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.09 · Radiative imbalance with the sky × Caloric (magneto/electro/elasto)family: Caloric (magneto/electro/elasto)D.12 × C.14 · Radiative imbalance with the sky × Electromagnetic inductionfamily: Electromagnetic induction

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→ Thermal shape-memory effectestablishedclaim record

   thermal → mechanical · loss to thermal

   • a shape-memory alloy (NiTi) cycled between a hot reservoir above its austenite finish temperature and a cold one below its martensite finish temperature, under load

   solid · temperature gradient required

   refs [5] [6]
4. 04
   Thermal shape-memory effect —produces→ Mechanical motionestablishedclaim record

   mechanical → mechanical

   refs [6] [5]
5. 05
   Mechanical motion —drives→ Rotating-machine generator actionestablishedclaim record

   mechanical → electrical · loss to thermal

   • a shaft turning a rotor inside a stator, or a magnet moved past a coil

   conductor required · magnetic field required

   refs [7] [8]
6. 06
   Rotating-machine generator action —produces→ Charge carriersestablishedclaim record

   electrical → electrical · loss to thermal

   refs [7] [9]
7. 07
   Charge carriers —converts into→ Electrical workestablishedclaim record

   electrical → electrical · loss to thermal

   • carriers driven through an external load at the potential difference the source maintains

   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]
   K. Otsuka (ed.), C. M. Wayman (ed.). Shape Memory Materials (1998)

   Cambridge University Press · book, no DOI · record
6. [6]
   P. Kumar et al.. Shape memory alloy engine for high efficiency low-temperature gradient thermal to electrical conversion (2019)

   Applied Energy 251, 113277 · doi:10.1016/j.apenergy.2019.05.080 · crossref ✓ 2026-09-20 · record
7. [7]
   M. Faraday. Experimental researches in electricity (1832)

   Philosophical Transactions of the Royal Society 122, 125–162 · doi:10.1098/rstl.1832.0006 · crossref ✓ 2026-09-19 · record
8. [8]
   S. L. Dixon, C. A. Hall. Fluid Mechanics and Thermodynamics of Turbomachinery (7th ed.) (2014)

   Butterworth-Heinemann · doi:10.1016/C2011-0-05059-7 · crossref ✓ 2026-09-19 · record
9. [9]
   L. D. Landau, E. M. Lifshitz, L. P. Pitaevskii. Electrodynamics of Continuous Media (Course of Theoretical Physics, Vol. 8, 2nd ed.) (1984)

   Pergamon · book, no DOI · record
10. [10]
    N. W. Ashcroft, N. D. Mermin. Solid State Physics (1976)

    Holt, Rinehart and Winston · book, no DOI · record