Wireless sensor nodes (WSNs) are widely used in the field of environmental detection;\nhowever, they face serious power supply problems caused by the complexity of the environmental\nlayout. In this study, a new ultra-low-power hybrid energy harvesting (HEH) system for two types\nof microenergy collection (photovoltaic (PV) and soil-temperature-difference thermoelectric (TE))\nwas designed to provide stable power to WSNs. The power supply capabilities of two microenergy\nsources were assessed by analyzing the electrical characteristics and performing continuous energy\ndata collection. The HEH system consisted of two separated power converters and an electronic\nmultiplexer circuit to avoid impedance mismatch and improve efficiency. The feasibility of the\nself-powered HEH system was verified by consumption analysis of the HEH system, the WSNs,\nand the data analysis of the collected microenergy. Taking the summation of PV and TEG input\npower of 1.26 mW (PPV:PTEG was about 3:1) as an example, the power loss of the HEH system\naccounted for 33.8% of the total input power. Furthermore, the ratio decreased as the value of the\ninput power increased.
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