When you add a solar battery backup to your solar PV system, your lights stay on even when your neighbors are down. There are many benefits of a solar battery like the Tesla Powerwall or Enphase Encharge but one major benefit is that it can power your home during power outages.
Once you have solar panels installed, your home becomes a natural energy-producing goldmine. But wait- that means your home produces energy while the sun is shining. And although the sun produces enough potential energy in 1 minute to power the entire world, your solar panels can only take in so much at one time.
However, all the energy your panels produce during the day could be stored for use at night or during blackouts, for any reason. The answer to this problem is solar battery storage like Tesla Powerwall.
Jesus: Hey, Dad? God: Yes, Son? Jesus: Western civilization followed me home. Can I keep it? God: Certainly not! And put it down this minute--you don't know where it's been! Tom Robbins in Another Roadside Attraction