Environmental, energy and economic assessment of thermionic enhanced solar dish–Stirling power generation

Abstract

This paper proposed an innovative and comprehensive environmental, energy and economic framework for the potentially promising solar thermionic–Stirling power (TSP) technique, where thermionic emission is coupled to the conventional 10 kW dish–Stirling conversion. Carbon emissions of the thermionic energy converter were accounted for the first time, by referring to the industrial production of the raw materials. The TSP exhibits a net carbon emission of 17726.35 kgCO₂Eq in the entire life cycle from cradle to grave, where the thermionic converter and Stirling engine contributed 2.01 * 10³ and 5.38 * 10³ kgCO₂Eq respectively. The maximum daily power efficiency of the TSP is 32.91 % in Hangzhou at the emitter work function of 1.8 eV and the collector work function of 1.1 eV, with an efficiency enhancement by 28.04 % compared with that of the traditional dish–Stirling system. The specific carbon emission of the TSP is 19.9–33.2 gCO₂Eq/kWh for the investigated cities in China, while the carbon payback period ranges from 0.85 to 4.81 years. The TSP implemented in Hohhot achieves a LCoE of 49.73 US$/MWh due to sufficiently strong sunshine under the constrain of internal rate of return = 9 % and net present value ≥0.