Solar Energy Harvesting Research Articles

Investigation of graphene based disk-square integration resonator for enhanced solar absorption using machine learning for solar heaters

As worries about climate change and energy security grow, the need for clean and sustainable energy sources becomes increasingly critical. Among the possible alternatives, solar thermal technology provides a dependable and adaptable method for harnessing the sun's energy as heat. At the core of this technique is the solar thermal absorber, a critical component that converts sunlight into useful thermal energy. The Graphene Based Disk-Square Integration Resonator Solar Absorber (GBDSIRSA) structure is examined in this work between 200 and 2500 nm in wavelength. The GBDSIRSA has remarkable performance throughout a wide variety of spectral ranges, underscoring its adaptability and effectiveness. GBDSIRSA has exceptional efficiency in absorbing light over the full spectrum, from UV to MIR wavelengths, with an average absorptance of 97.73%. The absorptance rates are particularly high, achieving 94.02% in the UV, 96.36% in the VIS, 97.12% in the NIR, and an astounding 98.94% in the mid-infrared (MIR) region. The GBDSIRSA is independent of polarization effect and also an incident angle independent up to 80 degrees. The machine learning (Local Regression) approach used with test size of 0.2 and 1.8780 ×10-5 mean squared error for absorptance prediction has good prediction accuracy R2 of more than 95% which is applied to simulation resource reduction. Because of its wide absorptance spectrum, polarization and incident angle independence, the GBDSIRSA is a very promising technology for a variety of applications, including thermal imaging and renewable energy. It can efficiently harvest solar energy. All things considered, GBDSIRSA's remarkable absorptance properties highlight its promise as a top choice for cutting-edge optical and solar energy applications.

Comparative Study on Efficiency Analysis of Fixed and Dual-Axis Solar Tracking System

Solar energy is a crucial renewable energy source, offering sustainable solutions to address energy demands and combat climate change. Maximizing the efficiency of solar energy harvesting is essential for widespread adoption and integration into the energy landscape. Solar tracking systems play an important role in increasing the efficiency of solar panels by optimizing their orientation towards the sun throughout the day. This research presents a comparative analysis of the efficiency of dual-axis solar tracking systems using Light-Dependent Resistors (LDRs) as input devices. A closed-loop tracking technique is implemented to adjust the position of the solar panels based on real-time sensor feedback. A comparative study between LDRs demonstrates their effectiveness in detecting the sun's position, despite limitations such as susceptibility to ambient light conditions and saturation to light intensity. Through experimental evaluation and data analysis, this study provides valuable insights into the power output and assessment of efficiency variation of dual-axis solar tracking systems offering applications for optimizing solar energy harvesting in practical scenarios.

Maximizing solar energy generation: guidelines for optimizing photovoltaic panel placement on building facades

PurposeThis purpose of this paper is to address the research problem of optimizing photovoltaic (PV) panel placement on building facades to maximize solar energy generation.Design/methodology/approachThe study examines the significance of various design configurations and their implications for PV system performance. The research involves analysis of relevant literature and energy simulations. An exemplary case study is conducted in a hot climate zone to quantify the impacts of PV panel placement on energy generation. Various application scenarios are developed, resulting in 28 scenarios for PV on building facades. Energy simulations using Grasshopper Rhino software and Ladybug plugin components are performed.FindingsThe paper identifies key factors influencing PV panel placement and energy generation through qualitative analysis. It introduces an appropriateness matrix as a decision-making framework to evaluate placement options. The study identifies design configurations and external features impacting PV location selection and performs a qualitative classification to determine their impact on energy generation.Practical implicationsThe results and decision-making framework enable informed choices based on solar radiation levels, shading conditions, and building requirements. Optimizing PV panel placement enhances solar energy harvesting in buildings, benefiting architects and engineers.Originality/valueThe novel contributions of this paper include practical insights and guidance for strategically placing PV panels on building facades.

Superior Performance of Hollow Plasmonic Cubic Structures for Solar Energy Harvesting, Conversion, and Storage Systems

Superior Performance of Hollow Plasmonic Cubic Structures for Solar Energy Harvesting, Conversion, and Storage Systems

A review of the state of art and prospects in energy storage systems for energy harvesting applications

Due to the increasing trend in worldwide energy consumption, many new energy technology systems have emerged in the past decades. The implementation of energy storage system (ESS) technology in energy harvesting systems is significant to achieve flexibility and reliability in fulfilling the load demands. In this paper, several types of energy storage technologies available in the market are discussed to view their benefits and drawbacks. The main aim of this review is to provide a platform for readers especially those who seek to know more about ESS at a glance, to decide which ESS technology is best suited for any specific applications. This review would serve as a base for the initial state to make the right decision by referring to the criterias and characteristics of energy resources to get the optimal ESS technology. A comprehensive comparison among the various types of ESS technologies is outlined and elaborated to provide a better and clearer picture to the readers. Last but not least, the relevant recommendations and alternative choices for services related to the harvesting of solar PV energy are described too. It is hoped that the findings of this review article may be helpful to all readers interested in ESS technology.

Self-assembled Au-CQDs nanofluids with excellent solar absorption and medium–high temperature stability for solar energy harvesting

Nanofluids-based direct absorption solar collectors are promising candidates for medium–high-temperature solar energy harvesting. However, nanofluids’ complicated preparation process and undesirable high-temperature stability have hindered their practical applications. Herein, we propose a facile method for synthesizing gold/carbon quantum dots (Au-CQDs) nanofluids by directly carbonizing the base fluid and spontaneously assembling with Au nanoparticles (AuNPs) triggered by high temperatures. The results indicate that the self-assembled Au-CQDs nanofluids can maintain high stability at 110 °C for 100 h without precipitation and keep excellent photothermal conversion performance under 10 sun irradiation. The concentration and particle size of AuNPs are crucial factors affecting the self-assembly process. By modulating the microscopic morphologies of the self-assembled nanoparticles, the extinction coefficient of the prepared nanofluids is up to 88.7 % at a low loading of 30 ppm. The nanofluids can reach an equilibrium temperature of 50 °C under 1 sun irradiation, 10.4 °C higher than the base fluid due to the enhanced plasmonic effects and stability resulting from the CQDs dotted AuNPs. This work offers a new strategy to fabricate highly stable nanofluids with excellent light absorption properties for efficient solar thermal applications.

Solar Tracking and Monitoring System

Abstract: We will eventually have to deal with the depletion of fossil fuels and other non-renewable energy sources as they are running out rapidly. Having a large number of renewable alternative energy sources is crucial. The sun's radiation properties meet both requirements. As a result, new technologies focused on solar energy harvesting are starting to appear. Concentrated or photovoltaic panels may yield the highest efficiency. Due to the planet's rotation, which causes humans to view the sun at different times of the day the efficiency may reduce. Devices that direct a solar panel or concentrating panel during the day are incorporated in the design, along with light-trackers to boost the system's effectiveness. A solar tracker can monitor the sun's radiation in single direction. The device monitors daily tilt of the sun for optimal performance. The work focuses on the fundamentals of solar panel parameters and their application, as well as the design and construction of an automatic solar tracker prototype utilizing Arduino code based on microcontroller. By simulating the sun's 12-month tracking in a matter of minutes, the device incorporates automation mechanisms into the tracking system.

Unveiling the molecular symphony - A DFT exploration of structure, electronic dynamics, and excited state electron transfer in D-π-A systems, enhanced by TeO2@GQD multi-junctions for solar energy conversion in DSSC

Graphene and graphene-derived materials have sparked a lot of interest because of their unique physico-chemical features, that have positioned graphene as a promising material for future opto-electronics, and energy-harvesting devices. Graphene possesses outstanding mechanical characteristics and chemical inertness, as well as great mobility and optical transparency. Single-layer graphene has a high optical transmissivity that allows it to pass through a wide variety of light wavelengths, making it a popular material for optically conducting windows. Graphene-based metal and metal oxide nanocomposites require substantial investigations to understand the fundamental interactions between nanostructures and the graphene surface in DSSC, for understanding the characteristic features of such nanocomposites. In the present study different donor-π-acceptor, systems were used, which are different in the type of the π –spacer units only. This D-π-A system was then decorated on a (TiO2)9 semiconductor leading to shifting of the absorption wavelength, the absorbed wavelength was further shifted upon interaction with tellurium–oxide@graphene, thereby exploring its application in solar energy harvesting devices. The result of such substitution was assessed in terms of various parameters such as highest occupied molecular orbital (HOMO), least unoccupied molecular orbital (LUMO), energy gap (Egap), maximum wavelength (λmax), the free energy of electron injection efficiency (ΔGinject), open-circuit voltage (Voc), reorganization energy (Δreorg), etc by the DFT method with Gaussian 09 set of codes. The study can prove beneficial for understanding the mechanism of high optical absorption over a broad spectrum in such multijunction systems, the feature which makes them promising materials for efficient optical, electronic, and light-harvesting devices.

Study of KOH as alkali for enhancing performance of photo-galvanic cell in transparent cylindrical cell design

Photo-galvanic cells are liquid electrolyte-based dye-sensitized solar cells. Chemically, the dye/pigment photo-sensitizer, reductant, surfactant, and alkali materials are the main fabrication components of these cells. Most dye/pigment materials are more soluble and stable at high pH. The pH of Potassium hydroxide (an alkali of plant nutrient ‘potassium’ element) is very high. Therefore, Potassium hydroxide is supposed to be the best eco-friendly and effective alkali medium for photogalvanics. As far as alkali is concerned, NaOH has been exploited extensively in photo-galvanics. Although, the NaOH-based photo-galvanics show good electrical output, it is plagued with some drawbacks like shorter shelf life, high cost, unsafe for skin, low conductivity, low water solubility, etc. Therefore, in the present research, the KOH has been exploited as an alkali material for harvesting solar energy using the Sunset Yellow FCF dye sensitizer-Ascorbic acid reductant-CTAB surfactant cylindrical cell designed photo-galvanic system.In the present study, the observed optimum cell performance is as follows-open-circuit potential 777 mV, maximum current 25000 μA, short-circuit current 5600 μA, power 733.6 μW, fill factor 0.16, and efficiency is 19.77 % at pH 14.30. The Sunset Yellow FCF dye shows very high photostability and photo-absorption with KOH alkali. The power storage capacity is sufficiently robust, as the cell is capable of supplying power at its ∼36.16 % capacity after a very long time of 24 h. The KOH-Sunset Yellow FCF dye sensitizer-Ascorbic acid reductant-CTAB surfactant photo-galvanics in the present study show improved results over the reported results for the NaOH-Sunset Yellow FCF dye sensitizer-Ascorbic acid reductant-CTAB surfactant photo-galvanics. The reasons for the good photo-galvanics with KOH alkali may be attributed to some peculiar chemical and physical properties of KOH vis-à-vis the chemical and physical properties of NaOH.

Advancing the ethanol pathway during the competitive photocatalytic CO2 reduction in a defective transition metal dichalcogenide

The photocatalytic carbon dioxide (CO2) reduction is a very promising approach for harvesting solar energy and recycling carbon resources. However, the native defects induced competition among different pathways for photocarriers is inevitable and negatively affects the selectivity. This work studies the competition between the vacancy induced pathway and the normal in a molybdenum sulfide selenide during photocatalytic CO2 reduction. It has been revealed that the high concentration of chalcogen vacancies can open up the carbene pathway by lowering the free energy and adjusting the adsorptions for the critical intermediates of *CH2 to attract the neighboring *CO for the C-C coupling in the ethanol production, and therefore improve the ethanol production obviously. We propose that in the design of photocatalysts for C2+ production, construction of variant active sites for the coupling of matching intermediates should be fully considered when choosing the basic materials, dopants and native defects.

Solar-enhanced lithium extraction with self-sustaining water recycling from salt-lake brines

Lithium is an emerging strategic resource for modern energy transformation toward electrification and decarbonization. However, current mainstream direct lithium extraction technology via adsorption suffers from sluggish kinetics and intensive water usage, especially in arid/semiarid and cold salt-lake regions (natural land brines). Herein, an efficient proof-of-concept integrated solar microevaporator system is developed to realize synergetic solar-enhanced lithium recovery and water footprint management from hypersaline salt-lake brines. The 98% solar energy harvesting efficiency of the solar microevaporator system, elevating its local temperature, greatly promotes the endothermic Li+ extraction process and solar steam generation. Benefiting from the photothermal effect, enhanced water flux, and enriched local Li+ supply in nanoconfined space, a double-enhanced Li+ recovery capacity was delivered (increase from 12.4 to 28.7 mg g-1) under one sun, and adsorption kinetics rate (saturated within 6 h) also reached twice of that at 280 K (salt-lake temperature). Additionally, the self-assembly rotation feature endows the microevaporator system with distinct self-cleaning desalination ability, achieving near 100% water recovery from hypersaline brines for further self-sufficient Li+ elution. Outdoor comprehensive solar-powered experiment verified the feasibility of basically stable lithium recovery ability (>8 mg g-1) directly from natural hypersaline salt-lake brines with self-sustaining water recycling for Li+ elution (440 m3 water recovery per ton Li2CO3). This work offers an integrated solution for sustainable lithium recovery with near zero water/carbon consumption toward carbon neutrality.

Bi-directional high-performance metamaterial perfect absorber for solar harvesting and refractive index sensing

Metamaterial perfect absorbers have been widely studied due to their potential applications in fields such as sensors, saltwater purification, switching devices, solar energy harvesting and so on. However, it is difficult for absorbers to have both narrowband absorption and broadband absorption. Up to till now, there are few reports on such absorbers. In this paper, we present an absorber that achieves ultra-high performance in an ultra-simple structure, which can attain bifunctional perfect absorption of broadband and narrowband. It consists of a multilayer planar structure with top layer periodically arranged particles. When the light is incident vertically above the surface of the absorber, the proposed absorber exhibits narrow-band absorption with three absorption peaks, among which two absorption peaks have an absorption rate of 99.3 % and 99.9 %, and the full widths at half maximum (FWHM) are 3 nm and 11 nm, respectively. When the light is incident under the surface of the absorber, then the absorber exhibits broad-band absorption, with an average absorption of 97.3 % over a 1500 nm bandwidth (600 nm–2100nm). In addition, the proposed multifunctional perfect absorber has a narrow FWHM and a large broadband absorption range in the same band range. Moreover, the absorber is both polarization-independent and large incident angle-insensitive for both TE and TM-polarized waves. This absorber is of great value in areas such as bio-optical detection and solar energy harvesting.

A low voltage input boost converter with novel switch driver enhancement technology for indoor solar energy harvesting

In the indoor environment, the output voltage of a small photovoltaic cell is usually too low to charge the battery or utilize it directly. As a result, this paper proposed a low-voltage input boost converter with novel switch driver enhancement technology for indoor solar energy harvesting. The boost converter utilized switched-capacitor charge pump architecture. Compared with conventional charge pumps, the proposed boost converter uses driver enhancement technology, which improves the output current ability of the circuit and power conversion efficiency. Besides, an adaptive dead-time circuit is designed to further optimize conversion efficiency at low input voltage. The integrated circuit (IC) of the boost converter has been manufactured in a 180 nm BCD process and occupies an active chip area of 1.6mm × 0.6 mm. Experimental measurement results confirm that the voltage boost converter increased the input voltage by four times. And the lowest start-up voltage is 0.12 V. The voltage conversion efficiency is 98 % and the highest power conversion efficiency is 76.7 % at Vin of 0.5 V. The design is suitable for indoor solar energy harvesting.

Experimental study of a low-cost reversible thermal diode for advanced heat manipulation

A low-cost reversible thermal diode was fabricated by a copper tube loop incorporating a valve in the top channel for advanced thermal management. The inner surface of one vertical tube was treated to superhydrophobic, while that of the other vertical tube was modified to superhydrophilic and further loaded with a superhydrophilic copper mesh for water wicking. Furthermore, the valve in the top channel can behave as a switch to control the hot vapor flow between the two vertical tubes. Then, different heat powers from 5 W to 15 W were applied to investigate the rectification effect of the thermal diode under low (30 %), medium (50 %), and high (70 %) filling ratios (FR) of the working fluid. The results showed that its rectification ratio could exceed 2.8 with the help of the control valve at FR = 30 %. Furthermore, the rectification effect could be reversed by the valve without flipping the thermal diode. In reversible working mode, the reversed heat transport could reach twice of the forward heat transport at FR = 50 %. Therefore, owning to the reversible heat transfer capacity, this study can guide the advanced thermal diode design for unstable waste heat recovery, solar energy harvesting, building energy management, etc.

Industrial-Si-based photoanode for highly efficient and stable water splitting

Photoelectrochemical (PEC) water splitting is an effective and sustainable method for solar energy harvesting. However, the technology is still far away from practical application because of the high cost and low efficiency. Here, we report a low-cost, stable and high-performing industrial-Si-based photoanode (n-Indus-Si/Co-2mA-xs) that is fabricated by simple electrodeposition. Systematic characterizations such as scanning electron microscopy, X-ray photoelectron spectroscopy have been employed to characterize and understand the working mechanisms of this photoanode. The uniform and adherent dispersion of co-catalyst particles result in high built-in electric field, reduced charge transfer resistance, and abundant active sites. The core–shell structure of co-catalyst particles is formed after the activation process. The reconstructed morphology and modified chemical states of the surface co-catalyst particles improve the separation and transfer of charges, and the reaction kinetics for water oxidation greatly. Our work demonstrates that large-scale PEC water splitting can be achieved by engineering the industrial-Si-based photoelectrode, which shall guide the development of solar energy conversion in the industry.

Novel Materials for Effective Harvesting of Solar Energy

Novel Materials for Effective Harvesting of Solar Energy

MSAIL: Milligram-Scale Multi-Modal Sensor Platform for Monarch Butterfly Migration Tracking

Each fall, millions of monarch butterflies across the northern US and Canada migrate up to 4,000km to overwinter in specific mountain peaks in central Mexico. To track monarchs precisely and study their navigation, a monarch tracker must obtain daily localization of the butterfly as it progresses on its three-month journey. And, the tracker must perform this task while having a weight in the tens of milligrams (mg) and measuring a few millimeters (mm) in size to avoid interfering with the monarch's flight. This paper proposes mSAIL, 8 × 8 × 2.6mm and 62mg embedded system for monarch migration tracking, constructed using 8 prior custom-designed ICs providing solar energy harvesting, an ultra-low power processor, light/temperature sensors, power management, and a wireless transceiver, all integrated and 3D stacked on a micro PCB with an 8 × 8mm printed antenna. The proposed system is designed to record and compress light and temperature data during the migration path while harvesting solar energy for energy autonomy, and wirelessly transmit the data at the overwintering site in Mexico, from which the daily location of the butterfly can be estimated using a deep learning-based localization algorithm. A two-day trial experiment of mSAIL attached to a live butterfly in an outdoor botanical garden demonstrates the feasibility of individual butterfly localization and tracking.

Dual-mode harvest solar energy for photothermal Cu2-xSe biomineralization and seawater desalination by biotic-abiotic hybrid

Biotic-abiotic hybrid photocatalytic system is an innovative strategy to capture solar energy. Diversifying solar energy conversion products and balancing photoelectron generation and transduction are critical to unravel the potential of hybrid photocatalysis. Here, we harvest solar energy in a dual mode for Cu2-xSe nanoparticles biomineralization and seawater desalination by integrating the merits of Shewanella oneidensis MR-1 and biogenic nanoparticles. Photoelectrons generated by extracellular Se0 nanoparticles power Cu2-xSe synthesis through two pathways that either cross the outer membrane to activate periplasmic Cu(II) reduction or are directly delivered into the extracellular space for Cu(I) evolution. Meanwhile, photoelectrons drive periplasmic Cu(II) reduction by reversing MtrABC complexes in S. oneidensis. Moreover, the unique photothermal feature of the as-prepared Cu2-xSe nanoparticles, the natural hydrophilicity, and the linking properties of bacterium offer a convenient way to tailor photothermal membranes for solar water production. This study provides a paradigm for balancing the source and sink of photoelectrons and diversifying solar energy conversion products in biotic-abiotic hybrid platforms.

RECENT PROGRESS IN THE SYNTHESIS AND PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS BY GRAPHENE-BASED TiO2 NANOCOMPOSITE: A REVIEW

Numerous sustainable water processing techniques have been widely investigated and are capable of boosting the quality of water. Among these techniques, photonanocatalysis has stood tall with great promises in the last few decades. Nonetheless, a major challenge in the environmental remediation of photocatalyst technology is to develop an ideal photocatalyst that must have excellent photocatalytic efficiency, large specific surface area, maximum harvesting of solar energy, high durability and recyclability. Due to their stability, low toxicity, low cost and superhydrophilicity TiO2 has been used by researchers as an efficient photocatalyst for the degradation of organic pollutants. Unfortunately, it suffers greatly due to its high band gap with 3.2[Formula: see text]eV, insufficient visible light response, fast photogenerated electrons and holes recombination rate and serious agglomeration. Keeping these views, the present review highlights the principal results of studies on current practical synthesis and photocatalytic activity of graphene-based TiO2 nanocomposite materials for the treatment of water. The amalgamation of graphene oxide (GO) and reduced graphene oxide (rGO) with nanoscale TiO2 particles results in synergistic properties thereby tuning and increasing the functionality of the composite. In this regard, the review also addressed the progress and insight into graphene-based TiO2 nanocomposite in photocatalytic removal of organic pollutants including basis mechanism, possible key strategies of the composite, and an overview of how to elevate efficacy. Finally, brief challenges and future perspectives in this field are also presented. Indeed, this work illustrated that graphene-based TiO2 composite nanomaterials can be a green signal in the future of photocatalysis targeting water pollution remediation.

Unveiling excitons in two-dimensional -pnictogens.

In this paper, we investigate the optical, electronic, vibrational, and excitonic properties of four two-dimensional -pnictogen materials-nitrogenene, phosphorene, arsenene, and antimonene-via density functional theory calculations and the Bethe-Salpeter equation. These materials possess indirect gaps with significant exciton binding energies, demonstrating isotropic behavior under circular light polarization and anisotropic behavior under linear polarization by absorbing light within the visible solar spectrum (except for nitrogenene). Furthermore, we observed that Raman frequencies red-shift in heavier pnictogen atoms aligning with experimental observations; simultaneously, quasi-particle effects notably influence the linear optical response intensively. These monolayers' excitonic effects lead to optical band gaps optimized for solar energy harvesting, positioning them as promising candidates for advanced optoelectronic device applications.