Batteries
Backup is a time machine for sunlight.
Without a battery, most grid-tie systems go dark with the neighborhood. With one, you keep a chosen set of circuits alive.
In the playground you pick a pack that is currently offered for a new US home install — Tesla Powerwall 3, SolarEdge Home Battery 400V, LG RESU10H Prime or RESU16H Prime, or Enphase IQ Battery 5P or 10C — then a stack count within that product’s official limit. Usable kWh comes from the product, not a free-floating slider. Backup hours still use a fraction of household load, and an electric car from section 2 is part of that story.
Dollar savings are mostly time-of-use shifting and higher self-consumption. The outage value is real and hard to price. SolarNerdz shows both, with the knobs visible.
Questions? See Contacts.