A study of heat sink performance in air and soil for use in a thermoelectric energy harvesting device

Abstract

A suggested application of a thermoelectric generator is to exploit the natural temperature difference between the air and the soil to generate small amounts of electrical energy. Since the conversion efficiency of even the best thermoelectric generators available is very low, the performance of the heat sinks providing the heat flow is critical. By providing a constant heat input to various heat sinks, field tests of their thermal conductances in soil and in air were performed. A prototype device without a thermoelectric generator was constructed, buried, and monitored to experimentally measure the heat flow achievable in such a system. Theoretical considerations for design and selection of improved heat sinks are also presented. In particular, the method of shape factor analysis is used to give rough estimates and upper bounds for the thermal conductance of a passive heat sink buried in soil.

Energy Harvesting for Structural Health Monitoring Sensor Networks

“…Thermoelectric generators have been used for capturing ambient energy in various applications. Lawrence and Snyder [62] suggest a potential method of retrieving electric energy from the temperature difference that exists between the soil and the air. The results showed that a maximum instantaneous power of approximately 0.4 mW could be generated.…”

Thermoelectric module construction for low temperature gradient power generation

“…Some research has been done on exploiting the temperature difference between the air and earth to generate electrical power [7,8]. Temperature differences of about -0.35° to 0.7°C were measured.…”

Review of Energy Harvesting Technologies for Sustainable WSN

“…et al (2004). In the research area of thermal energy harvesting, both Stevens Stevens (1999) and Lawrence et al Lawrence et al (2002) consider the system design aspects for thermal energy scavenging via thermoelectric conversion that exploits the natural temperature difference between the ground and air. Similarly, Leonov et al Leonov et al (2007) have considered thermal energy harvesting through thermoelectric power generation from body heat to power www.intechopen.com wireless sensor nodes.…”