Best Practices During Power Outages

Powerwall brings you energy independence and security, so life in your home can carry on uninterrupted during a grid outage. During a power outage, Powerwall discharges its stored energy to provide power to your home. However, if your Powerwall is off-grid for what may become an extended duration, you may wish to familiarize yourself with the following best practices to extend the backup duration of your system during an outage.

How Powerwall Provides Backup Power

When a utility power outage does occur, your Powerwall instantly disconnects from the grid and restores backup power to your home in a fraction of a second, over one hundred times faster than typical standby generators. This means your appliances keep running without interruption, and there’s no need to reset your clocks. You may not even notice when an outage occurs.

If you have solar, your Powerwall can recharge from your solar system to run your home from solar and Powerwall even when the grid is down. A traditional solar system without a Powerwall does not function during a grid outage.

If more solar energy is produced than can be used or stored during an outage, Powerwall will turn off the solar system and turn it back on when the energy can be used again.

Backup Power Notifications

If the grid has been unavailable for at least five minutes, the Tesla app will alert you so you can manage energy usage accordingly. A second notification is sent when power is restored. To ensure you receive this alert, go to ‘Settings’ and select ‘Notifications’ in the Tesla app. You can set preferences for receiving all notifications, including power outages. Ensure that your device settings allow notifications from the Tesla app.

Preparing for an Outage

Storm Watch will automatically prepare your Powerwall system for the possibility of a grid outage during some extreme weather events. If your Powerwall is not actively in Storm Watch, you may also manually increase your backup reserve percentage in the mobile app to retain more energy in the event of a grid outage.

Before a potential outage, consider doing energy-intensive activities, including charging your car, running your air conditioner or doing dishes and laundry.

Power During a Grid Outage

Each Powerwall can provide up to 5 kW of continuous power. You can back up any number of appliances, so long as their combined power usage does not exceed the total power rating of your Powerwalls.  

Starting some loads with high inrush current during a power outage, like air conditioners and motors, may overload Powerwall and cause it to stop providing power to your home. If this occurs, turn off these loads, and Powerwall will attempt to restart within a minute. Otherwise, consider manually restarting Powerwall, as described below.

Vehicle Charging

During a power outage, Powerwall can coordinate with Tesla vehicles to charge without exceeding the power and energy needs of your home.

Energy Management During a Grid Outage

Weather events causing power outages may bring grid uncertainty where your outage could last days, not hours, with lower solar production. The best way to extend your use of Powerwall during a grid outage is to reduce the use of energy-intensive appliances like air conditioners, car charging, electric heaters and dishwashers.

Solar Panel Conditions

Some weather conditions may cause a reduction in your solar panel production, like depositing leaves or snow on your panels. Consider checking your panels daily during poor weather conditions to safely clear obstructions.

Solar Production During an Extended Outage

If Powerwall cannot charge at its expected rate, it will signal your solar inverter to reduce or turn off to protect your home from the excessive power produced. This typically occurs when Powerwall is approaching 100% charge. Once Powerwall has the ability to accept power again, your solar inverter will be signaled to produce and will re-start after the qualification period required by your local requirements.

Running Low on Energy

If Powerwall has less than 10% energy remaining, it will enter a standby state. Powerwall will automatically attempt to recharge from solar for 6 minutes every hour between 8 am and 4 pm local time. If enough solar is available to charge Powerwall, it will remain on. Otherwise, it will wait for the next hour.
 

Restarting Powerwall

If your Powerwall system stops producing power, it may be in a standby state after running low on energy or after repeated overloads. To restart your system, switch off any energy-intensive loads to reduce the amount of power needed. You can initiate a restart with a quick toggle of the on/off switch on any Powerwall in your system. Remember that in order to maintain a connection to the Gateway, you must leave the Powerwall switch in the ON position. 

A restart consumes some of Powerwall’s remaining stored energy. If energy is low and there is insufficient solar to charge, Powerwall will return to a standby state after 6 minutes, so it is best to initiate a restart during daylight hours.

Resetting Gateway

If the manual restart is not successful in bringing Powerwall back online, you can reset the entire system by power cycling your Gateway using the reset button. (This only reboots the Gateway, it does not reset any settings). If this is not successful, this usually means there is insufficient energy remaining to start the system, and you will need to wait for a grid connection to return.

Local Monitoring

The Tesla app may not have the latest data if your internet and cellular goes down. You can always see your Powerwall power flow and charge level by connecting to your Gateway to monitor your system locally from a web browser on your local network.