It's far less than the variance of direct solar irradiation hitting the Earth given varying differences in distance from the sun in the Earth's orbit. https://e

It's far less than the variance of direct solar irradiation hitting the Earth given varying differences in distance from the sun in the Earth's orbit. https://en.wikipedia.org/wiki/Solar_constant#Solar_irradiance https://en.wikipedia.org/wiki/Solar_constant#Solar_irradianc... It looks like direct solar radiance is actually 173,000 TW plus or minus 6,000 TW.