Roughly 50% of the radiation power arriving at sea level. But that's not specific for sunlight. Incandescendent lamps have an even larger IR share due to lower temperature.Most of the energy from the sun is infrared...
How to distinguish it without detailed spectral measurements from CFL or HID light, which have considerable UV A radiation?If truely trying to detect sunlight vs visible your only affordable option is detecting UV.
How to distinguish it without detailed spectral measurements from CFL or HID light, which have considerable UV A radiation?
It is a good ideaYour only real option is to detect visible or UV. You might try to use a UV sensor that detects NUV, near ultraviolet, which passes with more ease through glass(350 to 450nm length).
They are using regular (borosilicate) glass which still has limited UV-A transmission. Actually there's a big difference between CFL and HID. CFL have a low pressure mercury spectrum, and the dominant 254 nm line is completely absorbed by the glass tube. But there's still a less intense 370 nm line and possible NUV fluorescense. HID has a more solar like wide band spectrum, and it's surely exposing some UV-A. Indoor, or behind a car window, it won't be distinguishable from solar light very easily.And I believe all HID and CFL lights are required to be designed with a UV shield around them, so they shouldnt be an issue.