Radiative imbalance with the sky → Electrical work

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.12 × C.20 · Radiative imbalance with the sky × Photothermalfamily: PhotothermalD.12 × C.05 · Radiative imbalance with the sky × Thermogalvanicfamily: Thermogalvanic

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Radiative cooling power bound · resource-bound · listed, never decisive
  net cooling power ≲ 100–150 W/m² under a clear sky
• Carnot limit · formula-bound · hard, applies to this route
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c

Steps

1. 01
   Radiative imbalance with the sky —drives→ Radiative sky coolingreplicatedclaim record

   radiative → thermal

   • an emitter with high emissivity in the 8–13 µm window and high solar reflectance
   • a clear sky; humidity and cloud close the window

   refs [1] [2] [3]
2. 02
   Radiative sky cooling —produces→ Temperature gradientreplicatedclaim record

   thermal → thermal

   • the cooled surface sits a few kelvin below ambient air

   refs [1] [4] [3]
3. 03
   Temperature gradient —drives→ Thermogalvanic effectestablishedclaim record

   thermal → electrical · loss to thermal

   ΔE = (ΔS_rxn / nF) · ΔT · thermogalvanic Seebeck coefficient [V/K]

   • two identical electrodes in one redox electrolyte held at different temperatures
   • a redox couple with large reaction entropy (ferri/ferrocyanide gives ≈ −1.4 mV/K)

   liquid · aqueous medium required · temperature gradient required

   refs [5] [6]
4. 04
   Thermogalvanic effect —produces→ Ionic currentestablishedclaim record

   electrical → electrical · loss to thermal

   refs [6]
5. 05
   Ionic current —converts into→ Electrical workestablishedclaim record

   electrical → electrical · loss to thermal

   • electrodes exchange the ionic current for an electronic current through the external load

   refs [7]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 7

1. [1]
   A. P. Raman et al.. Passive radiative cooling below ambient air temperature under direct sunlight (2014)

   Nature 515, 540–544 · doi:10.1038/nature13883 · crossref ✓ 2026-09-19 · record
2. [2]
   Y. Zhai et al.. Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling (2017)

   Science 355, 1062–1066 · doi:10.1126/science.aai7899 · crossref ✓ 2026-09-19 · record
3. [3]
   J.-l. Kou et al.. Daytime radiative cooling using near-black infrared emitters (2017)

   ACS Photonics 4, 626–630 · doi:10.1021/acsphotonics.6b00991 · crossref ✓ 2026-09-19 · record
4. [4]
   A. P. Raman, W. Li, S. Fan. Generating light from darkness (2019)

   Joule 3, 2679–2686 · doi:10.1016/j.joule.2019.08.009 · crossref ✓ 2026-09-19 · record
5. [5]
   T. I. Quickenden, Y. Mua. A review of power generation in aqueous thermogalvanic cells (1995)

   Journal of the Electrochemical Society 142, 3985 · doi:10.1149/1.2048446 · crossref ✓ 2026-09-19 · record
6. [6]
   M. F. Dupont, D. R. MacFarlane, J. M. Pringle. Thermo-electrochemical cells for waste heat harvesting – progress and perspectives (2017)

   Chemical Communications 53, 6288–6302 · doi:10.1039/C7CC02160G · crossref ✓ 2026-09-19 · record
7. [7]
   A. J. Bard, L. R. Faulkner. Electrochemical Methods: Fundamentals and Applications (2nd ed.) (2001)

   Wiley · book, no DOI · record