Solar modules you can buy for your house usually have quoted power ratings at "max STC" or Standard Testing Conditions, which are based on insolation on Earth's surface.

https://wiki.pvmet.org/index.php?title=Standard_Test_Conditi...

So, a "400W panel" is rated to produce 400W at standard testing conditions.

I'm not sure how relevant that is to the numbers being thrown around in this thread, but thought I'd provide context.