Renewable Solar Energy Research Articles

Tailoring and properties of a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture

Using renewable solar energy sources instead of heat energy to desorb CO2 from adsorbents is a promising strategy for reducing the energy consumption of adsorbent regeneration. However, the photothermal temperature of adsorbents with high CO2 adsorption capacity cannot desorb CO2 efficiently in a real sunlight environment. Here, a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture was designed via bionic electrostatic and chemical cross-linking assembly of cellulose nanofibers, thermosensitive polymer poly(N-isopropylacrylamide), nano-graphene oxide and polyethyleneimine. Excellent photothermal transformation characteristics, thermosensitivity and high density of amino adsorption sites were synchronously endowed onto cellulose nanofibers with hydroxyl groups. The thermosensitivity and hydroxyl synergy of the adsorbent enables it an ultralow regeneration temperature (60 °C) by preventing the formation of refractory urea. Interestingly, the adsorbent possesses a high CO2 adsorption capacity (6.52 mmol/g) and can be efficiently regenerated by using renewable solar energy, indicating that it is a promising strategy for greatly reducing the energy consumption for adsorbent regeneration.

A Janus solar evaporator with photocatalysis and salt resistance for water purification

The expeditious advancement of solar-driven interfacial steam generation by utilizing renewable and free solar energy is a promising strategy for remedying the water crisis. However, salt accumulation on solar evaporators and organic pollutants increases in the remaining bulk water block its commercial potential for practical applications. Herein, a Janus solar evaporator was designed by using a commercialized melamine sponge as the matrix, followed by PDMS modification and deposition of Chinese ink, and TiO2 nanoparticles. The Janus photothermal melamine sponge (JPMS) was designed with containing a hydrophobic salt resistance layer, and a composite photothermal and photocatalysis layer from top to bottom. The applicability of the developed JPMS was systematically investigated for water evaporation, photocatalytic degradation, desalination as well as wastewater treatment. The JPMS exhibits an evaporation rate of 1.49 kg m-2h−1 with a corresponding efficiency of 93.54% under 1 sun illumination. Notably, the JPMS also exhibits the high efficiency of synergic photocatalysis for organic pollutants and acquires an excellent salt rejection capability. Integration of SISG, photocatalytic, and salt resistance may be viewed as a prospective avenue for water purifying.

Fuzzy entropy type II method for optimizing clean and renewable solar energy

Fuzzy entropy type II method for optimizing clean and renewable solar energy

Construction of 2D up-conversion calcium copper silicate nanosheet for efficient photocatalytic nitrogen fixation under full spectrum

Using clean and renewable solar energy to convert nitrogen to ammonia is promising, however the low utilization of light and the high cost of catalyst restrain its application. Herein, novel two-dimensional(2D) silicate CaCuSi 4 O 10 nanosheet was prepared by high-temperature solid state method using silica derived from palygorskite clay (Pal) and calcium carbonate derived from egg shells, respectively. The photocatalytic nitrogen fixation was performed using CaCuSi 4 O 10 compound as catalyst. The effect of flux content on the ammonia generation rate was investigated. Results demonstrated that the 2D CaCuSi 4 O 10 nanosheet can chemically adsorb and activate N 2 due to the high surface area along with abundant oxygen vacancies. The ammonia evolution rate of CaCuSi 4 O 10 can reach up to 60.3 μmol·g −1 ·h −1 and 15.6 μmol·g −1 ·h −1 under simulated solar light and near infrared (NIR) light irradiation, respectively. The enhanced photocatalytic nitrogen fixation can be ascribed to the up-conversion capability of CaCuSi 4 O 10 , which converts NIR into visible and UV light improving the utilization efficiency of full solar spectrum. Current study may offer a promising strategy for cost-effective photocatalytic nitrogen fixation under full spectrum. • 2D silicate CaCuSi 4 O 10 nanosheet prepared using mineral and biomass. • CaCuSi 4 O 10 compound owned abundant oxygen vacancies favoring N 2 activation. • Up-conversion capability of CaCuSi 4 O 10 improved solar energy utilization. • CaCuSi 4 O 10 nanosheet demonstrated cost-effective photocatalytic nitrogen fixation.

A thermally-driven seawater desalination system: Proof of concept and vision for future sustainability

Since the 1970s, commercial-scale thermally-driven seawater desalination plants have been powered by low-grade energy sources, drawn either with low-pressure bled-steam from steam turbines or the solar renewable energy harvested that are supplied at relatively low temperatures. Despite the increasing trend of seawater reverse osmosis plants, the role of thermal desalination methods (such as multi-stage flashing and multi-effect distillation) in GCC countries is still relevant in the Arabian Gulf, arising from higher salinity, the frequent algae blooms of seawater and their ability to utilize low temperature heat sources. Given the urgent need for lowering both the capital and operating costs of all processes within the desalination industry and better thermodynamic adaptation of low-grade heat input from renewable sources, the present paper addresses the abovementioned issues by investigating the direct contact spray evaporation and condensation (DCSEC) method. A DCSEC system comprises only hollow chambers (devoid of membranes or tubes, minimal use of chemical and maintenance) where vapor generation (flashing) utilizes the enthalpy difference between the sprayed feed seawater and the saturated vapor enthalpy of the vessels. Concomitantly, vapor is condensed with spray droplets of cooler water (potable) in adjacent condenser vessels, employing a simple design concept. We present detailed design and real seawater experiments data of a DCSEC system for the first time. The water production cost is calculated as $0.52/m 3 , which is one of the lowest figures reported compared to commercial processes presented by Global Water Intelligence.

Plasmonic MoO2 coupled with sulfur-incorporated NiMoO4 as multifunctional heterostructures for solar thermoelectric self-powered urea electrolysis

Efficient conversion and utilization of abundant renewable solar energy is highly desirable for the sustainable production of green hydrogen, but it is still a great challenge. In the present study, the multifunctional heterostructure of MoO2 coupled with sulfur-incorporated NiMoO4 (S-NiMo) on nickel foam (NF) was explored to construct a self-powered hydrogen production system that ingeniously integrates a solar thermoelectric generator (STEG) and a urea electrolyzer. The plasmonic MoO2 in S-NiMo/NF acts as a solar absorption unit to covert solar energy into thermal energy, which can combine with thermoelectric (TE) module for efficient power generation. When served as an electrocatalyst, the S-NiMo/NF exhibits excellent electrocatalytic performances to promote hydrogen evolution reaction (HER), urea oxidation reaction (UOR) and overall urea electrolysis. Under simulated solar irradiation at light intensity of 5 sun, the S-NiMo/NF-based STEG-urea electrolyzer system can produce 2.68 μmol of hydrogen per minute via the four-series connected S-NiMo/NF-STEGs. This self-powered thermoelectric urea electrolysis system offers new opportunities to convert renewable solar energy into green hydrogen.

Solar Renewable Energy System (SRES) for an Educational Institute

This paper highlights a Solar energy generation plant as Renewable energy source (SRES) on the criterion of cost involvement using net present value (NPV) method and its payback period. The reliability of the system and economic considerations of SRES are analyzed in depth for an educational institute. This is an installed off-grid system which comprises a wind energy source of 1.5 kW and solar energy source of 6 kW. The present work is focused on cost and performance analysis of solar energy systems only. The SRES considered here is connected to the light load of the department containing all lights, fans, personal computers, printers and LCD display. The results obtained proves that SRES has the potential to fulfill the demand reliably throughout the year. The cost analysis using NPV method is included with the existing MAHADISCOM as one of the projects and SRES as another project. Both the projects are analyzed by assuming the lifespan of 11 years. The payback period of the SRES system is 3.3 years and hence after that the energy will be available free of cost through the mentioned system. This analysis is done for the site located in the state of Maharashtra, India, and can be used as very useful research for future perspectives.

An Approach on Developing a Dynamic Wind-Solar Map for Tracking Electricity Production Potential and Energy Harvest

Increasing energy demand brings in technical, environmental and economic problems as the production processes evolve. In this parallel, many countries are trying to satisfy the increasing energy demand using renewable energy sources. The scope of this study is to develope a mathematical model and data monitoring-evaluation software for wind and solar renewable energy sources, which can dynamically evaluate meteorological data measurements and make more precise energy harvest estimation with the data obtained. It is aimed to create a web based “Dynamic Wind-Sun Map of Turkey”. Through the developed software; instant data can be analyzed and instantaneous electrical energy values produced from wind and solar energy sources can be calculated. Thus, it can help create a system that allows regional management in energy production and is compatible. Within the scope of the study, a mathematical model expressing the problem was created by using some mathematical optimization methods. The created model was converted into a web-based software. PHP software development platform and MySQL database language were used during the software creation. The software developed within the scope of the study has analogues in the world literature. However, no study has been found in this context in Turkey. Especially since it can use real-time data and includes wind-photovoltaic calculations together, this software distinguishes it from its peers.

Self-Assembled Supercrystals Enhance the Photothermal Conversion for Solar Evaporation and Water Purification.

Photothermal materials can convert renewable solar energy into thermal energy and have great potential for solar water evaporation. Copper sulfide (Cu2- x S) is an easily available and inexpensive plasmonic material with a high photothermal conversion efficiency and can be applied to solar evaporation and water purification. Monodispersed Cu7 S4 nanoparticles (NPs) and supercrystalline self-assembled superparticles are obtained via wet chemical synthesis and micelle self-assembly. The photothermal properties of the superstructures are investigated using the finite difference time domain method and laser radiation photothermography. The results show that the electromagnetic field intensity and photothermal efficiency of the self-assembly are significantly higher than those of isolated NPs, which is due to the plasmonic coupling of the NPs. The evaporation efficiency of the superstructure is significantly higher than that of isolated NPs, the metal salt ion and total organic carbon concentrations in the waterbody significantly decrease after evaporation, and the water polluted by high salt and organic dye concentrations is purified. The water quality significantly improves after the lake water from Fuxian Lake in the Yunnan-Guizhou Plateau of China is used for solar evaporation. The color changes from pale yellow to colorless and the ion and total organic carbon contents significantly decrease.

China's Electric Power Industry: State and Development Prospects in the Context of Carbon Neutral Industry

China has set a goal of achieving peak carbon emissions by 2030 and carbon neutrality by 2060. Increasing the electricity utilization factor is the key to achieving this goal. The article considers the development of China's electric power industry in recent years and compares the installed electrical capacity, electricity production and consumption, investments in the electric power industry, and analyzes the characteristics and potential of China's renewable energy sources, including hydraulic, wind and solar energy. Increasing the electricity production from renewable energy sources, promoting the substitution of conventional fossil energy sources such as oil with electricity, increasing the share of electricity in the total energy consumption, and strengthening international cooperation in the field of electricity generation from renewable energy sources are important measures to reduce carbon dioxide emissions and solve the climate change problem. The promotion of environmentally clean transport facilities such as electric vehicles and electric bicycles, combination of renewable energy sources with energy storages, and prioritizing the construction of demonstration projects in remote industrial and rural areas are measures that will help to gradually increase the utilization factor of renewable energy sources in China.

Cubist Regression, Random Forest and Support Vector Regression for Solar Power Prediction

At a time when the energy transition is inescapable and artificial intelligence is rapidly advancing in all directions, solar renewable energy output forecasting is becoming a popular concept, especially with the availability of large data sets and the critical requirement to forecast these energies, known to have a random nature. Therefore, the main goal of this study is to investigate and exploit artificial intelligence's revolutionary potential for the prediction of the electricity generated by solar photovoltaic panels. The main algorithms that will be studied in this article are cubist regression, random forest and support vector regression. This forecast is beneficial to both providers and consumers, since it will enable for more efficient use of solar renewable energy supplies, which intermittency makes their integration into the existing electrical networks a challenging task.

Design of frustrated Lewis pair in defective TiO2 for photocatalytic non-oxidative methane coupling

The efficient C–H polarization is the prerequisite for the low-temperature photocatalytic CH 4 conversion, which is restricted by the poor C–H stretching ability of short-distance adjacent lattice atoms. Here, a frustrated Lewis pair (FLP) composed of doped metal in TiO 2 as Lewis acid (LA) and neighboring Ti–OH as Lewis base (LB) with a long distance (0.31–0.37 nm) was designed through DFT calculation and fabricated by hydrogenation treatment of metal-doped TiO 2 –SiO 2 with macroporous-mesoporous structure. Benefitting from the long LA-LB distance and matched acid-base intensity, hydrogenated Ga-doped composite achieves superior C–H stretching with a high photocatalytic CH 4 conversion rate (139 μmol g −1 h −1 ). The photo-irradiation causes electron excitation from Ga to Ti–OH according to the time-dependent DFT calculation and in situ EPR analysis, which promotes the formation and coupling of ·CH 3 . This work provides a key underpinning for regulating the characteristics of FLP for C–H activation and C–C coupling via light irradiation. • Frustrated Lewis pair (FLP) in defective TiO 2 was designed by DFT calculation • 139 μmol g −1 h −1 CH 4 conversion rate in NOCM is achieved under irradiation • FLP with long distance and suitable Lewis intensity is conducive to C–H stretching • Photo-irradiation promotes the formation and coupling of CH 3 The serious greenhouse effect caused by the massive use of fossil energy is an inevitable environmental problem in today’s world. In particular, the greenhouse effect of methane is 25 times that of CO 2 . However, the traditional methane conversion process consumes a great deal of energy. This study emphasizes the efficient conversion of methane driven by green and renewable solar energy under mild conditions. Its fundamental principle is to generate a charge by using light in semiconductors. The efficient conversion of methane is attributed to the unique active sites designed on TiO 2 , such as magnets, which attract C and H, respectively, effectively break the C–H bond, and generate high-value products under the action of a photogenerated charge. This research does not require the high temperature and high pressure of traditional industry and is of great significance to realize energy development and environmental protection that is beneficial to all. Long LA–LB distance and strong acid and base intensities promote the stretching of the C–H bond. The effect of light irradiation on improving the intensities of LA Ga and LB Ti–OH was confirmed based on the electron transition from LA to LB, which is the key to forming methyl and hydrogen radicals for the further coupling production of C 2 H 6 .

Photocatalytic Methane Conversion: Insight into the Mechanism of C(sp 3 )–H Bond Activation

Photocatalytic Methane Conversion: Insight into the Mechanism of C(sp ³ )–H Bond Activation

Design and Simulation of Grid-Connected Solar PV System Using PVSYST, PVGIS and HOMER Software

In this paper, the design and simulation of a 5 MW solar power plant in Ghor province, Afghanistan have been investigated. A suitable place at a distance of about 8.17 km from the center of the province was selected as the power plant location. The main objective of this study is the investigation of solar renewable energy resources' capacity for generation of electrical energy from domestic resources to provide reliable and sustainable energy in the center of the Ghor province which is currently not connected to the national electrical grid. In this power plant, 6399 kWp, STP-320 W PV module, and 5300 kW Growatt convertor type were used. The PVSYST, PVGIS, and HOMER renewable energy simulation tools were used for analyzing the system. The results obtained from each simulation tool were compared together. Analysis of the results using HOMER and PVGIS shows that the annual energy generated using each simulation tool is about 11698 MWh and 10673 MWh respectively while the result from PVSYST is 11938 MWh per year. According to the obtained values, results from PVSYST depict 240 MWh more energy generation than HOMER and 1265 MWh than PVGIS simulation tools annually. These values indicate that PVSYST produces higher annual power for this system than HOMER and PVGIS. Comparing the annual generated power results of the simulations with reference to the PVSYST results, it can be concluded that PVGIS is 10.6% lower and HOMER is 2% lower. There is about a 2% difference between PVSYST and HOMER.

Integration of renewable energy in wastewater treatment during COVID-19 pandemic: Challenges, opportunities, and progressive research trends

SARS-CoV-2 has aroused drastic effects on the global economy and public health. In response to this, personal protective equipment, hand hygiene, and social distancing have been considered the most important ways to prevent the direct spread of the virus. SARS-CoV-2 would be possible survive in wastewater for a few days, leading to secondary transmission via contact with water and wastewater. Thus, the most economical and practical approaches for decentralized wastewater treatment are renewable energies such as the solar energy disinfestation process. However, as freshwater requirements increase and fossil fuels become unsustainable, renewable energy becomes more attractive for desalination applications. Solar photovoltaic, membrane-based, and electricity desalination technologies are becoming increasingly popular due to their lower energy requirements. Several aquatic environments could be benefitted from solar energy wastewater disinfection. Besides, utilizing solar energy during the day can inactivate SARS-CoV-2 to nearly 90%. However, conventional membrane-based desalination practices have also been integrated, including reverse osmosis (RO) and electrodialysis (ED). Several exciting membrane processes have been developed recently, including membrane distillation (MD), pressure-reduced osmosis (PRO), and reverse electrodialysis (RED). Such operations can produce clean and sustainable electricity from brine and impaired water, generally considered hazardous to the environment. As a result, neither PRO nor RED can produce electricity without mixing a high salinity solution (such as seawater or brine and wastewater, respectively) with a low salinity solution. Herein, we critically review the progress in applying renewable energy such as solar energy and geothermal energy for generating electricity from wastewater treatment and uniquely discuss the effects of these two types of renewable energy on SARS-CoV-2 in air and wastewater treatment. We also highlight the significant process made on the membrane processes utilizing renewable energy and research gaps from the standpoint of producing clean and sustainable energy. The significant points of this review are: (1) among various types of renewable energy, solar energy and geothermal energy have been predominantly studied for wastewater treatment, (2) effects of these two types of renewable energy on SARS-CoV-2 in air and wastewater treatment are critically analyzed, and (3) the knowledge gaps and anticipated future research outlook have been consequently proposed thereof.

Solar-absorbing energy storage materials demonstrating superior solar-thermal conversion and solar-persistent luminescence conversion towards building thermal management and passive illumination

Nowadays, building energy consumption accounts for more than 50% of the total energy consumption. Exploiting advanced solar energy strategy is of great significance to achieve the building energy saving by spontaneously providing energy for a building. Herein, novel solar-absorbing energy storage materials constructed by solar-thermal conversion material, phase change material gel and persistent luminescence material are proposed to efficiently utilize the full spectrum of renewable solar energy towards the building thermal management and passive illumination. A flow chemical synthesis strategy is designed to continuously prepare the solar-thermal conversion material N, S-co-doped conjugated polybenzobisthiazole towards the robust solar energy harvesting (solar absorbance of 94.1%) and considerable thermal energy production (solar-thermal conversion efficiency of 88.3%). The liquid phase blending and sol–gel transition are proposed to fabricate the phase change material gels demonstrating high latent heat of 192.12 Jg−1 and self-supporting capacity, which can store the heat generated by N, S-co-doped conjugated polybenzobisthiazole and release the heat in the night. The persistent luminescence materials can absorb the ultraviolet–visible light in the solar spectrum in the daytime and emit the multicolour luminescence in the night. Taking advantages of the synergistic effect of the functional components, the proposed solar-absorbing energy storage materials demonstrate full spectrum utilization of solar energy (total solar absorbance of 91.93%) towards the building thermal management and passive illumination with a solar-light conversion efficiency of 1.65% and a solar-thermal conversion efficiency of 10.52%. The solar-absorbing energy storage materials create a state-of-the-art alternative for the next-generation energy saving buildings.

Functionality Analysis of Electric Actuators in Renewable Energy Systems-A Review.

Various mechanical, hydraulic, pneumatic, electrical, and hybrid actuators can alter motion per the requirements of particular applications. However, except for electrical ones, all actuators are restricted due to their size, complex auxiliary equipment, frequent need for maintenance, and sluggish environment in renewable applications. This brief review paper highlights some unique and significant research works on applying electrical actuators to renewable applications. Four renewable energy resources, i.e., solar, wind, bio-energy, and geothermal energy, are considered to review electric actuators applicable to renewable energy systems. This review analyses the types of actuators associated with the mentioned renewable application, their functioning, their motion type, present use, advantages, disadvantages, and operational problems. The information gathered in this paper may open up new ways of optimization opportunities and control challenges in electrical actuators, thereby making more efficient systems. Furthermore, some energy-efficient and cost-effective replacements of convectional actuators with new innovative ones are suggested. This work aims to benefit scientists and new entrants working on actuators in renewable energy systems.

Solar-driven purification of highly polluted saline wastewater into clean water by carbonized lotus seedpod

Purifying wastewater is one of the most practical methods to respond the global clean-water crisis. Among the various wastewaters, saline wastewater is hard to be treated by common water treatment technologies due to its high salinity. Interfacial solar water evaporation is a promising method for saline wastewater purification by completely separating water and solute only by renewable solar energy. Herein, inspired by lotus seedpods’ natural bi-functional structures: vascular bundles for water transport and “air chambers” for thermal insulation, we report a carbonized lotus seedpod for solar-driven saline wastewater decontamination. After photothermal evaporation, the COD (initial value: 365.3 mg L-1) removal efficiency of actual saline wastewater reaches 84.6%. And the concentrations of Na+, K+, Ca2+, and Mg2+ in condensate water reduced by approximately 3 orders of magnitude. These results demonstrate the talent of low-cost lotus seedpods ($3/kg) for solar wastewater purification, and provide inspirations for development of solar thermal-conversion devices.

Estimation of loads for off-grid solar photovoltaic systems

Solar power is a renewable energy technology that turns sunlight into electricity using solar panels. The generated electricity can be stored or utilized immediately, returned to the grid, or combined with a renewable electricity source or several renewable technologies solar energy systems are a supply that is both dependable and environmentally friendly of energy that may be used for a range of applications, including commercial, industry, farming, and livestock needs. The system requires practically no maintenance, making it perfect for isolated locations. The near-zero operating costs outweigh the initial hefty installation costs. When evaluated at an ambient temperature of 25°C, a typical photovoltaic (PV) module outputs power with a maximum output voltage of roughly 17V. However, on a very warm day, it can drop to around 15V, and on a very freezing day, it can drop to around 15V, it can soar to 18V.

Hilbert–Huang transform and decision tree based islanding and fault recognition in renewable energy penetrated distribution system

A fast protection algorithm based on Hilbert–Huang transform (HHT) is proposed in this paper for islanding and fault detection, classification, and location in a distribution system penetrated by a solar renewable energy source. The three-phase current signals measured at the substation are utilized to extract the instantaneous features from the first level residue using Hilbert Transform (HT) after empirical mode decomposition (EMD). The feature indices computed per phase for each event using minimum post-disturbance data are then fed to a decision tree machine learning (DTML-1) model to classify disturbances into four classes: normal, fault, islanding, and switching transient. Once a fault is determined, another DTML-2 model classifies the fault into one of the seven types of faults, namely 3P-ABC (three-phase faults), 2P-AB, 2P-BC, 2P-AC (two-phase faults), 1P-AG, 1P-BG, and 1P-CG (single-phase faults). Subsequently, seven DT models based on the fault type locate the IEEE 13 bus system’s zone of fault. Variations in noise levels, DG capacity, and fault incidence angles test the proposed algorithm to achieve a good accuracy level in less time. Switching transients like capacitor switching, feeder on/off, and transformer excitation/de-excitation are also successfully classified within a quarter cycle contaminated with noise levels of 20 dB SNR.