Tesla Powerwall review: A game changer at a solid price

Tesla has finally released its much anticipated Powerwall 3 and the latest version of its home battery doesn’t disappoint. The Tesla Powerwall 3 is a big step up from the Powerwall 2, boasting some key improvements while still maintaining a reasonable price point. A few major changes like switching to LFP cells and increased maximum output make it a worthwhile investment for most homeowners. It’s easier than ever to install, and the newly integrated hybrid inverter means the Powerwall 3 can seamlessly merge with your existing solar panel system, which is a huge added advantage. 

Some of the most important qualities to consider when choosing a home battery are capabilities like how much energy the battery can store, how much of your house it can power and for how long, whether or not your battery can power your home if the electrical grid is down, and if it has enough power to turn on major appliances like your AC. The Tesla Powerwall 3 delivers on all of them.

We’ll walk you through the key specs and features and review the pros and cons of Tesla’s latest home battery so you can decide if it’s the right choice for your home energy needs. If you like what you see, the Powerwall 3 is available to purchase on the EnergySage Marketplace.

Easier installation

One of the major changes to the Powerwall is the introduction of an integrated hybrid inverter, which makes it much easier to install, especially if you already have solar panels on your roof. An integrated inverter means you don’t have to spend extra money buying a separate inverter like you did with the Powerwall 2 and many other batteries. And, given that the price of the Powerwall 3 is similar to the Powerwall 2, which was just a battery, it’s basically like getting an inverter for free. The inverter has rapid shutdown capability which means you can use it with both your battery and your solar panels, simplifying solar installations if you’re looking for both solar and storage at the same time. 

The Powerwall 3 also features a simplified and sleeker design, which translates to faster and easier installations. It also weighs less than the Powerwall 2, further increasing the ease of connection. The Powerwall 3 can be mounted on the floor or the wall. Most EnergySage customers who’ve reviewed the Powerwall 3 are happy with the experience they had working with Tesla’s install crew, saying that their installers have been both professional and knowledgeable.

Keep in mind that the Powerwall 2 and 3 don’t work together. If you already own a Powerwall 2 and you need more backup power, you’ll have to buy another 2 instead of upgrading to the 3. 

More power output

For home batteries, the two most important specs to look for are:

• Continuous maximum power output: How much stuff a battery can run all at the same time, measured in kilowatts (kW).

• Usable capacity: How long a battery can run your stuff, measured in kilowatt hours (kWh).

When you divide the capacity by the maximum output, it tells you the minimum amount of time a battery can keep your home running on its own. 

With the Powerwall 3, that’s about 2 hours, depending on the variant. The real-world backup window is probably longer than that, because you generally won’t draw the maximum amount of power from your battery consistently during a long outage.

The Powerwall 3 provides 11.5 kW of continuous power, which is more than double what it used to be, and much higher than many other batteries on the market. Continuous power refers to how much power the battery can manage at any given time. So the increased power output means it can now support bigger appliances – another improvement from the Powerwall 2.

According to Tesla, a single unit “can support the power needs of most homes.” The Powerwall 3 now supports up to four units on one system. The solar to battery grid efficiency is up to 89%, and solar to home grid efficiency is at 97.5%. However, the Powerwall 3 still stores 13.5 kWh, which isn’t a change from the 2 and while good, is pretty standard for most home batteries. 

Safer battery chemistry

One of the biggest upgrades you’ll find with the Powerwall 3 is the switch to Lithium iron phosphate (LFP) battery cells from nickel manganese cobalt (NMC) cells (which is what the Powerwall 2 uses). While both are Lithium-ion batteries, LFP battery cells are more stable and safer than NMC cells, and also provide more longevity and durability – that translates to more battery cycles, giving the product a longer lifespan overall. 

This isn't to say that NMC batteries aren't safe. They are, and typically offer more power density at a lower price than LFP batteries. But most of the industry has shifted towards LFP batteries given the longevity and added safety characteristics mentioned above, so it’s nice to see Tesla finally move in that direction as well.

Not including the cost of installation, the Powerwall 3 costs $9,300 with the gateway and accessories. Depending on where you live, taxes push the total price up to $10,184 before any federal or state incentives are taken into account. But if you take advantage of the federal solar tax credit you’ll receive a 30% credit on the total cost, which lowers the price by about $3,000, bringing it closer to $7,000. You can expect your install to add around $6,000 to your total cost depending on where you live and the complexity of the installation. Note: the cost of installing your Powerwall 3 is also eligible for the ITC. 

A single Powerwall 3 will suffice for partial home backup, but if you’re really looking for whole home backup from your battery, keep in mind that it will significantly raise the price you pay as you’ll need to purchase multiple batteries for your property.

Even though versions of the Powerwall have been out for almost a decade, it remains wildly popular. And Tesla's newest version, the Powerwall 3, is the best one yet. "I'd say the Powerwall is still the industry standard," says Spencer Fields, head of research at EnergySage. In 2023, the Powerwall's previous version was the second most-quoted battery on EnergySage, behind only Enphase. What’s the key to its continued success? The brand name probably helps, and installers tell us that they like working with it. More importantly, though, it’s well-rounded and reasonably priced.

The low price is hard to beat 

Plenty of batteries can effectively provide a few hours of backup power, and help you squeeze extra value out of your solar panels in some circumstances. The Powerwall just costs less than almost all of them.

On the EnergySage Marketplace, the typical quoted all-in cost of installation for a single Powerwall with everything included (battery, inverter, backup switch and load manager, permitting, and labor) is about $1,065 per kWh of capacity so far in 2024. That price doesn't specifically reflect the Powerwall 3 because of how new it is––but based on what we're seeing on Tesla's website right now, you can expect similar costs for the updated model. 

That's 16% less than the average on the EnergySage Marketplace and about 20% less than the other most popular battery brand, Enphase. Those prices are also before the 30% federal tax credit and any state, local, or utility incentives you might qualify for, which bring the overall cost down much more.

At roughly $16,000 all-in, the Powerwall’s total cost with installation isn't the lowest we regularly see on the EnergySage Marketplace. Plenty of other popular brands go for $15,000 total. The Powerwall holds more electricity than those batteries, though (13.5 kWh vs. 10 kWh, typically), and that extra capacity often helps owners offset enough of their nighttime, non-solar energy use to make up the cost difference. The extra energy can be useful in backup scenarios, too.

It's pretty good for lengthy blackouts

If multi-day power outages are a regular part of life where you live, the Tesla Powerwall 3 could be a good fit. With its much higher continuous output (measured in kW – 11.5 kW compared to the 5 kW that came with the Powerwall 2), you can run more or bigger loads, like an air conditioner or a heat pump, during an outage. What hasn't changed, though, is the capacity (measured in kWh).

But you can always install multiple Powerwall 3’s together, although they aren’t compatible with the older Powerwall 2. According to Tesla, you can string together up to four Powerwall 3 units in a series, which is enough power to keep most homes running for a couple of days, even without solar power refilling the system. That said, some other brands do still offer more flexibility for making your system size larger, now or in the future. 

"Storage isn't one size fits all," Fields says, "and the building blocks for the other brands are better." Homegrid in particular makes it easier to add both capacity (kWh) and power output (kW) in more manageable increments and at better price points, without having to purchase an entire additional battery to get more storage capacity. Alternatively, you could look into a generator-integrated system, like Generac's PWRCell battery.

Owners seem to like it

At least as far as we can tell. The Tesla brand earns a 4.5 out of 5 star rating on the EnergySage Marketplace, based on more than 600 reviews. Most of those reviews are about Tesla installers rather than the equipment itself. But since you would be getting a Powerwall installed by a certified Tesla pro, that rating bodes well for your installation experience. 

Detailed user reviews about the Powerwall are hard to come by. That's probably because after you install a Powerwall, it's more about what you don't notice. When the grid goes out, the Powerwall will kick on before you see the lights flicker and you likely won't even need to reset clocks on stoves and microwaves. You might notice a lower electric bill if you're stuck with one of those solar billing plans that favors the utilities (like in California). The battery itself? It's just a box, sitting somewhere inconspicuous. But it’s sleekly branded.  

Influential YouTuber Matt Ferrell posted a few videos about his experience with his Powerwall. His only specific feedback about the product (rather than battery storage in general) is that he likes the Tesla app because it has a clean interface and makes it easy to choose a preferred charging behavior for your situation.

The app is too basic for some owners' preferences

You still use the standard Tesla mobile app with the Powerwall 3. The app offers time-based control which enhances the value of your stored energy. If you have a variable rate plan, like time-of-use (TOU) rates or demand charges, you can “program Powerwall to use your stored energy when prices spike, saving money over time,” Tesla says. Some owners think the app still remains basic overall, however, and has room for improvement

While some people like the Powerwall app's clean interface and relative simplicity, others find it lacks the control they would like. "If you like self-driving cars, you will love it. Set and forget for 25 years. If you want control, it falls short by a mile," wrote one user on the EnergySage Marketplace. 

One Redditor pointed out that the app has no setting that dynamically switches between charging from solar panels or the grid. Few people will need this setting since almost nobody is on a residential electric rate plan with prices that change in real time. (You can set up the app to switch behaviors at certain times of day to take advantage of time-of-use plans.) Another Redditor who chose Enphase over Tesla points out: "Enphase is easier to get a bit creative with, has programmable relay outputs which can be used to load shed or keep stuff online when there's no grid but plenty of solar, etc." Several other battery brands offer controls more like Enphase's.  

The Powerwall also has a feature called StormWatch that claims to prioritize charging the battery in anticipation of significant weather events (just in case you need backup power). Reviews are mixed. Some owners claim it works no problem, others claim it never works, or only works intermittently.

Tesla's inverter isn't the best choice for every roof

The Powerwall 3's integrated inverter is one of its biggest selling points. But if you have a roof with more than a few juts, angles, and shaded areas, you'll need to pair your Powerwall 3 with a different inverter, meaning you get no value out of this feature. 

Tesla's inverter doesn't optimize the power output of each solar panel like leading brands such as Enphase and SolarEdge. The most popular inverters manage the power at a panel-by-panel level. The Tesla inverter now groups the panels into six zones (which is an upgrade from the Powerwall+ which only offered four zones). So if one panel in that zone gets shaded and the power output drops, every other panel in that zone also drops to that lower power level, even if they're getting direct, unimpeded sunshine. 

If shifting shade patterns aren't an issue on your roof, you'll have no problem with the Powerwall 3 inverter. Even if some of your solar panels get shade, a good installer can probably design around it. But the more nuance you have in your roof, the stronger the case for picking a non-Tesla inverter, which makes the Powerwall 3 a less compelling purchase. 

You think you might want a bigger battery system down the line

If you want to scale up your system later on, the Powerwall 3 is only scalable up to four units, giving you a maximum of 54 kWh. Previously, the Powerwall 2 allowed you to scale up to 10 units, allowing for greater capacity than the 3. Remember, if you have an existing Powerwall 2 and you want more capacity, you’ll have to buy another 2 as the Powerwall 2 and 3 don’t work together.

Overall, the Tesla Powerwall 3’s significantly higher power output is a game changer for home batteries. Although the Powerwall 3 is a big step up when it comes to its increased power and integrated hybrid inverter, which home battery is best for you will always depend on the size of your home, your specific energy needs and how much money you’re looking to spend.

Overall, the Tesla Powerwall 3’s significantly higher power output is a game changer for home batteries. Although the Powerwall 3 is a big step up from the Powerwall 2 when it comes to its increased power and integrated hybrid inverter, which home battery is best for you will always depend on the size of your home, your specific energy needs and how much money you’re looking to spend.

This article was originally published on August 7, 2022, and has been updated.