Generally speaking, the size of a solar system is determined by the amount of power you want to produce. For example, let’s say your family uses 3,500 kilowatt hours of electricity every year. If you wanted to offset that usage by 100%, you would need a PV system large enough to produce 3,500 kilowatts of power in a year. If you wanted to offset your power usage by 50%, then a system that would produce 1,750 kilowatt hours of power a year would suffice. The next consideration is available area for the PV array itself. For example, to produce 1,000 watts of power, an area of about 10 square meters is required.
The next consideration is overall cost. How much can you afford? Maybe you’d like to offset your usage by 100%, but it is more than you want to spend. If so, you could choose to offset your usage by 50% and add on to your system in the future. Your solar installer will be more than happy to present you with different options to meet your budget and get you on your way to saving money and reducing your carbon footprint.