A good website to assist in calculating the amount of solar you need is: https://pvwatts.nrel.gov/.

The National Renewable Energy Laboratory developed this tool called PVWatts for this purpose. It estimates the energy production and cost of energy of grid-connected PV energy systems for any address in the world. It allows homeowners, small building owners, installers, and manufacturers to easily develop estimates of the performance of potential PV installations and can even compare solar’s cost to utility bills. These tools are great for getting started, but make sure to work with a solar installer for a custom estimate of how much power your solar energy system is likely to generate.

Keep in mind of any trees that will shade the solar panels will cause less production along with panels that will not be facing south.