Study on Pyroelectric Harvesters Integrating Solar Radiation with Wind Power

Chun-Ching Hsiao,An-Shen Siao,Jia-Wai Jhang

doi:10.3390/en8077465

Chun-Ching Hsiao, An-Shen Siao + Show 1 more

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https://doi.org/10.3390/en8077465

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Abstract

Pyroelectric harvesters use temperature fluctuations to generate electrical outputs. Solar radiation and waste heat are rich energy sources that can be harvested. Pyroelectric energy converters offer a novel and direct energy-conversion technology by transforming time-dependent temperatures directly into electricity. Moreover, the great challenge for pyroelectric energy harvesting lies in finding promising temperature variations or an alternating thermal loading in real situations. Hence, in this article, a novel pyroelectric harvester integrating solar radiation with wind power by the pyroelectric effect is proposed. Solar radiation is a thermal source, and wind is a dynamic potential. A disk generator is used for harvesting wind power. A mechanism is considered to convert the rotary energy of the disk generator to drive a shutter for generating temperature variations in pyroelectric cells using a planetary gear system. The optimal period of the pyroelectric cells is 35 s to harvest the stored energy, about 70 μJ, while the rotary velocity of the disk generator is about 31 RPM and the wind speed is about 1 m/s. In this state, the stored energy acquired from the pyroelectric harvester is about 75% more than that from the disk generator. Although the generated energy of the proposed pyroelectric harvester is less than that of the disk generator, the pyroelectric harvester plays a complementary role when the disk generator is inactive in situations of low wind speed.

Highlights

Heat sources are an important source of energy, which can be harvested for driving electronic devices and systems
We have proposed a novel pyroelectric harvester integrating solar radiation with wind power by the pyroelectric effect
The planetary gear system was designed as a reducer, with a speed reduction ratio of 1:36 by a two-gear train reduction while the input from the disk generator was set in the sun gear and the output to the shutter was set in the planet pinions under the ring gear fixed

Summary

Introduction

Heat sources are an important source of energy, which can be harvested for driving electronic devices and systems. Direct energy conversion using thermoelectric generators mainly relies on this effect to convert a steady-state temperature difference at the junction of two dissimilar metals or semiconductors into an electromagnetic force or electrical energy. Pyroelectric devices can directly convert time-dependent temperature oscillations into electricity [1,2,3]. When the temperature of pyroelectric materials increases (dT/dt > 0), polarization decreases due to the re-orientation of the dipole moment, resulting in an electrical current in an external circuit. When the temperature of pyroelectric materials decreases (dT/dt < 0), polarization increases as dipoles gain their orientation. This results in an electrical current in the reverse direction.

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