tesla powerwall review

The Tesla Powerwall home battery complete review

Tesla’s rebranding of residential-use batteries is in line with their legacy of reimagining existing products. Tesla’s battery may represent the first time in history that everyday homeowners are truly excited about the potential of storing energy at their home. The Powerwall, combined with the exciting Tesla Solar Roof, are both potential cornerstones of Elon Musk’s sustainable energy vision for the future.

This is an unbiased review: EnergySage is not paid to review brands or products, nor do we earn money from affiliate advertising in this article. The content of this blog is based on research and information available at the time of writing. Learn more about our mission and how we make money as a company.

Key takeaways


  • The Tesla Powerwall costs $8,500 before installation and between $12,000 and $16,500 for a full system installation (before incentives and taxes).
  • The Tesla Powerwall’s 14 kilowatt hour lithium-ion home battery is capable of electrifying a home on it’s own.
  • You may need several Powerwall batteries in order to truly go “off the grid”.
  • A qualified EnergySage-approved installer can give you the best information about the Tesla home battery system and other energy storage options available to homeowners today.

What’s in this article?

How the Tesla Powerwall works

The Powerwall pairs well with solar panel systems, especially if your utility has reduced or removed net metering, introduced time-of-use rates, or instituted demand charges. But, can the Tesla Powerwall power a home? In short, yes—installing a storage solution like the Tesla Powerwall with a solar energy system allows you to maintain a sustained power supply during the day or night, as long as you store enough solar power from your panels when the sun is shining.

As with many other home battery products, the Tesla Powerwall is sized for day-to-day use at your home and is often paired with a solar panel system. When your solar panels produce more electricity than you can use in your home, you can store the excess electricity in the battery system instead of sending it back into the grid. Later, when your panels aren’t producing enough electricity to meet your home’s needs, you can use the electricity stored in your battery instead of having to buy it from your utility company.

Find out what solar + storage costs in your area in 2022

How much does the Tesla Powerwall cost?

The Tesla Powerwall costs $8,500 before installation. The cost of a Powerwall battery stands at $7,500 alone, and its supporting hardware costs $1,000. Add on installation costs, and a Powerwall generally ranges in price between $12,000 and $16,500 for a full system installation (before incentives).

That cost number includes the battery, an inverter, various other equipment costs, and estimated installation costs. The cost of installing a battery isn’t as straightforward as looking up the list price for an individual component–i.e., your battery. In fact, depending on your electrical setup, among other factors, installation costs can vary widely.

If you want to install the Powerwall as part of a solar-plus-storage system, the actual Tesla Powerwall cost is just one part of the equation. A 5 kilowatt (kW) solar energy system costs anywhere from $9,000 to $15,000 depending on where you live and the type of equipment you choose.

Tesla Powerwall cost over time

ProductPrice
Powerwall 1 (April 2015, discontinued)$3000
Powerwall 2 (October 2016, discontinued)$5,500 to $6,500
Powerwall 2 (November 2020) $7,500
Powerwall + (April 2021, includes integrated solar inverter)$8500

That may sound like a lot of money, but installing a solar-plus-storage system and Tesla Powerwall can be a worthwhile investment. Whether or not the Tesla Powerwall makes sense for you is determined by the way that your electric utility structures its rates, as well as your reasons for installing a solar power battery. For example, if you want to become energy independent and are able to install several Powerwall batteries to increase energy storage capability, then investing in one is worth the time and money. It can also provide peace of mind during outages and natural disasters, and it can minimize your carbon footprint.

In some cases, depending on where you live, you may have access to financial incentives that can reduce your home energy storage installation costs. For instance, if you live in California, you could get a cash rebate that covers most of your home battery costs through the Self-Generation Incentive Program (SGIP). Other states (such as Massachusetts) are in the early stages of evaluating battery storage performance incentives as well, and several states already provide cash rebates to offset the Tesla Powerwall Cost.

Is the Tesla Powerwall worth it?

The Tesla Powerwall has been one of the most popular home battery options on the market for some time. The 14 kilowatt hour lithium-ion home battery is capable of electrifying a home when the grid goes down, and its price, storage capacity, and continuous power are some key metrics that make the Powerwall a very competitive home battery option. If you’re looking for a reliable battery that can back up your home for short outages, the Tesla Powerwall battery could be a great option for you.

While issues arise with just about every electrical product out there, it is worth mentioning that some customers have reported communication issues from Tesla when installing these products as well as some service outages.

Key things to know about the Tesla Powerwall

Tesla describes the Powerwall as a “rechargeable lithium ion battery with liquid thermal control.”  It is one of a few companies in the residential energy storage market that makes small-scale batteries for home energy storage. The first-generation Powerwall launched in April 2015, and updated Powerwall 2.0 models were announced in October 2016 and November 2020.

When evaluating the Powerwall, there are various important metrics and technical specifications to keep in mind. Among the most important are the size of the battery (power and capacity), its chemistry, depth of discharge, and roundtrip efficiency

Tesla Powerwall performance metrics over time

 Powerwall 1 (April 2015, discontinued)Powerwall 2 (October 2016, discontinued)Powerwall 2 (November 2020)Powerwall + (April 2021, includes integrated solar inverter)
Usable capacity6.4 kWh13.5 kWh13.5 kWh13.5 kWh
Continuous maximum power 3.3 kW5 kW5.8 kW5.8 kW (no sun) / 7.6 kW (full sun)
Weight
214 lb251.3 lb251.3 lb343.9 lb
Dimensions 51.3 in x 34 in x 7.2 in 45.3 in x 29.6 in x 5.75 in45.3 in x 29.6 in x 5.75 in62.8 in x 29.7 in x 6.3 in
Operating Temperature -4 to 110°F -4 to 122°F -4 to 122°F -4 to 122°F

Size

The Tesla Powerwall comes in only one size of 14 kilowatt-hours (kWh). Two important metrics to keep in mind when comparing the Powerwall to other home storage options are power and usable capacity. Power (measured in kilowatts, or kW) determines the maximum amount of electricity that can be output at a single time, while usable capacity (measured in kilowatt-hours, or kWh) is a measure of the maximum amount of electricity stored in your battery on a full charge. The Tesla Powerwall boasts a maximum power rating of 7.0 kW to go along with 13.5 kWh of usable capacity

Importantly, the Powerwall system is also modular, meaning you can add multiple battery products to your storage setup. For example, you might want to install multiple Powerwall batteries for a home with high energy demands and usage. The Tesla website indicates that you can add up to 10 Powerwall batteries together to form one massive storage system.

Think of your battery like water running through a pipe. The usable energy capacity is the amount of water available to push through the pipe, while power is the size of the pipe itself. Larger pipes allow more water to flow through at once, which depletes the water faster. Similarly, a battery with a high power rating can deliver more electricity at one time, but will burn through its available energy capacity faster too.

A battery’s power determines what appliances you can run with it at the same time, while usable capacity determines how long those appliances can be run. Batteries with a higher power rating are capable of powering more robust appliances or many appliances at once, while batteries with a higher usable capacity can store more total energy and thus can run your appliances for longer periods of time without needing to recharge.

Basic functionality

The functionality of one solar power battery next to another can vary; some batteries have excellent off-grid capabilities, while others offer software solutions specific to rate arbitrage. Here are the important qualities of the Tesla Powerwall:

Backup power

Tesla has made a concerted effort to ensure their battery solution is compatible with most common brands and types of off-grid and hybrid inverters. This means that, as long as your installer installs the correct components, your Tesla Powerwall battery will be able to provide backup power for your home when the grid goes down.

Chemistry

The Tesla Powerwall is a lithium-ion storage product; specifically, it is a lithium nickel manganese cobalt oxide (NMC) battery. This is one of the most common lithium-ion battery technologies, and for good reason: relative to other types of batteries, NMC batteries are known for their high energy density (the amount of energy they can store relative to the physical space they take up) and increased safety. To learn more about how different lithium-ion battery chemistries stack up against one another, check out our overview of battery chemistry differences.

Performance metrics

Two key ways to evaluate the performance of a solar battery are its depth of discharge and roundtrip efficiency

Depth of discharge (DoD) indicates the percentage of a battery’s energy that has been discharged relative to the overall capacity of the battery. Because the useful life of a battery decreases each time you charge, discharge, and re-charge–or cycle–your battery, many battery manufacturers specify a maximum DoD level for optimal battery performance. In general, batteries with a higher depth of discharge are considered better quality products. The Tesla Powerwall boasts a depth of discharge of 100 percent, reflective of its remarkably safe and advanced NMC battery chemistry.

Roundtrip efficiency is a measure of electrical losses involved with charging and discharging a battery. The higher the efficiency percentage, the more efficiently the battery is able to convert incoming electricity into stored electricity and then back into usable electricity. The Tesla Powerwall has a high roundtrip efficiency of 90 percent; this means that for every 10 kilowatt-hours (kWh) of electricity you put into the battery, you’ll receive 9 kWh of output.

How the Tesla Powerwall compares to other top home battery options

The Tesla Powerwall is hard to beat in terms of cost. But it certainly isn’t the only home energy storage system on the market with impressive specs. The Generac PWRCell and the Enphase IQ Battery are two other home batteries that may not stack up against the Powerwall in terms of market share, but have competitive qualities and performance metrics that put the Powerwall to the test.

Tesla Powerwall versus the Generac PWRCell & Enphase IQ Battery 10

 Generac PWRCell Enphase IQ Battery 10Tesla Powerwall
Weight 287 pounds 341 pounds 251.3 pounds
Warranty 10 years 10 years 10 years
Size22 x 10 x 68 in42.13 x 26.14 x 12.56 in45.3 x 29.6 x 5.75 in
Price$9,999 $18,000 $10,500
Storage Capacity 9+ kWh10.08 kWh13.5 kWh
Continuous Power 3.4+ kW3.84 kW5.6 kW
Peak Power6kW5kW10kW

Tesla Powerwall warranty coverage

Tesla Powerwall warranties


  • Warranty period: 10 years
  • Guaranteed end of warranty capacity: 70%
  • Check out this article for our in depth review of the Tesla Powerwall warranty.

In most cases, homes with a Tesla battery will charge and discharge their battery every day. So, how long do the Powerwall batteries last? The Powerwall comes with a 10-year warranty, and Tesla guarantees that the battery will maintain at least 70 percent of its capacity to hold a charge during that time period. 

Tesla’s battery technology is similar to other rechargeable batteries both large and small: as time goes on, the battery loses some of its ability to hold a charge. Think of how the battery life of a brand-new smartphone compares to one that is a few years old. As you continually charge and drain your phone’s battery, it starts to lose some of its ability to hold a charge.

The battery life of your Powerwall battery will deteriorate in the same way. That isn’t an indicator of a product flaw – all batteries lose some of their ability to hold a charge over time after extended usage, whether it’s an electric vehicle battery, a home energy battery, or a rechargeable AA battery. This is why Tesla offers a warranty that guarantees a certain percentage of storage capacity ten years in the future.

If you want to compare individual battery models side-by-side, our battery Buyer’s Guide lets you select products and compare them based on efficiency, capacity, power, and more.

Can you go off-grid with the Tesla Powerwall?

Installing a solar-plus-storage system at your home is a great way to take control of your electricity bill, but it doesn’t mean that you’re completely disconnected from your utility. Going “off the grid” with solar batteries is actually a more expensive and complicated proposition than you might think. Most home batteries, including the Powerwall, only have enough capacity to store a few hours of electricity. If you want to make sure you can maintain power to your property for days at a time, you’ll need to install several Powerwall batteries together to increase your storage and usage capabilities.

Where to buy the Tesla Powerwall

The Tesla Powerwall battery is currently available online through Tesla’s website and through any solar and/or energy storage installation company that carries the Powerwall in their inventory. Adding energy storage technology to your home is a complicated process that requires electrical expertise, certifications, and knowledge of the best practices required to install a solar-plus-storage system correctly.

A qualified EnergySage-approved company can give you the best recommendation about the Tesla home battery system and other energy storage options available to homeowners today. If you are interested in receiving competing installation quotes for solar and energy storage options from local installers near you, simply join the EnergySage Solar Marketplace today and indicate what products you’re interested in your profile’s preferences section.

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About Jacob Marsh

Jacob is a researcher and content writer at EnergySage, where he's an expert on current issues–and new technology!–in the solar industry. With a background in environmental and geological science, Jacob brings an analytical perspective and passion for conservation to help solar shoppers make the right energy choices for their wallet and the environment. Outside of EnergySage, you can find him playing Ultimate Frisbee or learning a new, obscure board game.

74 thoughts on “The Tesla Powerwall home battery complete review

  1. Curtis McCarthiy

    Will the power wall charge from the solar cells without the grid giving the solar cells a sine wave?
    Or is there a way to have my solar system keep the electricity on to my house when the grid goes down (and of course I isolate my house and solar panels from the gird) that will keep the lights and electrical equipment running? I wondered about have a back up generator just idling and having the solar cells provide the electricity during a grid power shut down but my solar installer said typical power generators don’t have the proper sine wave to allow it and it must be the grid talking to the solar cells. I know stand alone systems will use an electrical hot water heater as a power sink to contain the excess power solar can provide over the house solar needs.

    Reply
  2. J. Cummings

    This isn’t a review by a long shot. It’s a product overview using industry-supplied specs. A review would document finding an installer, the real product costs, a detailed installation review–including any install and connection issues, and a detailed, real-life test of performance under a variety of typical customer-use conditions. What passes for a review these days is pretty lame. Fail.

    Reply
  3. Pete

    I have an existing solar system with a inverter. I have 1500 sq. feet home. Would one powerwall battery be sufficient for my home?

    Reply
  4. Cliff Gold

    Why does a Powerwall battery cost so much more than an EV battery (per kWh). A 13 kWh Powerwall battery costs $7500. A 40 kWh Nissan Leaf battery costs $5500.

    Reply
  5. Steve Lympany

    Hi, please do a review of the PW re: time based control. It doesn’t work properly. There’re lots of complaints about the app online eg reddit
    Thanks
    Steve

    Reply
  6. Scott Wahlstrom

    Hello,

    I had a similar issue after a solar/powerwall installation. I learned through repeated customer service calls that the department that works through the related paperwork issues was backed up. This cost me almost five weeks of delay.

    Keep on them. and make multiple calls to get support.

    Best of luck! – Great product…

    Reply
  7. Yong Xie

    I just learned that Tesla has not filed the paperwork for “Approval to Power On” ten days after the installation which only took two days. I paid off in full right after the installation.

    Could anybody tell me if this is normal?

    Reply
    1. Yatin

      Can you call me 1-714-745-5877
      I had Tesla install solar panels with powerwall just a few days ago. When signing the contract they told us solar panels comes with a powerwall battery. We cannot just buy solar panels.
      A couple of days prior to installation, the requirement to purchase the powerwall was removed.
      I want them to remove the powerwall but they will not

      Reply
  8. Hampton Gardner

    I put up a deposit a couple of years ago and no one has contacted be back. I live in Mississippi I hac=ve bought Batterys from another company.. Im tired of waiting on Tesla. I want my Deposit Back how do I go about getting it back.

    Reply
  9. RECEP

    Is there anyone reach these data :How many parallel and series connection of cells in the Powerwall? Which brand of BMS and inverter inside the Powerwall?

    Reply

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