Design Of Energy Harvesting System Research Articles

Investigation of the integration of an oscillating aerofoil-based energy harvester into the building roof

The increasing energy efficiency requirements have led to innovative renewable energy solutions being integrated into buildings. Several works have shown the potential of micro wind turbines on buildings. However, their implementations have been hindered by several challenges. Flow energy harvesting devices such as oscillating aerofoils provide potential, yet a literature gap exists regarding their integration into buildings. This study addresses this gap by investigating oscillating aerofoil wind energy harvesting system performance through numerical modelling. A coupled numerical model was introduced, integrating a novel computational approach using ANSYS Fluent with one degree of freedom in rotational motion. This methodology was introduced to analyze the dynamic behaviour and predict mechanical power output of the oscillating aerofoil wind energy harvesting system, which is a novel exploration in existing literature. Moreover, validation of the computational fluid dynamics model was conducted through using experimental wind tunnel data in the literature, and results demonstrated agreement between numerical and experimental results. To improve the wind energy harvesting system of a single oscillating aerofoil, it was integrated into building roof to take advantage of acceleration effects of building roof shape. The design improvement comprises of a novel wind energy harvesting system design of an oscillating aerofoil integrated into three different building roof including flat, pitched, and curved shapes to enhance energy efficiency. The numerical analysis demonstrated that integrating an oscillating NACA 0012 aerofoil into a curved roof resulted in the highest average power output. Specifically, the integration of the curved roof and the aerofoil yielded 18 watts, while the flat roof generated only 0.6 watts at a wind speed of 3 m/s. Integration into a pitched roof achieved 12 watts at 9 m/s. Comparatively, integrating the curved roof with the aerofoil increased power output by 50% compared to the pitched roof design at 9 m/s wind speed. Thus, variations in wind speed significantly impact performance. In addition, changes in wind direction from 0 to 10 degrees led to reduced efficiency and lower predicted power output. Lastly, the power spectral density for NACA 0012 integrated into the pitched and curved roof buildings revealed peaks at 5.8 Hz in 9 m/s wind speed conditions.

Outer isolated detached resonance curve and its implications of a two-stage nonlinear dynamic system

This paper presents an innovative study of a two-stage nonlinear dynamic system, providing insights into the occurrence of Large-Amplitude Long-Duration Vibration State (LALDVS) and outer isolated detached resonance curves (OIDRCs). The Lagrange equations and the incremental harmonic balance method (IHBM) are used to uncover the fundamental mechanism of OIDRCs and to discover two and three OIDRCs that have not been previously reported. Multiple OIDRCs could have significant practical implications in engineering, as they indicate the possibility of unpredictable and potentially hazardous vibrations under certain operating conditions. The existence of OIDRCs depends on the jump frequency point being a Neimark-Sacker bifurcation, and the resulting phase diagram provides vital insights into the stability and bifurcation behaviors of the system. This work also explores the effect of stiffness on the nonlinear response behavior of the system and identifies the range of stiffness values that lead to LALDVS. The correctness of the theoretical calculation results is validated by comparing them with vibration experiment and simulation calculations. These results have practical implications for engineering and energy harvesting research, including identifying potential hazards associated with vibration and designing systems that maximize energy harvesting efficiency. Overall, these findings are innovative and have significant implications for predicting potentially hazardous vibrations in engineering and the design of energy harvesting systems.

Influence of the configuration of elastic and dissipative elements on the energy harvesting efficiency of a tunnel effect energy harvester

Paper presents computer simulations conducted to study the influence of the configuration of an energy harvesting system with tunnel mechanical characteristics in terms of its energy generation efficiency. In this context, numerical simulation experiments were carried out to assess the impact of physical properties and initial conditions on the occurrence of coexisting solutions and its energy efficiency. Chaotic motion zones were identified on the basis of Lyapunov exponent. To be able to choose the best solution in terms of energy efficiency, studies on the use of impulse excitation to change the orbit of the solution were also presented. Results show that modifying the energy harvesting system design with an impulse excitation subsystem can significantly improve (up to tenfold) the amount of energy harvested from vibrating mechanical devices.

A survey on RF energy harvesting techniques for lifetime enhancement of wireless sensor networks

Lifetime enhancement of wireless sensor networks (WSNs) has been a significant challenge for the researchers for the last two decades. In WSNs, sensor nodes operate in an unattended environment and hence sensor nodes become useless when their battery is depleted. It is important to note that although there is a lot of radio frequency (RF) energy available everywhere, it has a low power density. First, we discuss some basics and framework of wireless energy harvesting systems. This research next examines RF energy harvesting strategies and techniques to enhance the RF to DC conversion efficiency of the rectenna system. The main challenge for RF energy harvesting system design is to achieve maximum PCE at low input power by using different rectifier circuit and antenna topologies or based on the bands they use. We also review the rectifying circuit's performance, including the impedance matching circuit, rectifier circuit, DC filter, and load.On the basis of their structure, attributes, and materials, the most recent antenna designs are featured. Finally, we consider some of its real-world issues and potential future work.

New Practical Nonlinear Energy-Harvesting Models for Wireless-Powered Communications

As a massive number of nodes are expected to be connected to each other in next-generation wireless networks, the power supply of such multiple-antenna nodes is a challenge and requires new and sustainable solutions. Radio frequency energy harvesting (EH) is among the promising approaches to solve this issue. In this paper, two new mathematically tractable nonlinear EH (NL-EH) models are proposed, for which the system performance is evaluated in terms of average harvested power, throughput, and bit error probability. The system consists of one multiantenna power-constraint source harvesting its power from a dedicated power beacon and transmitting its signal to a destination equipped with multiple antennas. For a comprehensive analysis of the system, closed-form expressions are derived for Nakagami- m fading channels and the special case of Rayleigh channels. For comparison purposes, the performance derivations in Nakagami- m fading channels are provided for linear and piece-wise linear EH models given in the literature. Besides, the simulation results are obtained by applying the Monte-Carlo method for NL-EH models existing in the literature. The results provide a broadening view of EH systems and thoroughly compare the proposed NL-EH models with linear, piece-wise linear, and NL-EH models available in the literature. Hence, these provide better insights towards the analyses and design of EH systems.

Perpetual Motion Wind Turbine Generator for Novelty Energy Harvesting System; Conceptual Design Approach

This paper deals with optimal design of energy harvesting system with perpetual motion. This design gives flexibility in promoting new sources of generation of electrical energy. The demand of electrical energy is increasing exponentially day by day so it is necessary to find alternative ways of energy generation at low cost. Additionally, by considering the fossil fuels are going to be replenished so the sources should be other than fossil fuels. The substitute of fossil fuels is the renewable energy source. Wind energy is one of major sources of renewable energy. The perpetual motion in this system is another new innovation. The whole system can be used for generating electrical energy without any harm to nature. With this system, the dependency on the continuous natural wind energy source can be eliminated at all. The perpetual motion system will produce the wind to energy harvesting system so that the wind turbine generator can be operated and then generate the electricity. The system also can be run continuously without depending on the current condition of the weather. The energy generated by perpetual motion machines (PMM) are usually discounted by the scientific community since they are considered impossible at industrial level but for small operations PMM can become very efficient.

Low-Cost Sensors for Indoor PV Energy Harvesting Estimation Based on Machine Learning

With the number of communicating sensors linked to the Internet of Things (IoT) ecosystem increasing dramatically, well-designed indoor light energy harvesting solutions are needed. A first step in this direction would be to be able to accurately estimate the harvestable energy in a specific light environment. However, inside, this energy varies in spectral composition and intensity, depending on the emission source as well as the time of day. These challenging conditions mean that it has become necessary to obtain accurate information about these variations and determine their impact on energy recovery performance. In this context, this manuscript presented a method to apply an innovative energy harvesting estimation method to obtain practical and accurate insight for the design of energy harvesting systems in indoor environments. It used a very low-cost device to obtain spectral information and fed it to supervised machine learning classification methods to recognize light sources. From the recognized light source, a model developed for flexible GaAs solar cells was able to estimate the harvestable energy. To validate this method in real indoor conditions, the estimates were compared to the energy harvested by an energy harvesting prototype. The mean absolute error percentage between estimates and the experimental measurements was less than 5% after more than 2 weeks of observation. This demonstrated the potential of this low-cost estimation system to obtain reliable information to design energetically autonomous devices.

Investigations on energy harvesting systems incorporating mechanical and electrical nonlinearities to charge reusable batteries

This report analyzes the electromechanical coupling evident in vibration energy harvesting systems that charge reusable batteries. A model of a vibration energy harvesting system with far-from-equilibrium nonlinearities is considered for sake of capitalizing on high-energy forced vibrations. The piezoelectric structure is coupled with nonlinear interface circuits that leverage rectification and control stages to enhance power delivery to the battery. Three circuits, namely standard energy harvesting (SEH) circuit, parallel synchronized switching harvesting on inductor (P-SSHI) circuit, and synchronized charge extraction (SCE) are considered as interfaces between the nonlinear energy harvester and a battery. A simplified power calculation is numerically verified to accurately estimate the harvested power respectively delivered from three interface circuits to the battery. The investigations reveal that increasing required battery voltage may inhibit means to achieve high-energy vibrations and thus prevent battery charging. By a conservation of energy, it is shown that the phase lag between beam velocity and the base acceleration is the primary indicator of interference between dynamic energy flows in the electromechanical sub-systems. This research sheds light on the influences of energy storage components on the functioning of nonlinear vibration energy harvesting systems. Moreover, the principles uncovered for the inhibition of high-energy oscillation may guide future nonlinear energy harvesting system design to extract the best power out from the ambient vibration environments.

Energy Harvesting System Design and Optimization Using High Bandwidth Rectenna for Wireless Sensor Networks

Energy Harvesting System Design and Optimization Using High Bandwidth Rectenna for Wireless Sensor Networks

Design of a solar energy harvesting system for supplying energy to an autonomous wireless sensor node

Introduction: This paper is the product of the research “Generation of a modular electronic platform for the conformation of a WSN” developed in the EAFIT University in 2019.
 Problem: Wireless Sensor Networks (WSNs) are used as a technology of information and communication (TIC) to automate processes. Its implementation is considered non-efficient, because of their high cost concerning to the batteries replacement that the nodes conforming the WSN, require.
 Objective: The objective of the research is to develop more efficient solar energy harvesting systems that can guarantee an average performance of the wireless sensor node at a low cost.
 Methodology: Here we present the design and the implementation of a solar energy harvesting system that integrates a buck converter, a maximum power point tracking (MPPT) control, and a wireless sensor node. Besides, we do measures of voltage at the output of the buck converter and estimation of energy autonomy in the wireless sensor node.
 Results: Autonomous operation with the solar energy harvesting system was rich for the node sending packages each 20 min.
 Conclusion: This article presented a solar energy harvesting system with the implementation of an MPPT control.
 Originality: Through this research, parameters of the MPPT control are formulated for the first time for the solar energy harvesting system design, based on the duty cycle limits.
 Limitations: The availability of the devices used in the implementation of the proposed design.

Environment and Application Testbed for Low-Power Energy Harvesting System Design

Energy harvesting systems strongly depend on the nondeterministic behavior of the environment. Systematic and thorough evaluation of these systems demands for tools that consistently reproduce these conditions and allow for closely integrating highly dynamic applications. To this end, a testbed is introduced that allows us to precisely and repeatedly force an energy harvesting system under test using thermal and radiative sources in a controlled environment while allowing to sinking arbitrary current profiles. The coordinated control of the boundary conditions on the input and output sides enables detailed evaluation, exploration, and dimensioning of different aspects of energy management and harvesting systems. By reproducing environmental traces at a higher rate than normally occurring in nature, the testbed allows us to substantially shorten the time needed for experimental evaluations. This approach enables fast and consistent evaluation of energy harvesting systems under a wide coverage of operating conditions.

Design of Energy Harvesting System Based on Building Integrated Photovoltaic at Academic Building ITERA

In this paper, a solar energy harvesting with the integrated grid system is designed at rooftop of Academic Building Institut Teknologi Sumatera (ITERA; latitude: -5.360091, longitude: 105.315441). The produced energy from solar energy harvesting in yearly was simulated using PVSyst. The solar energy harvesting consists of a photovoltaic array with nominal power 136 kWp and inverter system with nominal power 120 kWac. Total of producing useful energy 3.4 kWh/kWp/day. The energy loss in this system was reported due to the temperature effect, photovoltaic module quality loss, and inverter loss. The total of energy loss from an energy harvesting system reached 1.06 kWh/kWp/day. The performance ratio was found to be 0.763.

Metasurface: Enhancing gain of antenna and energy harvesting system design

Metasurface: Enhancing gain of antenna and energy harvesting system design

Two-dimensional octagonal phononic crystals for highly dense piezoelectric energy harvesting

Piezoelectric energy harvesting at multi-scales has received considerable attention as an attractive powering technology which enables sustainable self-powered operation of small electronics such as wireless sensors. Self-powered wireless sensors for structural health monitoring, biomedical and wearable applications would be great potential applications with high market demand. A key challenge has been insufficient power generation for practical applications, which necessitates a new paradigm in the design of energy harvesting systems. In this work, drastic enhancement of harvesting performance along with energy focusing is demonstrated both analytically and experimentally by introducing metamaterial-based energy harvesting (MEH) systems. Metamaterials, artificially engineered structures, exhibit unique properties including band gap and negative refractive index and thus enable us to manipulate mechanical wave propagations. Wave guide and localization toward a desired position can lead to amplification of harvestable input mechanical energy. In this work, systematic design of two-dimensional octagonal phononic crystals (PnCs) through geometric and band gap optimization process is proposed and followed by experimental demonstration. Energy confinement and localization at the defect of proposed PnCs leads to successful enhancement of harvesting power up to 22.8 times compare to the case without the presence of metamaterial.

A Floating Platform with Embedded Wave Energy Harvesting Arrays in Regular and Irregular Seas

This paper presents a study on a cost-effective engineering model that integrates an array of floating wave energy converters with a vast platform, a viable option for multi-functional performance in renewable energy capture and ocean space utilization. The wave energy converters are floating buoyance columns flexibly connected with the elastic platform. Hydrodynamic interactions among the columns are analyzed using an exact matrix transform method based on linear wave theory in the frequency domain. A parametric governing equation of compounded wave energy converter referred to as a wave farm is formulated by using Hamilton’s principle which can be discretized using the Galerkin method. The effects of wave conditions and the parameters of hydraulic power take-off (PTO) on the wave energy absorption and dynamic characteristics of the energy harvesting system are investigated. Furthermore, the wave energy capture on irregular waves is also discussed. This research work aims at providing a theoretical guidance for wave energy harvesting system design.

Vibrational energy harvesting by exploring structural benefits and nonlinear characteristics

Traditional energy harvesters are often of low efficiency due to very limited energy harvesting bandwidth, which should also be enough close to the ambient excitation frequency. To overcome this difficulty, some attempts can be seen in the literature typically with the purposes of either increasing the energy harvesting bandwidth with a harvester array, or enhancing the energy harvesting bandwidth and peak with nonlinear coupling effect etc. This paper presents an alternative way which can achieve tuneable resonant frequency (from high frequency to ultralow frequency) and improved energy harvesting bandwidth and peak simultaneously by employing special structural benefits and advantageous displacement-dependent nonlinear damping property. The proposed energy harvesting system employs a lever systems combined with an X-shape supporting structure and demonstrates very adjustable stiffness and unique nonlinear damping characteristics which are very beneficial for energy harvesting. It is shown that the energy harvesting performance of the proposed system is directly determined by several easy-to-tune structural parameters and also by the relative displacement in a special nonlinear manner, which provides a great flexibility and/or a unique tool for tuning and improving energy harvesting efficiency via matching excitation frequencies and covering a broader frequency band. This study potentially provides a new insight into the design of energy harvesting systems by employing structural benefits and geometrical nonlinearities.

From functional analysis to energy harvesting system design: application to car suspension

In the context of global energy demand increase, working on energy efficiency is essential. This paper deals with energy harvesting on car suspensions. In order to have a real added value, some criteria must be considered: the need to design a system that would be easily integrated into cars, the possibility to locally use the recovered energy to add new functionalities that can improve the security or the comfort of the car, and the necessity to not degrade and, if possible, to improve (semi-active or active dampers) the performances of the suspension. From the mechanical point of view, the functional analysis is used to define and to characterize the main suspension parts, to investigate the connexions and the energy flows and to identify the key elements for energy recovery. Then, quarter car and half car models implemented with Matlab/Simulink software are presented in order to evaluate the quantity of energy that could be recovered. Three locations are presented and evaluated. Simulations results will finally give an overview on the implementation opportunities.

Functional Interfaces for Biomimetic Energy Harvesting: CNT-DNA Matrix for Enzyme Assembly

The development of 3D structures exploring the properties of nano-materials and biological molecules allows us to mimic natural metabolic processes such as Krebs or Calvin cycle by creating “artificial” metabolic pathways called metabolons. The utilization of metabolons in biomimetic energy-harvesting systems leads to increased fuel oxidation and as a result increased Columbic efficiency. The specific order and minimized distance between the enzymes from those metabolons are the main reasons for subsequent and more effective fuel consumption.In this study a complex carbon nanotubes (CNTs) – DNA matrix for specific enzyme immobilization was created. It composed of “brush” type aligned CNTs covalently attached on electrochemically modified gold surface. This forest like CNTs structure was used as a substrate for the development of a DNA scaffold. This DNA scaffold had a designed sequence that allows strong attachment of DNA to the CNTs surface by wrapping the nanotubes through pi-pi stacking and at the same time has a unique nine base pair motif that was further hybridized. The hybridized part of the DNA was used to specifically attach zinc finger (Znf268) that was genetically fused to small laccase (SLAC).Zinc fingers are small protein structural motifs that can recognize dsDNA and specifically bind to it. We used this property to control the SLAC immobilization by fusing the Znf268 to the enzyme and attaching it to the CNTs-DNA scaffold (Fig. 1). Due to the specific interactions of zinc fingers with DNA we will be able to immobilize enzymes in particular order and distance creating metabolons.Figure 2 shows Atomic Force Microscopy (AFM) images of the gold surface at the different stages of its modification to the creation of the CNTs forest. The modification procedures were also confirmed with x-ray photoelectron spectroscopy (XPS).To prove the concept we used SLAC, which is an enzyme from the family of well-known multi-copper oxidases that are able to reduce oxygen and form water [1]. The enzyme was immobilized by the described approach and characterized by XPS (Fig. 3). The presence of copper in the XPS spectrum unambiguously proofs the success of the immobilization procedure. The developed herein approach for specific enzyme immobilization can be applied for all types of enzymes for the development of bio-cathodes as well as bio-anodes in the design of energy-harvesting systems.The developed herein approach for specific enzyme immobilization can be applied for all types of enzymes for the development of bio-cathodes as well as bio-anodes in the design of energy-harvesting systems.[1] Szilvay, G., S. Brocato, D. Ivnitski, C. Li, P. De La Iglesia, C. Lau, E. Chi, M. Werner-Washburne, S. Banta P. Atanassov Chem. Commun., 2011, 47, 7464–7466.

A comparison of power output from linear and nonlinear kinetic energy harvesters using real vibration data

The design of vibration energy harvesters (VEHs) is highly dependent upon the characteristics of the environmental vibrations present in the intended application. VEHs can be linear resonant systems tuned to particular frequencies or nonlinear systems with either bistable operation or a Duffing-type response. This paper provides detailed vibration data from a range of applications, which has been made freely available for download through the Energy Harvesting Network’s online data repository. In particular, this research shows that simulation is essential in designing and selecting the most suitable vibration energy harvester for particular applications. This is illustrated through C-based simulations of different types of VEHs, using real vibration data from a diesel ferry engine, a combined heat and power pump, a petrol car engine and a helicopter. The analysis shows that a bistable energy harvester only has a higher output power than a linear or Duffing-type nonlinear energy harvester with the same Q-factor when it is subjected to white noise vibration. The analysis also indicates that piezoelectric transduction mechanisms are more suitable for bistable energy harvesters than electromagnetic transduction. Furthermore, the linear energy harvester has a higher output power compared to the Duffing-type nonlinear energy harvester with the same Q factor in most cases. The Duffing-type nonlinear energy harvester can generate more power than the linear energy harvester only when it is excited at vibrations with multiple peaks and the frequencies of these peaks are within its bandwidth. Through these new observations, this paper illustrates the importance of simulation in the design of energy harvesting systems, with particular emphasis on the need to incorporate real vibration data.

Individual GaN Nanowires Exhibit Strong Piezoelectricity in 3D

Semiconductor GaN NWs are promising components in next generation nano- and optoelectronic systems. In addition to their direct band gap, they exhibit piezoelectricity, which renders them particularly attractive in energy harvesting applications for self-powered devices. Nanowires are often considered as one-dimensional nanostructures; however, the electromechanical coupling leads to a third rank tensor that for wurtzite crystals (GaN NWs) possesses three independent coefficients, d(33), d(13), and d(15). Therefore, the full piezoelectric characterization of individual GaN NWs requires application of electric fields in different directions and measurements of associated displacements on the order of several picometers. In this Letter, we present an experimental approach based on scanning probe microscopy to directly quantify the three-dimensional piezoelectric response of individual GaN NWs. Experimental results reveal that GaN NWs exhibit strong piezoelectricity in three dimensions, with up to six times the effect in bulk. Based on finite element modeling, this finding has major implication on the design of energy harvesting systems exhibiting unprecedented levels of power density production. The presented method is applicable to other piezoelectric NW materials as well as wires manufactured along different crystallographic orientations.