Battery-Less Environment Sensor Using Thermoelectric Energy Harvesting from Soil-Ambient Air Temperature Differences

Area of Science:

• Environmental Science
• Electrical Engineering
• Computer Science

Background:

• Energy harvesting is crucial for the longevity of Internet of Things (IoT) devices and Wireless Sensor Networks (WSNs).
• Environmental sensing applications require autonomous, long-lasting devices, making energy harvesting essential.
• Thermal energy harvesting, utilizing temperature gradients, is a viable power source for such devices.

Purpose of the Study:

• To design and demonstrate a proof-of-concept environmental sensing node powered by soil thermal energy.
• To evaluate the energy harvesting potential from soil and air temperature differences in diverse locations.
• To develop a battery-less system using supercapacitors for energy storage and management.

Main Methods:

• Designed an environmental sensing node incorporating a thermal energy harvester.
• Collected soil and air temperature data from Belgium and Iceland to assess energy production potential.
• Developed a power management circuit and utilized a supercapacitor for energy storage.
• Deployed and evaluated the performance of the field prototype.

Main Results:

• The system harvests an average of 178.74 mJ per day.
• The harvested energy is sufficient for at least 5 DASH7 communication protocol transmissions and 100 sensing tasks daily.
• The battery-less design with supercapacitor storage proved effective.

Conclusions:

• Soil temperature gradients can effectively power environmental sensing nodes.
• The developed energy harvesting system enables autonomous, long-term environmental monitoring.
• This approach significantly extends the operational lifetime of IoT devices in remote applications.