Powerwall FAQs



Overview

What is Powerwall?
What can I use Powerwall for?
How can I control Powerwall?
Can Powerwall work without Internet?
How do I buy and install a Powerwall?

Solar Integration

Can I add a Powerwall to my existing solar system?
During a power outage, can my solar recharge Powerwall?
How large a PV system can I connect with one Powerwall?
Can Powerwall go off-grid?

Generator Integration

How would Powerwall be installed with a backup generator?
How does Powerwall work with an existing backup generator?
Can my generator charge Powerwall?
Does Powerwall work with existing battery systems?
I have a wind turbine/hydro turbine. Can I charge Powerwall with it?

Installations

What are the different components that make up a Powerwall system?
What does a Powerwall system look like with all the additional equipment installed?
What does a multiple Powerwall installation look like?
What are the environmental requirements for a Powerwall installation?
What are the different options for the site survey to plan my Powerwall installation?
Will I need to upgrade my home electrical system for my Powerwall installation?
What should I do to prepare for my Powerwall installation?
How long does the installation take?
When can I start using my Powerwall?

Functionality

How does Backup work?
How does Self-Powered mode work?
How does Load-Shifting Time of Use work?
How can I monitor Powerwall operation?
Can Powerwall charge from the grid?
Can Powerwall charge my Tesla vehicle or an EV?

Backup Power

During a power outage, how long will Powerwall last?
During a power outage, how quickly does Powerwall restore power to my home?
How many appliances can I back up with a single Powerwall?  What loads will require multiple Powerwalls to back up?
During a utility power outage, how do I extend the amount of time my home can run on Powerwall?
What happens if I overload the system's backup capabilities?

Powerwall App

How do I download and set up the Tesla mobile app?
What is the Power Flow in the app?
How do I see energy usage history?
How can I change Powerwall's operating mode?
Is there a website where I can monitor my Powerwall from my desktop computer?
Why is my Powerwall not charging?
Why does the Tesla mobile app show power flows/values that appear inaccurate?

Ownership

What are the terms of the Powerwall warranty?
Where can I find Powerwall specifications?
Where can I find the Powerwall Owner's Manual and specification sheet for Powerwall?
Can you tell me more about the California Self Generation Incentive Program (SGIP)?
Does Powerwall qualify for the Federal Investment Tax Credit (ITC)?


Overview

What is Powerwall?
Powerwall is a rechargeable home battery system that stores energy from solar or from the grid and makes it available on demand. It can power your home during the night or back up your home in the event of a power outage. With its built-in battery inverter, Powerwall is compact and easy to integrate into your home. As with all Tesla products, new features will be added to Powerwall with over-the-air updates.

What can I use Powerwall for?
Powerwall can be used for a variety of applications, including:

  • Self-Powering your Home
    With Powerwall you can use more of your solar by storing the excess energy and using it at night, which roughly doubles the amount of solar energy that directly powers your home.
  • Backup Power
    Powerwall provides seamless backup power in the event of a utility power outage. In a longer outage, Powerwall can recharge from your solar power system. If necessary, you can even run your home from solar and Powerwall indefinitely.
  • Home Energy Monitoring
    You can monitor your solar, Powerwall and home energy use in real time with the Tesla mobile app.
  • Time-of-Use Load Shifting
    If your utility offers a time-of-use rate plan, Powerwall can charge when rates are low and use that energy during expensive times to reduce your electricity bill. This feature will be available at a later date by an over-the-air update.

How can I control Powerwall?
The Tesla mobile app allows you to manage all of your Tesla products - Model S, Model X, Model 3 and Powerwall - anytime, anywhere. With the Tesla mobile app, you can choose between different modes, such as Backup Only or Self-Powered. In Self-Powered mode, you can reserve a percentage of your Powerwall for an outage. As with all Tesla products, we will continue to add new features and modes over time.

Can Powerwall work without Internet?
Powerwall needs an Internet connection (over wired Ethernet or your home Wi-Fi) or a cellular connection to receive software updates and to communicate with the Tesla mobile app for energy monitoring. A reliable connection is required to provide new product features over time. If its connection is temporarily lost, Powerwall can continue to operate with its most recent settings, but it should not be installed in a location without Internet or cellular service.

How do I buy and install a Powerwall?

  • Place a deposit
  • Complete a home assessment by either a web based self survey or with a Tesla site surveyor
  • Review and approve your custom design with your product specialist
  • Schedule installation of Powerwall at your convenience
  • Installation and setup is performed by Tesla or by a Tesla Certified Installer

Solar Integration

Can I add a Powerwall to my existing solar system?
Yes, Powerwall can be integrated with your existing solar system. Powerwall is compatible with solar inverters from SMA, SolarEdge, Fronius, Enphase micro inverter, Delta and ABB. We continue to explore compatibility with other inverter companies.

During a power outage, can my solar recharge Powerwall?
Yes, Powerwall is able to keep a home solar system running during a power outage to recharge during extended outages. When more solar is being produced than can be used or stored, Powerwall is able to turn off the solar system and turn it back on when the energy can be used again.

How large a PV system can I connect with one Powerwall?
To ensure reliable operation during grid outages, at least 1 Powerwall is required for each 7.6kW AC of solar included in the backup circuit.

Can Powerwall go off-grid?
“Off-grid” can have different meanings:
If you are looking to be less reliant on your utility, Powerwall in the Self-Powered mode provides energy independence by using less grid power. This feature is available today.
When there is a utility power outage, Powerwall and your solar power system can provide backup power to your home. This feature is available today.

If you are in a remote area without access to utility power, Powerwall and solar can offer an off-grid solution. For our remote off-grid offering, please place a deposit here and someone will contact you to discuss further.

Generator Integration

How would Powerwall be installed with a backup generator?
Powerwall can be added to an existing system that has solar panels and a backup generator connected with an external Automatic Transfer Switch (ATS) or Manual Transfer Switch (MTS). Powerwall is installed between the electrical service entrance and the transfer switch, where it charges from solar while the grid is operational.

How does Powerwall work with an existing backup generator?
In an outage, Powerwall responds immediately and provides backup power before the ATS is able to detect the outage. The ATS switches to the generator only when the Powerwall state of charge drops below a set threshold, or if loads exceed Powerwall's maximum output.  When grid power returns, the ATS turns off the generator and Powerwall can again charge from solar.

If Powerwall is installed with an MTS, manual operation of the switch is required to power the home with the generator.

Can my generator charge Powerwall?
Powerwall does not currently have the ability to charge from a generator. Please stay tuned for future updates.

Does Powerwall work with existing battery systems?
Powerwall does not currently have the ability to work with existing battery systems. Please stay tuned for future updates.

I have a wind turbine/hydro turbine. Can I charge Powerwall with it?
Powerwall does not currently integrate with other renewable generation equipment. Please stay tuned for future updates.

Installations

What are the different components that make up a Powerwall system?
A Powerwall system consists of at least one Powerwall battery and a Backup Gateway. The Backup Gateway provides energy management, metering and monitoring functions for Powerwall. It controls connection to the grid, safely disconnecting your home and starting backup operation during an outage. The Backup Gateway also includes communication functions for up to 10 Powerwalls, and receives over-the-air updates for the system.

What does a Powerwall system look like with all the additional equipment installed?
A Powerwall installation includes at least one Powerwall battery, a Backup Gateway, and standard electrical hardware such as circuit breaker panels, conduit, junction boxes, or electrical disconnects as required by your particular installation and local electrical codes. In some cases, conduit and other electrical hardware can be hidden within the wall for an additional cost.

What does a multiple Powerwall installation look like?
Multiple Powerwalls can be mounted as single side-by-side units on a wall or on the floor, or stacked front-to-back (up to 3 deep per stack) on the floor only. When mounted side-by-side on a wall, Powerwall units must have sufficient clearance on each side for electrical connections and proper ventilation.  When stacked front-to-back, Powerwalls must be floor-mounted, the stack must be anchored to an adjacent wall, and the Powerwalls must be joined together with Powerwall Stack Kit hardware.  For stacked systems with more than 3 Powerwalls, separate stacks of 3 units should be installed, with each stack attached to a wall.

What are the environmental requirements for a Powerwall installation?
Powerwall and Backup Gateway units are rated for installation indoors or outdoors, and can operate within a wide range of temperatures, from -20°C to 50°C (-4°F to 122°F). At the high and low ends of this temperature range, Powerwall may limit charge or discharge power based on battery cell temperature to improve battery lifespan. To optimize performance, avoid installing Powerwall in locations exposed to direct sunlight or subject to sustained high or low temperatures.

While humidity and rain do not pose a risk, Powerwall should not be installed in locations subject to flooding or near water sources such as downspouts, faucets or sprinkler systems.  In order to maintain proper ventilation, Powerwall should be kept clear of debris such as leaves and dense brush, and of accumulated snow.

What are the different options for the site survey to plan my Powerwall installation?
Your Powerwall site survey can be completed remotely using our self-survey option. This is the fastest and most convienient method for getting an estimate. You will need to complete an online form and submit photos showing the required information.

If you prefer, we can offer a professional survey and come to your home to gather the necessary information. This may delay the process and will require you to be home and provide access to the required areas.

Will I need to upgrade my home electrical system for my Powerwall installation?
Tesla design teams will assess your home's electrical system based on your site survey and include any electrical upgrades your home may require in your propsal.

What should I do to prepare for my Powerwall installation?

  • Allow a full day for installers to be onsite.
  • Ensure that your electrical panel, any existing solar equipment, and the area where Powerwall is to be installed are accessible and clear of obstacles.
  • Plan for your home to be without power for at least 4 hours to allow installers to make final electrical connections.

How long does the installation take?
Installation time will depend on the size of your system and the complexity of the electrical work required. A typical installation is completed in one full day.

Depending on the complexity of the electrical work required, the power to your home will be off for a minumum of 4 hours and possibly longer.

When can I start using my Powerwall?
After Powerwall is installed, your utility will provide a Permission to Operate (PTO). Powerwall and any newly installed solar will then be operational. Be sure to download the Tesla mobile app from the iOS or Android app store.

Functionality

How does Backup work?
In the event of a utility power outage, the Backup Gateway immediately disconnects the home electrical system from the utility and restores power to the home. Whereas a traditional solar system typically shuts down during a grid outage to prevent any power from going back into the grid, because the Backup Gateway manages the grid connection, solar can continue to operate. Powerwall is able to coordinate its charge and discharge based on home usage and solar production, while curtailing solar production when necessary.

How does Self-Powered mode work?
In Self-Powered mode, Powerwall charges from the excess solar energy generated during the day, and discharges to power your home at night.

When solar is producing more power than the home is using, Powerwall captures and stores that energy. When the home is consuming more energy than solar is providing, Powerwall discharges enough energy to offset the home usage. If solar is producing more than Powerwall can store, or the home needs more than Powerwall can provide, the remainder is automatically exported or imported from the grid respectively.

How does Load-Shifting Time of Use work?
This feature will be available in early 2018.

If you have solar, Powerwall will be able to store solar energy when rates are lower, and discharge that energy to offset your usage when rates are higher. As a standalone, Powerwall will be able to store grid energy when rates are lower and discharge that energy to offset your usage when rates are higher. Using the Tesla mobile app, you will be able to customize a charge/discharge schedule based on your utility's Time-of-Use rate plan.

How can I monitor Powerwall operation?
As long as your Powerwall is connected to the Internet, you will be able to use the Tesla mobile app to monitor your home energy system in real time and view your energy usage history. During a grid outage, Internet is often still available and you will be able to view Powerwall status. If the Internet connection is lost, Powerwall will continue to operate with its most recent settings but you will not be able to monitor operation or change settings until connectivity is restored.

Can Powerwall charge from the grid?
When Powerwall is installed without solar, it can charge from the grid to support backup operation.

When Powerwall is installed with solar, it is not currently able to charge from the grid. Powerwall installations on new and existing solar systems are designed to qualify for the Federal Investment Tax Credit, which requires 100% charging from the solar. Powerwall installations must also comply with rules around grid charging which vary by utility.

Can Powerwall charge my Tesla vehicle or an EV?
Yes, Powerwall can provide stored solar energy to your EV through your home electrical panel. However, there is no direct connection between Powerwall and the EV wall connector.

Backup Power

During a power outage, how long will Powerwall last?
An average home uses approximately 25 kWh of energy per day. A small home may use as little as 10 kWh and a large home may use 40 kWh or more per day. Each Powerwall provides 13.5 kWh of usable energy for backup power. You can use the Tesla mobile app to monitor your usage and conserve power to extend your backup coverage for a day or more. Additionally, when Powerwall is paired with solar it can continue to recharge and has the potential to run your home indefinitely. Understand how long Powerwall will last in an outage based on your daily routines here.

During a power outage, how quickly does Powerwall restore power to my home?
Powerwall can detect an outage, disconnect from the grid and bring power back to your home in a fraction of a second. Unlike backup generators, Powerwall can keep your appliances running without interruption. You will not even notice that the power went out.

How many appliances can I back up with a single Powerwall?  What loads will require multiple Powerwalls to back up?
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. For the power needs of typical appliances,visit here for more information.

During a utility power outage, how do I extend the amount of time my home can run on Powerwall?
The best way to extend your usage of Powerwall during an outage is to limit the energy consumption of your home. You can do this by monitoring your use of non-essential or energy-hungry appliances like air conditioners, plasma TVs, hairdryers, and hot tubs. For more information about typical power consumption of different household appliances, visit here.

What happens if I overload the system's backup capabilities?
If you exceed Powerwall's power (5kW each) or energy (13.5kWh each) capabilities, it will safely shut down similar to your home circuit breaker. To resume Powerwall operation, turn off all lights and appliances in your home, then toggle the on/off switch located on the side of Powerwall. If, after an extended utility outage, Powerwall is depleted, then wait for the next sunny day before toggling the on/off switch.

Powerwall App

How do I download and set up the Tesla mobile app?
The Tesla app is available on the iTunes and Google Play stores. You can download the Tesla mobile app from your regular app store on your device.

Log in using your Tesla account information and you will see all your Tesla products in one place.

What is the Power Flow in the app?
Power Flow shows real time power generated from your solar system, stored/discharged by Powerwall, used by your home, and exported/imported from the grid. It can be accessed from the Powerwall home screen. You will have real-time visibility into your home energy system.

How do I see energy usage history?
From the Power Flow screen, select any power source, or the bar chart icon on the top right, to access the graph page. From there you can select 'Today' to change the time period and access more data.

How can I change Powerwall's operating mode?
From the Powerwall home screen, select Customize. From here you can select your mode of operation. Use Backup-Only mode if you would like to keep all of Powerwall's capacity for a utility outage, or Self-Powered if you would like to store excess solar energy for use at night. When in Self-Powered mode, you can scroll down to set your backup reserve to keep a portion of Powerwall capacity for a utility outage. For a balance of backup protection and a Self-Powered home, try setting your backup reserve to so that your Powerwall reaches full charge just as the sun is setting each day.

Is there a website where I can monitor my Powerwall from my desktop computer?
At this time, you can only monitor your system via the Tesla mobile app.

Why is my Powerwall not charging?
When installed with PV, Powerwall is designed to charge from solar energy. If your solar system is not yet operational Powerwall will not be able to charge. If your solar system is operational and you are in Self-Powered Mode, Powerwall will charge with any excess solar that your home doesn't immediately use. Smaller solar systems sometimes do not produce more than your home is currently using. You can increase the backup reserve or switch to Backup-only which will prioritize charging Powerwall with any solar production.

For further support you can reach us at (877) 798-3752 Select option 2, then 5.

Why does the Tesla mobile app show power flows/values that appear inaccurate?
Power flow shows the instantaneous flow of power of your home energy system. On a typical day a combination of solar, grid, and Powerwall may be powering your home. Solar energy may flow to the grid when your home does not need it and Powerwall is full. When charging your Powerwall to its backup reserve level or in Backup-only mode, solar power will flow directly from solar to Powerwall while grid energy is drawn for the home.

For further support you can reach us at (877) 798-3752 Select option 2, then 5.

Ownership

What are the terms of the Powerwall warranty?
Powerwall comes with a 10-year unlimited cycle warranty with guaranteed energy retention level when used in Self-Powered or Backup mode. The warranty is available here.

Where can I find Powerwall specifications?
You can find the specifications for Powerwall here.

Where can I find the Powerwall Owner's Manual and specification sheet for Powerwall?
You can find the Owner's Manuals for Powerwall here.

Can you tell me more about the California Self Generation Incentive Program (SGIP)?
You can learn more about SGIP here.

Does Powerwall qualify for the Federal Investment Tax Credit (ITC)?
Powerwall 2 is designed to qualify for the Federal Investment Tax Credit (ITC) when it is installed on an existing or new solar system and is charged 100% with solar energy. It does not qualify when installed without solar or if solar is installed after the Powerwall. You should always consult your tax professional for your particular situation.

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