How much energy in joules can the solar panel produce each day?

Suppose one square meter panel of solar cells has an efficiency of 30% and receives the equivalent of 4 hours of direct sunlight per day. How much energy in joules can it produce each day? What average power of watts does the panel produce? If the solar cells were efficient they would generate about 1000 watts of power per square meter of surface area when exposed to direct sunlight.