Solar flux is half gone by the time it gets to the ground (reflection, cloud absorption)
Witness the clause 'at its zenith'. That means, too much atmosphere is in the way the rest of the day to matter.
In space, the sun is always at its zenith, if you look the right direction. Further, you have the opportunity to convert all of it, rather than the 50% that reaches the ground.
Witness the clause 'at its zenith'. That means, too much atmosphere is in the way the rest of the day to matter.
In space, the sun is always at its zenith, if you look the right direction. Further, you have the opportunity to convert all of it, rather than the 50% that reaches the ground.