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Title: Theoretical efficiency limits for thermoradiative energy conversion

A new method to produce electricity from heat called thermoradiative energy conversion is analyzed. The method is based on sustaining a difference in the chemical potential for electron populations above and below an energy gap and let this difference drive a current through an electric circuit. The difference in chemical potential originates from an imbalance in the excitation and de-excitation of electrons across the energy gap. The method has similarities to thermophotovoltaics and conventional photovoltaics. While photovoltaic cells absorb thermal radiation from a body with higher temperature than the cell itself, thermoradiative cells are hot during operation and emit a net outflow of photons to colder surroundings. A thermoradiative cell with an energy gap of 0.25 eV at a temperature of 500 K in surroundings at 300 K is found to have a theoretical efficiency limit of 33.2%. For a high-temperature thermoradiative cell with an energy gap of 0.4 eV, a theoretical efficiency close to 50% is found while the cell produces 1000 W/m{sup 2} has a temperature of 1000 K and is placed in surroundings with a temperature of 300 K. Some aspects related to the practical implementation of the concept are discussed and some challenges are addressed. It is, for example, obvious that there ismore » an upper boundary for the temperature under which solid state devices can work properly over time. No conclusions are drawn with regard to such practical boundaries, because the work is aimed at establishing upper limits for ideal thermoradiative devices.« less
Authors:
 [1]
  1. Department of Engineering Sciences, University of Agder, Jon Lilletuns vei 9, 4879 Grimstad (Norway)
Publication Date:
OSTI Identifier:
22413065
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DE-EXCITATION; EFFICIENCY; ELECTRICITY; ELECTRONIC STRUCTURE; ELECTRONS; ENERGY CONVERSION; ENERGY GAP; EXCITATION; PHOTONS; PHOTOVOLTAIC CELLS; PHOTOVOLTAIC EFFECT; POTENTIALS; SOLIDS; TEMPERATURE DEPENDENCE; THERMAL RADIATION