Powerwall is configured to meet your home’s specific energy needs. Use the Tesla app to monitor and manage your solar system’s performance with features and control modes such as Backup Reserve, Self-Powered, Time-Based Control and Advanced Setting.
When temperatures are below freezing, Preconditioning is enabled, heating your Powerwall to improve operation and charging performance.
Learn more about the following modes for your Powerwall:
The Backup Reserve setting lets you customise the level of energy security that Powerwall provides during a grid outage. Set your preferred reserve percentage by adjusting the slider at the top of the ‘Settings’ screen:
- If you prefer to reserve more energy for use during a grid outage or if your area is more prone to outages, you can set a higher reserve percentage.
- If you prefer to optimise your Powerwall's performance in Self-Powered or Time-Based Control mode, you can set a lower reserve percentage.
During an outage, your stored backup reserve becomes available, and Powerwall will discharge below your reserve percentage if required. When the outage is resolved, your Powerwall will prioritise charging above your reserve percentage before resuming normal operation. You may use Powerwall as a backup-only appliance by selecting Self-Powered mode with a Backup Reserve of 100%.
Note: Setting a backup reserve of 100% effectively prevents use of Self-Powered and Time-Based Control mode. This will negatively impact the potential economic benefits of those modes and increase your reliance on the grid.
Low Backup Reserve
If you set your reserve percentage below 20%, a ‘Low Backup Reserve’ indicator will be displayed, and your Powerwall may not have enough stored energy to provide backup support during an extended grid outage.
If a grid outage occurs while your Powerwall’s stored energy is below 5%, you will immediately lose power to your home, and Powerwall will save this energy and wait to recharge itself via solar the next morning. In the morning, your Powerwall will periodically provide power to your home until there is enough solar power available to both power your home and recharge itself. To learn more about this behaviour, visit Best Practices During Power Cuts.
Note: Consider your personal economic needs and energy security outlook when setting Backup Reserve. Setting a higher reserve percentage saves more energy for protection during an outage, while setting a lower reserve percentage allows optimised performance when in Self-Powered or Time-Based Control mode.
When Self-Powered mode is selected, your Powerwall stores solar energy not used during the day to power your home at night. Your Powerwall will charge when excess solar power is produced, and this stored energy will be used when your home requires more power than your solar system can provide.
When you produce enough solar power to offset your home’s current consumption and Powerwall is fully charged, any excess solar power will export to the grid. Similarly, when you consume more power than what’s available from your solar system and stored in Powerwall, you will import power from the grid.
Self-Powered mode allows you to store excess energy for use at night and is the most effective way to reduce your carbon footprint and gain energy independence. Learn more about energy data and impact cards in the Tesla app.
How to Set Up Self-Powered
To set up Self-Powered mode in the Tesla app, follow these steps:
1. From the home screen, open the ‘Settings’ menu.
2. Open the ‘Powerwall’ menu.
3. Under ‘Operational Mode,’ select ‘Self-Powered.’
4. Set your preferred Backup Reserve by adjusting the slider at the top of the screen.
Time-Based Control (also referred to as load shifting) helps you maximise savings through smart charging and discharging of your Powerwall. If your electricity prices vary during the day, you are likely on a time-of-use plan, and Time-Based Control would present the best economic value for your system. Time-of-use plans are utility rate structures where electricity prices may vary depending on the time of day, the day itself or the season.
Utilities usually break time-of-use plans into three periods:
- Peak: High energy demand hours with most expensive prices
- Off-Peak: Low energy demand hours with least expensive prices
- Mid-Peak: All other times
How to Set Up Time-Based Control
Before setting up Time-Based Control mode, obtain your specific time-of-use plan, which is typically found on your electric utility website or your bill. Once you have set your preferred rate plan, you can always change it through the following steps:
- From the home screen, open the ‘Settings’ menu.
- Open the 'Powerwall' menu.
- Under ‘Operational Mode,’ select ‘Time-Based Control.’
- Set your preferred rate plan by tapping the ‘Utility Rate Plan’ card.
- Set your preferred Backup Reserve by adjusting the slider at the top of the screen.
For more information on how your solar and Powerwall system will operate while in Time-Based Control mode, visit the Time-Based Control User Guide.
Some utilities allow Powerwall to send energy back to the grid and claim credits during peak times. When Powerwall is allowed to send energy to the grid, the following energy export options will be available in the Tesla app.
When set to ‘Solar,’ Powerwall will only discharge energy to match your home loads during high-cost time periods, forcing all solar production to export. Use this option if you wish to earn credits when energy is expensive, but also keep energy stored in Powerwall to reduce your reliance on the grid. This is the default setting.
When set to ‘Everything,’ Powerwall will discharge as much as possible when the cost of energy is expensive, sending solar and Powerwall energy to the grid and discharging all the way to your set Backup Reserve. Use this option if you want to maximise savings.
Note: If ‘Energy Exports’ is not available in the Tesla app, your utility does not allow Powerwall to export energy to the grid for any Time of Use purposes.
Powerwall has one advanced setting that impacts how the system exports and imports energy to and from the grid. This setting may have other effects with your utility company. If these are not clear, confirm with your installer before adjusting Advanced Setting in the Tesla app.
Powerwall can charge from the grid under certain conditions. The ability to charge from the grid is set by your local utility company or installer. When Powerwall is not able to charge from the grid, you will see a ‘Grid Charging Restricted’ message – this is most common when the utility prevents charging, or when the system is owned by a third party, such as through a lease. When Powerwall can charge from the grid, the following options will be available in the Tesla app, with the default setting of ‘No.’
When set to ‘No,’ Powerwall will not charge from the grid. This will increase your Self-Powered performance and reduce your reliance on the grid.
When set to ‘Yes,’ Powerwall will charge from the grid if there is insufficient solar available to maintain the Backup Reserve or if there is a financial benefit when in Time-Based Control mode. Consider your energy goals and consult your tax advisor regarding any tax-related impacts before enabling Grid Charging.
When temperatures are low, all batteries have a reduced ability to charge. To help Powerwall counteract this, Powerwall uses Preconditioning. When temperatures are below freezing, Preconditioning turns on and heats your Powerwall to improve operation and charging performance. To heat itself, Powerwall draws a small amount of energy, which then allows higher-power charging.
During a cold night, your Powerwall automatically preheats before sunrise so that maximum solar energy can be captured during the day. Preconditioning, in combination with Tesla’s unique liquid thermal management system, allows your Powerwall to operate at lower temperatures than any other home battery.
You cannot customise this mode because Powerwall can best detect its internal temperature and knows when to enable Preconditioning.
During Preconditioning, the Power Flow screen may show energy flowing to your Powerwall from solar or the grid. This is normal behaviour, and the energy is only being used to heat, not to charge.
During winter months, a small amount of your Powerwall capacity is reserved to improve performance in cold weather. This may change your visible total capacity in the Tesla app. Rest assured, your total capacity has not changed — this small reserve is just set aside to improve performance.
- Powerwall: 22.9+
- Tesla app: 4.7+