Unveiling the photocatalytic marvels: Recent advances in solar heterojunctions for environmental remediation and energy harvesting.

In the quest for effective solutions to address Environ. Pollut. and meet the escalating energy demands, heterojunction photocatalysts have emerged as a captivating and versatile technology. These photocatalysts have garnered significant interest due to their wide-ranging applications, including wastewater treatment, air purification, CO2 capture, and hydrogen generation via water splitting. This technique harnesses the power of semiconductors, which are activated under light illumination, providing the necessary energy for catalytic reactions. With visible light constituting a substantial portion (46%) of the solar spectrum, the development of visible-light-driven semiconductors has become imperative. Heterojunction photocatalysts offer a promising strategy to overcome the limitations associated with activating semiconductors under visible light. In this comprehensive review, we present the recent advancements in the field of photocatalytic degradation of contaminants across diverse media, as well as the remarkable progress made in renewable energy production. Moreover, we delve into the crucial role played by various operating parameters in influencing the photocatalytic performance of heterojunction systems. Finally, we address emerging challenges and propose novel perspectives to provide valuable insights for future advancements in this dynamic research domain. By unraveling the potential of heterojunction photocatalysts, this review contributes to the broader understanding of their applications and paves the way for exciting avenues of exploration and innovation.

Experimental study on the various varieties of photovoltaic panels (PVs) cooling systems to increase their electrical efficiency.

This study investigates the impact of cooling methods on the electrical efficiency of photovoltaic panels (PVs). The efficiency of four cooling techniques is experimentally analyzed. The most effective approach is identified as water-spray cooling on the front surface of PVs, which increases efficiency by 3.9% compared to the case without cooling. The results show that water-spray cooling raises the PV's temperature to 41°C, while improving its average daytime efficiency to 22%. Air-cooling, water-cooling in the tubes behind the PV, and aluminum oxide-water nanofluid cooling in the tubes behind the PV improve efficiency by 1.1%, 1.9%, and 2.7%, respectively. The findings highlight the potential of water-spray cooling as a cost-effective and efficient method to enhance PV efficiency and contribute to the global effort towards renewable energy.

Coordinated active-reactive power optimization considering photovoltaic abandon based on second order cone programming in active distribution networks.

On the basis of predecessors' coordination optimization of active and reactive power in distribution network, For the necessity of the optimal operation in the distribution network, part of power generated from photovoltaic (PV) cannot be sold to users, and cannot enjoy subsidies. Similarly, the network loss in the power transmission will also bring a certain economic loss. This paper comprehensively considers the economic loss caused by the network loss and PV abandon of the distribution system, and establishes a model to minimize the economic loss. To solve this problem efficiently, the method of DistFlow equation and mixed integer second order cone programming (MISOCP) is used to solve the problem, in this method, the original mixed integer nonlinear programming non-convex problem is transformed into a convex problem, which makes the optimization problem easy to solve. The modified IEEE 33 and IEEE 69 distribution networks are tested by the above method. The optimized results are able to meet the target and have very small relaxation gaps, and the voltage level is also optimized. This coordinated optimization approach helps to optimize the economic operation for active distribution networks with PVs.

Electrogenic performance and carbon sequestration potential of biophotovoltaics.

Biophotovoltaics (BPV) is a clean and sustainable solar energy generation technology that operates by utilizing photosynthetic autotrophic microorganisms to capture light energy and generate electricity. However, a major challenge faced by BPV systems is the relatively low electron transfer efficiency from the photosystem to the extracellular electrode, which limits its electrical output. Additionally, the transfer mechanisms of photosynthetic microorganism metabolites in the entire system are still not fully clear. In response to this, this article briefly introduces the basic BPV principles, reviews its development history, and summarizes measures to optimize its electrogenic efficiency. Furthermore, recent studies have found that constructing photosynthetic-electrogenic microbial consortia can achieve high power density and stability in BPV systems. Therefore, the article discusses the potential application of constructing photosynthetic-electrogenic microbial aggregates in BPV systems. Since photosynthetic-electrogenic microbial communities can also exist in natural ecosystems, their potential contribution to the carbon cycle is worth further attention.

A comparative study of thermal radiation model in Chinese solar greenhouse.

The performance of three widely used thermal radiation models, the P-1 model, the surface-to-surface (S2S) model and the Discrete-Ordinates (DO) model, were evaluated for simulation temperature in Chinses solar greenhouse. The thermal radiation models were evaluated by comparing the numerical results with experimental data at representative points in the CSG. For indoor rear wall, the indoor soil and indoor air, the models showed good agreement between the experimental data and the simulated results correspond to P1, S2S and DO respectively. This work provides information for simulate greenhouse temperature and use specific radiation models for the most suitable thermal environment for crop growth.

A modified fractional short circuit current MPPT and multicellular converter for improving power quality and efficiency in PV chain.

This article presents the contribution of multicellular converters in improving of the quality of power produced in photovoltaic chain, with the aim of exploiting the maximum power produced by the photovoltaic generator with low oscillations around of the maximum power point (MPP) at steady state and to reduce switching losses. After modeling the multicellular parallel boost converter, fractional short circuit current (FSCC) MPPT was modified to get an estimated photocurrent as a reference to control the inductance current for good functioning of the converter in pursuit of the maximum power point. To verify the performance of the proposed solution, the system was submitted to irradiance and temperature variations. The simulations carried out in the Matlab/Simulink environment presented satisfactory results of the proposed solution, in comparison with the high-gain quadratic boost converter we have a response time of 0.04 s, power oscillations at maximum point around 0.05 W and efficiency of 99.08%; in comparison with the interleaved high-gain boost converter the results show a response time of 0.1 s for the transferred power, a very low output voltage ripples of 0.001% and 98.37% as efficiency of the chain. The proposed solution can be connected to a grid with a reduction of level of the inverter and active filter.

[Occupational hazards of crystalline silicon solar cell manufacturing industry].

The wide use of crystalline silicon solar cells in the field of new energy is an important boost for China to achieve the environmental protection goal as soon as possible. However, the production and manufacturing processes of these cells give rise to various occupational hazards at workplace, thus posing health risks to workers. This review provided an overview of production processes of crystalline silicon solar cells, the characteristics of occupational health hazards (productive dust; physical factors, productive toxicant) and proposed occupational protection suggestions.

Comparison of Pb-based and Sn-based perovskite solar cells using SCAPS simulation: optimal efficiency of eco-friendly CsSnI3 devices.

In this study, we employed the one-dimensional solar cell capacitance simulator (SCAPS-1D) software to optimize the performance of Pb-based and Sn-based (Pb-free) all-inorganic perovskites (AIPs) and organic-inorganic perovskites (OIPs) in perovskite solar cell (PSC) structures. Due to the higher stability of AIPs, the performance of PSCs incorporating Cs-based perovskites was compared with that of FA-based perovskites, which are more stable than their MA-based counterparts. The impact of AIPs such as CsPbCl3, CsPbBr3, CsPbI3, CsSnCl3, CsSnBr3, and CsSnI3, as well as including FAPbCl3, FAPbBr3, FAPbI3, FASnCl3, FASnBr3, and FASnI3, was investigated. SnO2 and Cu2O were selected as an inorganic electron transport layer (ETL) and a hole transport layer (HTL), respectively. CsSnBr3, CsSnI3, FASnCl3, and FASnBr3 exhibited higher efficiency compared to their Pb-based counterparts. Additionally, most Cs-based perovskites, excluding CsPbI3, demonstrated better performance relative to their FA counterparts. CsSnI3 AIP device also shows the highest short circuit current density (JSC) of 32.85 mA/cm2, the best power conversion efficiency (PCE) of 16.00%, and the least recombination at the SnO2/CsSnI3 interface. The thickness, doping, and total defect density of CsSnI3 PSC have been systematically investigated and optimized to obtain the PCE of 17.36%. These findings highlight the potential of CsSnI3 PSCs as efficient and environmentally friendly PSCs.

Experimental analysis of dust's impact on solar photovoltaic system efficiency in arid environments: a case study in Southern Algeria.

The purpose of this study is to explore the effects of accumulated dust and weather conditions on the energy generated by solar photovoltaic panels in Ouargla, Algeria, between May 3 and August 3, 2023. For this experiment, two monocrystalline panels with a power output of 390 W manufactured by Zergoune Green Energy Company, as well as data-logging equipment, were used. The first panel was perfectly cleaned before starting every test and the second panel remained uncleaned. On day 90, the cleaned panel maintained an average power of 193 W, while the dusty panel exhibited a lower average power of 139 W. The greatest average reduction in efficiency, approximately 36.32%, occurred after 3 months of exposure to weather conditions. The scanning electron microscope (SEM) analysis demonstrates the existence of microscopic dust particles which prevent part of solar radiation away instead of being absorbed by the photovoltaic cells, leading to a drop in the efficiency of the PV module. The primary chemical elements found in dust are oxygen, silicon, aluminum, and magnesium.

Protocol for fabricating long-lasting passivated perovskite solar cells.

Preparation of perovskite solar cells (PSCs) with long-lasting passivation effectiveness is challenging. Here, we present a protocol for fabricating efficient and stable passivated perovskite solar cells. We describe steps for preparing the electron transporting layer (ETL) via chemical bath deposition and perovskite film. We then detail procedures for passivating the surface defects with excess terpyridine ligands and stability characterization. This protocol features a passivator-terpyridine whose passivation effect is independent of concentration, which greatly improves the durability of the passivation. For complete details on the use and execution of this protocol, please refer to Wang et al.1.

Status of photovoltaic water pumping systems in Iran: A comprehensive review.

This study investigates the current status of photovoltaic water pumping systems (PVWPSs) in Iran, a country endowed with significant solar irradiation potential, notably in its southern and central regions. Despite this potential, there is a scarcity of comprehensive studies on solar water pumping systems within the country. This purpose of this study is to conduct a thorough review of the existing literature to assess the state of solar water pumping in Iran. The adoption of PVWPS across various provinces demonstrates the system's versatility, proving effective in both highly sunny and less irradiated regions. Iran's widespread utilization of PVWPS is attributed to its ample irradiations, even in its northern areas, which possess lower solar irradiance levels. There are limited comprehensive studies encompassing technical, economic, environmental, and social aspects of solar PV water pumping projects in Iran. Most of the research has been conducted during the last few years, indicating an increased recognition of the possible advantages of this technology. Finally, this review provides valuable insights for researchers and farmers, showcasing the benefits of solar PVWPS. It sets the stage for further innovation and implementation in the country's agricultural landscape, emphasizing the need for continued exploration and adoption of this sustainable approach.

Ambient energy harvesters in wearable electronics: fundamentals, methodologies, and applications.

In recent years, wearable sensor devices with exceptional portability and the ability to continuously monitor physiological signals in real time have played increasingly prominent roles in the fields of disease diagnosis and health management. This transformation has been largely facilitated by materials science and micro/nano-processing technologies. However, as this technology continues to evolve, the demand for multifunctionality and flexibility in wearable devices has become increasingly urgent, thereby highlighting the problem of stable and sustainable miniaturized power supplies. Here, we comprehensively review the current mainstream energy technologies for powering wearable sensors, including batteries, supercapacitors, solar cells, biofuel cells, thermoelectric generators, radio frequency energy harvesters, and kinetic energy harvesters, as well as hybrid power systems that integrate multiple energy conversion modes. In addition, we consider the energy conversion mechanisms, fundamental characteristics, and typical application cases of these energy sources across various fields. In particular, we focus on the crucial roles of different materials, such as nanomaterials and nano-processing techniques, for enhancing the performance of devices. Finally, the challenges that affect power supplies for wearable electronic products and their future developmental trends are discussed in order to provide valuable references and insights for researchers in related fields.

Development of biomass aerogels with aligned channels: For continuous treatment of oily wastewater and solar-powered oil evaporation.

A biomass CS/CNTs@MTMS (MCCS) aerogel with both aligned channel network, superhydrophobicity, and photothermal conversion ability was prepared by a green and facile strategy of directed freeze-drying and chemical vapor deposition using chitosan (CS), carbon nanotubes (CNTs), and methyltrimethoxysilane (MTMS) as the building materials. Capacity to adsorb a large variety of oils and organic solvents, with an adsorption capacity of up to 34-83 g/g. After 10 cycles, the adsorption capacity of MCCS remained at 94 % of the initial capacity, providing excellent reusability. In addition, due to its unique network of aligned channels, the MCCS can continuously separate oil and water, making it a sustainable oil-water separator. More interestingly, the MCCS aerogel has excellent photothermal conversion capabilities, and it was utilized to evaporate oil collected during the oil-water separation process using solar energy. This work provides an opportunity to design novel self-cleaning photothermally driven oil-water separation biomass materials with superhydrophobicity-strong lipophilicity.

Fuzzy logic-based prediction and parametric optimizing using particle swarm optimization for performance improvement in pyramid solar still.

The primary objective of this study is to develop a robust model that employs a fuzzy logic interface (FL) and particle swarm optimization (PSO) to forecast the optimal parameters of a pyramid solar still (PSS). The model considers a range of environmental variables and varying levels of silver nanoparticles (Ag) mixed with paraffin wax, serving as a phase change material (PCM). The study focuses on three key factors: solar intensity ranging from 350 to 950 W/m2, water depth varying between 4 and 8 cm, and silver (Ag) nanoparticle concentration ranging from 0.5 to 1.5% and corresponding output responses are productivity (P), glass temperature (Tg), and basin water temperature (Tw). The experimental design is based on Taguchi's L9 orthogonal array. A technique for ordering preference by similarity to the ideal solution (TOPSIS) is utilized to optimize the process parameters of PSS. Incorporating a fuzzy inference system (FIS) aims to minimize the uncertainty within the system, and the particle swarm optimization algorithm is employed to fine-tune the optimal settings. These methodologies are employed to forecast the optimal conditions required to enhance the productivity of the PSS.

An artificial gorilla troops optimizer for stochastic unit commitment problem solution incorporating solar, wind, and load uncertainties.

The unit commitment (UC) optimization issue is a vital issue in the operation and management of power systems. In recent years, the significant inroads of renewable energy (RE) resources, especially wind power and solar energy generation systems, into power systems have led to a huge increment in levels of uncertainty in power systems. Consequently, solution the UC is being more complicated. In this work, the UC problem solution is addressed using the Artificial Gorilla Troops Optimizer (GTO) for three cases including solving the UC at deterministic state, solving the UC under uncertainties of system and sources with and without RE sources. The uncertainty modelling of the load and RE sources (wind power and solar energy) are made through representing each uncertain variable with a suitable probability density function (PDF) and then the Monte Carlo Simulation (MCS) method is employed to generate a large number of scenarios then a scenario reduction technique known as backward reduction algorithm (BRA) is applied to establish a meaningful overall interpretation of the results. The results show that the overall cost per day is reduced from 0.2181% to 3.7528% at the deterministic state. In addition to that the overall cost reduction per day is 19.23% with integration of the RE resources. According to the results analysis, the main findings from this work are that the GTO is a powerful optimizer in addressing the deterministic UC problem with better cost and faster convergence curve and that RE resources help greatly in running cost saving. Also uncertainty consideration makes the system more reliable and realistic.

Improved cooling of photovoltaic panels by natural convection flow in a channel with adiabatic extensions.

In hot dry regions, photovoltaic modules are exposed to excessive temperatures, which leads to a drop in performance and the risk of overheating. The present numerical study aims to evaluate the natural air cooling of PV modules by an inclined chimney mounted at the back. The basic equations were solved using the finite volume method. The validity of the model is verified by comparison with the data available in the literature. Thermal and dynamic flow patterns are analyzed for a variety of parameters: Rayleigh numbers from 102 to 106, PV panel tilt angle from 15° to 90°, and channel aspect ratios from 1/20 to 1/5. A critical aspect ratio has been determined to minimize overheating of the PV module. According to the computational results, the tilt angle and modified Rayleigh number increase the mass flow rate and mean Nusselt number. The overheating zone with maximum temperatures is located in the upper part of the photovoltaic panel. The addition of an extension to both channel's inlet and outlet was found to improve the cooling of the photovoltaic panels; however, only the extensions downstream of the channel are truly effective. The critical lengths at which channel performance improves significantly were identified by examining the impact of longer extensions on channel performance. Increasing the extension length from 0 to 3H improves the mass flow rate by 65%, the average Nusselt number by 13.4%, and leads to an 11% decrease in maximum temperature when Ra* = 106. This cooling technique is particularly promising for hot dry regions where water is scarce.

New boost type single phase inverters for photovoltaic applications with reduced device count.

In recent years, single-stage boost inverters with common ground have shaped the inverter markets due to the many benefits associated with these types of inverters, including their high efficiency, single control scheme, and integrated boost converter. A new boost-type inverter that utilizes a common ground and has fewer switches is proposed in this article. It uses two DC-link capacitors connected in parallel and discharged independently while being charged simultaneously. The voltage for the positive and negative half cycles is supplied by the capacitors located at the top and bottom of the circuit, respectively. In addition, a comparison is made between the proposed circuit and the boost inverter already in use in the literature. Using PLECS as the computing software, the efficiencies are determined depending on the various percentages of output power. To validate performance, present experimental data, and attain the best possible efficiency of 97%, a 400 W prototype model is constructed. In addition to that, the breakdown of the costs is shown.

The Effect of Conjugated Nitrile Structures as Acceptor Moieties on the Photovoltaic Properties of Dye-Sensitized Solar Cells: DFT and TD-DFT Investigation.

A major challenge in improving the overall efficiency of dye-sensitized solar cells is improving the optoelectronic properties of small molecule acceptors. This work primarily investigated the effects of conjugation in nitriles incorporated as acceptor moieties into a newly designed series of D-A-A dyes. Density functional theory was employed to specifically study how single-double and single-triple conjugation in nitriles alters the optical and electronic properties of these dyes. The Cy-4c dye with a highly conjugated nitrile unit attained the smallest band gap (1.80 eV), even smaller than that of the strong cyanacrylic anchor group (2.07 eV). The dyes lacking conjugation in nitrile groups did not contribute to the LUMO, while LUMOs extended from donors to conjugated nitrile components, facilitating intramolecular charge transfer and causing a strong bind to the film surface. Density of state analysis revealed a considerable impact of conjugated nitrile on the electronic properties of dyes through an effective contribution in the LUMO, exceeding the role of the well-known strong 2,1,3-benzothiadiazole acceptor unit. The excited state properties and the absorption spectra were investigated using time-dependent density functional theory (TD-DFT). Conjugation in the nitrile unit caused the absorption band to broaden, strengthen, and shift toward the near-infrared region. The proposed dyes also showed optimum photovoltaic properties; all dyes possess high light-harvesting efficiency (LHE) values, specifically 96% for the dyes Cy-3b and Cy-4c, which had the most conjugated nitrile moieties. The dyes with higher degrees of conjugation had longer excitation lifetime values, which promote charge transfer by causing steady charge recombination at the interface. These findings may provide new insights into the structure of conjugated nitriles and their function as acceptor moieties in DSSCS, which may lead to the development of extremely effective photosensitizers for solar cells.

Carbon-based brilliance: a novel approach to renewable energy in radiotherapy centers.

The energy produced from other sources which does neither come from fossil fuels nor contribute in the production of any greenhouse effects that causes climate changes is called as 'Alternative Energy'. Since our world's primary energy sources such as coal, oil and natural gases are exploited to a greater extent, we are in an urge to switch to an alternative energy. Scattered radiation, a common byproduct in radiation therapy and diagnostic radiology, presents a unique opportunity in the realm of alternative energy. As a potential source of interference, scattered radiation can be repurposed to contribute to sustainable energy solutions. Addressing the issue of scattered radiation wastage and utilizing it for alternative energy, an activated carbon-based solar cell emerges as a solution. This solar cell, a conventional one in which cadmium Telluride is replaced by coconut shell based carbon material, has the potential in producing a significant amount of electrical energy by utilizing scattered radiation from radiotherapy and radiology machines. Furthermore, this activated carbon based-material undergoes thorough characterization into various teletherapy and radiology machines, and it can be seamlessly integrated into clinical practices.

A 3D self-floating solar vapor generator based on a novel self-healing aero-hydrogel containing peach gum polysaccharide with durability and continuous operation.

Solar energy interfacial evaporation represents a promising and sustainable approach with considerable potential for seawater desalination and wastewater treatment. Nonetheless, creating durable evaporators for continuous operation presents a challenge. Motivated by natural self-healing mechanisms, this study developed a novel 3D hybrid aero-hydrogel, which exhibited a self-healing efficiency of 89.4 % and an elongation at break post-healing of 637.7 %, featuring self-healing capabilities and continuous operation potential. Especially, the incorporation of hyperbranched water-soluble polymers (peach gum polysaccharide) endow the final solar water evaporators with a lower evaporation enthalpy of water, resulting in that the refined SVG3, with a notable water surface architecture and an expanded evaporation area, achieved a steam generation rate of 2.13 kg m-2 h-1 under 1 Sun. Notably, SVG2 achieved a high evaporation rate of 2.43 kg m-2 h-1 with the combined energy input of 1 Sun and 6 V, significantly surpassing the rate of 1.96 kg m-2 h-1 without voltage input. The results indicate that electrical energy significantly enhances and synergizes with SVG, facilitating continuous operation both day and night through the combined use of solar energy and electrical input. This study offers insightful perspectives for the strategic design of multifunctional hydrogels for solar water evaporation.