que significa bateria solar?

A device that reserves energy for later consumption that is charged by a connected solar system. The stored electricity is consumed after sundown, during energy demand peaks, or during a power outage. Most common on residential or commercial buildings
When you install a solar battery as part of your solar panel system, you are able to store excess solar electricity at your home instead of sending it back to the grid. If your solar panels are producing more electricity than you need, the excess energy goes towards charging the battery. Later, when your solar panels aren’t producing electricity, you can draw down the energy you stored earlier in your battery for night use. You’ll only send electricity back to the grid when your battery is fully charged, and you’ll only draw electricity from the grid when your battery is depleted.
What this means in practical terms is that homes with solar-plus-storage can store excess solar power onsite for use later when the sun isn’t shining. As a bonus, since solar batteries store energy at your home, they also offer short-term backup power in the event that there’s a power outage in your area.