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.37 · Radiative imbalance with the sky × Thermo-osmoticfamily: Thermo-osmoticD.12 × C.23 · Radiative imbalance with the sky × Electrokineticfamily: Electrokinetic

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
• Onsager–Casimir reciprocity · constitutive-relation · listed, never decisive
  L_ij(B) = ε_i ε_j L_ji(−B): the cross-coefficients of coupled linear transport are equal up to the time-reversal parities ε of the variables and reversal of the magnetic field; L_ij = L_ji is the zero-field, even-parity case

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→ Thermo-osmosisestablishedclaim record

   thermal → kinetic · loss to thermal

   • a membrane separating two reservoirs of the same liquid at different temperatures; the flow direction depends on the membrane–liquid interaction

   selective membrane required · temperature gradient required · liquid

   refs [5] [6]
4. 04
   Thermo-osmosis —couples to→ Streaming potentialdemonstratedclaim record

   kinetic → electrical · loss to thermal

   • a charged, ion-selective nanochannel or nanoporous membrane contains an electrolyte
   • a sustained temperature difference drives thermo-osmotic liquid motion along the charged interface
   • electrical-double-layer counter-ions are preferentially transported by that flow
   • no external electrical bias is required for the measured short-circuit current
   • pressure-driven current is absent, negligible or separately controlled when the thermo-driven contribution is attributed

   aqueous medium required · selective membrane required · temperature gradient required · bulk flow required

   One physical experiment (Zhao et al. 2020): a track-etched polyimide membrane between hot and cold reservoirs gave a streaming current rising linearly with ΔT to 14 nA at 47.5 °C over 0.5 cm², direction set by the surface charge (pH). One paper is demonstrated, not established.

   refs [7]
5. 05
   Streaming potential —produces→ Ionic currentestablishedclaim record

   electrical → electrical

   refs [8] [9]
6. 06
   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 [10]

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 · 10

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]
   V. M. Barragán, S. Kjelstrup. Thermo-osmosis in Membrane Systems: A Review (2017)

   Journal of Non-Equilibrium Thermodynamics, 42 · doi:10.1515/jnet-2016-0088 · crossref ✓ 2026-09-20 · record
6. [6]
   S. R. de Groot, P. Mazur. Non-Equilibrium Thermodynamics (1962)

   North-Holland · book, no DOI · record
7. [7]
   X. Zhao et al.. pH-regulated thermo-driven nanofluidics for nanoconfined mass transport and energy conversion (2020)

   Nanoscale Advances 2, 4070–4076 · doi:10.1039/D0NA00429D · crossref ✓ 2026-09-20 · record
8. [8]
   J. Yang et al.. Electrokinetic microchannel battery by means of electrokinetic and microfluidic phenomena (2003)

   Journal of Micromechanics and Microengineering 13, 963 · doi:10.1088/0960-1317/13/6/320 · crossref ✓ 2026-09-19 · record
9. [9]
   R. J. Hunter. Zeta Potential in Colloid Science: Principles and Applications (1981)

   Academic Press · doi:10.1016/C2013-0-07389-6 · crossref ✓ 2026-09-19 · record
10. [10]
    A. J. Bard, L. R. Faulkner. Electrochemical Methods: Fundamentals and Applications (2nd ed.) (2001)

    Wiley · book, no DOI · record