Spray-on thermoelectric energy harvester

MRS Advances ◽  
2018 ◽  
Vol 4 (15) ◽  
pp. 851-855 ◽  
Author(s):  
Robert E. Peale ◽  
Seth Calhoun ◽  
Nagendra Dhakal ◽  
Isaiah O. Oladeji ◽  
Francisco J. González

AbstractThermoelectric (TE) thin films have promise for harvesting electrical energy from waste heat. We demonstrate TE materials and thermocouples deposited by aqueous spray deposition on glass. The n-type material was CdO doped with Mn and Sn. Two p-type materials were investigated, namely PbS with co-growth of CdS and doped with Na and Na2CoO4. Seebeck coefficients, resistivity, and power generation for thermocouples were characterized.

2012 ◽  
Vol 185 ◽  
pp. 77-80 ◽  
Author(s):  
Marcus Chiang Mun Leong ◽  
Fabian Chiang Mun Chun ◽  
Jae Lee Kai Wei ◽  
Peng Qi Zhen ◽  
Ye Ko San ◽  
...  

Recently, thermoelectric thin films have been gaining attention as potential thermoelectric generators that can be used to power external devices. Such films can recover electrical energy from waste heat and are environmentally friendly. Micro fabrication of thin films is achieved by sputtering on silicon films. In this study, the sputtering of Bismuth Telluride (N-type, P-type) films was investigated. Research has verified the efficiency of Bismuth Telluride films, but little is known about how the sputtering process affects the film's quality. Thus, the focus of this study explores how sputtering parameters of discontinuous sputtering intervals, exposure to normal atmospheric conditions and in situ annealing affect the thickness, thermoelectric properties, and microstructure of films. This will bring about a better understanding of the relationship between the sputtering process and the properties of the produced film for both N and P type materials. Recommendations based on this study can contribute to the production of more efficient thin films suitable for energy harvest application.


Thermoelectric energy harvester is known as a type of energy harvesting technologies which extracts waste heat from a target device or object to generate electrical power. The low power generation from thermoelectric energy harvester, though, is always a critical consideration in designing a self-sustaining system. The energy harvesting system is usually aided by a power management solution to further enhance the power generation for better performance. Therefore, maximizing the power generated from the thermoelectric sensor itself is essential in order to select the most suitable power management approach. This paper presumed the methodology to maximize power generation of thermoelectric and further discussion is reviewed in the report.


Author(s):  
Kyoung Joon Kim

A thermoelectric energy recovery module (TERM) is proposed. The TERM seeks to generate electrical energy from waste heat of power amplifier transistors. The TERM consists of a thermoelectric generator (TEG), a heat spreader, and a heat sink. A fully-coupled thermoelectric (TE) model of the TERM is developed to predict the power generation and the thermal performance of the TERM. A first order prototype of the TERM and a measurement setup are constructed to demonstrate the TERM performance. Power generation values and junction temperatures of a heat source are measured at various source heat flows. The measured results are used to verify the predicted results and to demonstrate the TERM performance. Load resistance effects to the TERM performance are also investigated utilizing the TE model and the measurement setup.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4561 ◽  
Author(s):  
Nguyen T. Hung ◽  
Ahmad R. T. Nugraha ◽  
Riichiro Saito

Thermoelectric (TE) material is a class of materials that can convert heat to electrical energy directly in a solid-state-device without any moving parts and that is environmentally friendly. The study and development of TE materials have grown quickly in the past decade. However, their development goes slowly by the lack of cheap TE materials with high Seebeck coefficient and good electrical conductivity. Carbon nanotubes (CNTs) are particularly attractive as TE materials because of at least three reasons: (1) CNTs possess various band gaps depending on their structure, (2) CNTs represent unique one-dimensional carbon materials which naturally satisfies the conditions of quantum confinement effect to enhance the TE efficiency and (3) CNTs provide us with a platform for developing lightweight and flexible TE devices due to their mechanical properties. The TE power factor is reported to reach 700–1000 W / m K 2 for both p-type and n-type CNTs when purified to contain only doped semiconducting CNT species. Therefore, CNTs are promising for a variety of TE applications in which the heat source is unlimited, such as waste heat or solar heat although their figure of merit Z T is still modest (0.05 at 300 K). In this paper, we review in detail from the basic concept of TE field to the fundamental TE properties of CNTs, as well as their applications. Furthermore, the strategies are discussed to improve the TE properties of CNTs. Finally, we give our perspectives on the tremendous potential of CNTs-based TE materials and composites.


2013 ◽  
Vol 1490 ◽  
pp. 185-190 ◽  
Author(s):  
Tomoyuki Nakamura ◽  
Kazuya Hatakeyama ◽  
Masahiro Minowa ◽  
Youhiko Mito ◽  
Koya Arai ◽  
...  

ABSTRACTThermoelectric power generation has been attracting attention as a technology for waste heat utilization in which thermal energy is directly converted into electric energy. It is well known that layered cobalt oxide compounds such as NaCo2O4 and Ca3Co4O9 have high thermoelectric properties in p-type oxide semiconductors. However, in most cases, the thermoelectric properties in n-type oxide materials are not as high. Therefore, n-type magnesium silicide (Mg2Si) has been studied as an alternative due to its non-toxicity, environmental friendliness, lightweight property, and comparative abundance compared with other TE systems. In this study, we fabricated π-structure thermoelectric power generation devices using p-type NaCo2O4 elements and n-type Mg2Si elements. The p- and n-type sintering bodies were fabricated by spark plasma sintering (SPS). To reduce the resistance at the interface between elements and electrodes, we processed the surface of the elements before fabricating the devices. The end face of a Mg2Si element was covered with Ni by SPS and that of a NaCo2O4 element was coated with Ag by silver paste and soldering.The thermoelectric device consisted of 18 pairs of p-type and n-type legs connected with Ag electrodes. The cross-sectional and thickness dimensions of the p-type elements were 3.0 mm × 5.0 mm × 7.6 mm (t) and those of the n-type elements were 3.0 mm × 3.0 mm × 7.6 mm (t). The open circuit voltage was 1.9 V and the maximum output power was 1.4 W at a heat source temperature of 873 K and a cooling water temperature of 283 K in air.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amrit P. Sharma ◽  
Makhes K. Behera ◽  
Dhiren K. Pradhan ◽  
Sangram K. Pradhan ◽  
Carl E. Bonner ◽  
...  

AbstractOne of the ways to mitigate the world energy crisis is to harvest clean and green energy from waste-heat, which is abundant, ubiquitous, and free. Energy harvesting of this waste-heat is one of the most encouraging methods to capture freely accessible electrical energy. Ferroelectric materials can be used to harvest energy for low power electronic devices, as they exhibit switchable polarization, excellent piezoelectric and pyroelectric properties. The most important characteristic of ferroelectric materials, in the context of energy harvesting, is their ability to generate electric power from a time-dependent temperature change. In this work, we grew highly c-axis oriented heterostructures of BaZr0.2Ti0.8O3 (barium zirconium titanate, BZT)/Ba0.7Ca0.3TiO3 (barium calcium titanate, BCT) on SrRuO3 (strontium ruthenate, SRO) and deposited on SrTiO3 (strontium titanate, STO) single crystalline substrate using pulsed laser deposition (PLD) technique. We investigated the structural, electrical, dielectric, and pyroelectric properties of the above-mentioned fabricated heterostructures. The wide range of θ–2θ X-ray diffraction (XRD) patterns only shows (00l) reflection peaks of heterostructures and the substrate which confirmed that the films are highly c-axis oriented. We are also capable to convert the low-grade waste-heat into electrical energy by measuring various temperature-dependent ferroelectric hysteresis loops of our nanostructure films via pyroelectric Ericsson cycles and the structures show an energy conversion density ~ 10,970 kJ/m3 per cycle. These devices exhibit a large pyroelectric current density of ~ 25 mA/m2 with 11.8 °C of temperature fluctuation and the corresponding pyroelectric coefficient of 3425 μC/m2K. Our research findings suggest that these lead-free relaxor-ferroelectric heterostructures might be the potential candidates to harvest electrical energy from waste low-grade thermal energy.


2019 ◽  
Vol 109 ◽  
pp. 00066
Author(s):  
Yurii Oksen ◽  
Olena Trofymova ◽  
Oleksandr Bobryshov ◽  
Anatolii Lukisha ◽  
Volodymyr Pryvalov

The schema for gas engine waste heat recovery to electrical power by dual circuit power generation unit with different working agents has been developed. The method and the most efficient power generation unit heat mode calculation algorithm under the conditions of the given restrictions on the temperature differences in the heat exchangers has been developed. Based on the mathematical modeling of heat modes it has been stated that 4200 kW of heat power can be utilized to generate 520 kW of electrical power for JMS 620 gas engine. It has been calculated that the efficiency of secondary heat recovery to electrical power reaches 12.3 % which leads general efficiency increase for a gas engine from 42.9 up to 50.0 %.


Author(s):  
O. Aldraihem ◽  
A. Baz

The onset of self-excited oscillations is developed theoretically for a traveling wave thermo-acoustic-piezoelectric (TAP) energy harvester. The harvester is intended for converting thermal energy, such as solar or waste heat energy, directly into electrical energy without the need for any moving components. The thermal energy is utilized to generate a steep temperature gradient along a porous stack. At a specific threshold of the temperature gradient, self-sustained acoustic waves are generated inside an acoustic resonator. The resulting pressure fluctuations excite a piezoelectric diaphragm, placed at the end of the resonator, which converts the acoustic energy directly into electrical energy. The pressure pulsations are amplified by using an acoustic feedback loop which introduces appropriate phasing that make the pulsations take the form of traveling waves. Such traveling waves render the harvester to be inherently reversible and thus highly efficient. The behavior of this class of harvesters is modeled using the lumped-parameter approach. The developed model is a multi-field model which combines the descriptions of the acoustic resonator, feedback loop, and the stack with the characteristics of the piezoelectric diaphragm. A new method is proposed here to analyze the onset of self-sustained oscillations of the traveling wave engine using the classical control theory. The predictions of the developed models are validated against published results. Such models present invaluable tools for the design of efficient thermo-acoustic-piezoelectric (TAP) energy harvesters and engines.


2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Michael Bittner ◽  
Benjamin Geppert ◽  
Nikola Kanas ◽  
Sathya Prakash Singh ◽  
Kjell Wiik ◽  
...  

AbstractA thermoelectric generator couples an entropy current with an electrical current in a way, that thermal energy is transformed to electrical energy. Hereby the thermoelectric energy conversion can be described in terms of fluxes of entropy and electric charge at locally different temperature and electric potential. Crucial for the function of a thermoelectric generator is the sign and strength of the coupling between the entropy current and the electrical current in the thermoelectric materials. For high-temperature application, tin-doped indium oxide (In


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