Unlike CSP, PV technology is not reliant on direct irradiation, which makes it more effective in converting diffuse radiation
The second component is the diffuse radiation
, which arises from the scattering of light produced in the atmosphere due to reflection and absorption by air molecules.
This fact may be partly explained by the steadiness of the radiation inside the greenhouse due to the low temporal variation of the solar radiation in tropical climates, the high fraction of diffuse radiation
due to the high cloudiness of the atmosphere in equatorial areas (SHARMA & PAL, 1965) and the low transmissivity of the plastic film to the radiation, in general, and to the diffuse radiation
1, showing the Rayleigh optical depth as a function of wavelength together with the fractional contribution of the diffuse radiation
to the global horizontal irradiance (diffuse fraction) under cloud-free conditions.
But on overcast days, the relative contribution of diffuse radiation
may be larger and can exceed the contribution of direct radiation.
However, the opposite behavior is observed during the major dust storm on MY 28, when a local minimum in the amount of diffuse radiation
occurred because virtually all the incoming radiation interacted with atmospheric dust, and therefore the fraction of absorbed and reflected radiation by the particles increased significantly.
For the diffuse radiation
transmitted through the windows and direct reflected solar gains, three methods are considered: area ratio, absorptance weighted area ratio, and radiosity.
The extragalactic background light (EBL) is the diffuse radiation
from all stars and galaxies, a dim but pervasive glow that fills the universe.
direct) radiation through the atmosphere, DiffFrac is the fraction of diffuse radiation
through the atmosphere, SOF is the sky obscuration factor of the canopy as a function of solar elevation zenith angle, and [[bar.
In monsoon months the contribution of diffuse radiation
is below 20%.
ij] is the fraction of diffuse radiation
leaving surface that is intercepted by surface j.
The detector has angular response very close to an ideal cosine function (Lambertian response) making it suitable for measurements of diffuse radiation
or radiation generated by extended sources.