Technically you can support a Tesla Powerwall with a single solar panel, however, it would take a very long time for your battery to recharge. A 7.6 kW system, or about 23 panels, can recharge a Powerwall in 2 hours under perfect conditions. The “best” system size for a Powerwall is one that is tailored to fit your home’s energy demands and your battery backup goals.  You can learn more about the sizing solar systems for battery backup by downloading our Tesla Powerwall Guide.