Adding
solar in the future won't change your interior wiring requirements. The PV panels are wired to an inverter which then goes to your main power panel. If you want to do anything now, you may want to add a box next to your main panel so you can easily access your main panel without having to cut through the wall. Run your interior wiring through conduits, so you have easy access to make any changes in the future, along with protecting the wires from rodent damage.
It sounds like you'll be supplementing your electric company with the solar. Your electric meter will run backward during the day and forward at night. If you produce more than you use, most companies are required to buy your excess
energy, though they pay at a significantly reduced rate from what they'll
sell it for. Though this eliminates the need for expensive batteries, codes generally prevent you from using the energy from your PV panels when the electric company has a power outage.