A 12kW solar system produces around 12,000 watts per hour in full sun. That's a lot of energy! Think of it this way: a light bulb typically uses 60 watts. It's substantial power which can be used for average-sized to large houses. Also, it can be used in. A 12-kilowatt (kW) solar system refers to the array's maximum potential power output under ideal laboratory conditions, which is the instantaneous rate of energy production. This size is typically selected for large residences, homes with high energy loads like electric vehicle charging, or properties. A 12 kW system is a good size for most homes, and it will produce sufficient kilowatt-hours (kWh) of electricity per year.