Design and Performance Evaluation of a Phase-Change-Material-Integrated Thermoelectric Energy Harvesting Block for Building Exterior Waste Heat Recovery

Abstract

This study is about design and evaluation of a passive generator, energy harvesting block. Based on experiments of monthly wall temperature profile, this study gives a prediction of annual electricity generation by the Energy harvesting block. The Energy harvesting block is a thermoelectric generator-based passive energy harvesting system integrated with phase-change material which is designed to harvest energy from waste heat on exterior walls of buildings. The heat source of the Energy harvesting block is the waste heat on building exterior walls which is formed by solar radiation. The thermoelectric generator in the Energy harvesting block converts heat into electricity by Seebeck effect. To maintain the temperature difference between hot and cold sides of thermoelectric generator, phase-change material was used to cool the cold side, acting as a heat sink where phase-change material stores heat into latent heat. Experimentations were conducted on conditions of monthly representative wall temperature profiles. Voltage and temperature data was collected to check the phase-change and electricity generation. The results showed 2075 Wh/m2 of electricity generated for a year. Average generation power was 0.03 W, and 0.3 V. It was shown that 3-4 Energy harvesting block can supply enough electricity for a modern digital circuit which is used in sensors and controllers.