Policies and regulations for solar photovoltaic end-of-life waste management: Insights from China and the USA.

The solar photovoltaic (PV) industry has experienced rapid growth in recent years, resulting in a substantial increase in the amount of end-of-life (EOL) waste generated by these panels. Proper waste management is crucial to minimize environmental and health risks. The purpose of this study is to examine the EOL solar PV waste management policies and regulations in China and the United States, identifying challenges and recommending policy implications for enhancing sustainable waste management practices. China has promulgated policies and regulations for managing PV EOL waste, including the National Solid Waste Law and GB or GB/T standards. In the US, federal regulations and guidelines such as the Resource Conservation and Recovery Act (RCRA) and state-specific hazardous waste programs, universal waste rules, and waste recycling programs are enacted. The findings of this study indicate that China and the US face distinct challenges in solar PV end-of-life waste management. China lacks comprehensive local government-level regulations, while the USA exhibits variations in coverage and specific management requirements across states. In light of these observations, as policy implications, it is recommended. Firstly, there is a need for greater harmonization between federal and local/state-level policies and regulations. Secondly, continued research and development efforts are crucial to explore cost-effective and environmentally responsible recycling and disposal options for PV panels. Furthermore, promoting collaboration among policymakers, industry stakeholders, and researchers can facilitate knowledge sharing and the exchange of best practices. Such measures will contribute to the effective and sustainable management of solar PV EOL waste in China and the USA.

Cellulose/inorganic nanoparticles-based nano-biocomposite for abatement of water and wastewater pollutants.

Nanostructured materials offer a significant role in wastewater treatment with diminished capital and operational expense, low dose, and pollutant selectivity. Specifically, the nanocomposites of cellulose with inorganic nanoparticles (NPs) have drawn a prodigious interest because of the extraordinary cellulose properties, high specific surface area, and pollutant selectivity of NPs. Integrating inorganic NPs with cellulose biopolymers for wastewater treatment is a promising advantage for inorganic NPs, such as colloidal stability, agglomeration prevention, and easy isolation of magnetic material after use. This article presents a comprehensive overview of water treatment approaches following wastewater remediation by green and environmentally friendly cellulose/inorganic nanoparticles-based bio-nanocomposites. The functionalization of cellulose, functionalization mechanism, and engineered hybrid materials were thoroughly discussed. Moreover, we also highlighted the purification of wastewater through the composites of cellulose/inorganic nanoparticles via adsorption, photocatalytic and antibacterial approach.

Environmental impacts of hazardous waste, and management strategies to reconcile circular economy and eco-sustainability.

The rise in living standards and the continuous development in the global economy led to the depletion of resources and increased waste generation per capita. This waste might posture a significant threat to human health or the environmental matrices (water, air, soil) when inadequately treated, transported, stored, or managed/disposed of. Therefore, effective waste management in an economically viable and environmentally friendly way has become meaningful. Prominent technology is the need of the day for circular economy and sustainable development to reduce the speed of depletion in resources and produce an alternative means for the future demands in the different sectors of science and technology. In order to meet the potential requirements for energy production or producing secondary raw material, solid waste may be the prime source. The activities of living organisms convert waste products in one form or another in which electronic waste (e-waste) is a modern-day problem that is growing by leaps and bounds. The disposal protocols of the e-waste management need to be given proper attention to avoid its hazardous impacts. The e-waste is obtained from any equipment or devices that run by electricity or batteries like laptops, palmtops, computers, televisions, mobile phones, digital video discs (DVD), and many more. E-waste is one of the rapidly growing causes of world pollution today. Plenty of research is available in the scientific literature, which shows different approaches being set up and followed to manage and dispose of waste products. These strategies to manage waste products designed by the states all over the globe revolves around minimal production, authentic techniques for the management of waste produced, reuse and recycling, etc. The virtual survey of the available literature on waste management shows that it lacks specificity regarding the management of waste products parallel to ecological sustainability. The presented review covers the sources, potential environmental impacts, and highlights the importance of waste management strategies to provide the latest and updated knowledge. The review also put forward the countermeasures that need to be taken on national and International levels addressing the sensitive issue of waste management.

Solution Processed Zn1-x-ySmxCuyO Nanorod Arrays for Dye Sensitized Solar Cells.

Cu- and Sm-doped ZnO nanorod arrays were grown with 1 wt% of Sm and different weight percents (0.0, 0.5, 1.0 and 1.5 wt%) of Cu by two-step hydrothermal method. The influence of Cu concentration and precursor of Sm on the structural, optical and photovoltaic properties of ZnO nanorod arrays was investigated. An X-ray diffraction study showed that the nanorod arrays grown along the (002) plane, i.e., c-axis, had hexagonal wurtzite crystal structure. The lattice strain is present in all samples and shows an increasing trend with Cu/Sm concentration. Field emission scanning electron microscopy was used to investigate the morphology and the nanorod arrays grown vertically on the FTO substrates. The diameter of nanorod arrays ranged from 68 nm to 137 nm and was found highly dependent on Cu concentration and Sm precursor while the density of nanorod arrays almost remains the same. The grown nanorod arrays served as photoelectrodes for fabricating dye-sensitized solar cells (DSSCs). The overall light to electricity conversion efficiency ranged from 1.74% (sample S1, doped with 1 wt% of Sm and 0.0 wt% of Cu) to more than 4.14% (sample S4, doped with 1 wt% of Sm and 1.5 wt% of Cu), which is 60% higher than former sample S1. The increment in DSSCs efficiency is attributed either because of the doping of Sm3+ ions which increase the absorption region of light spectrum by up/down conversion or the doping of Cu ions which decrease the recombination and backward transfer of photo-generated electrons and increase the electron transport mobility. This work indicates that the coupled use of Cu and Sm in ZnO nanorod array films have the potential to enhance the performance of dye-sensitized solar cells.

Characteristics and Photovoltaic Applications of Au-Doped ZnO-Sm Nanoparticle Films.

Au-doped ZnO-samarium nitrate (Sm) nanoparticles with fixed concentrations of Sm (1 wt %) and various concentrations of Au (0.0, 0.5, 1.0 and 1.5 wt %) were prepared and used as photoelectrodes to enhance the photovoltaic efficiency of dye-sensitized solar cells (DSSCs). The cell fabricated with 1.5 wt % of Au-doped ZnO-Sm nanoparticles film achieved an optimal efficiency of 4.35%, which is about 76% higher than that of 0.0 wt % of Au-doped ZnO-Sm-based cell (2.47%). This increase might be due to the formation of a blocking layer at the ZnO-Sm/Au interface, which inhibits the recombination of electrons. This increase may also be attributed to the addition of rare-earth ions in ZnO to enhance the non-absorbable wavelength region of light via up/down-conversion of near-infrared and ultraviolet radiations to visible emission and reduce the recombination loss of electron in the cell. The efficiency of cells may be increased by the blocking layer and up/down-conversion process and thus promote the overall performance of the cells. This work indicates that Au-doped ZnO-Sm nanoparticle films have the potential to increase the performance of DSSCs.

A research on conventional and modern algorithms for maximum power extraction from wind energy conversion system: a review.

In the last few decades, wind energy has become a significant source of the renewable energy system, and it is essential to use wind energy for generating power and run the wind turbine system (WTs) at a higher level. With the rapid penetration of wind energy in the distributed generation system (DGS) and isolated micro-grid (MG), the WT runs at its optimal energy conversion output. For this, WT has to track or drive at the optimal power point tracking algorithm. However, various publications are available on MPPT algorithms for wind energy system (WES) applications, making a choice on exact trackers for a particular algorithm because each tracker has its advantages and disadvantages. Therefore, our primary goal is to review and evaluate the exact tracking algorithm for WES applications in this manuscript. To introduce the power controller, it is essential to track maximum power despite wind energy results. Besides, many algorithms have been evaluated, and their maximum output is achieved compared to their performance. This research paper will help researchers provide an accurate reference for future recommendations by selecting the best tracking algorithms in WES.

Solar still desalination system equipped with paraffin as phase change material: exergoeconomic analysis and multi-objective optimization.

The current work is about analysis and multi-objective optimization (MOO) of weir-type solar still systems equipped with phase change material (PCM) regarding the exergetic and economic performance. To do so, the energetic and exergetic modeling of the suggested system is conducted then the substantial economic factors is applied to obtain the total cost rate of the considered SSDS. The total exergetic efficiency and total annual cost (TAC) is considered objective functions. Four parameters include mass of the PCM (mPCM), inlet brine water flow rate ([Formula: see text]), gap distance (d), and insulation width (xins) is chosen as decision variables. Moreover, a genetic algorithm-based MOO was applied to find the optimum states of evaluated solar still unit. The outputs represented that increasing the brine feed water mass flow rate does not affect the TAC while decreasing distilled water production rate. The scattered distribution of optimum states infers that the optimum value of PCM mass is about 1 kg. In addition, applied MOO reveals that with optimization of the studied system, the exergy efficiency increases about 1.47% and the annual distilled water increases 4.35% compared with the non-optimized system. The suggested system is capable to produce fresh water in remote areas without any pollution as well as in a low cost rate.