Tesla Powerwall Alternatives
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It is said that successful people (read: companies) do not do different things; they just do the same things differently. Tesla might not have invented the electric car or batteries, but it certainly came up with ways to improve these technologies and their respective business models. In just a few years, the Tesla Powerwall has established itself as one of the sleekest, most reliable, and reasonably-priced energy storage options in the market.
The residential energy storage market is expected to grow fourfold to $26.4 billion by 2027, at a striking CAGR of 19.7%. It’s no wonder that CEO Elon Musk said at a recent Tesla conference call that the company might soon be making a million powerwalls every year – a prediction aptly called wild by some experts. But it doesn’t sound so wild when you consider that Tesla already has a backlog of 80,000 powerwalls, worth $500 million!
And that’s exactly why any discussion on residential energy storage is incomplete without Tesla. In the coming sections, we help you discover everything about the Tesla Powerwall, from its specifications to its pros and cons, while also exploring some of the best alternatives.
Understanding the Tesla Powerwall
In Tesla’s own words, “Powerwall is a rechargeable home battery system designed to maximize your home’s energy independence.” The powerwall stores excess energy from your solar power and supplies the same amount of energy to your house at night or during power outages, saving you money and ensuring continuous (more or less) power delivery.
How the Powerwall Works (source: Tesla)
It also comes with time-based control that allows users to decide when and how much energy to use from the grid, helping them save even more money if they live in areas with time-of-use pricing.
The makers have added another cool feature into the Powerwall – the device autonomously communicates with the National Weather Service and prioritizes charging in anticipation of severe weather.
The product comes with an admirable 13.5 kWh capacity battery – a lithium-ion unit with an NMC (Nickel-Manganese-Cobalt) chemistry. Thanks to Tesla and a few other players, the lithium battery technology can be said to have truly matured, allowing an almost complete transition from the bulky, high-maintenance, and short-lasting lead-acid batteries.
The powerwall can handle a continuous 5.8 kW (also 7.6 kW for the Powerwall+, Tesla’s integrated battery+inverter system) and a peak 10 kW output for backup. Depending on your power requirements, you can connect up to 10 powerwalls to create a larger battery bank.
With the dimensions of 45.3 in x 29.6 in x 5.75 in and a notable 251 lbs, the boxy battery still manages to look sleek and modern, thanks to Tesla’s signature minimal yet futuristic design. You can mount it on the wall or the ground, and its dust and water resistance means you can even place it on outer walls, although we think a garage or carport would be best suited.
Tesla provides a 10-year warranty for the Powerwall, which is at par with many other options, but that’s only part of the story. Let’s find out what’s hot and what’s not about the Powerwall!
Let’s begin with what matters most for most people – the price tag! The Powerwall has a sticker price of $7,800, which is a price of $577 per kWh of battery capacity. Compare this to other popular products (Panasonic – $701/kWh, LG – $601/kWh), and it does not look so bad.
Of course, there are additional costs, like supporting hardware costs and installation costs, but for something that will last a minimum of 10 years, it’s not terrible.
Speaking of longevity, the Powerwall might share the same number of warranty span with LG or other brands, but Tesla is the only one that provides unlimited cycles in its warranty, making it a genuine 10-year warranty.
On the other hand, a battery warranty with limited cycles might be less than 10 years if you complete the specified number of cycles.
The Tesla battery also triumphs in the Depth-of-Discharge (DoD). DoD is nothing but the actual, usable amount of battery capacity. Historically, batteries often had disappointing DoDs like 60% or 70%, where the remaining 30-40% of the battery capacity wasn’t usable, meaning a 10 kWh battery bank was, in reality, a 6 or 7 kWh one. Tesla’s Li-NMC battery offers a 100% DoD.
Not just that, its round-trip efficiency clocks at 90%, meaning if you put in 10 kWh of energy into it, you will get around 9 kWh when you extract it, which is better than many other options in the market.
Batteries can be AC-coupled or DC-coupled. An AC-coupled battery like the Tesla Powerwall is slightly less efficient but provides greater flexibility and scalability because you can charge it through an AC source.
DC-coupled batteries are slightly more efficient, but they cannot supply power to the house simultaneously with solar since there’s just one centralized inverter. Also, DC-coupled units would be difficult to scale up, say, in the event of creating a small micro-grid out of the devices.
DC-coupled vs AC-Coupled System Layouts (Source: NREL)
The powerwall is the only battery system in the market which employs a liquid thermal management system. Instead of passive air-cooled systems, like in an LG battery, Tesla’s uses a chemical coolant circulated through the unit to reduce heating.
This design delivers effective cooling, and you can install it without leaving space between the wall, improving the aesthetics of the unit.
Tesla Powerwall Exploded View
Unlike many other companies, Tesla manufactures its own battery cells, thanks to the enormous investment and experience of the company in the lithium battery area from its electric cars. This avoids the hassle of dealing with a different company for warranty procedures when something goes wrong with your battery.
Additionally, while many manufacturers require customers to ship the battery back at their own expense (which can be a few hundred dollars!), Tesla right away sends a new device and picks up the old one once the new one has arrived.
The powerwall receives updates from the company regularly and automatically, and this not only fixes bugs but also adds some new and cool features every now and then.
If you already own a solar power system and are looking to buy a Tesla Powerwall, then it’s not your best day. A few months ago, Tesla decided that it would only sell the Powerwall together with its solar panels or solar roof.
So, if you have already bought and installed solar panels from, say, LG or SunPower, then the Powerwall is not an option for you. This is probably its greatest drawback.
The exclusivity is not limited to the purchase but also the installation. Unlike other storage products, you cannot simply buy the Powerwall and install it yourself or call your favorite electrician. You must use one of Tesla’s recognized system installers, which not only takes away the flexibility but also adds to the cost. The installation costs can sometimes take the price to as high as $15,000 per powerwall.
The company website answers the question of “Can Powerwall work without internet?” with “Powerwall needs an internet connection…”. Although the connection is mainly needed to communicate status, update stats and receive software updates, there is less clarity on whether it is essential.
When your internet goes down, or worse, you are planning to install the unit in a remote cabin where there’s no internet, the Powerwall might not be your best choice.
As mentioned, although Li-NMC technology offers many benefits over traditional lead-acid cells, it also brings with it a few concerns. For instance, if not disposed of properly, the cobalt in the cells can enter the environment and prove harmful.
Additionally, while NMC promises 500-1,000 life cycles, LFP (Lithium Iron Phosphate) can deliver up to 3,000 cycles.
However, despite deciding to shift to LFPs for their utility-scale batteries, Tesla is still sticking to Li-NMC for their residential product.
If you are either unable or unwilling to buy the Powerwall for one of the above reasons, you need to look at other alternatives. There are many battery products in the market today, and while not all have the benefits of the Powerwall, many are better than the Powerwall in some respects. Let’s take a look at some of the best ones:
1. LG Chem RESU 10H:
The closest competitor to the powerwall is LG’s RESU battery. LG sells a huge quantity of RESU’s every year, thanks to a legacy of decades that makes people trust in them as a brand.
The RESU is a 9.8 kWh Lithium battery and works perfectly with SolarEdge or SMA inverters. Unlike the powerwall, it’s a DC-coupled unit, meaning it is slightly more efficient. It also offers many similar advantages like in-house manufactured cells, brand reliability, expandability, and decent aesthetics.
Where the RESU lags, however, is its warranty. Despite the same 10-year warranty period, the warranty says that the battery will operate with at least 60% of its original capacity by the end of 10 years, which isn’t quite impressive.
On the pricing side, the device, including hardware and installation, costs between $10,000 and $14,000, which is a bit more expensive per kWh than the Tesla Powerwall.
2. Panasonic EverVolt:
Another global electronics brand, Panasonic, is a popular name in solar as well as batteries. It doesn’t only make and offer its energy storage systems, but also provides battery cells to other brands.
Interestingly, Panasonic offers both DC and AC-coupled batteries and in two different sizes – 11.4 kWh and 17.1 kWh. The EverVolt offers perfectly reliable batteries, but these too fail to impress with a solid warranty – Panasonic also promises only 60% capacity after 10 years, just like LG.
A typical Panasonic AC-coupled EverVolt costs between $15,000 and $20,000, higher than both Tesla and LG.
3. Fortress eVault and eVault Max:
We’ve all seen movies of underdogs winning grand championships, and if there’s a lesser-known brand that threatens to become that champion in the energy storage world, it’s Fortress Power.
Pennsylvania-based Fortress offers two incredible battery options – eVault and eVault Max. Both units offer an astounding 18.5 kWh capacity – claimed to have “the largest capacity in the market”.
The eVault can be expanded to 222 kWh, usable not just for homes but entire buildings, while the eVault Max is AC-coupled, and you can expand it to a whopping 370 kWh.
Both batteries boast LFP technology and a 10-year warranty with an amazing 6,000+ cycles. Not just that, Fortress claims a 98% round trip efficiency, which is significantly greater than that of the Powerwall.
Both the eVault and eVault Max cost around the $13,000 mark and do not require specialized and expensive installations, making them seriously affordable per kWh of capacity.
4. BigBattery KONG:
If you are awed by the eVaults, wait till you meet the KONG! As the name suggests, the BigBattery KONG is a mammoth 12 kWh energy storage unit, but the best part – it comes with a ridiculously low price tag of $4,299, making it the most affordable on this list, at a mere $358 per kWh.
You might wonder about the brand and its experience, but BigBattery is a California-based company that claims to be the “ largest supplier of surplus batteries in the United States”, and has facilities in the USA, Singapore, Hong Kong, and China.
The BigBattery KONG also uses lithium-iron-phosphate battery cells and offers a comprehensive 10-year warranty with up to 3,000 charging cycles and 100% depth-of-discharge, making it one of the most attractive options on this list.
5. Watts Battery:
Subtitled “Lego-like energy to meet your lifestyle”, Watts Battery is a novel, modular concept that tries (and succeeds) in simplifying energy storage for homes. Instead of one bulky box, one module of the Watts Battery is a tiny 1.2 kWh battery+inverter. Ten such modules can be stacked, quite literally, to reach a capacity of 12 kWh, making it the most innovative item on this list.
Each module supports up to 1 kW of solar power and provides 1.5 kW (3 kW peak) of continuous output. Like the Powerwall, it connects to the internet and provides real-time data on your mobile device.
Watts Battery advertises its product by saying “no technician, no drilling, no additional connectors, or devices”, which certainly grabs our attention. And although setting up the first module might require some work, the entire system is pretty straightforward to set up, unlike Tesla or LG’s highly technical installations.
Watts Battery offers a slightly lower warranty period of 7 years, but at over 2,000 lifecycles, which is not bad. Each block of the Watts Battery costs $2,000, making it slightly expensive, but the simplicity and low installation costs compensate for some of it.
6. Pika Harbor 6 Smart Battery:
A bright-colored energy storage unit, just like its colorful name, the Pika Harbor is a DC-coupled, Li-ion, modular battery unit powered using 3-6 modules. You can use it for time-of-use optimization, demand charge management, and even zero-export applications, with up to 17.1 kWh of capacity.
The battery can provide up to 10 kW of continuous power when needed. With a decent round-trip efficiency of 96.5%, a depth-of-discharge 84.5%, and a 10-year warranty, Pika just about keeps up with the competition.
Pika Energy is a Generac company and employs battery cells manufactured by Panasonic, and is quite reliable; however, the RMA process might pose a challenge for the same reason. The Harbor 6 costs up to $20,000 with installation and is more expensive than the Powerwall.
7. Electriq Power PowerPod 2:
Electriq Power is another company in the long list of Californian companies that “started-in-a-garage-and-grew-rapidly”. Electriq’s PowerPod 2 is an intriguing energy storage system that comes in 10, 15, and 20 kWh capacities and both DC and AC-coupled versions.
It uses an LFP battery and boasts all the smart features similar to the Powerwall, such as a smart app and real-time monitoring. The unit also comes with a 10-year warranty and promises at least 70% capacity by year 10.
It might not be gorgeous, but Electriq’s offering is one of the best-looking options on the list and even seems to have a personality of its own. Installing the PowerPod 2 costs between $13,000 and $19,000 and is just a bit more expensive than the Powerwall.
Tesla’s Powerwall, like most of its other products, is a thoughtfully designed energy storage product that deserves the tremendous popularity it has garnered. A reasonable price-point, reliable performance, and top-notch service set it apart.
However, the inability to purchase a Powerwall separately, relatively higher installation costs and a long waiting period forces, us to look at other options.
The best Powerwall alternatives are a mix of legendary brands, like LG and Panasonic, and upcoming but ambitious brands that offer a lot more at a lot lower costs, such as Fortress and BigBattery, and finally, brands that reimagine product design, such as the Watts Battery.
Ultimately, there is no single winner in the never-ending battery storage systems race, and like any other complex piece of machinery, the best option is the one that suits your needs best.