Impact of external electric resistance on the power generation in the thermoelectric energy harvesting blocks

Abstract

Energy can be harvested from various energy sources within a building. In this study, a thermoelectric generator-assisted energy harvesting block was proposed, aiming to utilize the waste heat source of the exterior wall of the building. The energy harvesting block comprises a thermoelectric generator and phase change material for converting waste heat from the building envelope and heat flux from the outside into electricity. Multiple energy harvesting blocks are required to construct an energy harvesting block wall. Thus, the electrical arrangements of multiple energy harvesting blocks and their effects on external resistance were analyzed. The arrangements consisted of a series array, parallel array, and combination array. Experiments were performed with a total of nine cases by connecting 1.6 Ω, 15 Ω, and 60 Ω with the same external resistance as the internal resistance of each array. The temperature and closed-circuit voltage were measured based on the sol-air temperature profile in December. The voltage and current were more affected by the connected external resistance than by the type of array. The maximum generated energy was 0.837 Wh/day when 60 Ω was connected to the series arrangement. In terms of the generated energy, the series arrangement was the most advantageous.