Direct thermal to electrical energy conversion using very low bandgap TPV cells in a gas-fired furnace system

•A gas-fired power system using InGaAsSb TPV cells is designed, tested and developed.•The thermal radiation was emitted by a novel super alloy emitter in the TPV system.•The electric output of InGaAsSb TPV cells is characterized under various conditions.•A power density of 0.65 W/cm2 is produced at the emitter temperature of 1197 °C.•TPV power generation is feasible in gas-fired furnaces for combined heat and power.

In this paper, electricity generation using very low bandgap InGaAsSb thermophotovoltaic (TPV) cells whose bandgap is 0.53 eV was investigated in a gas-fired furnace system where thermal radiation was emitted from a metal alloy emitter. The electric output of the InGaAsSb TPV cells was characterized under various operating conditions. The cell short circuit density was measured to be 3.01 A/cm2 at an emitter temperature of 1197 °C. At this emitter temperature, an electric power density of 0.65 W/cm2 was produced by the TPV cells. Experimental results show that direct thermal to electrical energy conversion was achieved in a gas-fired heating furnace system. Such a system could be employed to form a micro-combined heat and power (micro-CHP) process where exhaust heat is utilized for home heating needs. The TPV integrated energy system provides an effective means for primary energy savings.