AndewJ

Welcome to Africa!

Efficiency is expressed as kWh/kW (kilowatt hours per kilowatt). So time (hours) is implicit in an efficiency calculation. The 5 hours is a rule of thumb. We get (according to the rule) about 5 hours usable sunlight. So production (in kWh) equals the size of your array times by 5. I find this an over simplification since we do not get 5 hours of sunshine at 100% of PV array capacity. Because of this over simplification and readily available hard data I would rather look at efficiency and the average for South Africa is 3.5 kWh/kW This data is largely recorded by Axperts so it maybe different to other systems. So if you want to go back to hours it is the equivalent to 3½ hours of sunshine at 100% production.
 Look at any PV production graph and you will see that it is a bell curve and usually the peak is anywhere between 80 and 95% of the PV array's capacity. I mention this since I made the mistake thinking I should be getting 3000W for portion of the day on most days. This was part of my initial calculation in terms of powering appliances during the day. Now that I have gained some practical experience I know it just does not work like that.