Hybrid Harvester Research Articles

Scotch yoke structure inspired piezoelectric-electromagnetic hybrid harvester for wave energy harvesting

This paper presents a piezoelectric-electromagnetic hybrid harvester for wave energy harvesting inspired by a scotch yoke structure for obtaining energy from irregular and low-frequency waves. Through simplification of the energy harvester model, the kinematic equations of the scotch yoke are established. One of the advantages of the harvester is that the wave energy can be harvested by an up-conversion mechanism, The piezoelectric transducer (PZT) and electromagnetic generator (EMG) transform the wave excitation into electricity, and by utilizing the frequency up-conversion mechanism, the PZTs’ harvesting efficiency is increased, the influencing factors of the output power of the harvester are explored by simulation and experimental studies, The results of the experiment demonstrate that this harvester could generate an ultimate output power of 286.36 mW at ultra-low frequency (1.4 Hz) operating frequency. This study offers a practical solution for harvesting low-frequency and disordered wave energy and makes significant progress in harvesting low-frequency and irregular wave energy.

Genetic Diversity of Yellow and Red Berries Arabica Coffee Populations Grown in a Mix Populations in Garut, West Java, Indonesia, Based on SSR Markers

Farmers in Garut, West Java, grow mixed varieties of Arabica coffee (Coffea arabica L.). Subsequently, they use harvested beans as seeds. Intercrossing among varieties may result in hybrid progenies and harvesting hybrid progenies as seed results in genetic variations. This research aims to evaluate the genetic diversity of Arabica coffee grown in a mixed population. Ninety-one Arabica coffees comprised 37 Arabica cv. “Ahernt GRT KN” (yellow-), 45 “Sigararutang” (red-), and nine “S795” (red berries) were sampled. Twenty SSR primer pairs were validated using 15 samples representing three varieties; six were polymorphic and used to genotype 91 Arabica accessions. Genetic data were analyzed using PowerMaker 3.25 and Darwin version 6 software. The results showed that the six SSR loci generated from 2 – 3 alleles, with an average of 2.17 alleles per locus. Genetic analysis of Arabica coffee from Garut, West Java, generated SSR markers with an average PIC of 0,33 across loci and varieties. The PIC within Arabica coffee cv. “Ahernt GRT KN” and “Sigararutang” were low, and within “S795” was moderate. Those PICs indicate the presence of more genetic diversity within “S795” than the other two cultivars. The Ho across Arabica coffee cv. “Sigararutang” and “S795” were lower than the He values, confirming their self-pollination nature. However, the Ho values of Arabica coffee cv. “Ahernt GRT KN” was larger than the others, indicating the presence of residual heterozygosity and a low percentage of recent outcrossing. The low Ho values of “Sigararutang” suggest that Arabica coffee is homozygous. Arabica coffee cv. “S795” also showed a low Ho value, but its moderate He value indicates the presence of more genetic diversity than the othercultivars.

Noncontact magnetically coupled piezo-electromagnetic rotary energy harvester

Aiming at the problems of high environmental vibration frequency, low output power and short life of the energy harvesters, a noncontact magnetically coupled piezo-electromagnetic rotary energy harvester is proposed in this paper. It consists of a base, a top cover, a rotating body, a cantilever beam, a permanent magnet, a coil, a hollow tube and a clamp. The novel hybrid harvester can produce both piezoelectric and electromagnetic energy at the same time, and in addition, it can efficiently generate electricity at low ambient vibration. Moreover, the piezoelectric material is protected from direct collision by noncontact magnetic coupling excitation. In order to conduct a comprehensive study on the performance of the piezoelectric-electromagnetic rotary energy harvester, we set up a rotating test platform to carry out systematic test verification, and to determine the distance between the permanent magnet and the rotating body and the number of permanent magnets on the rotating body. The test results show that when four permanent magnets are uniformly pasted on the rotating body and the rotating speed is 775 r/min, the piezoelectric and electromagnetic output power are 3.4 mW and 2.69 mW, respectively, and the total hybrid output power is 6.09 mW.

A hybrid harvester using a magnetically coupled pendulum structure for limb movement

ABSTRACT Energy harvesting and conversion devices can provide power solutions for wearable devices. In this paper, a piezo-electromagnetic hybrid energy harvester (PEMHEH) using a magnetically-coupled pendulum structure for low-frequency limb movement is proposed. PEMHEH consists of a piezoelectric generator (PEG) unit including a main piezoelectric transducer, an auxiliary piezoelectric transducer (APT), and an electromagnetic generator (EMG) unit. It can reduce the starting frequency and increase the output performance by adopting a slidable mass block, the APT, and the rational magnetic pole arrangement. Its theoretical model is established, and magnetic simulation and experimental tests are carried out. The results show it can be started at 0.4 Hz excitation, and the output performance is maximized at 2 Hz. The maximum voltages of the piezoelectric generator and electromagnetic generator units are 5.29 V and 457 mV, and the maximum power is 286.16 μW (30 kΩ) and 11.25 μW (2 kΩ). The PEMHEH can light up LED boards at a 1 Hz excitation frequency. It has the potential to power wearable devices.

Hybrid Time Series Model for Advanced Predictive Analysis in COVID-19 Vaccination

This study aims to enhance the prediction of COVID-19 vaccination trends using a novel integrated forecasting model, facilitating better public health decision-making and resource allocation during the pandemic. As the COVID-19 pandemic continues to impact global health, accurately forecasting vaccination trends is critical for effective public health response and strategy development. Traditional forecasting models often fail to capture the complex dynamics of pandemic-driven vaccination rates. The analysis utilizes a comprehensive dataset comprising over 68,487 entries, detailing daily vaccination statistics across various demographics and geographic locations. This dataset provides a robust foundation for modeling and forecasting efforts. It utilizes advanced time series analysis techniques and machine learning algorithms to accurately predict future vaccination patterns based on the Hybrid Harvest model, which combines the strengths of ARIMA and Prophet models. Hybrid Harvest exhibits superior performance, with mean-square errors (MSEs) of 0.1323, and root-mean-square errors (RMSEs) of 0.0305. Based on these results, the model is significantly more accurate than traditional forecasting methods when predicting vaccination trends. It offers significant advances in forecasting COVID-19 vaccination trends through integration of ARIMA and Prophet models. The model serves as a powerful tool for policymakers to plan vaccination campaigns efficiently and effectively.

A piezo-electromagnetic hybrid multi-directional vibration energy harvester in freight trains

Rail freight systems are widely acknowledged for their operational efficiency across various nations. However, a prevailing limitation lies in the absence of power supply within standard freight wagons, impeding the installation of essential sensors to monitor train operation. This paper provides an innovative solution to this issue, where a novel device is developed to harvest vibration energy from freight trains to power operational condition monitoring sensors. The proposed device integrates a piezoelectric energy harvester with an electromagnetic counterpart, utilizing a spring-mass structure to capture vibration energy and transfer it to cantilever beams through magnetic coupling. A cantilever beam with variable width and a distinctive “checkmark” shape is employed to ensure even stress distribution to enhance piezoelectric material efficiency. The optimal spatial configuration between magnets and coils, as well as inter-magnet spacing, is determined through finite element analysis and empirical testing. Experimental results under the excitation with a frequency of 9.5 Hz and a vertical amplitude of 2 mm show the hybrid harvester can generate a maximum power of 3.276 mW. This hybrid energy harvesting system has the potential to provide dependable power to electronic components, including temperature sensors and accelerometers, crucial for monitoring rail freight train operations.

Numerical study of a synergistic hybrid energy harvesting system for bladeless wind turbines

Using energy of the fluid flow over an oscillating vertically-mounted flexible cylinder, as a representative configuration of bladeless wind turbines (BWTs), has recently attracted wide attention in the fluid mechanics community. In this paper, the fluid–structure interactions of a novel BWT-based hybrid piezo-electromagnetic energy harvesting system have been numerically studied in the vortex-induced-vibration (VIV) lock-in region by using the Reynolds Averaged Navier-Stokes (RANS) equations with the SST k-ω turbulence model. It is found that by implementing the electromagnetic (EMT) and/or piezoelectric (PVDF) transducers, the lock-in region becomes wider (up to 33% for the hybrid system) while being shifted to the higher Reynolds number (Re) range. Also, the dimensionless BWT cross-flow tip displacement amplitude (Yamp∗) is seen to reduce about 20%, 70%, and 70% by using the single-alone EMT-based, single-along piezo-based, and the hybrid harvester, respectively, which can potentially lead to substantial improvements in the fatigue life of the system Furthermore, the synergetic action of the hybrid system is observed to cause an overall increase in the harvested energy levels besides broadening of the associated range, as each of energy harvesting components appears to produce higher output power as compared to the respective single-alone system. In other words, up to 260% increase (100% increase) in the overall harvested energy level and up to 300% increase (60% increase) in the harvestable Re range with respect to the single-alone piezo-based (EMT-based) system are obtained, in which about 50% (about 10%) synergetic effects can be associated with the EMT- and piezo-based transducers, respectively.

Energy generation through a hybrid energy harvester under random excitation

This manuscript analyses a multi-frequency based coupled piezo-electromagnetic hybrid vibration energy harvester. Most of the energy harvesting devices discussed in the literature are based on the assumption that the base excitation is harmonic. However, in general, energy harvesting devices are deployed in an ambient environment, which is random in nature. Hence, in this regard, the manuscript discusses the power harvesting capabilities of the hybrid energy harvester under random base excitation using analytical and experimental studies. Acceleration with band limited Gaussian noise has been provided as an input to the base of the harvester. Comparative studies are also made to understand the performance of the hybrid harvester over conventional standalone piezoelectric and electromagnetic harvesters under the same support excitation. Thus, the novelty of the present work is to analyse a novel design of a hybrid harvester to improve harvesting performance across a wide range of frequencies under random base excitation compared to conventional harvesters. The results demonstrate that the proposed hybrid energy harvester can yield sufficient power over a wide range of frequencies. In addition, parametric studies have also been performed to characterize the system parameters in order to enhance the performance of the harvester. Studies show that the harvested power can be enhanced by maximizing the values of mass ratio, frequency ratio, non-dimensional electromechanical coupling coefficient and minimizing the values of structural damping ratios. Finally, practical applications of the proposed device have also been reported.

LCEMILCP: Design of a Low-complexity Energy Harvesting Model Via Incremental Learning and Continuous Power Quality Optimization Process in Wsn

Optimization of energy harvesting requires design of low complexity & high efficiency models that can work with maximum power gain levels. To design such models, researchers have proposed multiple techniques, that can assist in improving power quality via selection of optimum harvesting sources in multisource environments. But these models require continuous reconfiguration of static rules, which limits their efficiency when applied to large-scale network scenarios. Moreover, most of these models also showcase higher complexity due to reconfiguration, which reduces their scalability performance. To overcome this limitation, a novel Low-Complexity Energy Harvesting Model via Incremental Learning and Continuous Power Quality Optimization process is discussed in this text. The proposed model initially uses a Q-Learning based power evaluation method, that is capable of generating high-efficiency configurations of multisource harvesting devices. This is cascaded with design of a Particle Swarm Optimizer (PSO), that assists in performing continuous power quality optimizations. The combined model is capable of selecting hybrid harvesting source configurations, and incrementally tune it for optimum harvesting performance. This is achieved via modelling a reward function that incorporates power gain along with low-complexity source selection process. The selection process is further enhanced via PSO based continuous learning for improving harvesting source configurations. The proposed model was tested on a wide variety of network scenarios, and its QoS efficiency levels were compared with different state-of-the-art methods. Based on this comparison, it was observed that the proposed model is capable of improving power gain by 8.3%, while minimizing harvesting delay by 6.5%, and improving harvesting throughput by 5.9%, which makes it useful for large-scale multisource harvesting applications.

Synergy Unleashed: Piezo–Tribo Hybrid Harvester for Sustainable Power Generation Toward Augmented and Virtual Reality Applications

Recently, piezo–tribo hybrid nanogenerators are developed using the synergistic effect. Exploration of multi‐crystalline piezoelectric materials adds the advantage of mechanically to electrically converting hybrid systems. On the way, the multi‐crystalline 0.3Ba0.7Ca0.3TiO3–0.7BaSn0.12Ti0.88O3 (BCST) materials are characterized by the structural, vibrational, and ferroelectric properties. The synergistic effect‐based polydimethylsiloxane/BCST hybrid composite film is prepared for multi‐energy harvesting. The triboelectric nanogenerator produces a maximum output voltage of 210 V. The hybrid device obtains the maximum output performance of 326 V. The harvested energy is used to charge commercial capacitors and power low‐power electronics. The signal processing and analysis unit is constructed for monitoring or functioning in real‐time finger movement. In the future, this kind of system can be coupled with augmented and virtual reality applications.

Synergistic Effect of Carbon Nanotube Yarn Hybrid Energy Harvesters Based on Mechanical Stretching and Glucose

Energy harvesting, as a sustainable power source for implantable medical devices within the human body, is an intriguing area of research. The utilization of biochemical and biomechanical energy derived from the body offers a promising sustainable energy source. However, obtaining high power density in vivo is a challenge. Herein, energy harvesting is demonstrated using hybrid energy harvesters that simultaneously use mechanical energy from stretching and chemical energy from glucose. The hybrid energy harvesters operate as both biofuel cells (BFC) and mechano‐electrochemical energy harvesters (MEEH) within a single electrochemical cell. As a result, the hybrid energy harvesters offer a maximum power density of 17.8 W kg−1 and an average power density of 15.1 W kg−1. These values increase by 14.5% in maximum power density and 16.8% in average power density, compared to the sum of the power density obtained by mechanical stretching and glucose oxidation individually. Based on their improved performance and compact size, owing to the synergistic effect of the two electrochemical harvesting methods, these hybrid harvesters have the potential to be applied to implantable power sources.

Hybrid harvesting of wind and wave energy based on triboelectric-piezoelectric nanogenerators

Triboelectric nanogenerator (TENG) is an emerging energy harvesting technology that can effectively convert various forms of environmental mechanical energy, including oceanic wind, wave energy, seawater temperature difference energy and others. However, the ocean environment is unstable and lacks a long-term steady state of energy. This leads to low energy harvesting efficiency for existing devices based on triboelectric nanogenerators. To solve this challenge, a hybrid harvesting device based on triboelectric-piezoelectric nanogenerators has been proposed to harvest both wind and wave energy. The device comprises three energy harvesting modules: wind energy harvesting triboelectric nanogenerator (WD-TENG), wind energy harvesting pizeoelectric nanogenerator (WD-PENG) and wave energy harvesting triboelectric nanogenerator (WE-TENG), all of which can work together or independently. This provides a significant improvement in the technical reliability of micro-nano energy harvesting technology in the ocean and other unstable environments. In a simulated environment, each module generates 3.975 mW, 1.160 mW and 0.2925 mW of electricity and the corresponding power density is 5.064 W/m3, 1.478 W/m3 and 1.092 W/m3. With the help of an energy collection circuit, the device powers LEDs, temperature and humidity sensors. This innovative solution offers new possibilities for self-sustaining ocean sensors and electronics, and may be widely applied in the next generation of the Internet of Underwater Things (IoUT).

Unlocking the Potential: Impact of Plant Growth Regulators on Hybrid Rice Growth, Grain Yield and Harvest Index

Aim: This research focused on rice, especially in Asia, and examined how plant growth regulators, including hormones and synthetic compounds, affect crucial plant processes. The findings strongly support the use of foliar Indole-3-Acetic Acid (IAA) application to enhance hybrid rice growth, grain yield, and harvest index, promising advancements in agriculture.
 Study Design: Randomised Block Design with 11 treatments.
 Place and Duration of Study: The study, conducted at the Student Instructional Farm of C. S. Azad University of Agriculture & Technology in Kanpur, aimed to investigate the impact of foliar application of plant growth regulators on rice growth and yield during 2021 and 2022.
 Methodology: The experiment employed a rigorous randomized block design, testing various treatments involving the foliar application of IAA (25 & 50 ppm), IBA (25 & 50 ppm), NAA (25 & 50 ppm), Ascorbic Acid (50 & 100 ppm), and Kinetin (5 & 10 ppm). The profound effects of these different regulator concentrations were observed at key developmental stages, including tillering, anthesis, dough, and maturity.
 Results: Significant improvements in growth parameters, such as leaf and stem dry weights per plant, along with total leaf area per plant, were evident with the application of IAA at 50 ppm. Moreover, a notable increase in grain yield per plant and harvest index was observed at maturity, primarily with the foliar spray of IAA at 50 ppm, followed closely by IAA at 25 ppm. This consistent trend was also observed in yield-related attributes.
 Conclusion: The use of Indole-3-acetic acid (IAA) significantly impacted plant growth and yield, including leaf and stem dry weights, leaf area, grain yield, and harvest index, showing promise for enhancing hybrid rice production.

A Hybrid Solar-RF Energy Harvesting System Based on an EM4325-Embedded RFID Tag

This paper presents the deployment of a hybrid energy harvesting system that combines a wireless energy harvesting (EH) system and a 6 V, 170 mA monocrystalline solar energy derived from the Sun’s rays. The hybrid energy harvesting (HEH) system comprises the rectifier, the solar cell panel, the charging circuit, and the EM4325 embedded RFID tag. This study aims to design an efficient EH system capable of increasing the read range of an active RFID tag. The proposed approach integrates a meandered line radio frequency identification (RFID) tag with an EM4325 IC chip as the receiver antenna. A halfwave doubler RF rectifier circuit is connected to the antenna using a 50 Ω SMA connector to convert the captured RF waves into usable electrical power. A solar energy charging module equipped with a Maximum Power Point Tracking (MPPT) system, a rechargeable lithium-ion battery, and a DC-DC converter is configured to manage and store the harvested energy efficiently. The UHF tag antenna operates at 919 MHz, achieving a peak gain of 3.54 dB. The proposed rectenna achieves a maximum measured harvested power conversion efficiency (PCE) of 55.14% for an input power (Pin) of 15 dBm at a distance of 5.10 cm, while the solar cell panel realizes 3.92 W of power. Experimental results demonstrate the hybrid harvester system’s effectiveness, achieving a PCE of 86.49% at an output voltage (VDC) of 5.35 V. The main advantage of this approach is the creation of a compact hybrid RF and solar EH system by combining the solar cell panel with the antenna, thus enabling multi-functionality.

A Self-Powered Interface Circuit for Simultaneous Piezoelectric and Electromagnetic Energy Extraction

A self-powered circuit for the combination of synchronized electric charge extraction (SECE) and synchronous magnetic flux extraction (SMFE) interfaces (SP-SECE-SMFE) is proposed, which can simultaneously extract energy from piezoelectric transducer (PZT) and electromagnetic transducer (EMT). It reveals that when the energy extraction time of PZT and EMT is consistent, the electromagnetic energy harvested by SP-SECE-SMFE is greatly improved due to the action of the pulse piezoelectric voltage, and demonstrates how to use a resistance to adjust the energy extraction time of PZT. Simulation results show that the output power of SP-SECE-SMFE for the hybrid harvesting of piezoelectric and electromagnetic energy is 1.4-2.4 times higher than that of the sum when they are harvested separately under different frequencies and loads. Experimental results show that the maximum output power achieved by SP-SECE-SMFE is 1.7 times higher than that of the sum when are they harvested by the self-powered circuits of SECE and SMFE respectively, and is 2.2 times higher than that of the half-bridge rectifier circuit. The simulation and experimental results show the superiority of the proposed SP-SECE-SMFE circuit.

Are piezoelectric-electromagnetic hybrid energy harvesting systems beneficial?

The primary objective of this work is to investigate the performance of a hybrid energy harvesting system consisting of piezoelectric and electromagnetic transducers. We first show that a single–mechanism generator with negligible electrical losses, referred to as an electrically-lossless harvester, can reach the theoretical power bound regardless of the coupling strength between the mechanical and electrical domains, which renders the use of hybrid systems unnecessary. For a more realistic analysis, the electrically parasitic losses are then taken into account. We introduce effective figures of merit for the piezoelectric and electromagnetic generators that combine transducer coupling and resistive losses. The maximum output power of single-transducer and hybrid systems are determined analytically, expressed as functions of effective figures of merit. We find that there is no benefit to utilizing a hybrid system if one of the two, or both, effective figures of merit exceeds a threshold of . We also derive the narrow conditions under which a resonant hybrid harvester system with multiple transduction mechanisms can outperform its counterpart which uses a single energy conversion. In order to provide a comprehensive assessment of the configurations considered, we analyze the relationships between optimizing system efficiency and maximizing output power. We reveal that the two problems generally yield different solutions. However, for a hybrid structure, these objectives result in a unique solution when the effective figures of merit of the two transductions are equal. This is a distinctive property of a hybrid system compared to a single-mechanism device.

Dual-functional synergetic energy harvesting and flow-induced vibration control of an electromagnetic-based square cylinder integrated with a flexible bimorph piezoelectric wake splitter plate

A dual-purpose FIV-based hydroelastic energy harvesting and cylinder response suppression strategy that functions based on the synergy of piezoelectric and electromagnetic transduction (EMT) mechanisms is proposed and numerically implemented. The hybrid harvester consists of a linearly sprung (1DOF) square cylinder fitted on the wake side with a thin flexural-mode cantilever bimorph piezoelectric (PVDF) splitter plate in real-time collaboration with a transversely hooked induction-based magnet-coil type transducer. The Reynolds averaged Navier–Stokes (RANS) equations with the shear stress transport (SST) k-ω turbulence closure model are selected for qualitative/quantitative prediction of hydrodynamic flow behavior in a relatively wide Reynolds numbers range. Numerical simulations show that increasing Reynolds number for the single-alone EMT-equipped cylinder in the low to intermediate range (2×103≤Re≤3×104) can noticeably improve the system hydrokinetic energy harvesting performance where a distinct coupled VIV/galloping effect is observed. Also, the hybrid piezoelectromagnetic harvester is capable of effectively suppressing the key response parameters and considerably increase the total system electrical output in an extended working bandwidth (3×104<Re≤4×105). In particular, in contrast to the conventional fixed-base cylinder configurations, maximum power extraction can be achieved over most span of the flexible piezoelectric splitter plate at Re=4×105 where the flapping oscillations of splitter plate synchronizes with the downstream alternating wake vortices.

Plucking and linear-to-rotary hybrid harvester for low-amplitude vibrations of high-speed railway with an innovative three-step amplification mechanism

By harvesting the pervasive vibration energy, self-powered wireless sensor network (WSN) installed along the track can play an important role in structure health monitoring of high-speed railway. However, a considerable part of vibration energy of the rail is difficult to be harvested due to the characteristics of ultra-low frequency, small amplitude and large load. A hybrid frequency up-conversion energy harvester is designed and optimized in this paper aiming to address this critical problem. By utilization of a unique three-step amplification design for reducing inefficient transmission due to the possible gap of gear or ball-screw systems, high-efficient energy harvesting is realized for the small-amplitude excitation with both electromagnetic and piezoelectric conversion structures. The experiment results verify that the gapless amplification achieved by the flexible hinge structure as the first-step mechanism is effective for solving the gap issue. Compared with harvesters without the flexible hinges, the power is 250% higher under an excitation of low frequency (5 Hz) and ultra-small amplitude (0.3 mm). Moreover, based on the hybrid energy harvesting mechanism, more appreciable energy is obtained by introducing the plucking piezoelectric structure in addition to the electromagnetic unit.

A hybrid vibration energy harvester with integrated piezoelectric and electrostatic devices

In recent years, energy harvesting technology has become a promising power supply method for low-power wireless sensor nodes. According to the application requirements of energy acquisition, a piezoelectric and electrostatic hybrid vibration energy harvester (HVEH) is proposed in this paper. Compared with other vibration energy harvesters, the proposed hybrid harvester is easier to miniaturize and integrate into a MEMS. The electromechanical coupling model of the hybrid harvester is established. The optimal design of the proposed harvester is carried out based on numerical simulation. The optimal matching impedance of piezoelectric and electrostatic modules are calculated based on numerical simulation and validated through experiments, which are 80–90 kΩ and 15–20 MΩ, respectively. The output power of the HVEH is increased by 0.04%, 0.08%, 0.102%, and 0.097%, when the excitation acceleration is 0.1 g, 0.15 g, 0.2 g, and 0.25 g, respectively, compared with the single piezoelectric module.

Aerodynamic performance improvements for a Savonius turbine above a forward-facing step via inclined solar panel: A computational study

The transformation of urban energy structure is an urgent problem to be solved in sustainable construction. To fully exploit and utilise renewable energy, this study proposes a novel wind–solar energy hybrid harvesting system that combines an inclined solar panel and a Savonius wind turbine installed on a building roof. The effects of the tilt angle of the solar panels and tip speed ratios (TSRs) on the aerodynamic performance of the turbine were investigated using high-fidelity large-eddy simulations (LES) at a Reynolds number of Re = 4.45 × 105. Five tilt angles in the range of 30°–60° were tested, and the range of TSR was 0.2–1.6. For comparison, two other installation cases were also studied, including the case of a Savonius turbine alone and the case of a single Savonius turbine placed at a fixed height position on a forward-facing step. The results showed that the power coefficient of the Savonius turbine increased and then decreased with tilt angle or TSR. When TSR = 1, the power coefficient in the system reached a maximum value of Cpmax = 0.638 at a tilt angle of 45°, 254.4% and 11.7% higher than those of the other two installation cases, respectively. The flow-field comparison results reveal why the proposed system can improve the energy harvesting efficiency. The presence of a solar panel with a suitable tilt angle increases the velocity and volume of the airflow hitting the advancing blade, creating a greater pressure difference around the blades that is caused mainly by the decrease in the low pressure on the concave surface of the advancing blade. Thus, the net torque applied to the turbine blades increases, which is conducive to driving turbine rotation. The proposed system is beneficial for improving the aerodynamic performance of Savonius turbines and the utilisation of renewable energy in urban areas.