How much power does a 7kW solar system produce per day compared to a 15kW solar system? As a general rule of thumb, a 7kW solar system should produce between 30kWh and 40kWh every day whereas a 15kW system can produce an average of 60kWh each day. 15KW is enough to power almost all of the appliances of a residential place including 20 fans, 30 lights, 3 ACs of 1.5 tons, 1 iron, 2 refrigerator, 1 water pump, 3 LED TV, 1 washing machine.
As you can guess by the amount of roof space required, a 15kW is a serious amount of solar for the ordinary home – and in many cases it will be too much. In most cases, it will only be appropriate if you're using over 50kWh of energy on average per day – a number much more likely to apply to a business than a home.