618 research outputs found
Analysis of Potential and Efficiency of Electric Generation Using Thermoelectric Effect
This research identifies the electrical potential associated with Thermoelectric Generators (TEG) under the incidence of solar rays and performs efficiency comparison using this type of devices and those photovoltaic. TEG characterization and modeling is presented to favor the estimation of the electrical potential, defined as power density (W/m2). The proper operation of thermal harvesting lays in maintaining a temperature difference of at least 26.31K between the TEG sides. With this requirement fulfilled, power conversion eficiencies of about 26.43% are obtained, higher than that of high-quality solar panels and without efficiency reductions associated with heating and soiling, while keeping the same superficial area of only 16cm 2. An estimate of at least 407.3mW corresponding to 2.44Wh of available energy is found considering specific operation hours determined statistically for a given geographic location. Thus, given such performance metric, a complete power unit is devised complementing the thermoelectric energy harvesting with a Li-Po battery to guarantee in that way a continuous operation. The total energy available from the prototype allows maintaining a battery discharge percentage of 38.05% considering the energy budget of a low-power remote sensor.MaestríaMagister en Ingeniería Electrónic
Review of Safety Evaluation of Thermal Wearable Power Harvesting Device
Thermal wearable power harvesting device is developing fast nowadays. The increasing demand on simple and easily handled devices forcing researches to find a better on improving the performance and safety of the devices. Thermal power harvesting is using the heat from the surrounding and human body to generate power. So, the safety precaution needs to be taken in order to keep it safe to use. This paper reviews the use of wearable technology, the basic concept, methods and future of power harvesting technology, ideas of thermoelectric power generators and its related work as well the safety evaluation for international standard of wearable devices
A Survey of Energy Harvesting Sources for IoT Device
Environmental Energy is an alternative energy for wireless devices. A Survey of Energy Harvesting Sources for IoT Device is proposed. This paper identifies the sources of energy harvesting, methods and power density of each technique. Many reassert have carried to extract energy from environment. The IoT and M2M are connected through internet or local area network and these devices come with batteries. The maintenance and charging of batteries becomes tedious due to thousands of device are connected. The concept of Energy harvesting gives the solution for powering IoT, M2M, Wireless nodes etc. The process of extracting energy from the surrounding environment is termed as energy harvesting and derived from windmill and water wheel, thermal, mechanical, solar
A review of commercial energy harvesters for autonomous sensors
Current commercial autonomous sensors are mainly powered by primary batteries. Batteries need to be replaced and hence can become the largest and most expensive part of the system.
On the other hand, our environment is full of waste and unused energy such as that coming from the sun or mechanical vibrations.
As a result, commercial energy harvesters are increasingly available to power autonomous sensors. This work presents and analyses commercial energy harvesters currently available. First, environmental energy sources are classified and described. Then,
energy harvesting principles are described and some guidelines are given to calculate the maximum power consumption allowed and the
energy storage capacity required for the autonomous sensor.
Finally, commercial energy harvesters are evaluated to determine their capability to power a commercial autonomous sensor in some
given circumstances
Energy autonomous systems : future trends in devices, technology, and systems
The rapid evolution of electronic devices since the beginning of the nanoelectronics era has brought about exceptional computational power in an ever shrinking system footprint. This has enabled among others the wealth of nomadic battery powered wireless systems (smart phones, mp3 players, GPS, …) that society currently enjoys. Emerging integration technologies enabling even smaller volumes and the associated increased functional density may bring about a new revolution in systems targeting wearable healthcare, wellness, lifestyle and industrial monitoring applications
Energy Harvesting Technologies for Achieving Self-Powered Wireless Sensor Networks in Machine Condition Monitoring:A Review
Condition monitoring can reduce machine breakdown losses, increase productivity and operation safety, and therefore deliver significant benefits to many industries. The emergence of wireless sensor networks (WSNs) with smart processing ability play an ever-growing role in online condition monitoring of machines. WSNs are cost-effective networking systems for machine condition monitoring. It avoids cable usage and eases system deployment in industry, which leads to significant savings. Powering the nodes is one of the major challenges for a true WSN system, especially when positioned at inaccessible or dangerous locations and in harsh environments. Promising energy harvesting technologies have attracted the attention of engineers because they convert microwatt or milliwatt level power from the environment to implement maintenance-free machine condition monitoring systems with WSNs. The motivation of this review is to investigate the energy sources, stimulate the application of energy harvesting based WSNs, and evaluate the improvement of energy harvesting systems for mechanical condition monitoring. This paper overviews the principles of a number of energy harvesting technologies applicable to industrial machines by investigating the power consumption of WSNs and the potential energy sources in mechanical systems. Many models or prototypes with different features are reviewed, especially in the mechanical field. Energy harvesting technologies are evaluated for further development according to the comparison of their advantages and disadvantages. Finally, a discussion of the challenges and potential future research of energy harvesting systems powering WSNs for machine condition monitoring is made
Energy Neutral Design of Embedded Systems for Resource Constrained Monitoring Applications
Automatic monitoring of environments, resouces and human processes are crucial and foundamental tasks to improve people's quality of life and to safeguard the natural environment. Today, new technologies give us the possibility to shape a greener and safer future. The more specialized is the kind of monitoring we want to achieve, more tight are the constraints in terms of reliability, low energy and maintenance-free autonomy. The challenge in case of tight energy constraints is to find new techniques to save as much power as possible or to retrieve it from the very same environment where the system operates, towards the realization of energy neutral embedded monitoring systems. Energy efficiency and battery autonomy of such devices are still the major problem impacting reliability and penetration of such systems in risk-related activities of our daily life. Energy management must not be optimized to the detriment of the quality of monitoring and sensors can not be operated without supply. In this thesis, I present different embedded system designs to bridge this gap, both from the hardware and software sides, considering specific resource constrained scenarios as case studies that have been used to develop solutions with much broader validity. Results achieved demonstrate that energy neutrality in monitoring under resource constrained conditions can be obtained without compromising efficiency and reliability of the outcomes
Energy harvesting towards self-powered iot devices
The internet of things (IoT) manages a large infrastructure of web-enabled smart devices, small devices that use embedded systems, such as processors, sensors, and communication hardware to collect, send, and elaborate on data acquired from their environment. Thus, from a practical point of view, such devices are composed of power-efficient storage, scalable, and lightweight nodes needing power and batteries to operate. From the above reason, it appears clear that energy harvesting plays an important role in increasing the efficiency and lifetime of IoT devices. Moreover, from acquiring energy by the surrounding operational environment, energy harvesting is important to make the IoT device network more sustainable from the environmental point of view. Different state-of-the-art energy harvesters based on mechanical, aeroelastic, wind, solar, radiofrequency, and pyroelectric mechanisms are discussed in this review article. To reduce the power consumption of the batteries, a vital role is played by power management integrated circuits (PMICs), which help to enhance the system's life span. Moreover, PMICs from different manufacturers that provide power management to IoT devices have been discussed in this paper. Furthermore, the energy harvesting networks can expose themselves to prominent security issues putting the secrecy of the system to risk. These possible attacks are also discussed in this review article
Review of Contemporary Energy Harvesting Techniques and Their Feasibility in Wireless Geophones
Energy harvesting converts ambient energy to electrical energy providing
numerous opportunities to realize wireless sensors. Seismic exploration is a
prime avenue to benefit from it as energy harvesting equipped geophones would
relieve the burden of cables which account for the biggest chunk of exploration
cost and equipment weight. Since numerous energies are abundantly available in
seismic fields, these can be harvested to power up geophones. However, due to
the random and intermittent nature of the harvested energy, it is important
that geophones must be equipped to tap from several energy sources for a stable
operation. It may involve some initial installation cost but in the long run,
it is cost-effective and beneficial as the sources for energy harvesting are
available naturally. Extensive research has been carried out in recent years to
harvest energies from various sources. However, there has not been a thorough
investigation of utilizing these developments in the seismic context. In this
survey, a comprehensive literature review is provided on the research progress
in energy harvesting methods suitable for direct adaptation in geophones.
Specifically, the focus is on small form factor energy harvesting circuits and
systems capable of harvesting energy from wind, sun, vibrations, temperature
difference, and radio frequencies. Furthermore, case studies are presented to
assess the suitability of the studied energy harvesting methods. Finally, a
design of energy harvesting equipped geophone is also proposed
High-performance, flexible thermoelectric generator based on bulk materials
the Centers for Mechanical Engineering Research and Education at MIT and SUSTec
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