On the potential of waste heat recovery by means of thermoelectricity

Waste heat is a byproduct of all power generation and industrial processes and represents one of the largest sources of inexpensive, clean, and fuel-free energy available. Thermoelectric generators are a promising technology for converting waste heat directly into higher-value electrical energy. Advantages include the absence of moving parts or working fluids, ease of scalability, low maintenance costs, the ability to operate under noncontinuous conditions, and a long lifespan. This study presents a newly developed system for radiant waste heat recovery utilizing a bismuth-telluride-based thermoelectric module. Particular emphasis has been placed on designing a resilient energy recovery system that can withstand the harsh conditions typical of energy-intensive industries while optimizing power output. This design is supported by numerical and analytical computational models. Data obtained from experiments conducted on a high-temperature test stand and from simulations are used for the levelized cost of electricity calculation. The electrical power generated by the thermoelectric generator, as determined from measurement data and validated by computational models, was found to be 4.68 W when a single thermoelectric module measuring 40 × 40 mm 2 was used. Upscaling the system to one square meter, assuming a fill factor of 64%, would result in an output power of 1.87 kW, corresponding to a levelized cost of electricity ranging from 13.7 to 22.1 ct / kWh. This work presents a prototype thermoelectric generator developed for the medium to high temperature range. While laboratory testing has shown high performance, further evaluation is needed to assess its durability under industrial conditions. Ongoing tasks include determining the lifespan of the thermoelectric modules by conducting extended field tests and upscaling the system while ensuring that industrial processes are not disrupted. Although the levelized cost of energy calculation reflects the economic feasibility of this technology and its competitive energy costs, further advancements and cost reductions are necessary to compete with renewable sources.