy Applications for Environmental Sustainability
摘要： Energy and environment are the opposite sides of the same coin. Increasing energy production depends on the fossil fuel availability and is the main cause of the environmental degradation by emission of greenhouse gases. To overcome the environmental degradation problem, the whole world is moving towards the renewable energy technologies. The sun is the main direct source of all forms of energy present on the earth. The solar energy can prove to be the sustainable future for maintaining energy demand. Solar energy is the utmost auspicious technology because it can be used for heating as well as electricity production. This technology is the most mature technology and can be used at large or small scale as cleanest source of energy. This chapter deals with the different solar energy technologies mainly working towards the environmental sustainability and cleaning.
关键词： Energy,Solar energy,Environmental sustainability,Environment
更新于2025-09-09 09:28:46
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Photo- and electro-responsive phase change materials based on highly anisotropic microcrystalline cellulose/graphene nanoplatelet structure
摘要： Phase change materials (PCMs) exhibit great potential applications in many fields, such as energy-saving building, solar energy harvesting, waste heat utilization, constant temperature protection and thermal management of microelectronic devices. In this work, we proposed a facile and novel method to prepare the composite PCMs. Through the combination of pre-refrigeration and freeze-drying techniques using the microcrystalline cellulose (MCC)/graphene nanoplatelets (GNPs) hydrogels, which were firstly prepared through solution compounding, gelling and solvent exchanging successively, the porous MCC/GNP aerogels with highly oriented stacking of MCC/GNP were successfully obtained. The composite PCMs based on the highly anisotropic MCC/GNP aerogel and polyethylene glycol (PEG) exhibited relatively high thermal conductivity (1.03 W/mK) at low GNP content (1.51 wt%), high latent heat (182.6 J/g) which was 99.84% of pure PEG, excellent encapsulation ability and mechanical stability. Further results showed that the composite PCMs exhibited excellent solar energy harvesting/electrical energy transformation, storage and release abilities. In addition, a simple heating device was designed to verify the application of the composite PCMs as the temperature protection element. The measurements showed that the presence of the PCMs prevented the rapidly rising of temperature during the heating process while maintained the temperature at relatively high level in a long time during the cooling process.
关键词： Phase change materials,Mechanical stability,Anisotropic structure,Solar energy/electrical energy comprehensive utilization
更新于2025-09-09 09:28:46
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Reference Module in Chemistry, Molecular Sciences and Chemical Engineering || Application of Luminescence Spectroscopy in New Materials for Solar Energy Utilization
摘要： The most important problems of our age are the search of new energy sources and the ways to decrease the pollution from organic fuels. Solar energy could provide a partial solution to the problem. If luminescent solar concentrators (LSCs) will be applied to the existing and modern buildings a part of the problem could be solved. In the following I describe the principle of LSCs and the ways by which their efficiency can be achieved.
关键词： Luminescence Spectroscopy,Solar Energy,Lanthanides,New Materials,Luminescent Solar Concentrators,Surface Plasmons
更新于2025-09-09 09:28:46
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Energy-exergy modeling of solar radiation with most influencing input parameters
摘要： In this study, a new soft computing model Gaussian process regression (GPR) was evaluated for modeling the total solar radiation (TSR) and exergy (Ф) in Hakkari province (the region with the highest sunshine duration), Turkey. For this purpose, meteorological data include average, maximum and minimum temperature (Tave, Tmax, Tmin), relative humidity (H), sea level pressure (P), wind speed (W), and total sunbathing time (TST), wihch were used, and sensitivity analysis was applied for evaluating the results of TSR and Ф modeling. The results showed that all the input variables have significant impact on TSR and Ф modeling. Mean absolute percentage error and coefficient of determination (R2) for TSR and Ф predicted by GPR were 1.51–7.02% and 0.97–0.95, respectively. Application of five-fold cross validation method showed that GPR model is able to predict the TSR and Ф with a small size of data, but for more accuracy, it is suggested to use more than 70% of total data set for training the models. This research showed that GPR has a good ability for modeling the TSR and Ф with high accuracy, and so the engineers can use this method for the TSR and Ф prediction without using the solar radiation or exergy-to-energy ratio.
关键词： solar energy,Solar radiation exergy,Hakkari province of Turkey,Gaussian process regression (GPR),modeling
更新于2025-09-09 09:28:46
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Daily Variation Law of Solar Radiation Flux Density Incident on the Horizontal Surface
摘要： The instantaneous solar radiation flux density incident on the horizontal surface near the ground, consisted of three sections, direct radiation, scattered radiation, and thermal radiation flowing down through the atmosphere, directly or indirectly comes from the sun. The dynamics of the solar radiation flux density incident on the horizontal surface near the ground influence all life processes and environment. In this study, the daily variation law of solar radiation flux density incident on the horizontal surface developed. The results showed that generally, sky conditions is stable, and the daily dynamic in the solar radiation flux density incident on the horizontal surface near the ground is the function of time, and can be described by a normal distribution model in a day. The main parameters of the model change with date and the meteorological conditions in a day.
关键词： Environment,Diurnal total solar energy,Hour,Sky conditions,Solar radiation,Daily variation law,Horizontal surface,Flux density
更新于2025-09-09 09:28:46
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Can Nanofluids Lead to Commercial Usage in Solar Engineering
摘要： The efficiency concept has been the major concern of specialists and analysts in the vital flied of energy. The energy efficiency corresponds with the productivity of resources consumption since there is a worrying limitation on the fossil fuel reserves of the earth. Although the price of fuel has been diminished significantly in recent years, the constraint of its availability in not-too-far future has put the pressure on the governments to intend toward the renewable energies more than ever. Furthermore, nobody can really estimate that what would be occurred in the global economic market in the next years. Solar energy considered as one of the most reliable and available sources of energy which can be renewed continuously. That is why the different technologies, i.e. PV and thermal systems, have been developed and studied yet. Apart from the improvements which originated from design and technology progress, the appearance of nanotechnology caused significant advancement in solar engineering similar with the other fields of study. There are numerous researches on the field of solar energy with the applications of nanotechnology. For instance, currently the solar energy can be observed in heating, cooling, power generation, energy storage, transportation, medical etc. As long as nanotechnology proposed, the solar engineers has made their efforts to enhance the performance of solar systems and achieve the higher efficiencies. In the case of solar collector systems, nanomaterial’s can be added into absorber surfaces or heat transfer fluids which would result in enhancement of thermal and optical properties of the systems. Nanomaterial’s categorized as follows: Organic: fullerene, nanotube, electrospun nanofibers Inorganic: metal, metal oxides, quantum dots hybrid. Based on the application, nanomaterial’s can be mixed with the fluids which called Nanofluids. In other words, the suspension of nanoparticles in liquids considered as Nanofluids. Common liquids as the base fluid are water, ethylene, glycol and oil and the nanoparticles which have been used in literatures for dispersing in base fluid include carbon nanotube, alumina, titanium dioxide, silver, copper, graphite, etc. Nanofluids are made by mechanical (one-step or two-step) or chemical methods [1]. The synthesis is the main process which involved in preparation of the Nanofluids. On the other hand, the combination of nanomaterial’s with phase change materials (PCMs) known as Nano composites. Each type of Nanofluids or Nano composites exhibits the special properties. For example, the Nanofluids are more applicable in solar collectors for power generation and Nano composites are preferably considered in thermal storage projects i.e. heat or cold storage which would provide the industrial or domestic requirements of different climates. The hybrid systems exploit the most benefits of nanomaterials for simultaneous power generation and thermal storage. Furthermore, using the PCMs can increase the operating time of the system during the night or cloudy situations. Nanofluid phase change materials (NPCMs) have opened a new field of study for researchers. In fact, a NPCM is a liquid in which nanoparticles that change phase are added in order to enhance the thermal properties of this fluid. Despite the fact that all researches have been conducted theoretically and experimentally in all around the world, prove that the application of Nanofluids would lead to enhancement of optical and thermo-physical (conductive and convective) behaviour of solar systems, the applications of Nanofluids limited to the noncommercial projects [2]. Two main reasons interfere with the aim of commercializing Nanofluids application for solar power generation or solar thermal storage. Firstly, the results of remarkable achievements of numerous researchers show an inconsistency in some cases and therefore, the uncertainty of the results may necessitate more detail studies to overcome some ambiguities. Secondly, it is obvious that the optical and thermal properties of Nanofluids would be enhanced rather the base fluids, however, their application issues including durability, sedimentation, agglomeration, viscosity problems, some design complexities and operating costs have not been studied exactly and sufficiently. Hence it seems there would be a rather long way to achieve the exact, clear and unique results to smooth commercializing of Nanofluids applications in solar engineering.
关键词： Nanotechnology,Thermal Storage,Solar Energy,Nanofluids,Solar Engineering
更新于2025-09-09 09:28:46
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Environmental impact analysis applied to solar pasteurization systems
摘要： In many under-developed regions of the world, most people live in rural villages, where the electrical grid is often not available and traditional potabilization systems would be too expensive and technologically too complex to be implemented. Thus every year, millions of people in the world die due to diseases related to water contamination. Solar Pasteurization Systems represents a promising alternative to address such problems, as they can thermally disinfect water employing solar energy alone, without using fossil fuels or electrical grid connection. Evaluating the cradle-to-grave environmental footprint of Solar Pasteurization Systems, and in general of technologies aimed at producing safe drinking water, represents an issue of major importance. This is relevant because an effective solution has to be, at the same time, environmentally and locally sustainable for a given geographical context. In this work, a complete Life Cycle Assessment and Exergo-environmental analysis are performed in order to calculate and compare the eco-profiles of two Solar Pasteurization technologies: a Natural Circulation and a Thermostatic Valve System. Results show that Natural Circulations Systems are generally more environmentally sustainable (0.30 mPt/l) than the Thermostatic Valve System (0.83 mPt/l) thanks to the higher productivity of treated water. A sensitivity analysis is performed to investigate the dependency of the model systems from different operational and environmental conditions, at different installation sites, i.e. Somalia, Brazil and Italy. The main difference is represented by the productivity of the systems. In all cases the solar collector array is the main item responsible for environmental burdens, impacting for almost 45% of the total score. The analysis also shows that the use of solar energy in Pasteurization is important to avoid direct emissions and to lower the global environmental impact connected with thermal energy production compared to the eco-profiles of other widely diffused pasteurization technologies based on the combustion of fossil fuels or biomass that can be used to provide the same function (in general higher than 1.2 mPt/l). Moreover, with the aim of qualitatively assessing the benefit associated with the potential implementation of solar pasteurization systems, an improvement of the sanitary conditions is envisioned, especially in under-developed countries where, definitively, a large scale diffusion would be recommended.
关键词： Solar Pasteurization,Solar Energy,Life Cycle Assessment,Exergo-environmental analysis,Water Disinfection,Water Treatment
更新于2025-09-09 09:28:46
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Review of Solar Cooling Technologies
摘要： Solar cooling is a clean and cost-effective technology, solar cooling offer environmental benefits including reducing main grid demand and shift the load during peak usage and reduced greenhouse gas emissions. The main objective of this paper is to review and analyze different solar cooling technologies that can be used to provide the required cooling and refrigeration effect from solar energy. This paper is covering a wide range of solar cooling technologies including solar electrical refrigeration system, thermo-mechanical combined power and cooling systems and advanced triple effect refrigeration cycles. This paper includes comparisons of different technologies highlighting the advantages and disadvantages. This comparison would assist the decision makers to select the proper solar cooling technology for specific application.
关键词： Solar cooling,Solar Energy,Air Conditioning,Refrigeration
更新于2025-09-09 09:28:46
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Cloud shadow speed sensor
摘要： Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system is presented that measures cloud shadow motion vectors to estimate power plant ramp rates and provide short-term solar irradiance forecasts. The cloud shadow speed sensor (CSS) is constructed using an array of luminance sensors and a high-speed data acquisition system to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud shadow motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground-measured irradiance (linear cloud edge, LCE), and a UC San Diego sky imager (USI). The CSS detected artificial shadow directions and speeds to within 15? and 6 % accuracy, respectively. The CSS detected (real) cloud shadow directions and speeds with average weighted root-mean-square difference of 22? and 1.9 m s?1 when compared to USI and 33? and 1.5 m s?1 when compared to LCE results.
关键词： cloud motion vectors,solar irradiance,cloud shadow speed sensor,forecasting,solar energy
更新于2025-09-09 09:28:46
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Tomography-based determination of Nusselt number correlation for the porous volumetric solar receiver with different geometrical parameters
摘要： Pore-scale numerical models of the porous volumetric solar receiver are established in this paper. By using the X-ray computed tomography and the imaging processing techniques, models of porous media with different geometrical parameters are reconstructed. The conjugate heat transfer process in the porous volumetric solar receiver is solved based on the direct pore-scale numerical simulation. The turbulent effect of fluid flow inside porous geometry is considered by the Shear-Stress Transport k-ω model and the absorbed solar energy is simulated by following the Beer’s law. The results present that the inlet velocity and the geometrical parameters influence the thermal performance of the porous volumetric solar receiver. Larger inlet velocity tends to enhance the convective heat transfer between fluid and solid phases meanwhile decreases noticeably the overall temperature. Receiver with larger porosity is preferred because it limits the reflection losses. The Nusselt number increases as the porosity becomes larger. As a result, the general correlation of Nusselt number for the porous volumetric solar receiver is derived as a function of porosity and Reynolds number. This correlation is applicable with the porosity ranging from 0.74 to 0.89 and the pore Reynolds number ranging from 3 to 233.
关键词： Solar energy,Pore-scale numerical simulation,Convective heat transfer,Volumetric solar receiver,Nusselt number correlation,Porous media
更新于2025-09-09 09:28:46