Solar energy: the physics of the greenhouse effect
- 1 July 1975
- journal article
- Published by Optica Publishing Group in Applied Optics
- Vol. 14 (7), 1503-1508
- https://doi.org/10.1364/ao.14.001503
Abstract
For practical reasons, it is likely that low-temperature solar collectors have a more immediate future than high-temperature or photovoltaic generation of electricity. This paper discusses the physics of bare and covered flat-plate collectors. The greenhouse effect is the result of reducing convection to the point that radiation trapping becomes important. Nevertheless, at collector temperatures within 20–30°C of ambient, convection from the collector surface is so important that a special absorber with low ir emissivity may be no more efficient than a good, black absorber. At higher temperatures, selective absorbers are desirable. In the low temperature range, collection efficiency can be kept well over 80%, but falls rapidly with increasing collector temperature. This suggests that solar power may see early application in conjunction with heat pumps for heating and air conditioning.This publication has 3 references indexed in Scilit:
- Physics looks at solar energyPhysics Today, 1972
- Spectral and directional thermal radiation characteristics of selective sufaces for solar collectorsSolar Energy, 1962
- Spectral Radiance of Sky and Terrain at Wavelengths between 1 and 20 Microns II Sky Measurements*Journal of the Optical Society of America, 1960