scholarly journals Evaluating Energy Generation Capacity of PVDF Sensors: Effects of Sensor Geometry and Loading

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1895
Author(s):  
Mohammad Uddin ◽  
Shane Alford ◽  
Syed Mahfuzul Aziz

This paper focuses on the energy generating capacity of polyvinylidene difluoride (PVDF) piezoelectric material through a number of prototype sensors with different geometric and loading characteristics. The effect of sensor configuration, surface area, dielectric thickness, aspect ratio, loading frequency and strain on electrical power output was investigated systematically. Results showed that parallel bimorph sensor was found to be the best energy harvester, with measured capacitance being reasonably acceptable. Power output increased with the increase of sensor’s surface area, loading frequency, and mechanical strain, but decreased with the increase of the sensor thickness. For all scenarios, sensors under flicking loading exhibited higher power output than that under bending. A widely used energy harvesting circuit had been utilized successfully to convert the AC signal to DC, but at the sacrifice of some losses in power output. This study provided a useful insight and experimental validation into the optimization process for an energy harvester based on human movement for future development.

Author(s):  
Y. Yang ◽  
J. Y. Chang ◽  
L. P. Wang

The photon transport and energy conversion of a near-field thermophotovoltaic (TPV) system with a selective emitter composed of alternate tungsten and alumina layers and a photovoltaic cell sandwiched by electrical contacts are theoretically investigated in this paper. Fluctuational electrodynamics along with the dyadic Green’s function for a multilayered structure is applied to calculate the spectral heat flux, and photocurrent generation and electrical power output are solved from the photon-coupled charge transport equations. The tungsten and alumina layer thicknesses are optimized to match the spectral heat flux with the bandgap of TPV cell. The spectral heat flux is much enhanced when plain tungsten emitter is replaced with the multilayer emitter due to the mechanism of surface plasmon polariton coupling in the tungsten thin film. In addition, the invalidity of effective medium theory to predict photon transport in the near field with multilayer emitters is discussed. Effects of a gold back reflector and indium tin oxide front coating with nanometer thickness, which could practically act as the electrodes to collect the photon-generated charges on the TPV cell, are explored. Conversion efficiency of 23.7% and electrical power output of 0.31 MW/m2 are achieved at 100 nm vacuum gap when the emitter and receiver are respectively at temperatures of 2000 K and 300 K.


Author(s):  
Mohamad Modrek ◽  
Ali Al-Alili

Photovoltaic thermal collectors (PVT) combines technologies of photovoltaic panels and solar thermal collectors into a hybrid system by attaching an absorber to the back surface of a PV panel. PVT collectors have gained a lot of attention recently due to the high energy output per unit area compared to a standalone system of PV panels and solar thermal collectors. In this study, performance of a liquid cooled flat PVT collector under the climatic conditions of Abu Dhabi, United Arab Emirates was experimentally investigated. The electrical performances of the PVT collector was compared to that of a standalone PV panel. Moreover, effect of sand accumulation on performance of PVT collectors was examined. Additionally, effect of mass flow rate on thermal and electrical output of PVT collector was studied. Electrical power output is slightly affected by changes in mass flow rate. However, thermal energy increased by 22% with increasing flow rate. Electrical power output of a PV panel was found to be 38% lower compared to electrical output of PVT collectors. Dust accumulation on PVT surface reduced electrical power output up to 7% compared with a reference PVT collector.


2018 ◽  
Vol 171 ◽  
pp. 02002
Author(s):  
Elie Karam ◽  
Patrick Moukarzel ◽  
Maya Chamoun ◽  
Charbel Habchi ◽  
Charbel Bou-Mosleh

Due to global warming and the high toxic gas emissions of traditional power generation methods, renewable energy has become a very active topic in many applications. This study focuses on one versatile type of solar energy: Hybrid Photovoltaic Thermal System (hybrid PV/T). Hybrid PV/T combines both PV and thermal application and by doing this the efficiency of the system will increase by taking advantage of the temperature loss from PV module. The solar radiation and heat will be harnessed to deliver electricity and hot water simultaneously. In the present study a solar system is designed to recycle the heat and improve the temperature loss from PV module in order to supply both electricity and domestic hot water. The project was tested twice in Zouk Mosbeh - Lebanon; on May 18, 2016, and June 7, 2016. The average electrical efficiency was around 11.5% with an average electrical power output of 174.22 W, while with cooling, the average electrical efficiency reaches 11% with a power output of 200 W. The temperature increases by about 7 degrees Celsius from the inlet. The 1D conduction model is also performed in order to design the hybrid PV/T system.


Author(s):  
Abbas F. Jasim ◽  
Hao Wang ◽  
Greg Yesner ◽  
Ahmad Safari ◽  
Pat Szary

This study investigated the energy harvesting performance of a piezoelectric module in asphalt pavements through laboratory testing and multi-physics based simulation. The energy harvester module was assembled with layers of Bridge transducers and tested in the laboratory. A decoupled approach was used to study the interaction between the energy harvester and the surrounding pavement. The effects of embedment location, vehicle speed, and temperature on energy harvesting performance were investigated. The analysis findings indicate that the embedment location and vehicle speed affects the resulted power output of the piezoelectric energy harvesting system. The embedment depth of the energy module affects both the magnitude and frequency of stress pulse on top of the energy module induced by tire loading. On the other hand, higher vehicle speed causes greater loading frequency and thus greater power output; the effect of pavement temperature is negligible. The analysis of total power output before reaching fatigue failure of the energy module can be used to determine the optimum embedment location in the asphalt layer. The proposed energy harvesting system provides great potential to generate green energy from waste kinetic energy in roadway pavements. Field study is recommended to verify these findings with long-term performance monitoring of pavement with embedded energy harvesters.


Author(s):  
Nathan Tom

This paper begins with a brief review of the time-domain equation of motion for a generic floating body. The equation of motion of the floating body was modified to account for the influence of a power-take-off unit (PTO) to predict the hydrodynamic and electromechanical performance of the coupled system. As the damping coefficient is considered the dominant contribution to the PTO reaction force, the optimum non time-varying damping values were first presented for all frequencies, recovering the well-known impedance-matching principle at the coupled resonance frequency. In an effort to further maximize power absorption in both regular and irregular wave environments, nonlinear model predictive control (NMPC) was applied to the model-scale point absorber developed at UC Berkeley. The proposed NMPC strategy requires a PTO unit that could be turned on and off instantaneously, leading, interestingly to electrical sequences where the generator would be inactive for up to 60% of the wave period. In order to validate the effectiveness of this NMPC strategy, an in-house designed permanent magnet linear generator (PMLG) was chosen as the PTO. The time-varying performance of the PMLG was first characterized by dry-bench tests, using mechanical relays to control the electromagnetic conversion process. Following this, the physical set-up was transferred to the wave tank. The on/off sequencing of the PMLG was tested under regular and irregular wave excitation to validate NMPC simulations using control inputs obtained from running the control algorithm offline. Experimental results indicate that successful implementation was achieved and the absorbed power using NMPC was up to 50% greater than the passive system, which utilized no controller. However, after considering the PMLG mechanical-to-electrical conversion efficiency the useful electrical power output was not consistently maximized. To improve output power, a mathematical relation between the efficiency and damping magnitude of the PMLG was inserted in the system model to maximize the electrical power output through continued use of NMPC. Of significance, results from these latter simulations provided a damping time series that was active over a larger portion of the wave period and required the actuation of the applied electrical load connected to the PMLG, rather than a simple on/off type control.


Author(s):  
Edwar Romero ◽  
Michael R. Neuman ◽  
Robert O. Warrington

Energy harvesting from environmental sources such as motion, light, and temperature changes, has been demonstrated with commercially viable products (such as human-powered flashlights, solar-powered calculators, and thermal-powered wristwatches). Vibration or motion is an attractive environmental energy source due to its abundance and availability. A new electromagnetic energy harvester presented here is found to be capable for scavenging energy from human motion. The electrical power output of an inertial energy scavenger is proportional to the acceleration-squared-to-frequency (ASTF) and the quality (Q) factor. Human motion is associated with large ASTF values and low Q factors while machine vibrations are usually related with the opposite. Thus, passive energy harvesting from human activities could generate as much power as the one available from machine harvesters. The limit for such inertial generator is estimated to be on the order of 1mW/cm3. This paper reviews the energy harvesting limits, the energy generation from human activities, and the development of a new oscillating electromagnetic generator. This energy harvester is built with a permanent magnet (PM) ring with multiple poles and a gear-shaped planar coil. The PM ring has attached an eccentric proof mass for converting external movement into oscillations or rotations, these oscillations induce an electrical potential on the planar coil. As much as 3.45μW of power have been generated with a prototype at a frequency of 2.7Hz on a laboratory shaker and 2.35μW had been obtained when positioned laterally on the hip while walking.


INSIST ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 81
Author(s):  
Adhy Prayitno ◽  
Muhammad Irvan ◽  
Sigit Nurharsanto ◽  
Wahyu Fajar Yantoa

Observations and measurements have been conducted towards a solar panel electric power output that is utilized by a solar tracking system. The electrical power output depends on the position of the sun and time and the direction of the panel surface against the angle of the incident light. For power optimization, the solar panel surface should always be directed perpendicular to the direction of the sunlight falling to the surface of the panel. The application of the solar tracking system controlled by a micro controller gives the expected results. The electrical power output of a static solar panel mounted on a fixed position becomes the benchmark of the output electric power value in this study. The measurement results of the electric power output of the solar panel with sun tracking system shows a significant increase in sunny weather conditions.The average increase of that is about 57.3%.Keywords: LDR, micro controller, optimal power output, performance improvment, sun tracking,


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