When you come to install a solar system, unless you decide to do it yourself, the company you choose to perform an installation will provide the panels for you, and will advise you on your options. A 4 kW solar panel system will cost you between $10,000 and $11,500 to install. If you want to up the juice a little bit, a 5 kW system will cost between $12,500 and $14,000 to install.