Thermodynamic limits of energy harvesting from outgoing thermal radiation

Buddhiraju, Siddharth; Santhanam, Parthiban; Fan, Shanhui

doi:10.1073/pnas.1717595115

Cited by 98 publications

(76 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, most conventional radiative cooling technologies only work at nighttime since solar heating is dominant during the daytime. To realize the envisioned all-day continuous cooling, it is essential to achieve efficient radiative cooling during the daytime, when peak cooling demand actually occurs [6][7][8][9] .…”

mentioning

confidence: 99%

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

et al. 2019

View full text Add to dashboard Cite

Radiative cooling is a passive cooling strategy with zero consumption of electricity, and it can be used to radiate heat from buildings to reduce air conditioning requirements. Although this technology can work well during optimal atmospheric conditions at nighttime, it is essential to achieve efficient cooling during daytime when peak cooling demand actually occurs. In this article, we report an inexpensive planar polydimethylsiloxane (PDMS)/metal thermal emitter, i.e., a thin film structure, which was fabricated using a fast solution coating process that is scalable for large area manufacturing. By performing tests under different environmental conditions, temperature reductions of 9.5 °C and 11.0 °C were demonstrated in the laboratory and outdoor environment, respectively, with an average cooling power of ~120 W/m 2 for the thin film thermal emitter. In addition, a spectral-selective structure was designed and implemented to suppress the solar input and control the divergence of the thermal emission beam. This enhanced the directionality of the thermal emissions, so the emitter's cooling performance was less dependent on the surrounding environment. Outdoor experiments were performed in Buffalo NY realizing continuous allday cooling of 2~9 °C on a typical clear sunny day at Northern United States latitudes. This practical strategy that cools without electricity input could have a significant impact on global energy consumption.

show abstract

mentioning

confidence: 99%

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

et al. 2019

View full text Add to dashboard Cite

show abstract

“…such that η hot cannot exceed 0.25 [9], the limiting value for T e /T c → 0, where η Carnot → 1. In the limit of small temperature differences, the efficiency can approach half the Carnot efficiency.…”

Section: Landsberg Efficiencymentioning

confidence: 99%

“…(7)-(9)], which is accurate for large band gaps and/or large negative bias and introduces only small inaccuracies even for band gaps as small as E g ≈ kT c . Equations (7)- (9) for the fluxes then becomė…”

Section: Thermoradiative Diodementioning

confidence: 99%

See 1 more Smart Citation

Fundamental Efficiency Bounds for the Conversion of a Radiative Heat Engine’s Own Emission into Work

et al. 2019

View full text Add to dashboard Cite

The thermoradiative diode is a novel heat engine that converts athermal radiative emission from a hot converter to a colder environment into work. This stands in contrast to essentially all radiative heat engines realized to date, where an external hot reservoir radiates toward a converter that resides at (and can be reversibly coupled to) a cold reservoir. We derive the fundamental bounds on conversion efficiency and power production for generalized far-field hot-side heat engines with radiative exchange that can be black body (thermal) or, more generally, athermal. This is followed by the corresponding derivation for the rich landscape of performance bounds for the specific case of thermoradiative diodes, including why the Landsberg-efficiency limit associated with heat engines that include radiative exchange can be surpassed, and how the ultimate Carnot-efficiency limit could be approached.

show abstract

“…The cooling power of the radiator (right triangles) obtained for q i $ 23 is around 140 Wm À2 . 1,28 This gives the lowest temperature of the radiator.…”

Section: Tunable Daytime Passive Radiative Coolingmentioning

confidence: 99%