Hybrid Harvester Research Articles

Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction.

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

Hybrid vibration energy harvesting based on piezoelectric polyline beams with electret coupling

Aiming at harvesting vibration energy more efficiently, a hybrid energy harvester is proposed, which integrates the piezoelectric and electrostatic effects. It is composed of two piezoelectric polyline beams and an electret film. The two piezoelectric polyline beams stand closely, of which one is covered by an electret film, while the other is covered by a counter-electrode. Under base excitations, the electret film interacts with the electrode, by which the two polyline beams can excite each other and form a broad frequency band of large vibration, thereby generating a large output. The dynamical equations are derived and the simulations are carried out. For validation, the experiments are conducted. The experimental results prove that the hybrid harvester is more efficient in harvesting stochastic vibration energy. For PSD = 0.0041 g2/Hz, the two piezoelectric polyline beams can generate the power outputs of 47.9 and 23.6 µW, respectively.

A single-inductor thermoelectric and photovoltaic hybrid harvesting interface with time-multiplexed technology and accurate zero current detector

This paper presents a single-inductor thermoelectric and photovoltaic hybrid harvesting interface. The time-multiplexed technology is proposed to harvest the dual-energy sources within one operating cycle, providing more load power in smaller system volume. Furthermore, the proposed accurate zero current detector can avoid advance or delay of the current detection in discontinuous conduction mode, thereby improving power conversion efficiency. The proposed interface was implemented in a 0.18 ​μm CMOS process with the area of 1.68 ​× ​1.31 ​mm2. The open-circuit-voltage range of the TE and PV transducers is from 0.1 ​V to 0.4 ​V and 0.2 ​V–1 ​V, respectively. The measured results show that the proposed interface harvests PV and TE energy synergistically in one operating cycle, and the TEH time and the PVH time account for about 48% and 4% respectively. The peak tracking efficiency of TEH and PVH are 98% and 98.1%, respectively. The peak power conversion efficiency reaches 85.7% when the output of TE is 300 ​mV and PV is 1 ​V.

Performance comparison between dual cantilevered and touch based hybridized triboelectric harvesters

The demand for energy harvesting technologies has been increasing over the years attributed to its significance to low power applications. One of the key problems associated with the vibration-based harvester is the fact that these harvesters generate low usable power while maximum peak power can only be attained when the device frequency matches the source frequency. In this study, triboelectric mechanism was investigated in combination with the piezoelectric mechanism in order to enhance the performance of the harvester. Triboelectric mechanism functions in a way that two dissimilar materials were placed in contact and then separated in order to generate surface charges and electric potential between them. Main design factors such as materials, surface area, structure, effective length, and etc. play a significant part in the enhancement of the performance. This study proposed two distinct designs of dual cantilevered structure and touch-based triboelectric energy harvester and evaluated the efficiency of the output between both structures. In addition, the effect of extension and surface area of triboelectric materials was investigated while the influence of these factors on the performance of the harvester was evaluated. The highest value of peak power obtained for dual cantilevered hybrid harvester was 650 µW across a load of 160 kΩ and frequency of 26 Hz. On the other hand, touch-based energy harvester produced an output peak power of 1220 µW across a load of 400 kΩ at 25 Hz. Achieving these power outputs may be able to power up electronics such as smartwatches, hearing aid and etc. Future studies on reliable low power applications to further advance the green power technology will be investigated.

Frequency Up-Conversion Hybrid Energy Harvester Combining Piezoelectric and Electromagnetic Transduction Mechanisms

A hybrid energy harvester with frequency up-conversion structures is proposed. The harvester achieves a high power output by utilizing both piezoelectric and electromagnetic transduction mechanisms. The harvester comprises a flexible substrate and two (internal and external) cantilevers. The internal and external cantilevers used for piezoelectric and electromagnetic conversion, respectively, are arranged such that the piezoelectric internal cantilever can vibrate with a large displacement to produce high output power. We use a frequency up-conversion method to convert the bending of the harvester into the vibration of the structure so that the harvester can generate energy even from the mechanical motion with an extremely low frequency. Two harvester configurations are investigated to validate the effect of the relative positions of the coil and magnet on the output voltage of the harvester. The maximum power output of the hybrid harvester is 7.38 mW, with outputs of 1.35 and 6.03 mW for piezoelectric and electromagnetic conversion, respectively.

Effect of cutting depth during sugarcane (Saccharum spp. hybrid) harvest on root characteristics and yield.

Ratooning is an important cultivation practice in sugarcane production around the world, with underground buds on the remaining stalk acting as the source for establishment of a subsequent ratoon crop. However, the optimal depth of cutting during harvest in terms of yield and root growth remains unknown. We carried out a two-year field study to determine the effects of three cutting depths (0, 5 and 10 cm below the surface) ratoon cane root and yield. Results showed that cutting to a depth of 5 cm increased the root fresh weight and root volume by 21–59% and 41–127%, respectively, compared to cutting depths of 0 and 10 cm. Remarkably, cutting to a depth of 5 cm also had a significant effect on the development of fine roots, which is closely linked to cane yield. The effect was particularly noticeable in terms of two root traits, root volume and the surface area of roots with a diameter of 1.0–2.0mm, and root length and the number of root tips in roots with a diameter of 0–0.5mm. As a result, a cutting depth of 5 cm below the surface increased cane yield by 43 and 28% compared to depths of 0 and 10 cm below the surface, respectively. Overall, these findings suggest that a cutting depth of 5 cm is optimal in terms of sugarcane yield, largely due to the enhanced effect on root traits, especially the development of fine roots. These findings will help optimize sugarcane ratoon management and improve the ratoon cycle.

A Quad-Band Stacked Hybrid Ambient RF-Solar Energy Harvester With Higher RF-to-DC Rectification Efficiency

This article addresses the design and implementation of a novel quad-band electromagnetic (EM) and solar energy scavenging system, ensuring energy harvesting from ambient RF environment with excellent “cold start” power level. The proposed scavenger consists of a single port quad-band rectangular slot antenna, power film solar cell, a quad-band RF- to-DC converter, a microcell power management module, and a battery. The harmonic balance of EM solver is used to design and maximize the RF- to - DC rectification efficiency with the combination of the antenna and the solar cell. The power film solar cell is placed in the middle of the antenna with positive and negative edges connected to the top and bottom layer of the antenna so that total harvested energy passes through the rectifier and forms an ambient hybrid energy harvesting system. One significant benefit of this method is the utilization of the antenna free space for the effective area of the power film. Another important contribution is the employment of multiband antennas for increasing the total ambient RF scavenged energy. Besides, a cost-effective and flexible FR4 substrate and a micropower film solar cell are used to make it conformal and cheaper. The prototype of hybrid harvester demonstrated that with 360 lux ambient light intensity, at the solar cell can generate 0.109 V energy while the harvester can attain an extra 5% - 48% energy with ambient RF input level variation from −15 to −20 dBm. The rectifier circuit achieves 74.5% RF-to-DC rectification efficiency for the value of load resistance 2.7 $\text{k}\Omega $ . These performances depict that the proposed multiband ambient hybrid RF-solar power scavenger can raise the scavenged power level and offer energy multiplicity.

Review of vibration‐based electromagnetic–piezoelectric hybrid energy harvesters

SummaryThese days the health monitoring of machines and structures is performed using wireless sensor nodes (WSNs). The disadvantage of short life span of batteries in WSN is overcome by using energy harvesting techniques and the required power is extracted from the environment for operating WSNs. The energy available in environment is in the form of thermal, solar, wind, vibration, RF and acoustic energy. The Piezoelectric (PE), electromagnetic (EM), electrostatic and triboelectric transduction may be utilized to harvest power from vibration energy available on structure which otherwise may be going waste. Moreover, for enhancing power generation hybrid vibration energy harvesters are developed by combining two of such transduction mechanisms. The piezoelectric and electromagnetic based hybrid harvesters are discussed in this work for vibration energy harvesting. The hybrid vibration energy harvesters are classified here as resonant, frequency tuned, nonlinear, non‐resonant, multi‐mode and frequency up conversion harvesters. The architecture, input excitation levels and performance of the reported hybrid harvesters is discussed and compared to know the advantage of harvester's configuration. Moreover, all the reported harvesters are compared on the basis of input vibration to which these harvesters are subjected, their resonant frequencies, size, output voltage, power levels and power density. Most of the developed hybrid energy harvesters are resonant harvesters. The multi‐mode hybrid energy harvesters are generating comparatively higher power levels of up to 250.25 mW and power density 2669.3 µW/cm3 in the reported literature. The overall voltage and power generation range of the hybrid harvesters is from 0.131 mV to 26 V and 0.637 µW to 250.25 mW. Moreover, the power density for the reported energy harvesters is in the range from 1.96 µW/cm3 to 2669 µW/cm3.

Power harvesting footwear based on piezo-electromagnetic hybrid generator for sustainable wearable microelectronics

As wearable microelectronics become more ubiquitous, and the size and power requirements of such devices decrease, there is increasing research interest in harnessing power from ambient environmental sources through embedded systems as alternative to battery replacements. Accordingly, a multimodal hybrid piezo-electromagnetic insole energy harvester (PEM-IEH) has been presented in this paper as a means to reclaim the biomechanical energy wasted in the surroundings during daily walking. The hybrid device consists of two piezo-ceramic wafer plates, two magnets, and two wound coils. The designed harvester has been simulated, fabricated and experimentally validated. From the frequency response, the hybrid harvester exhibits four resonant frequencies concentrated around 8, 25, 50, and 51 Hz. A maximum combined power of 1400 µW is generated across the optimal load resistances of upper and lower electromagnetic generators at first resonant frequency (8 Hz) under 0.5 g base acceleration, and a 269 µW peak power is obtained across the optimum load resistances of the upper and lower piezoelectric generators at 4th resonance (51 Hz) under 0.5 g. The miniature (46.8 cm3) and lightweight (43.3 g) harvester was incorporated into the sole of an adult-sized commercial shoe, and has been shown to be able to charge a 100 µF capacitor, up to 2.4 Volt within approximately 10 min of slow jogging. The capacitor charging performance presents a remarkable potential application of the harvester in development of micro-power monitoring sensors and wearable microelectronic gadgets where batteries pose a practical bottleneck.

Influence of mechanized timber harvesting on soil compaction in northern hardwood forests

AbstractEvaluating and refining methods to minimize soil compaction during timber harvesting is important for maintaining soil health and long‐term forest productivity. This is especially important when harvesting methods change over time. In this study, a hybrid harvesting method was used with the trees cut by one machine, in‐forest processing of trees by other machines, and transporting the wood to the roadside by a forwarder on silt loam soils during the summer months. Two methods for sampling soils with mixed horizons in logging trails were developed to determine the baseline values of soil bulk density for long‐term monitoring and to compare soils from nonmixed B horizons with those of B horizons from nontrafficked areas. For both methods, paired soil samples, in and outside of logging trails, were collected to determine the difference in bulk density between trails and nontrafficked areas. Soil compaction in trails was greatest where the soils adjacent to trails had low bulk densities and for locations that were closest to landings. These results are important in the context of climate change, as more summer logging is expected to occur in areas traditionally cut in the winter because of longer frost‐free periods and more winter precipitation occurring as rain. More logging during the expanding snow‐free season could translate to a greater degree of compaction and longer soil recovery times over a larger portion of the forested landscape.

Mechanical Energy Harvesting Taxonomy for Industrial Environments: Application to the Railway Industry

Traditional industry is experiencing a worldwide evolution with Industry 4.0. Wireless sensor networks (WSNs) have a main role in this evolution as an essential part of data acquisition. The way in which WSNs are powered is one of the main challenges to face if industry wants to achieve the digital transformation. Energy harvesting technologies are one of the possible solutions to this challenge. The main purpose of this paper is to present a novel method to taxonomize knowledge in the field of mechanical energy harvesting to enhance the use of energy harvesting technologies in industrial applications. The methodology is based on the analysis of key parameters and performance metrics for existing technologies. The taxonomy is applied to rail axles in order to select the energy harvesting technology that is more appropriate for this specific location, demonstrating the potential of mechanical energy harvesting technologies (MEHTs) for the railway industry, as a use case of industrial environment. In addition, the taxonomy allows to identify the upcoming challenges for research purposes while analyzing the compatibility among mechanical energy harvesting technologies in order to create hybrid harvesters.

A vibration‐based electromagnetic and piezoelectric hybrid energy harvester

This work presents the fabrication and testing of a vibration-based single energy hybrid harvester (VSEHH). Electromagnetic and piezoelectric transduction mechanisms are utilized for energy extraction in the developed harvester. Electromagnetic portion of the device composed of a permanent magnet, planar coil and wound coil, however, for piezoelectric portion polyvinylidene difluoride (PVDF) membrane is used. In the harvester the PVDF membrane having the magnet is kept loose in order to exploit the spring softening nonlinearity. At lower base excitation levels (less than 0.5g) the response of the VSEHH is linear, however, from 0.5 to 2.5g the harvester exhibits spring softening nonlinearity and at acceleration levels greater than 2.5g, the spring hardening nonlinearity is invoked. Because of nonlinear behavior of the harvester, the shift of resonant frequency, the sudden jump-up and jump-down phenomena result in the enhancement of the harvester's frequency bandwidth. Under sinusoidal excitation and at 123 Hz frequency and 4g acceleration, the electromagnetic portion of the harvester produced 40.6 mV load voltage and 212.7 μW with planar coil and 73.5 mV load voltage and 319.1 μW power with wound coil. Moreover, under the same vibrations condition a load voltage of 2930 mV and power of 57.6 μW is generated by the piezoelectric portion of the harvester. Collectively, the harvester is capable of producing a power of 589.4 μW and a power density of 334.13 μW/cm3. Furthermore, when subjected to broadband random vibrations, two central frequency peaks are produced, one is due to spring softening and the other corresponds to the spring hardening of the membrane.

Multimodal Hybrid Piezoelectric-Electromagnetic Insole Energy Harvester Using PVDF Generators

Harvesting biomechanical energy is a viable solution to sustainably powering wearable electronics for continuous health monitoring, remote sensing, and motion tracking. A hybrid insole energy harvester (HIEH), capable of harvesting energy from low-frequency walking step motion, to supply power to wearable sensors, has been reported in this paper. The multimodal and multi-degrees-of-freedom low frequency walking energy harvester has a lightweight of 33.2 g and occupies a small volume of 44.1 cm3. Experimentally, the HIEH exhibits six resonant frequencies, corresponding to the resonances of the intermediate square spiral planar spring at 9.7, 41 Hz, 50 Hz, and 55 Hz, the Polyvinylidene fluoride (PVDF) beam-I at 16.5 Hz and PVDF beam-II at 25 Hz. The upper and lower electromagnetic (EM) generators are capable of delivering peak powers of 58 µW and 51 µW under 0.6 g, by EM induction at 9.7 Hz, across optimum load resistances of 13.5 Ω and 16.5 Ω, respectively. Moreover, PVDF-I and PVDF-II generate root mean square (RMS) voltages of 3.34 V and 3.83 V across 9 MΩ load resistance, under 0.6 g base acceleration. As compared to individual harvesting units, the hybrid harvester performed much better, generated about 7 V open-circuit voltage and charged a 100 µF capacitor up to 2.9 V using a hand movement for about eight minutes, which is 30% more voltage than the standalone piezoelectric unit in the same amount of time. The designed HIEH can be a potential mobile source to sustainably power wearable electronics and wireless body sensors.

Two-span piezoelectric beam energy harvesting

This paper reports an analytical study of nonlinear vibratory energy harvesting via a two-span piezoelectric beam. The distributed parameter electromechanical model is applied to explore the benefits of nonlinear interaction between buckled beam spans. The Galerkin truncation method and harmonic balance method are applied together to find forced responses of the energy harvesting system. The effects of axial pre-pressure on energy harvesting are also explored. The analytical results are supported by utilizing direct time integration of the equation of motion. The amplitude and voltage output frequency response functions (FRF) of single-span, buckled, and two-span piezoelectric beam configurations reveal some differences. For example, the voltage output FRF of the two-span buckled configuration is larger than that of the other two configurations at high frequencies, whereas at low frequencies, the voltage output FRF of two-span unbuckled configuration is larger than that of the other two configurations. Moreover, two-span buckled configuration has more natural frequencies lying at the concerned frequency range. Finally, a hybrid harvester is proposed, which combines harvested voltage from single-span buckled, two-span, and two-span buckled piezoelectric beam to cover a demand of broadband voltages output.

Right-of-Way Monitoring Camera Storage Energy Around High Voltage Power Transmission Using Hybrid Energy Harvesting-Mfield, Efield to Super Capacitor Batteries Back-Up Charger

Magnetic and electric fields are the loss of the field that occur continually around high voltage transmission lines in the power systems. The current and voltage are significant variables for generating magnetic and electric fields respectively. This research is interested in the development of these fields to store harvested energy and the correct way of using camera node monitoring. In this work, the authors purpose energy harvesting from magnetic and electric fields, with a case study based on 230 kV and 500 kV in the Thai power transmission system. Two approaches are used for the hybrid harvester, with the first method using the number of coil turns in each dielectric physical model, such as air, metal, or ferrite dielectric to harvest the magnetic field from the power line. The number of coils uses N-turn, 250 N, 600 N, and 1000 N, with a dielectric distance of 4, 6, and 10 cm is used. The second approach is electric field harvest, using a varied electrode plate from ground to an electric conductor, with three plates used in the experimental model. At the investigational stage, the common plate is varied from the nearest conductor to the ground to analyses data results. After that, two sources of energy are taken to the hybrid storage harvester using the rectifier circuit and stored in a super capacitor. The energy from the backup super capacitor is used to supply to the right-of-way camera monitoring or other low energy source devices. This study result show that energy harvesting from the field harvest varied according to the number of coil turns, distance of the dielectric, size of the plate, and distance from the high voltage conductor. The voltage from field can be stored to super capacitor from 0 V to approximately 0.8 V in 180 min for a magnetic field yield. Furthermore, the electric field harvesting can charge the supper capacitor from 0 to 15 V in 180 min. The research therefore combines two approaches for charging in the battery backup using low energy devices, referred to as a hybrid harvesting approach. This research is advantageous for right-of-way camera monitoring supply on high voltage–power transmission lines.

A triboelectric and pyroelectric hybrid energy harvester for recovering energy from low-grade waste fluids

Low-grade waste energy is widely available in industrial processes, and it typically appears in the form of thermal fluids. Types of technologies are developed for harvesting the thermal energy from these fluids. However, the thermal fluid not only possesses thermal energy, but also contains a large amount of kinetic energy. In this study, a hybrid device is proposed for harvesting both the thermal and kinetic energy of the thermal fluids. A free-standing type triboelectric nanogenerator (TENG) is employed for harvesting the kinetic energy, while a pyroelectric generator (PENG) is used for harvesting the thermal energy. Output performance of discrete water droplets with temperature of 5 °C, 25 °C, 45 °C and 65 °C are compared in both the TENG and PENG devices. The effects of the device inclination angle, and droplet released height are discussed. The analyses are conducted based on high-speed video recording of the droplet dynamics on the device as well as numerical simulation. The results indicate the droplet temperature, device inclination angle and droplet released height affect the droplet dynamics significantly. Further, the variation of droplet dynamics greatly affects the output performance of both the TENG and PENG. The peak output power of the TENG decreases with the increase of droplet temperature, while the output power of the PENG increases with the temperature variation. A hybrid energy harvester was fabricated and a peak power density of 2.6 μW/cm2 was achieved. A maximum energy increment of 238% was obtained by the hybrid harvester, as compared to the pure PENG device. The harvested energy was able to light up 28 commercial LED light bulbs.

A comparison of the Trojan Y Chromosome strategy to harvesting models for eradication of nonnative species

AbstractThe Trojan Y Chromosome strategy (TYC) is a promising eradication method for biological control of nonnative species. The strategy works by manipulating the sex ratio of a population through the introduction ofsupermalesthat guarantee male offspring. In the current study, we compare the TYC method with a pure harvesting strategy. We also analyze a hybrid harvesting model that mirrors the TYC strategy. The dynamic analysis leads to results on stability of solutions and bifurcations of the model. Several conclusions about the different strategies are established via optimal control methods. In particular, the results affirm that either a pure harvesting or hybrid strategy may work better than the TYC method at controlling a nonnative species population.Recommendations for resource managersWhere harvesting is feasible, it is as effective if not more effective than the classical TYC method. Therein managers may attempt harvesting female fish while stocking males or harvesting both male and female fishes.Managers may attempt linear harvesting, saturating density‐dependent harvesting, and unbounded density‐dependent harvesting. Linear harvesting is seen to be the most effective.We caution against the outright use of harvesting due to various density‐dependent effects that may arise. To this end hybrid models that involve a combination of harvesting and TYC‐type methods might be a better strategy.One may also use harvesting as a tool in mesocosm settings to predict the efficacy of the TYC strategy in the wild.

Hybrid Harvesting Strategies to Overcome Resource Constraints: Evidence from Social Enterprises in Kenya

Hybrid organisations combine different elements from the for-profit and non-profit domains, and they usually operate in a resource-scarce environment. For these reasons, they continuously face various resources constraints, yet their hybrid nature could be translated into an opportunity. The purpose of our study was to investigate how a hybrid organisation can overcome resource constraints in developing countries by exploiting their own hybrid nature. In the unique research setting offered by Kenyan social enterprises, we identified five creative approaches implemented by social enterprises. Finally, we present a grounded model that clearly explains which hybrid harvesting strategies can be implemented to overcome resource constraints, exploiting their hybrid potential. Our work contributes to knowledge about resource constraints in the social entrepreneurship literature and extends social bricolage theory. Limitations and future research approaches are also presented.

Study on the Output Performance of a Nonlinear Hybrid Piezoelectric-Electromagnetic Harvester under Harmonic Excitation

The nonlinear energy harvester has become a hot topic due to its broad bandwidth and lower resonant frequency. Based on the preliminary test and analyses in our previous work, further analyses and tests on the influence of parameters, including the nonlinear magnetic force of the hybrid energy harvesting structure on its output performance under harmonic excitation, are performed in this paper, which will provide powerful support for structural optimization. For designing a nonlinear piezoelectric-electromagnetic hybrid energy harvester, the state equation of electromechanical coupling, the harmonic response and average output power, voltage, and current of a nonlinear hybrid energy harvester under harmonic excitation are derived by the harmonic balance method. The effects of the excitation acceleration and the external load on the output performance of the nonlinear hybrid energy harvester are verified through experimental tests. The results showed that the output power of the nonlinear hybrid energy harvester increases with the increase in the acceleration of harmonic excitation, and the increase is affected by external load. When the piezoelectric-electromagnetic hybrid harvester operates at the optimal load and the resonant frequency, the average output power reaches its maximum value and the increase of the load of the piezoelectric unit makes the resonant frequency of the energy harvesting system increase. Compared with linear harvesting structures, the nonlinear hybrid harvester has better flexibility of environmental adaptability and is more suitable for harvesting energy in low-frequency environments.

Dynamics and energy generation of a hybrid energy harvester under colored noise excitations

A hybrid energy harvester combining piezoelectric and electromagnetic transduction mechanisms is presented, which can be extensively applied in harvest vibration energy. This paper studies power harvested from the hybrid harvester under additive and multiplicative Gaussian colored noise excitations. Based on the stochastic averaging method, approximate methods have been adopted to obtain the Fokker-Planck-Kolmogorov equation and reveal interesting dynamics related to the stationary probability density, mean harvested power and mean switching time. It is observed that noise intensities, correlation times and other system parameters will induce the appearance of stochastic bifurcation. Furthermore, the mean harvested power is carried out to understand the device output performance of the hybrid generators. The hybrid energy harvested can be enhanced by suitable choice of noise intensities, correlation times and other system parameters. Finally, the mean switching times of the periodic attractors are investigated. The phenomenon of noise-enhanced stability has been carried out to evaluate the performance of the hybrid energy harvester. The occurrence of the noise-induced stability phenomenon signifies that the stability of the large-amplitude periodic attractor can be enhanced by the noises, which is very beneficial for energy harvesting.