Usually, when we discuss solar installation, we care more about solar energy generated per square meter because not everyone has an easy or sizable access to an open roof that has no shadow of trees, branches, leaves, or any other obstacles that blocks sun rays.
If you are calculating solar panel energy output per square meter then know that under best conditions where sky is clear and sunny, each square meter of solar panel could generate somewhere from 140 Watts to 200 Watts. Similarly, each day it can produce around 1000 Watt hours (assuming you’ll get at least 6 hours of clear sun time).
We took above range of energy from Polycrystalline solar cells. There is a monocrystalline-type of solar cells that produces more amount of energy in the same area, if you are using that then the per square meter area will generate from 180 Watts to 240 Watts under clear conditions. Similarly, each day it can produce around 1200 Watts hours.
So, maximum solar power per square meter would be ~200 watts. Similarly, solar energy per square meter per day would be ~1000 watts. You should also realize that solar cell output per square meter may vary throughout the time, season, and region.