Power Generation at Low Temperatures Using Thermoelectric Generators and Cost Analysis

Interest in thermoelectric generators (TEGs) for waste heat recovery (WHR) and geothermal energy has grown significantly in recent years due to the ability to convert low-grade thermal energy into electricity, which is essential to reduce carbon emissions. One of the main challenges in TEG power generation is the expandability and the number of layers in TEG devices. The currently reported maximum number of layers is six. In this study, the expandable TEG devices with different number of layers, up to 20, were designed and manufactured. The field tests have been then conducted with these TEG devices using the waste heat from a coal bed methane power plant at a temperature of around 80°C. To our best knowledge, this is the lowest temperature at which TEG field tests have been implemented. At a flow rate of about 3 m³/hr, a TEG unit with a volume of about 3 m³ can generate a power of 15 kW at a temperature difference of 60°C. The power density and power per unit area of the TEG are investigated and compared to those of diesel generators and photovoltaic panels at different temperature differences. Furthermore, to offer guidance for the commercial-scale implementation of TEG, we have estimated the fabrication and installation costs, as well as the levelized cost of electricity, across various temperature differences. The results indicate that TEG is a feasible and promising technology for large-scale power generation and WHR.