Solar panels ... wattage of your panels. For this example, let's go with the average of 400 watts per panel. Using an address in Las Vegas as an example, you'll divide 7,157 kWh by 1.8 by 400 ...

For example, based on the average solar panel cost we calculated at $3.24 per watt with installation, a 6 kW system would run around $19,440, while a 12 kW system would double the cost.