Tesla Powerwall and Charging from the Grid

Tesla Powerwall and Charging from the Grid

Tesla’s Powerwall invention has become increasingly popular since its debut in 2015. The Powerwall battery system can store energy from the electrical grid, making it a worthy competitor for the traditional generator.

Tesla’s Powerwall can charge from the grid through two modes: Backup-Only and Time-Based Control. Once the system is installed, the rechargeable battery will pull energy from the electrical grid and store it. When the grid shuts down, the Powerwall immediately goes into action and supplies your house with energy.

You won’t notice a thing! If you have ever had to fumble around in the pitch dark, looking for a flashlight or a candle to light, you know how inconvenient it is when the power goes out. The Powerwall can also be connected to solar power for 100% clean energy. Read on to see if the Powerwall is worth the investment.

What is Tesla Powerwall?

Tesla describes Powerwall as “a rechargeable home battery system designed to maximize your home’s energy independence” (Tesla). The main purpose of the device is to store back-up energy for times when your home’s main energy source is not available. The battery even detects outages and kicks in right when you need it.

The battery is made of lithium-ion and is essentially a smarter, more modern generator.

While generators are bulky, the sleek design of the Powerwall will fit conveniently under your main electrical panel. You can control the Powerwall using Tesla’s app. The app allows you to change the settings on your phone.

How Much Energy Do You Get from Powerwall?

According to Tesla’s website, one Powerwall can run 5 kilowatts of continuous power and can support:

  • Lights
  • Electrical outlets
  • 120V small appliances.

You can stack up to 10 Powerwall units to get more stored energy. How many you need depends on your needs.

How Many Powerwall Units Do I Need to Install?

If you are just concerned with covering your essentials in the case of an outage, one Powerwall will probably cover that need. If you want to run larger appliances, you will need more.

Before you buy, evaluate your personal needs and consult with a Tesla representative to determine what you need.

Installation of a Powerwall comes with the Powerwall itself, a gateway, and electrical hardware. The gateway acts as a communication bridge between the Powerwall and the grid or solar panels. There are several setups and systems to choose from, so you can walk through it with an expert.

Two Ways Powerwall Can Charge from the Grid

You can choose how Powerwall pulls power from the grid, depending on your main reason for installing it.

Back-up Only Mode

Backup-Only mode is particularly useful for people who live in areas where extreme weather frequently causes power outages or for people who live in areas with unreliable electricity. Here is how it works

  • Storage: The Powerwall stores energy until it reaches 100% capacity.
  • Use: Energy is saved and used only during a power outage.

Time-Based Control Mode

The Time-Based Control mode is for people whose electricity costs fluctuate based on demand. In this setup, the Powerwall pulls electricity from the grid during low-demand times.


  • Electricity costs more during peak usage times, such as during regular business hours.
  • Electricity costs less during low demand times, like the middle of the night.  

With Time-Based Control, you can use the stored energy during peak-usage times without paying the higher cost.

Can I Install Powerwall to Pull from Grid and Solar Power?

Self-Powered Mode

Tesla’s Powerwall is compatible with solar energy. This is called the Self-Powered mode.

  • The system charges during sunlight hours and then automatically uses that collected solar energy to give your home electricity at night.
  • For people who live in sunny climates, this will give you clean energy 24/7.
  • This is a great option for those who want to live an environmentally friendly lifestyle.

Choose to Store Energy from the Grid or from Solar Power

It is important to note that you cannot charge from the grid and from solar energy. At the time of installation, you will need to decide which energy source you want the Powerwall to charge from.

Why Can’t I Use Both Grid and Solar Power?

If you choose to store energy from solar power, you can apply for solar power tax credits and programs to cover the cost of the Powerwall. The Powerwall cannot switch between grid and solar because then it would no longer be a clean energy product, and customers would be ineligible for the cost-saving tax credits and programs.

The Powerwall Knows When a Storm is Coming

Using smart technology, the Powerwall knows when severe weather is coming, that might lead to a power outage. In this mode, the battery ramps up to store as much energy as possible in preparation for the outage.

The device communicates with the National Weather Service. When it receives an alert of coming severe weather, the Powerwall automatically switches to Storm Watch mode.

This is a convenient feature since homeowners do not have to do anything. You’ll receive an alert through the Tesla app letting you know that severe weather is coming, and that the Powerwall has switched itself to Storm Watch mode. 

Will Charging from the Grid Save on Electric Costs?     

Two Modes Allow You to Save on Electric Costs

The Powerwall can help you save money on your electricity bill. Using the Time-Based Control mode will help you save on electric costs by pulling energy from the grid during times when electricity is cheaper. You can cut your electricity bill to 0 if you exclusively use solar power.

Overall Savings Will Depend on Your Situation

You will need to do a cost-benefit analysis. You can use your electricity bill to determine your average energy costs a month. For most people, the amount you would save in electricity costs would not be more than the cost of installing the Powerwall. The initial costs of solar panels and the Powerwall are steep.

The best way to get the most bang for your buck is to offset the initial cost with government incentive programs. So, let’s talk a bit about that cost.

How Much Does the Powerwall Cost?

The biggest drawback of the Powerwall is that it is an expensive investment. The cost is between $8,000 and $15,600 for one Powerwall and comes with a 10-year warranty. If you need more than one Powerwall, this could really add up to a pricey investment. Installation costs and government incentives affect the price you’ll pay.

Government Incentives to Offset the Cost

If you use the Powerwall with solar panels, you can apply for the federal solar tax credit and get a few thousand dollars back. This is the reason why you cannot switch between charging using solar energy and charging using the grid.

If you receive the tax credit, you must exclusively use solar charging. Certain states also have programs to help cover the costs of sustainable energy. Check out your state’s programs—you might be surprised at how affordable the Powerwall is with these incentives.

Final Thoughts

You can absolutely charge the Powerwall using the electrical grid.

The initial cost may be high, but the two main reasons many people invest in the Powerwall are to become energy independent by using solar power or to ensure their home will have electricity during a power outage. That is where Powerwall excels. If power outages are common in your area, the Powerwall could give you peace of mind.

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The articles here on ThatTeslaChannel.com are created by Greg, a Tesla vehicle and Tesla solar expert with nearly half a decade of hands-on experience. The information on this site is fact-checked and tested in-person to ensure the best possible level of accuracy.

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