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irradiance:


When testing solar panels, they are ISO tested at a fixed temperature and exposure: 25.0 degrees C and 1,000
watts of "irradiance" per square meter. Although I don't think it's stated, I'm assuming they are also insuring
that the light is coming straight down and not being allowed to strike the panels at an angle, since anging the
panel away from the sun is known to dramatically affect panel efficiency.

At earth's orbital distance from the sun, each square meter is hit by 127,000 Lumens of light, or 1366 watts
of light energy.

https://kogalla.com/blogs/tech-trail/how-many-lumens-is-the-sun#:~:text=For%20our%20sun%20or%20any,That%20is%20very%20bright.

This disagrees with other information I have found online that suggests that even at the equator at high noon,
light intensity is less than 1,000 watts per square meter, and you will get less than the ISO rated power.


Solar Irradiance calculator


daily sunshine (Europe):


panel tilt angles:



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