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Tesla Powerwall 3 VS 2: Differences & Improvements

tesla powerwall affixed to side of house

If you’ve invested in solar panels for your home’s roof, you’ll need a battery to store and convert solar power into usable electricity. Tesla, the iconic electric car manufacturer, offers a popular solar battery called the Powerwall. The current model is the Powerwall 2, but this year Tesla will introduce the newest model, the Powerwall 3. 

In this article, we’ll take a look at the differences between the existing model and the newer Powerwall model: the Tesla Powerwall 3 vs 2. This should give you a better understanding of the two in case you’re looking to use a Tesla battery in conjunction with your home’s solar system. Investing in solar power for your roof is a heavy cost upfront, but will allow you and your loved ones many benefits down the line. Instant Roofer can help you figure out the cost and find a roofer near by that can help plan out this investment. Our solar roof calculator will help give you an accurate estimate as well as connect you with professionals in your area.

Tesla Powerwall 3 VS 2: Differences

What are the differences between a Tesla Powerwall 3 vs 2? Though minor, there are a few key differences between Tesla’s current home battery and the one they’re about to unveil. These differences are important to keep in mind when shopping for a battery. You’ve likely invested a lot of money in your home’s solar power system (check out our solar panel cost calculator if you’re just beginning your solar journey), so you want to be sure you’re covered in a power outage, when it matters most. 

All-In-One Vs Separate Installation

First, let’s examine a key difference between the Tesla Powerwall 3 vs 2. Installing a Powerwall 2 requires a separate inverter, while the Powerwall 3 comes with a built-in inverter. An inverter is a crucially important part of any solar power system: it works to convert the power generated by a solar system (direct current, or DC power) into the type of electricity used by the electric grid (alternating current, or AC power) to power homes and businesses. 

With its own built-in inverter, the Powerwall 3 boasts a simpler, more streamlined installation process. But it’s important to note that this “all in one” installation requires that your Powerwall 3 has a direct connection to your solar panels. 

Battery Efficiency

Battery efficiency, often referred to as round-trip efficiency, is an important aspect of solar power systems. In simple terms, it’s the amount of power you get from a fully charged battery after accounting for the amount of power it takes to convert from DC to AC energy. While the Powerwall 2 system offers an impressive 90% round-trip efficiency, the Powerwall 3 is able to convert as much as 97.5% of the solar power it collects to grid energy: a new industry standard. 

Energy Capacity

When it comes to power performance differences in the Tesla Powerwall 3 vs 2, there’s not much to speak of. Both batteries offer a total energy capacity of 13.5 kilowatt hours, and are suitable for use in a residential or small commercial setting. One notable difference between the two is the number of units you can stack. The Powerwall 2 allows you to stack as many as 10 units for a total energy storage of 135 kilowatt hours. In contrast, the Powerwall 3 will only allow for 4 total units for a capacity of up to 54 kilowatt hours of total energy storage. 

It’s important to know that the Powerwall 3 isn’t backward compatible with the Powerwall 2. In other words, you can’t add Powerwall 3 units to your current stack of Powerwall 2 units in order to increase the energy storage capacity. Therefore, the Powerwall 3 is best suited for new systems rather than existing systems as a result of this one drawback. 

On-Grid Power

Here’s the area where the Powerwall 3 stands out from both the Powerwall 2 and other competitors. With a continuous power output of 11.5 kilowatt hours, the Powerwall 3 is capable of providing more than twice the amount of power as the Powerwall 2, which only offers an industry standard 5 kilowatt hours. Continuous power output differs from peak output in that it’s the amount of energy used over time versus the battery’s top energy capacity. 

Energy Capability

Due mainly to its beefed up continuous power output, the Powerwall 3 is capable of powering a much greater load during a power outage. Things like heating and air conditioning units, electric vehicles and washers and dryers can all be powered using a Powerwall 3. By contrast, a Powerwall 2 is more suitable for things like lights and outlets. 

Cost & Affordability

While the Tesla website isn’t forthcoming about the exact price of a Powerwall unit without signing up or requesting a consultation, we found various online sources that reported the cost of the Powerwall system to be between $9,000 and $13,000. Costs vary only slightly between the Powerwall 2 and Powerwall 3 models, but there is a 30% federal tax credit associated with the purchase. This can help make it more affordable. 

Will the Tesla Powerwall 3 replace the Powerwall 2? 

No. There are two main reasons why the Powerwall 3 won’t fully replace the Powerwall 2, and this was likely done on purpose. First and foremost, the Powerwall 3 is not backwards compatible and therefore cannot be integrated into an existing Powerwall 2 system. Secondly, the Powerwall 3 is only capable of handling up to 54 kilowatt hours of storage by stacking a maximum of four units with 13.5 kWh each, versus a potential 135 kilowatt hours from stacking 10 units of a Powerwall 2 battery.  

Best Use Cases For Tesla Powerwall 3 VS 2

Many consumers wonder whether they should stick with the existing offering – the Powerwall 2 – or upgrade to the Powerwall 3 once it becomes widely available. Currently, the biggest deciding factor seems to hinge on a household’s continuous energy usage. While both the Powerwall 2 and 3 offer the same total energy capacity of 13.5 kWh, the Powerwall 3 offers more than twice the amount of continuous energy than the Powerwall 2 (at 11.5 and 5, respectively). So if a household has a continuous need for a large amount of energy during a power outage, the Powerwall 3 will be the better choice. 

Conclusion: Should You Invest?

Ultimately, the decision is yours! Below we’ve created a grid that shows you the values of each system. The Tesla Powerwall 2 is by no means out of service or ineffective, but the upgrades to the Tesla Powerwall 3 are definitely worth the investment especially if this is the first time you are purchasing a system.

FeaturePowerwall 3Powerwall 2
Round-trip efficiency97.5%90%
Total energy capacity13.5 kWh13.5 kWh
Stackable? Yes – 4 unitsYes – 10 units
Continuous power output11.5 kWh5 kWh
CapabilityLarge appliances, pool equipment, heating and A/C unitsLights and outlets

Fact Checked by Christin Perry 4/12/2024