Solar Reflectance
Solar reflectance is essentially albedo measured specifically against sunlight. A material with solar reflectance of 0.95 sends 95 % of the sun's energy back and only absorbs 5 %.
Scientific detail
Solar reflectance ρ_sol is the integral of hemispherical spectral reflectance weighted by the AM1.5G solar spectrum from 0.3 to 2.5 μm. It is one of the two properties (with thermal emittance) that determines a passive cooling material's Solar Reflectance Index (SRI) and its equilibrium sub-ambient performance under sunlight.
Related terms
Albedo
The fraction of sunlight a surface reflects — 0 is black, 1 is a perfect mirror.
Thermal Emittance
How efficiently a surface releases heat as infrared radiation.
Passive Daytime Radiative Cooling
A material that stays cooler than the air even under direct sunlight by radiating heat to the cold sky.
Cool Roofs (Reflective Roofs)
Roofs coated or built with high-reflectance materials so buildings absorb far less heat.
Where this concept shows up on MEER
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Explore in topic hubs
Curated collections of MEER research, projects, publications and stories that feature this term.
Passive Cooling
Everything MEER publishes on passive cooling — reflective roofs, PDRC materials, canopies, reservoir systems, projects, publications and stories, gathered in one place.
Radiative Cooling & PDRC
PDRC materials, the atmospheric window, thermal emittance and the practical engineering of surfaces that radiate heat directly to deep space.
Albedo & Reflectivity
Understanding planetary albedo, surface reflectivity, ice-albedo feedback, and why restoring Earth's reflectivity matters for global temperature.