Tedori-Callinan Lecture Series: 2017

Murthy"Innovations in Materials and Devices for Efficient Solar and Thermal Energy Utilization"

Presented by: Gang Chen, Carl Richard Soderberg Professor of Power Engineering and Head of the Department of Mechanical Engineering, Massachusetts Institute of Technology

Tuesday, October 3, 2017
10:45 a.m.
Wu and Chen Auditorium, Levine Hall

 

 

Sponsored by Penn Engineering and Mechanical Engineering and Applied Mechanics. View past speakers in the series. Learn more about the sponsor of this series.

Abstract

Human history has very much depended on how we used heat from the sun and terrestrial sources.  Over 90 precent of human society's energy input is used by first converting it into heat, and yet only 40 percent of the total energy input is utilized, significantly lower than what the second law of thermodynamics allows.  Understanding of basic heat carrier transport and energy conversion at nanoscale can lead to new materials and devices to improve the efficiency of heat utilization. 

This talk will present some of our work on developing advanced materials and devices to improve the efficiency of solar and thermal energy conversion devices and systems.  To lower the cost of solar energy to electricity conversion, we use nanostructures to reduce the thickness of crystalline silicon thin-film solar cells and optically-transparent and thermally-insulating aerogels to replace the vacuum-tube solar collectors in concentrated solar thermal systems.  We improve thermoelectric materials via nanostructuring and demonstrate significant improvements in the efficiency of solar thermoelectric energy conversion devices.  We also demonstrate the ability of boiling water under unconcentrated sunlight using spectrally selective surfaces.  For terrestrial thermal systems, we show that by reflecting infrared radiation back to its emitting heat source, we can significantly improve the efficiency of converting thermally-radiated photons into electricity via thermophotovoltaic devices and the luminous efficiency of incandescent light bulbs.  We can turn a battery into an efficient thermal-to-electrical energy converter by cycling it between high and low temperatures.  Although polymers are usually thermal insulators, we show that they can be made as thermally conductive as metals by aligning molecular orientations.  With properly chosen polymer fiber diameters, we design fabrics so that they are opaque to visible light and yet allow thermal radiation from human body to escape to environment for passively cooling.  Nanoscience foundations behind these diverse innovations will be explained along the way.


Biography:

Gang Chen is currently the Head of the Department of Mechanical Engineering and Carl Richard Soderberg Professor of Power Engineering at Massachusetts Institute of Technology (MIT), and is the director of the "Solid-State Solar-Thermal Energy Conversion Center (S3TEC Center)" - an Energy Frontier Research Center funded by the US Department of Energy. He obtained his PhD degree from the Mechanical Engineering Department, UC Berkeley. He was a faculty member at Duke University and UCLA, before joining MIT in 2001.

Dr. Chen received an NSF Young Investigator Award, an R&D 100 award, an ASME Heat Transfer Memorial Award, a Nukiyama Memorial Award by the Japan Heat Transfer Society, a World Technology Network Award in Energy, an Eringen Medal from the Society of Engineering Science, and the Capers and Marion McDonald Award for Excellences in Mentoring and Advising from MIT.  He is a fellow of American Association for Advancement of Science, APS, ASME, and Guggenheim Foundation.  He is an academician of Academia Sinica and a member of the US National Academy of Engineering.