The thumb rule for setting up solar panel is that you can set up a 1 kilowatt plant in an available space of 8 meters square.
So for 1 sq. m we can setup 1000/8= 165 watt
You won’t get a module with that capacity. so you can fit a 150 watt panel or a 200 watt panel.
Now you installed a 150 watt solar panel:
The amount of energy you harness depends on the amount of solar insolation your area receives. It’s different for different areas.
Let’s assume the Global horizontal index or the solar insolation for your region is 4.5 kWh/sq.mday
Therefore the energy produce per year
= Panel capacity * solar insolation* days of the year
= 150 * 4.5 * 365
= 261157 Whr or 261 KWhr per year.