Making the Old Solid Play New Fluid Tricks: Reimagining our Energy Systems

Speaker: Bikram Bhatia, University of Louisville

Abstract:  Our energy infrastructure predominantly relies on fluidic systems for energy generation, conversion, and storage, which are often complex, bulky, and primarily driven by fossil fuels. In this talk, I will highlight our work reinventing heat engines, heat pumps, and heat exchangers by substituting fluids with solids. This approach can significantly improve performance and open up new application possibilities.

The first part of the talk highlights novel radiative heat engines that combine the simplicity, compactness, reliability, and high power density of solid-state devices with the superior efficiency of conventional heat engines. We demonstrate thermodynamic cycles in pyroelectric materials and show how active thermal emission control, achieved through optical filters and reflectors, enhances their performance. Using an experimentally validated model that integrates thermodynamics and heat transfer, we simulate scaled-up performance and highlight the potential of radiative thermal switching in advancing solid-state heat engine technology.

The second part of the talk will center on heat pumps based on barocaloric cooling – the caloric response of solid materials subjected to applied hydrostatic pressure. These heat pumps are highly efficient, environmentally friendly, reliable, and present a promising alternative to existing vapor compression refrigeration systems. We specifically investigate the mechano-thermal response of low-cost polymers that combine a large barocaloric response with high compressibility. Additionally, as a step towards translating this promising material response into practical devices, we also quantify their performance at the system level.

Reimagining our energy systems using solid media could enhance energy efficiency, enable high-temperature and zero-gravity operations, and improve reliability. These innovative thermal systems offer compelling solutions for waste heat harvesting, air conditioning and refrigeration, solar energy conversion, and energy storage – paving the way for a sustainable energy future.