Collaborative Research: EAGER: CET: Efficient and power-dense heat utilization with zero-gap thermophotovoltaics

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

This EArly-concept Grants for Exploratory Research (EAGER) award is made in response to Dear Colleague Letter 23-109, as part of the NSF-wide Clean Energy Technology initiative. Harvesting the vast energy content in waste heat generated by U.S. industry, which accounts for two thirds of the total US energy consumption, is a major technological barrier in clean energy technology. Utilizing waste heat is a promising option to improve industrial energy efficiency with thermal processes for heavy-emission industries such as cement, iron, steel, and glassmaking. Solid-state thermal energy conversion technologies, such as thermoelectrics (TE) and thermophotovoltaics (TPV), could improve energy efficiency and accelerate decarbonization in numerous industries. However, these technologies have not been widely deployed due to fundamental constraints on efficiency or attainable power density. In this collaborative Clean Energy Technology EAGER project, Prof. Longji Cui (University of Colorado Boulder) and Prof. Eric Tervo (University of Wisconsin-Madison) explore the fundamental operational mechanisms of a novel solid-state energy conversion concept for waste heat recovery, called zero-gap thermophotovoltaics (zTPV). The outcomes of this project can address the bottlenecks in existing solid-state thermal energy technologies, increase the uptake of heat conversion technology in many industrial processes, and inspire further fundamental study in a broad range of relevant physics and power conversion mechanisms such as thermophotonics and infrared sensing. This project also focuses on the training of a diverse new generation of mechanical and electrical engineers to pursue broader career opportunities in renewable, thermal, and semiconductor industries, which helps to address the workforce shortage in the US in these areas. The principal investigators establish a comprehensive and predictive framework for zTPV through combined thermal and optoelectronic transport modelling and demonstrate the zTPV concept through fabrication and experiment. Additionally, they evaluate opportunities for critical material re-use and recycling. zTPV is fundamentally different from the existing TE and TPV methods and could lead to significant performance improvement over the state-of-the-art. Researchers at the University of Colorado Boulder and the University of Wisconsin-Madison develop a detailed theory and leverage it to provide quantitative predictions on device architecture, materials, and power generation. They also plan first-of-a-kind proof-of-concept experiments on the potentially disruptive zTPV concepts which could demonstrate the predicted orders of magnitude power enhancement capability over both of its far-field and near-field counterparts. The deep insights from this research into the fundamental limits to energy conversion by zTPV could profoundly impact the fields of solar-thermal conversion paired with moderate-temperature thermal storage, combined heat-and-power, and primary energy conversion with clean combustion processes such as hydrogen. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.