Thermodynamic Limits of Energy Harvesting from Outgoing Thermal Radiation

TL;DR

This paper establishes the fundamental thermodynamic limits for energy harvesting from outgoing thermal radiation, revealing that the maximum achievable power far exceeds previous estimates and extending the analysis to thermophotovoltaic efficiency.

Contribution

It introduces a duality relation between solar and thermal radiation harvesting engines and derives the ultimate limits for outgoing thermal radiation energy harvesting and thermophotovoltaic efficiency.

Findings

The ultimate limit for harvesting outgoing thermal radiation is significantly higher than previously believed.

A duality relation links solar and thermal radiation harvesting efficiencies.

Derived the maximum possible efficiency for thermophotovoltaic systems.

Abstract

We derive the thermodynamic limits of harvesting power from the outgoing thermal radiation from the ambient to the cold outer space. The derivations are based on a duality relation between thermal engines that harvest solar radiation and those that harvest outgoing thermal radiation. In particular, we derive the ultimate limit for harvesting outgoing thermal radiation, which is analogous to the Landersberg limit for solar energy harvesting, and show that the ultimate limit far exceeds what was previously thought to be possible. As an extension of our work, we also derive the ultimate limit of efficiency of thermophotovoltatic systems.