Energy Conversion Rate Research Articles

The high performance lithium metal composite anode by excessive alloying process

With the rapid development of technology and the severe environmental crisis, improving the utilization and conversion rate of sustainable energy has become an important way to alleviate ecological and sustainable development. Therefore, the development of a new generation of anode materials with high specific capacity, long cycle life has become the primary task. Elements that can react with lithium and form alloy can be used as electrode materials, but these materials have limited capacity and poor electrochemical property. Lithium metal, as the ideal anode in lithium batteries, are restrained because of the dendrites formation. Herein, we introduced lithium metal composite anode by excessive alloying process, and to some extent, lithium dendrite formation and electrochemical issues are solved. The results show that lithium metal can be deposited evenly on the silver and silicon electrode surface, and both silver and silicon can enhance the coulombic efficiency and improve the electrochemical stability. In particular, silver-lithium composite electrodes can maintain 70 cycles with coulombic efficiency over 60 % which is twice as much as bare Cu electrodes. By this way, we make a new lithium metal composite anode structure and provide excessive alloying process to extend the application of commercial anode.

Optimal integration of electrolysis, gasification and reforming for stable hydrogen production

Engineering industries such as petroleum and petrochemicals have strict requirements for the stability of hydrogen supply to ensure the safety and reliability of system operations. However, relying on a single hydrogen production technology is insufficient to meet the requirements of both stable and green hydrogen. This study proposes an integrated hydrogen production system combining water electrolysis, biomass gasification, and natural gas reforming to achieve stable and green hydrogen. To capitalise on the advantages of the individual technologies, the integration among the different hydrogen production methods considers not only energy but also materials. As a by-product of water electrolysis, oxygen can create a pure oxygen atmosphere for biomass gasification and natural gas reforming, thereby considerably improving the energy conversion rate. The heated gases from the biomass gasification transport thermal energy to the natural gas reforming. Stable and maximised hydrogen production can be achieved through optimal coordination of the three hydrogen production technologies and storage devices. Optimisation models are built for each component, and case studies show that the proposed integrated system exhibits energy efficiency of 64.19 %, which is 9.87 % higher than the 54.32 % efficiency of single-energy hydrogen production, and achieves an 67 % carbon emission reduction compared with the existing industrial technology. The integrated system proposed in this study provides a solution for stable hydrogen production under the broad requirement of carbon neutrality, and it will provide valuable guidance for future integrated hydrogen production system development and offer information that is of interest to operators and investors.

Improvement of the Airflow Energy Harvester Based on the New Diamagnetic Levitation Structure.

This paper presents an improved solution for the airflow energy harvester based on the push-pull diamagnetic levitation structure. A four-notch rotor is adopted to eliminate the offset of the floating rotor and substantially increase the energy conversion rate. The new rotor is a centrally symmetrical-shaped magnet, which ensures that it is not subjected to cyclically varying unbalanced radial forces, thus avoiding the rotor's offset. Considering the output voltage and power of several types of rotors, the four-notch rotor was found to be optimal. Furthermore, with the four-notch rotor, the overall average increase in axial magnetic spring stiffness is 9.666% and the average increase in maximum monostable levitation space is 1.67%, but the horizontal recovery force is reduced by 3.97%. The experimental results show that at an airflow rate of 3000 sccm, the peak voltage and rotation speed of the four-notch rotor are 2.709 V and 21,367 rpm, respectively, which are 40.80% and 5.99% higher compared to the three-notch rotor. The experimental results were consistent with the analytical simulation. Based on the improvement, the energy conversion factor of the airflow energy harvester increased to 0.127 mV/rpm, the output power increased to 138.47 mW and the energy conversion rate increased to 58.14%, while the trend of the levitation characteristics also matched the simulation results. In summary, the solution proposed in this paper significantly improves the performance of the airflow energy harvester.

Analysis and Optimization of the Milling Performance of an Industry-Scale VSM via Numerical Simulations.

Vertical stirred mills (VSM) are widely used for powder processing in many situations like mechanical alloying preparation and raw material crushing and shaping. Many structural and operational parameters like stirrer helix angle and rotating speed have great significance on VSM performance, especially in a large industry-scale situation. Therefore, it becomes essential to investigate these parameters systematically to obtain high energy efficiency and good product quality. In this work, the discrete element method (DEM) was used to examine the effects of stirrer helix angle (α), stirrer diameter (d), and rotating speed (n) on the grinding performance in an industrial VSM, and then the response surface method (RSM) was employed for multi-objective optimization in the VSM. It is found that a media vortex phenomenon may happen near the stirring shaft. The media collisions are significantly influenced by α, d, and n. Through multi-objective optimization design (MOD), the power consumption (P) of the stirrer reduced by 8.09%. The media collision energy (E) increased by 9.53%. The energy conversion rate (R) rises by 20.70%. The collision intensity and frequency are both improved. This optimization method can help determine good operating parameters based on certain structures.

Numerical and experimental analysis of a novel linear wave energy harvester

The power supply method of low-power sensors has partly restricted the exploration and utilization of marine resources. Low-density wave energy can be harvested and used to power low-power wireless sensor devices and promote the coordinated development of the marine environment. This paper designs a linear oscillating electromagnetic energy harvester with hollow spheres as buoys. Spherical buoys can provide resilience for the oscillating permanent magnet, which is sensitive to the wave vibration form. Under wave excitation with wide-amplitude and stochastic low-frequency distribution, the oscillating permanent magnet with intrinsic frequency of 1.1 Hz is forced to move reciprocally in the rolling slot. Multiple groups of induction coils used in series make the output voltage of the harvester more balanced and smooth, improving the conversion rate of wave energy. According to the experimental results, the harvester can generate a maximum output power of 18.4 mW and an average output power of 4.44 mW under the excitation of water waves with a maximum acceleration of 1.21 m/s2. The output power is sufficient for low-power wireless sensor devices.

Economic feasibility of achieving net-zero emission building (NZEB) by applying solar and geothermal energy sources to heat pump systems: A case in the United States residential sector

Buildings are one of the major sectors responsible for high energy demand and GHG emissions worldwide, which is driving expectations for implementing net-zero emission buildings (NZEBs) in many countries. Specifically, most developed countries have a carbon-neutral target set up for 2050, mandating all new buildings from then to be constructed as net-zero emission. Therefore, this paper investigated the economic feasibility of implementing NZEBs in the United States residential sector by combining a heat pump system with two renewable energy sources that are heavily supported by the federal government: solar and geothermal technologies. First, this study clearly demonstrates that “net-zero emission” is the most challenging task among neutralizing the energetic, economic, and environmental by-products from building operations. Moreover, this study analyzed the payback periods of multiple NZEB scenarios by considering the potential future changes in technology and policy necessarily required to meet the net-zero emission target by 2050. For reference, the technological and institutional factors were represented by “PV energy conversion rate” and “CO2 equivalent price of emission trading scheme (ETS)”, respectively. The results show that improving the PV energy conversion rate is much more effective in reducing the payback period of NZEBs compared to raising the CO2 equivalent price of ETS. However, the growing public awareness for this CO2 regulation policy will soon bring synergistic effect with the advancement of PV technology. In conclusion, this research framework clarifies the rather vague technological and institutional challenges that should be addressed to allow NZEBs to become economically feasible in the United States residential sector. Therefore, many building engineers, PV technicians, and policymakers should actively contribute to improving the techno-economic drivers for implementing NZEBs by 2050.

Transient process of mechanical response and energy conversion of rocks with different lithologies under impact loading

The mechanical response and energy utilization efficiency of rocks with different lithologies during percussion drilling are highly significant for optimizing engineering and tool parameters improving the efficiency of percussion drilling. In this study, dynamics tests were conducted on rocks of different lithologies, considering the impact compression and tensile process versus the strain rate effect of the rock. A high-speed camera was used to observe the generation and development of cracks during the transient fracture of the rock and analyze the time-varying effect of strain during fracture. A model of fracture energy changing with time was established, and the relationship between the strain rate and dynamic strength, failure time, and fracture energy was developed and verified. The results of this study revealed that, the higher the impact velocity and the harder the rock, the shorter the time required for the rock to break. This means that under the same impact conditions, it takes longer to break a soft rock. Moreover, the fracture energy conversion rate of a rock is greatly affected by the impact velocity, and the fracture energy of the rock increases as the strain rate increases. There was an optimal impact velocity for each type of rock and the fracture energy conversion rate was the highest at that velocity. When the strain rate was 50–150 s−1, the specimen strength and fracture energy showed similar trends: strength and fracture energy of granite were the highest, followed by that of tuff and sandstone. The specimen failure time displayed an opposite trend: sandstone had the longest failure time, followed by tuff and granite. The findings could form the basis for the further analysis of dynamic failure characteristics to improve the energy utilization rate and rock-breaking efficiency of different lithology rocks.

Development and prospect of flywheel energy storage technology: A citespace-based visual analysis

With the rise of new energy power generation, various energy storage methods have emerged, such as lithium battery energy storage, flywheel energy storage (FESS), supercapacitor, superconducting magnetic energy storage, etc. FESS has attracted worldwide attention due to its advantages of high energy storage density, fast charging and discharging speed, high energy conversion rate, easy maintenance, and no environmental pollution, and has been applied in aerospace, military, electric power, and transportation fields. This article uses the citespace review tool to intrinsically analyze and summarize the papers published from 2010 to 2022 in the field of FESS. Relevant knowledge maps such as keywords and research hotspots that carry out FESS research were obtained. Since this technology is developing gradually ►The historical development of FESS is summarized in this article for new/existing researchers. Finally ►This paper presents the future development trend based on reviewed literatures.

Post-evaluation analysis on urban coal, oil and gas resources comprehensive utilization governance project: A case study in Fuxian, China

China's energy and chemical enterprises in the resource-based urban cities face challenges of climate change targets. Coal, Oil and Gas Resources Comprehensive Utilization (COGRCU) project can address the carbon and hydrogen imbalance between conventional methanol from coal and natural gas. Moreover, it can improve energy conversion rates and carbon resource recovery. Therefore, it is a better way for energy and chemical enterprises to transition to sustainable development and advocated by enterprises in resource-based cities. In practice, the actual benefits of the COGRCU project are often different from those expected from prior assessments, and the main factors contributing to the differences need to be identified. Therefore, it is necessary to propose a post-evaluation methodology for the COGRCU project to assist energy and chemical enterprises in identifying these constraints and optimize project management. This study considers energy and monetary flows, combines emergy-based energy return on investment (EmEROI) and cost-benefit analysis (CBA), and proposes a post-evaluation methodology of the COGRCU project based on the case study of YC Group's Fuxian COGRCU project in Fuxian County. In addition, the emergy per unit money, emergy per unit labor, and bio-resources emergy per unit area of Yan'an City are measured. Results showed that indirect energy and labor input emergy are the primary contributors to improving the projects' energy efficiency. Operating costs reduction are the key factors for improving economic benefits. The indirect energy has the highest impact on the project's EmEROI, followed by labor, direct energy, and environmental governance. Several policy recommendations are raised, including strengthening policy support, such as advancing the formulation and revision of fiscal and tax policies, improving project assets and human resource management, and increasing environmental governance efforts.

Integrated core-shell assembly of Ni3S2 nanowires and CoMoP nanosheets as highly efficient bifunctional electrocatalysts for overall water splitting

A paradigm for the rational design of active, abundant, and inexpensive bifunctional electrocatalysts with acceptable electrochemical energy conversion rates has yet to be achieved. Here, we describe the assembly of a superior bifunctional electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities based on a CoMoP/Ni3S2 multicomponent, heterointerface consisting of a freestanding electrocatalyst prepared by hydrothermal-phosphidation, consisting of one-dimensional Ni3S2 covered with Cereus cactus–like hierarchical CoMoP nanosheets. The resulting three dimensional CoMoP/Ni3S2 core-shell heterostructure exhibited remarkable HER and OER electrocatalysis, benefiting from modulated electronic structures, rapid mass diffusion, reduced charge-transfer resistance, and a larger electrochemically active surface area. Due to these superior functionalities, the CoMoP/Ni3S2 requires only 96.8 mV (at η10) for HER catalysis and 270 mV (at η50) for an OER process. Furthermore, a stable water-splitting device using CoMoP/Ni3S2 for both the anode and cathode required a low cell voltage of 1.54 V at 10 mA cm−2. This work represents a significant advance in interface construction of transition-metal phosphide/sulfide for long-term water splitting.

Online evaluation of the boiler energy efficiency associated with the soot blowing in coal‐fired power plants

AbstractSoot blowing is a common practice in coal‐fired power plants to ensure high energy conversion rate. The period of the conventional soot blowing is usually fixed, without the consideration of the load change and feeding coal switching. For the purpose of the soot blowing optimization, an approach to quantitatively evaluate the performance of soot blowing operations is proposed. Different heat exchangers' thermal resistances are calculated based on dynamic mass and energy balance to monitor their ash fouling deposition, and then, the boiler energy efficiency is predicted, adopting the rolling extreme tree boosting algorithm, and finally, the efficiencies with and without soot blowing are computed separately. With the data collected from a 350 MW ultra‐supercritical unit, pseudo‐online simulations are performed. The results show that even if the energy efficiency of the unit has exceeded 94%, a full‐process soot blowing may further increase the efficiency in some extent. For those subcritical units, the benefits should be higher.

Energy Conversion Rate from Subinertial Surface Tides to Internal Tides

Abstract Subinertial, topographically trapped diurnal internal tides are an important energy source for turbulent mixing in the subarctic oceans. However, their generation may not be estimated by the conventional barotropic-to-baroclinic conversion because their vertical structure is sometimes barotropic, unlike superinertial internal tides that are always baroclinic. Here, a new energy diagram is presented, in which the barotropic mode is decomposed into the surface and topographic modes, with the latter being classified as part of the internal modes together with the baroclinic mode. The energy equation for the newly defined topographic mode is then derived, providing an appropriate formulation of the energy conversion rate from the subinertial surface tides to the topographically trapped internal tides. A series of numerical experiments confirm that the formulation successfully predicts the energy conversion rate for various cases, with the relative contribution of the baroclinic and topographic modes varying significantly depending on the bottom topography and stratification. Furthermore, this surface-to-internal conversion is demonstrated to give a significantly larger estimate than the barotropic-to-baroclinic conversion for subinertial tides. Applying the formulation to the results of a realistic numerical simulation in the Kuril Straits, an area with the strongest mixing due to subinertial diurnal tides, shows that the surface mode is converted into the baroclinic and topographic modes with comparable magnitudes, responsible for most of the energy dissipation in this area. These results indicate the need to reestimate the global distribution of the generation rate of the subinertial internal tides using our new formulation and to clarify their dissipation mechanisms. Significance Statement Diurnal internal tides in mid- to high-latitude oceans are very different from semidiurnal internal tides, in that they are trapped by topographic features and characterized by uniform rotation throughout the water column rather than by vertical oscillations within the water column. Focusing on this character, we formulate for the first time the generation rate of diurnal internal tides trapped over variable bottom topography. A series of idealized numerical experiments and application to the Kuril Straits show the validity and usefulness of this formulation, which provides a significantly larger generation estimate than previous studies. The results of this study are important for accurate global mapping of turbulent mixing induced by the breaking of internal tides.

Extended model of bouncing boundary for droplet collisions considering numerous different liquids

Sprays are widely utilised in different technical and industrial applications. The produced droplet size spectrum is one of the most important parameters that determine the spray characteristics and performance. Depending on the operational conditions and the spray structure, the droplet size spectrum obtained after atomisation will be of course modified by collisions between droplets. In numerical calculations, the Euler/Lagrangian approach is a favourable method for obtaining relatively accurate predictions of spraying processes. However, for correctly modelling droplet collisions, reliable boundary line correlations are needed for distinguishing the different droplet collision outcomes, which are bouncing, coalescence, and separations. These boundary lines are summarised in so-called collision maps to demark the various outcome scenarios. The result of a binary droplet collision depends on numerous parameters, namely, the kinetic properties (droplet velocities, droplet diameter ratio, impact angle) and the physical properties of gas and droplets (droplet liquid, density and viscosity, surface tension, type of gas phase, gas phase pressure and temperature). The boundary line for bouncing, primarily used in numerical studies so far, was derived based on experiments with ethanol droplets by Estrade et al. (1999). However, this theoretical derivation, based on an energy balance, unfortunately neglects viscous dissipation effects. Therefore, the deviations of the predicted bouncing region are pretty large for liquids with higher viscosity or other physical properties. Hence, a data-driven model is proposed in this paper, with new assumptions and definitions, considering the dissipated energy during the collision and the shape changes (i.e., deformation) of the collision complex. For that purpose, two new parameters are introduced in the model, namely a shape factor and an energy conversion rate, both depending on the impact parameter B, which describes the lateral displacement of droplets at a collision. Therefore, the new bouncing model is related to the degree of droplet deformation. The dependence on B could be described by linear correlations with two parameters for slope and intercept. These parameters are correlated with the Ohnesorge number, and polynomial fitting functions were derived with the help of numerous available experiments for different liquids. The upper limit of Ohnesorge numbers in the present study was Oh<0.35. Due to the dependence on the Ohnesorge number, the proposed model very well captures the effect of liquid properties on the bouncing boundary, however, not necessarily the influences of environmental conditions and interface modifications. The model was validated by comparison with numerous available experimental results.

Performance analysis of a novel solar radiation cascade conversion system for combined heat and power generation based on spectrum splitting and reshaping

In this paper, a novel cascading solar photovoltaic system with concentrating spectrum splitting and reshaping for combined heat and power generation is proposed for the first time to break through the limitations of photovoltaic efficiency. Two spectral splitters divide the solar spectrum into three parts, and each part of the spectrum is used by photovoltaics, thermophotovoltaics, and heat exchange fluids according to the photon grade. In addition, the heat exchange fluid also recovers the waste heat of concentrating photovoltaic and thermophotovoltaic cells. Therefore, the system achieves solar energy cascade utilization and has high electrical and thermal efficiency simultaneously. The effect of the fluid flow rate, solar irradiance, and cutoff wavelength of the spectral splitter on the hybrid system is discussed. The results show that under the conditions of 1000 sunlight and outlet fluid temperature of 60 °C, the solar energy conversion rate and exergy efficiency of the hybrid system are 90.17% and 39.84%, which are 63.97 percentage points and 11.62 percentage points higher than those of the single photovoltaic system, respectively.

Effects of alkaline thermal hydrolysis on the formation of refractory compounds and energy balance of anaerobic digestion of cattle manure

Anaerobic digestion (AD) coupled with thermal hydrolysis pretreatment (THP) is appealing because it enhances the energy conversion rate of organic wastes. Here, cattle manure, the most abundant organic waste, was thermally hydrolyzed as a pretreatment of AD. In order to increase the process efficiency, a NaOH solution was introduced. Increasing the amount of NaOH addition during the THP enhances lignin removal and solubilization of cattle manure. The thermally hydrolyzed cattle manure (at 160 °C with 2 % (dry wt.) NaOH addition) showed a significantly higher biochemical methane potential of 227.0 ± 11.0 mL-CH4/g-volatile solid compared to that of intact cattle manure (182.2 ± 2.5 mL-CH4/g-volatile solid). Refractory compounds (humic acid-like substances and furfural) were identified at THP temperatures above 180 °C without NaOH addition, and it was enhanced by increasing NaOH addition. Energy balance analysis showed that additional 161.4 ± 39.3 MJ of energy can be gained per ton of cattle manure by applying THP (at 160 °C without NaOH addition). This study provides insights into the changes in the physicochemical and biochemical properties of cattle manure caused by alkaline THP.

Monolithic Nickel Catalyst Featured with High-Density Crystalline Steps for Stable Hydrogen Evolution at Large Current Density.

Producing hydrogen via electrochemical water splitting with minimum environmental harm can help resolve the energy crisis in a sustainable way. Here, this work fabricates the pure nickel nanopyramid arrays (NNAs) with dense high-index crystalline steps as the cata electrode via a screw dislocation-dominated growth kinetic for long-term durable and large current density hydrogen evolution reaction. Such a monolithic NNAs electrode offers an ultralow overpotential of 469mV at a current density of 5000mA cm-2 in 1.0m KOH electrolyte and shows a high stability up to 7000 h at a current density of 1000mA cm-2 , which outperforms the reported catas and even the commercial platinum cata for long-term services under high current densities. Its unique structure can substantially stabilize the high-density surface crystalline steps on the catalytic electrode, which significantly elevates the catalytic activity and durability of nickel in an alkaline medium. In a typical commercial hydrogen gas generator, the total energy conversion rate of NNAs reaches 84.5% of that of a commercial Pt/Ti cata during a 60-day test of hydrogen production. This work approach can provide insights into the development of industry-compatible long-term durable, and high-performance non-noble metal catas for various applications.

Study on the Mechanical and Energy Evolution Characteristics of Oxidized Coal

ABSTRACT To study the variation laws of the mechanical properties of coal with different oxidation degrees, coal samples were subjected to constant temperature oxidation at 80°C, 120°C, 160°C and 200°C by using a coal oxidation spontaneous combustion test system. Through a uniaxial compression experiment, the variation laws of mechanical parameters, failure characteristics and energy dissipation law of coals with different oxidation degrees were analyzed and obtained. The study shows that the stress – strain curves of coal with different oxidation degrees vary in different stages. The peak stress, elastic modulus, secant modulus and Poisson’s ratio appear to decrease to different degrees with the deepening of oxidation, and the peak strain increases. The cracks on the surface of the coal samples increase and become more with the deepening of oxidation, the exothermic characteristics of the coal samples decrease, and the failure characteristics of the coal samples change from single shear-type failure characteristic to conjugate shear-type characteristic and then to shatter-type failure characteristic. With an increasing degree of oxidation, the total energy required for coal destruction gradually decreases, the conversion rate of total energy into elastic energy decreases, the dissipation energy gradually increases, and the release rate of elastic energy and the increase rate of dissipation energy gradually slow down after the peak strain.

Numerical simulation of cavitation performance in a scaled-up bath-type sonoreactor considering inhomogeneous bubble cloud

The bath-type sonoreactor holds great potential in industrial applications of process intensification. However, the scale-up of this bath-type sonoreactor is limited by a lack of investigation into sonoreactor design. In this work, we employed linearized wave equation considering inhomogeneous bubble distribution for simulation of scale-up bath-type sonoreactor design. Comprehensive validation experiments were conducted to verify simulation accuracy. This model predicts abnormal attenuation phenomenon during sound waves transmission that pose challenges for optimal design of sonoreactors. The result implies that increasing driving pressure cannot constantly increase conversion rate of cavitation energy. For example, as driving pressure increases, cavitation rate become stabilized to be a constant value of 0.4 and average cavitation pressure tends to be 1.1 times of driving pressure. Reactor width determines cavitation area and a width of 350 mm generates most cavitation volume under a liquid level of 100 mm. Regardless of the liquid level, increasing the driving pressure causes sound pressure in the near-field decrease due to abnormal attenuation. Once sound wave has travelled to a distance of 60–80 mm, cavitation will not make a noticeable difference.

Use of a commercial feed supplement based on yeast products and microalgae with or without nucleotide addition in calves

The use of feed additives with antioxidant and immune response modulatory activity could be a useful strategy in suckling calves to reduce morbidity and mortality. This strategy is based on several feed additives tested for these purposes. The aim of the paper is the examination of a commercial feed additive for adult cows for use in calves, with and without nucleotide supplementation. Seventy-five Holstein Friesian male calves were divided in 3 groups, with each calf randomly assigned to a group according to birth order. All calves received 2 L of pooled colostrum within 2 h of birth. The commercial feed supplement group was orally administered with 5 g/head of Decosel (dried brewer's yeast lysate (Saccharomyces cerevisiae), brewer's yeast walls (Saccharomyces cerevisiae), diatoms, spirulina, barley flour, calcium carbonate; Agroteam srl, Torrimpietra, Italy) and the nucleotides + commercial feed supplement group was orally administered with 5 g/head of an additive containing 2.5 g of Decosel and 2.5 g of nucleotides once daily from birth to 25 d. The control group was orally administered 20 mL of fresh water/head once daily. Calves that received the supplement and the nucleotides showed lower rates of protein and metabolizable energy conversion, with longer villi and greater crypt depth in duodenum. Moreover, the commercial feed supplement alone increased antioxidant capacity [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric-reducing antioxidant power] in plasma some activity of antioxidant liver enzymes, and peripheral blood mononuclear cell viability after in vitro concanavalin A and H2O2 stimuli. Dietary supplementation with a commercial feed supplement containing yeast products (yeast cell walls and hydrolyzed yeast) and microalgae enhanced the redox balance and gut morphology in calves, allowing calves to improve their immune response, increasing resistance to stress. Moreover, these beneficial effects were strongly potentiated when dietary nucleotides were added to the supplement.

Harvested Energy Prediction Technique for Solar-Powered Wireless Sensor Networks

Solar energy harvesting (EH) is one of the best promising approaches toward perpetual network operation, and it is implemented in various regions of interest (RoIs). However, saving external energy is the essential prime factor in any embedded sensor with finite storage capacity. Generally, the energy conversion rate of the solar system is too fast due to various environmental conditions. Besides, ambient resource energy is noncontrollable, and rechargeable battery only operates in outdoor ecological systems. Frequent environmental fluctuation in their prediction is imperative for initial energy control. Considering the challenges mentioned above, in this article, we propose a modified PROfile energy (Pro-energy) prediction technique to control unnecessary errors in solar-based harvesting systems related to the sensing devices, which estimates the most similar profile-based energy observation in previous time slots. Our proposed method uses prior energy measurements to show future energy status in the respective time slots. Experimental observations on various performance matrices validate that the modified Pro-energy prediction technique exhibits more promising and superior performance than existing EMWA, weather-conditioned moving average (WCMA), and Pro-energy methods.