How powerwall battery works ?

Powerwall gives you the ability to store energy for later use and works with or without solar to provide key security and financial benefits. Each Powerwall system includes at least one Powerwall and a Gateway, which provides energy monitoring, metering and management for the system. The Backup Gateway learns and adapts to your energy use over time, receives over-the-air updates just like the rest of products and is capable of managing up to ten Powerwalls.

With Solar

When the sun rises, solar begins powering the home. When additional power is required within the home, the home can pull from the utility grid. 

Powerwall is charged by solar during the day, when solar panels are producing more electricity than the home is consuming. Powerwall then stores that energy until the home needs it, such as when solar is no longer producing at night, or when the utility grid is offline during a power outage.

The next day when the sun comes out, solar recharges Powerwall so you have a cycle of clean, renewable energy. 

Without Solar

If your electricity rates vary throughout the day, Powerwall will charge when electricity costs are low and discharge when electricity costs are high, generating automatic savings. Powerwall will also provide seamless backup power by detecting grid outages and automatically becoming the home's main power source.