Energy Output Research Articles

Advances in Wearable Multifunctional Devices Based on Human‐Body Energy Harvesting

AbstractWearable electronics with multi‐functionalities are widely utilized in various domains, including everyday living, healthcare, military training, and sports. Advances in flexible electronic technology, new materials, artificial intelligence technology, and sensor technology have accelerated the rapid development of smart wearable devices toward multifunctional and highly integrated trends. The energy supply technology based on the human‐body energy harvesting method endows wearable, multifunctional electronic devices with sustainable, renewable, and self‐powered characteristics, which proposes a solution strategy for the function expansion and energy supply of wearable devices. Herein, this paper discusses recent research on various methods of harvesting human body energy and wearing parts respectively, focusing on the new materials, structures, and processes involved in the representative studies, as well as the impact on energy harvesting and output, and functional applications. Furthermore, the challenges and obstacles faced in the creation of wearable multifunctional devices based on human self‐sufficiency and propose solution strategies to propel them in order to advance the creation of the next wave of intelligent wearable technology are also discussed.

Water-flow-induced high-efficiency solar vapor generation and electricity collection

The interface photothermal evaporator still face challenges such as unstable operation, low evaporation efficiency, and insufficient energy utilization, particularly in high-concentration saltwater environments. This study proposes integrating a flow-induced power generation device within a photothermal-driven interface water evaporation system to address these issues. By leveraging the negative charge of carbon nanoparticles, a dual-electrode microchannel structure was optimized to establish an in-plane potential difference along the water transport path. The performance of the synchronized evaporation-flow-induced power generation system, with the carbon nanoparticle fabric as the core component, was thoroughly investigated, including its photothermal interface evaporation and power generation capabilities. Additionally, the controllability of the moisture content and water supply rate of the evaporation interface was achieved by adjusting the contact angle between the carbon nanoparticle fabric and bulk water, as well as the width of the water supply non-woven fabric. The synchronized evaporation-power generation system achieved an interface water evaporation rate of 1.44 kg m−2 h−1 and an output power density of 0.3 mW m−2 under 1 sun illumination (at a solar flux of q = 1 kW m−2). This study successfully obtained additional electrical energy output while prioritizing the evaporation rate, providing new insights for maximizing the energy efficiency of interfacial photothermal evaporation systems.

The nexus of sustainability and damping: A quasi-zero stiffness and pseudo-piecewise inerter damper for vehicle suspension

This paper proposes a vibration control-energy harvesting damper (VCEHD) for vehicle suspension. The principles used in the proposed VCEHD include quasi-zero stiffness (QZS), mechanical motion rectifier (MMR), and semi-active control. In the dynamic analysis, the authors found that the inherent disengagement and engagement properties of the MMR can undermine the robustness of the system, that is, the inherent properties of the MMR as an energy harvesting device are not conducive to vibration isolation. Therefore, it needs to be restrained. According to the numerical simulation results, VCEHD cannot simultaneously achieve the minimum body displacement and the maximum energy harvest, and the energy harvest performance needs to be partially sacrificed. The experimental results show that the maximum energy output is 14.70 mW/kg, and the minimum displacement transmissibility is 24.32%. Combined with the numerical simulation results, VCEHD can harvest 8.82–97.79 W of power in actual vehicle running, which can provide auxiliary power for intelligent vehicles.

Array analysis on a seawall type of deformable wave energy converters

There has been a significant interest in developing Flexible Wave Energy Converters (FlexWECs) that utilise structural deformations to generate electricity and mitigate destructive wave loads to the devices. In the meantime, FlexWECs are most likely to operate in an array format to enhance space usage and power output, as well as provide convenience for maintenance. In this context, the present paper develops a high-fidelity computational model to investigate the interaction of ocean surface waves with an array of seawall-type FlexWECs, which can meanwhile serve coastal engineering purposes. The fluid field is solved using the Navier-Stokes equations, and structural deformations are predicted using a nonlinear finite-element method. Hydroelastic interactions of up to seven deforming FlexWECs with the surrounding wave fields are demonstrated through systematic simulation cases. Based on the simulation results, analyses are conducted to investigate how the wave farm energy output is influenced by the gap between individual devices and the number of devices deployed. Accordingly, empirical design suggestions are provided. Overall, this work innovatively simulates the hydroelastic interactions between waves and multiple deforming structures, and the provided insights are useful for promoting the development of FlexWECs and their wave farms.

Biomass and energy potential of Erianthus arundinaceus and Saccharum spontaneum-derived novel sugarcane hybrids in rainfed environments

BackgroundEnergy canes are viable feedstocks for biomass industries due to their high biomass production potential, lower susceptibility to insects and diseases, better ability to adapt to extreme conditions and clean bioenergy. Interspecific hybrids (ISH) and intergeneric hybrids (IGH) have great potential to meet the growing demand of biomass, biomass-derived energy and feedstock.ResultsIn this study, two types of energy canes, Type I and Type II, derived from S. spontaneum and E. arundinaceous background were evaluated for high biomass, fiber and bioenergy potential under subtropical climate along with the check varieties Co 0238 and CoS 767. Out of 18 energy canes studied, six energy canes, viz., SBIEC11008 (204.15 t/ha), SBIEC11005 (192.93 t/ha), SBIEC13008 (201.26 t/ha), SBIEC13009 (196.58 t/ha), SBIEC13002 (170.15 t/ha), and SBIEC13007 (173.76 t/ha), consistently outperformed the check varieties under Type-I, whereas in type-II, SBIEC11004 (225.78 t/ha), SBIEC11006 (184.89 t/ha), and SBIEC14006 (184.73 t/ha) energy canes produced significantly higher biomass than commercial checks, indicating their superior potential for cogeneration. Estimated energy output from the energy canes (700–1300 GJ/ha/year) exceeded the range of co-varieties (400–500 GJ/ha/year) and energy utilization efficiency in plants and ratoon crops for energy canes viz., SBIEC11008 (3%, 1.97%), SBIEC14006 (1.93%, 2.4%), SBIEC11005 (1.7%, 1.9%), and SBIEC11001 (1.01%, 1.03%), was higher than best checks Co 0238 (0.77, 0.9%). Additionally, energy canes SBIEC 13001 (22.35%), SBIEC 11008 (22.50%), SBIEC 14006 (28.54%), SBIEC 11004 (30.17%) and SBIEC 11001 (27.03%) had higher fiber contents than the co-varieties (12.45%).ConclusionThe study gives insight about the potential energy canes for higher biomass and energy value. These energy cane presents a vital option to meet the future demand of bioenergy, fiber and fodder for biomass due to their versatile capacity to grow easily under marginal lands without competing with cultivated land worldwide.

Research on distributionally robust energy storage capacity allocation for output fluctuations in high permeability wind and solar distribution networks.

This paper presents a novel approach to addressing the challenges associated with energy storage capacity allocation in high-permeability wind and solar distribution networks. The proposed method is a two-phase distributed robust energy storage capacity allocation method, which aims to regulate the stochasticity and volatility of net energy output. Firstly, an energy storage capacity allocation model is established, which considers energy storage's investment and operation costs to minimize the total cost. Then, a two-stage distributed robust energy storage capacity allocation model is established with the confidence set of uncertainty probability distribution constrained by 1-norm and ∞-norm. Finally, a Column and Constraint Generation (C&CG) algorithm is used to solve the problem. The validity of the proposed energy storage capacity allocation model is confirmed by examining different wind and solar penetration levels. Furthermore, the model's superiority is demonstrated by comparing it with deterministic and robust models.

Impacts of caking on corn stover – An assessment of moisture content and consolidating pressure

Caking or time consolidation of powders is a serious problem which can hinder productivity and overall feasibility of various industrial processes. This study focuses on the impacts moisture content and consolidating pressures can have on 2 mm corn stover samples after undergoing a drying treatment at different times. Individually, moisture content and consolidating pressure did not exhibit any significant changes throughout the modified variable flow rate tests using the FT4 powder rheometer. However, applying both variables simultaneously yielded higher-than-usual energy outputs from the corn stover, indicative of biomass agglomeration due to the moisture and its subsequent evaporation while under pressure via the induced consolidating pressure. However, despite the increase in energy usage, time dried did not have a direct effect and demonstrated no trend.

Dual purpose ratooned rice improves agri-food production with reduced environmental cost

China is faced with the contemporaneous needs to improve resource-use efficiency, raise production and enhance environmental stewardship of status quo agrifood production systems. Dual purpose ratoon rice cropping systems comprise a promising innovation for addressing such challenges through production of forage and grain on the same land parcel. Here, we conducted life cycle assessments of forage-grain ratoon rice (FG-RR), contrasting sustainability indicators associated with FG-RR against those of traditional ratoon rice (productivity, environmental impact and economics) across four provinces in central China. Compared with conventional systems, we show that FG-RR systems had superior energy output (+37%) and energy use efficiency (+37%), but also lower global warming potential (−17%) and eutrophication potential (−13%). Such benefits were attributed to lower methane emissions and ammonia volatilization, together with enhanced nitrogen fertilizer management. We found that FG-RR systems had significantly higher productivity, with yields being 6%–152% greater than traditional production systems, particularly in the climatically challenged areas of Xinyang and Chizhou. We show that biophysical benefits translated to economic dividends, particularly in Chizhou, where net profits were as high as $716 ha−1. We conclude that FG-RR present a sustainable alternative to traditional rice farming methods, with substantial benefits in terms of production efficiency, environmental sustainability, and economic prosperity. We opine that adoption of FG-RR systems helps address challenges associated with suboptimal productivity, particularly in regions prone to environmental degradation and climatic challenges.

Harnessing the Intrinsic Ionic Rectification Properties of Blind‐Hole Nanoporous Anodic Alumina for Osmotic Energy Generation

AbstractThe full potential of blue energy as a sustainable technology for high‐performance energy generation remains elusive. Nanoporous anodic alumina (NAA) is extensively used as a passive structural support to develop a broad variety of ion exchange membranes based on other materials for osmosis‐driven energy generation. However, the intrinsic ionic current rectification (ICR) properties of the inherited hemispherical barrier oxide layer (BOL) closing the bottom tips of NAA's nanopores are overlooked. As‐produced NAA provides new avenues to control ionic transport through its BOL, acting as an ICR model system to study electric current associated with the selective flow of ions across anodic oxides. This study explores the intrinsic capability of NAA membranes for osmotic energy generation. NAA membranes with a working area of 13.4 mm2 can generate a power density yield of ≈2.8×10−4 W m−2 when subjected to a 105‐fold salinity ratio at a pH 3 in CaCl2 electrolyte, achieving a high efficiency of 7%. With better understanding of the mechanism of ion transport on osmotic generation, the intrinsic properties of NAA membranes can be tailor‐engineered to maximize blue energy yield, paving the way for future developments in a scalable technology suited for real‐life applications.

Hydrothermal carbonization of acerola (Malphigia Emarginata. D.C.) waste pretreated with supercritical CO2 and zinc chlorine as an additive

This study investigates the application of supercritical CO2 (SC-CO2) in acerola waste pretreatment for hydrothermal carbonization, examining the impact of ZnCl2 as an additive. Quantified response variables included hydrochar yield, high heat value, energy yield and oxygenated functional groups. Four equations were proposed to correlate the independent variables-additive concentration (C), temperature (T) and residence time (t)-with each response. Subsequently, a multiple-response optimization study was conducted to determine the best conditions, considering all responses. Utilizing SC-CO2 pretreatment and ZnCl2 additive resulted in hydrochar with the highest values for all responses. The optimum conditions obtained were T = 161.4°C, t = 105.5 min, and C = 1.43%. The hydrochar obtained under optimal conditions demonstrated that the supercritical CO2 pretreatment associated to the use of ZnCl2 additive increased the process yield in 11.02% and the energy yield in 13.02%, confirming the potential application of the hydrochar as a solid fuel.

Preparation and properties of nano B/NC/AP@F2602 double-layer energetic fiber

The nano-boron powder (n-B) exhibits remarkable efficacy as a combustion catalyst, making it a prime candidate for use in solid propellant metal burners. Nevertheless, throughout the storage phase, the surface of n-B powder is prone to oxidation and substantial agglomeration, resulting in challenges with ignition and incomplete energy dissipation when utilizing boron powder. In this study, we utilized the coaxial electrospinning technique to produce nanofibers comprised of nano-boron /nitrocellulose/ammonium perchlorate@fluororubber (n-B/NC/AP@F2602), with the nano boron uniformly distributed within the core-shell fibers. In the course of combustion, the fibrous composite of n-B/NC/AP@F2602 undergoes an escalation in the rates of energy output and energy release, owing to the constraints imposed by external F2602((C₂H₂F₂)n and (C₃F₆)n). The n-B/NC/AP@F2602 demonstrates a 1.4-fold increase in peak pressure and a 3.6-fold increase in maximum boost rate when compared to the n-B/NC/AP. The energy performance evaluation results reveal that the mean molecular weight (MC) of combusted products from n-B/NC/AP@F2602 is 29.2 g·mol−1, representing a substantial increase compared to that of n-B/NC/AP. The aforementioned findings exemplify that coaxial electrospinning is an exceedingly efficacious technique for enhancing nanostructures, thereby amplifying the reactivity of energetic particles and offering novel insights into their application in energetic materials.

Influence of geometry passive Q-switch based on a nanopowder-polymer on the characteristics of an erbium ring fiber laser

The presented work shows an influence of geometry passive Q-switch based on a nanopowder-polymer on the characteristics of an erbium ring fiber laser. The saturable absorber Bi2Te3 was applied to two types of specially prepared samples of thinned sections of optical fiber, and the resulting structures were built into the ring circuit of an erbium fiber laser. In the first case, the surface of the light guide segment was thinned by chemical etching, and in the second, by mechanical grinding. For the first time, the time-domain optical reflectometry technique was used to control the quality of the resulting sample surface and the resulting losses. For a more complete comparison, a set of different optical splitters was used, providing a change in the feedback coefficient in the resonator from 5 to 95 %. A study in the mode of passive Q-switching using polarized light showed that for both types of modulators there are optimal ratios of the amount of energy output from the resonator to obtain the highest values of the average generation power. The d-shape fiber modulator allows mode-locking to be observed without any additional changes to the laser circuit. The pulse duration in this case was 5 ns with a repetition rate of 4 MHz. A Q-switch based on a chemically thinned fiber segment made it possible to obtain narrower pulses in Q-switching mode (up to 700 ns at 38 kHz), a stable peak position in the transmission spectrum, and an average power of 34 mW.

Harnessing a Better Future: Exploring AI and ML Applications in Renewable Energy

Integrating machine learning (ML) and artificial intelligence (AI) with renewable energy sources, including biomass, biofuels, engines, and solar power, can revolutionize the energy industry. Biomass and biofuels have benefited significantly from implementing AI and ML algorithms that optimize feedstock, enhance resource management, and facilitate biofuel production. By applying insight derived from data analysis, stakeholders can improve the entire biofuel supply chain - including biomass conversion, fuel synthesis, agricultural growth, and harvesting - to mitigate environmental impacts and accelerate the transition to a low-carbon economy. Furthermore, implementing AI and ML in combustion systems and engines has yielded substantial improvements in fuel efficiency, emissions reduction, and overall performance. Enhancing engine design and control techniques with ML algorithms produces cleaner, more efficient engines with minimal environmental impact. This contributes to the sustainability of power generation and transportation. ML algorithms are employed in solar energy to analyze vast quantities of solar data to improve photovoltaic systems' design, operation, and maintenance. The ultimate goal is to increase energy output and system efficiency. Collaboration among academia, industry, and policymakers is imperative to expedite the transition to a sustainable energy future and harness the potential of AI and ML in renewable energy. By implementing these technologies, it is possible to establish a more sustainable energy ecosystem, which would benefit future generations.

Oriented pyrolysis of biomass for hydrogen-rich gas and biochar production: An energy, environment, and economic assessment based on life cycle assessment method

This study aimed to analyze a technology of hydrogen-rich gas from full-component oriented pyrolysis (FCOP) of biomass using energy, economic, and environmental life cycle assessment. Firstly, the study taked corn straw (CS) as the research object, the yield of hydrogen-rich gas and char produced by the oriented pyrolysis method are 78.26% and 20.35%, and the yield of biochar produced by activating char with phosphoric acid is 40%. Secondly, the system boundary of FCOP of biomass to produce hydrogen-rich gas and biochar was creatively designed, establishing the energy, environmental, and economic analysis comprehensive model. Various energy, economic, and environmental indicators were computed to facilitate process optimization for hydrogen-rich gas co-production biochar and explored the feasibility of the process. The results show that the stage of hydrogen-rich gas prepared by FCOP of biomass is an important factor affecting energy output and input, and has the highest standard pollutant emissions (92.11%). This process has low carbon emissions and GHG emissions, showing good sustainability and application prospects, which has important guiding significance for realizing cleaner production and solving the energy crisis. Thirdly, taking the large-scale system of producing hydrogen-rich gas co-production biochar, which processes 40,000 t of CS per year, as an example, the economic benefit analysis results were obtained, that is, IRR, NPV, and Pm are 22%, 6.33 million yuan, and 7.3 years, respectively. Meanwhile, the key factors, including the initial investment, expenses of biomass and catalyst, and the sale income of hydrogen and biochar, which are the main factors affecting the economic efficiency of technology, and uncertainties were identified through sensitivity analysis. Finally, we put forward in the background of ecological civilization, the research focus and thinking for the development of hydrogen production technology from pyrolysis/gasification of biomass were proposed. The results obtained can be valuable in practical applications to enhance the sustainability and viability of hydrogen production in biomass conversion and utilization activities. The applied energy, economic, and environmental methodologies appear to be reliable and comprehensive tools for assessing the whole-life sustainability and viability of biofuel.

Pilot-scale pyrolysis and activation of typical biomass chips in an interconnected dual fluidized bed: Comparison and analysis of products

A 150 kg/h novel pilot dual fluidized bed (DFB) was designed, constructed, and commissioned. In this study, six types of biomass chips were investigated and compared in interconnected pyrolysis and activation/gasification systems using dolomite as bed material, and employing steam and flue gas as activation agents. The maximum iodine and methylene blue adsorption capacities were 436.79 mg/g (pear wood char) and 203.65 mg/g (walnut wood char), respectively, indicating high adsorption capacity of char. The carbon fixation ratios were 34.70–53.75 wt%, and the maximum lower heating value of 9.34 MJ/Nm3 was achieved for pyrolysis gas with the highest CO and H2 contents of 44.30 vol% and 16.18 vol%, respectively. The maximum phenolic compounds reached 73.46% for mesquite wood chips oil. Oils collected from the riser contained fewer organic species compared to oil from pyrolyzer. Furthermore, energy efficiencies were found to range from 66.70% to 84.91%, and the total energy yields were 67.12–87.08%. The internal rate of return and payback period of the process were 33.25–44.29% and 3.0–2.2 years, respectively. Co-production of activated biochar, combustible gas, and oils from the interconnected DFB system exemplifies noteworthy environmental and economic advantages for sustainable energy practices.

Calculation Model for Evaluating Suspensions during Maneuvers of a 4WD Vehicle with a 6x6 Wheels

The article describes the purpose, scope, main parameters of the flowchart of the procedure used to calculate control devices when comparing vehicle suspension structures with a 6x6 wheel arrangement. Methods for comparing suspensions during maneuvers are described. A description of the cab suspension system, a block diagram of the simulation program is presented. The visualization of the process of rebuilding the studied model of a 6*6 vehicle with two different types of front suspension is shown. An estimate of the load on the front and rear axles during the rebuilding for a period of time t = 5 s, their energy output and inertia is given. The distribution of the load along the axes of the investigated 6*6 vehicle model is presented when rebuilding with the front suspension of the first and second types. The coordinates of the base points of the front axle allow you to evaluate the numerical values for specific coordinates at a given point in time.

Multi-scenario flexibility assessment of power systems considering renewable energy output uncertainty

The widespread adoption of renewable energy sources presents a significant challenge to the flexibility of power system. To assess the flexibility of the power system in scenarios with uncertain renewable energy output, it is crucial to quantify it quantitatively. This evaluation plays a vital role in planning flexible regulatory resources and dispatching resources for both the energy source and load. This study introduces a novel flexibility assessment model tailored for power grids with high renewable energy penetration, specifically addressing uncertainty associated with wind and PV. By analyzing the impact of wind and PV uncertainty on system flexibility, the paper proposes an improved cohesive hierarchical cluster analysis method, incorporating reliability considerations based on the Davies-Bouldin classification reliability index. Additionally, the study develops models for flexibility resources and demands within high renewable energy power systems, along with quantitative assessment indicators across three key aspects. Through a structured flexibility assessment process accounting for wind and PV uncertainty, the effectiveness of the proposed approach is validated using real-world data from a renewable energy power grid in Shandong province. A set of typical renewable energy output scenarios with uncertainty is constructed using the improved hierarchical cluster analysis method. The study then analyses the impact of different wind and PV penetration rates and the proportion of energy storage units on system flexibility by the flexibility assessment model to validate the proposed method's effectiveness.

Solar PV tracking system using arithmetic optimization with dual axis and sensor

Presently, PV system is considered the best renewable energy source for electricity production. In order to maximize energy output in photovoltaic systems, a system for tracking the sun's position and adjusting panel positions was created. Despite the fact that several models for tracking solar radiation have been suggested to improve energy production, it faces challenges in continuous tracking and power consumption. This paper proposes a novel sensor-based solar tracking system with numerical optimization to increase photovoltaic systems' energy output. The initial model was for a two-axis tracking system based on sensors. Solar panel and sun positions are detected by this system using ultraviolet and microelectromechanical sun sensors. To improve tracking movements and photovoltaic energy production, we recommend using solar sensors to construct a novel two-axis solar tracking device. This technology benefits from increased solar radiation and solar energy harvesting capabilities. The main disadvantage of dual-axis active solar tracking systems is that the drive mechanism frequently uses up the output power of the solar panels. As a result, the net power gain of the solar panel is less than its maximum. Further, a control system was developed with proportional integral derivative (PID) controller and arithmetic optimization (AO) to adjust the panel position relative to suns movement. The AO technique tunes the PID controller gains until it reaches its desired level to enhance the production of power. With the use of sensors, the tracking system can use mathematical optimization algorithms and the sun's position to minimize power consumption while still maintaining optimal solar panel positioning. The developed model was designed in the MATLAB software and the outcomes are analyzed. The paper also presents an energy analysis of the system, which evaluates the energy input, output and overall system efficiency. We recommend using solar sensors to create a unique dual-axis solar tracking system. This technology benefits from increased solar radiation and solar energy harvesting capabilities.

Comprehensive analysis of a high temperature solar powered trigeneration system: An energy, exergy, and exergo-environmental (3E) assessment

In the present work, helium serves as the primary working fluid within the supercritical Brayton cycle, employed to generate power through a solar power tower system. The conventional Brayton cycle for recovering the wasted heat is combined with a cascaded vapor absorption-compression refrigeration system to increase the overall system’s performance. Additional benefits of this integrated system include the ability to supply enhanced heating and cooling for food storage applications at lower temperatures. A comprehensive analysis of the combined system was conducted based on exergy, energy, and exergo-environmental (3E) factors a using computational technique engineering equation solver. The combined system’s energy, exergy efficiency, and power output were determined to be 28.82%, 39.53%, and 14.865 kW, respectively. The coefficient of performances for cooling and heating were observed as 0.5391 and 1.539 respectively. Approximately 78.18% of the total exergy destruction within the entire plant can be attributed to the solar subsystem, which amounts to 22.763 kW. As direct normal irradiance rises, the environmental impact index decreases from 1.6504 to 0.6801, while the system’s environmental stability factor improves, increasing from 0.3773 to 0.5952. Moreover, the parametric assessment highlights the substantial influence of heliostat and receiver efficiencies, as well as the helium turbine’s inlet temperature, on the trigeneration system’s performance. In addition, compared to previously published research, the current proposed system outperforms supercritical CO2 cycle systems and the conventional steam Rankine cycle systems.

Research and development factor mismatch, production losses, and energy efficiency: A study on Chinese regional economies

In the face of global economic development and increasing energy demands, the efficient allocation of Research and Development (R&D) resources emerges as a universal concern. This study illuminates the complex relationship between R&D factor mismatch, production losses, and changes in regional energy intensity. Utilizing factor mismatch accounting framework and the STIRPAT model, we systematically assess the impact of spatial mismatches in R&D factors on R&D output and regional energy intensity. The analysis unfolds in three steps, first, the estimation of the degree of spatial R&D factor mismatch and the resulting output gap; second, the calculation of R&D output loss as a function of spatial mismatch coefficient and output share per location; and third, the examination of changes in energy intensity induced by R&D factor mismatch in terms of Total Factor Productivity (TFP), factor mismatch, and output structure. Our findings reveal that R&D factor mismatches can hinder energy intensity reduction, and that regional disparities in the process of factor market marketization significantly contribute to variations in regional energy intensity. These insights emphasize the critical role of efficient R&D resource allocation in promoting energy conservation and productivity, providing substantial implications for policy-making in sustainable growth and energy efficiency across diverse economies.