If your home is gonna use 4,000 watts of power from the solar panels then your home would need between 12 to 18 solar panels to power the home.
However if you want even more power then you'd need around 35 to 60 solar panels to power the entire home depending on the wattage you're requiring.
Some places may only allow you to use partial solar power and force you to stay hooked up to the electrical grid so you would usually only have 12 to 18 solar panels on your home.
Solar panels are nice but they don't really save money and they're costly to install and purchase but they can be worth it to have even as a backup emergency power should the power go out.