If we were to plot the solar industry’s most important milestones on a timeline, an unmissable milestone would be the entry of Tesla’s sleek Powerwall battery on the solar landscape back in 2016. Its current version, also known as the Powerwall 2, is sleeker, more powerful, and of course, wildly popular!
For many decades, ugly, bulky, and maintenance-hungry lead-acid batteries have ruled the energy storage market. And although Tesla did not invent the lithium battery, it put the battery cells inside a sleek encasing, added quality electronics, and slapped an attractive price tag on it.
Before we talk about the current costing and alternative options, let’s quickly revisit the machine’s specs and features.
Tesla Powerwall 2 Specs and Features
-
Capacity:
The Powerwall comes with a 13.5 kWh storage capacity. For context, a typical Kiwi home uses 20-25 kWh daily. This makes the 13.5 kWh capacity sufficient for use during evenings and early mornings. The battery can pump out a maximum of 5 kW (peak 7 kW), making it capable of powering even the energy-hungry devices like fridges and ovens. -
Battery chemistry:
The battery features Li-NMC (lithium ion - nickel manganese cobalt) cells, which are incredibly efficient - especially when compared to their older, lead-acid counterparts. Lithium batteries are also much lighter and safer, and last longer. -
Efficiency and DoD:
The battery boasts some impressive specs. For instance, it has a Depth of Discharge of 100%, which allows you to utilize the entire rated capacity. Tesla’s batteries also have a remarkable 90% round-trip efficiency.
The Tesla Powerwall is unique even among lithium battery banks, because it manufactures its own battery cells, thanks to its enormous experience producing cutting-edge electric cars. -
Liquid cooling
While many modern batteries opt for a traditional fan cooling system, Tesla employs an innovative liquid-cooling system in its batteries. It circulates a chemical coolant through the battery, reducing heating and improving the performance as well as longevity.
Tesla Powerwall exploded view -
Smart monitoring:
Tesla’s Powerwall battery is a lot more than just a battery. It is a full-fledged energy storage system with smart features such as remote monitoring. Users can constantly check the battery’s status, state of charge, etc. The device also receives updates automatically when connected to the web.
Tesla Powerwall Monitoring -
AC-Coupled:
Solar batteries come in 2 main varieties - AC-coupled and DC-coupled. DC coupled batteries connect to a DC source, and are slightly more efficient, thanks to a lower number of AC-DC conversions in them. However, AC-coupled batteries offer more flexibility, since they can be charged directly from the grid and can easily be retrofitted to any existing solar power system.
The Powerwall is an AC-coupled battery, and it can be charged through your wall unit even when your panels aren’t generating any power.
DC-coupled vs AC-Coupled System Layouts
-
Functionality During Power Outages:
One of the key reasons for buying a Powerwall is its ability to power a home through a power outage. Some simpler batteries may not be able to smartly switch to an off-grid mode when the power goes out, but the Powerwall’s “Backup Reserve” mode kicks in within a fraction of a second, keeping your appliances running.
You can even set a higher or lower reserve percentage manually. It is also possible to discharge the battery below the set reserve percentage if the outage continues longer than expected. The “Storm Watch” feature is another interesting trick the battery employs to tackle outages. It receives severe weather alerts and lowers the reserve percentage automatically.
Here’s a snapshot of all the key specs of the Powerwall battery - NZ Model
Tesla Powerwall Specs - Model Available In New Zealand
Tesla Powerwall 2 Cost in New Zealand
When the Powerwall was announced, one of the things that caught everyone’s attention was its price tag. At USD $5,500, or about NZD $8,000, it was wonderfully inexpensive for a gadget of this nature.
However, the product underwent several ‘price adjustments’ over the years, which is another way of saying that Tesla kept on raising the Powerwall’s price year after year. Currently, the Powerwall costs around the $17,000 price mark, including installation.
Should You Buy the Tesla Powerwall?
Just like Tesla’s cars, its Powerwall home battery is an incredibly reliable machine. Customers who have bought the Powerwall have rarely regretted the investment, and a solar panel system and Powerwall combo works incredibly well for homeowners and small businesses.
That said, the Tesla Powerwall cannot lay claim to being the single best battery product on the market. Over the past few years, some solid alternatives have entered the market. Let’s take a look.
Tesla Powerwall Alternatives
Enphase IQ Battery
Enphase is the undisputed global leader in microinverters, and its IQ battery is another premium product (alongside its futuristic bidirectional EV charger). The battery comprises 12 integrated IQ8 microinverters, and a cutting-edge LFP battery, which is safer than Li-NMC and even lasts longer.
The battery has a “Time-of-use optimization” feature for greater savings, and has a sleek and compact, plug-and-play design. It comes with a 10 kWh storage capacity and a 3.08 kW continuous output, which is a much lower rate of output compared to Tesla Powerwalls 5 kW output.
Panasonic Sunvolt Series
Another huge name in electronics, Panasonic brings its massive experience to the battery world with its SunVolt battery series. Customers can choose between 4 LFP options ranging from 5.37 kWh to 21.48 kWh.
The battery claims superb efficiencies. However, the 5-year warranty could have been better.
Sonnen Evo Battery
With nearly 100,000 batteries installed globally, Sonnen is a German battery brand with a solid reputation. Its current product line-up is similar to the Powerwalls - you can choose a Sonnen battery or Sonnen hybrid setup, which comes with a battery + inverter combo (like the Powerwall+).
The battery is scalable, and the smallest unit offers 5 kWh capacity, which can be increased in 2.5 kWh increments. It houses superior LFP cells, Smart Plug Integration and remote activation features.
BYD Battery Box
Chinese electric automaker BYD recently became the largest manufacturer of EVs, overtaking Tesla. It now threatens Tesla and other companies once again with its affordable home battery solutions. The BYD Battery Box is a simple but reliable battery unit with a modular design.
It uses the LFP chemistry and can be scaled up from 3.8 kWh all the way up to 245.8 kWh. BYD uses its patented plum design to fit the batteries together like lego blocks, eliminating the need for complicated wiring.
Huawei Luna Series
Another Chinese electronics giant, Huawei offers solar inverters and batteries in NZ. The Luna battery series includes premium offerings in a scalable 5-30 kWh capacity (2.5-5 kW continuous output).
The battery boasts 100% DoD and comes with the state-of-the-art LFP chemistry.
Q Cells Q. Home Core Battery
Q Cells is a global solar brand with a powerful presence. Its Q. Home Core battery is designed in Germany and offers an exceptional 15-year warranty. The product houses premium Samsung battery cells, which offer 6.8 kWh, 13.7 kWh, and 20.5 kWh capacities in a scalable design.
The Q.ommand feature allows users to monitor and manage the battery performance from a remote application.
Other Noteworthy Solar Battery Options
While the above-listed products are some of the best solar battery options in NZ, there are a few other choices not described above. These include the following:
- Sungrow SBR HV 9.6 battery, which can be scaled up to an impressive 100 kWh and has an LFP chemistry.
- Alpha Smile battery series, which comes with aesthetically pleasing designs, massive scalability and a fast discharging option. There is also a hybrid battery + inverter option to choose from.
- Freedom batteries offer both residential and commercial options with 5-15 kWh options
- Energizer Homepower, which also comes with an LFP chemistry and offers 6.1-24.4 kWh capacities.
- Solax Triple Power battery series, which include 4.5 and 6.3 kWh options.
Here’s a compilation of all the battery options available in New Zealand, with their key features and specs.
Final Thoughts
Solar batteries are increasingly becoming an important component of home solar systems - whether you are trying to save power bills or fight power outages caused by cyclones.
Among solar batteries, the buzz that started with the first ever Tesla Powerwall has still not died down -making it one of the most popular options of all time. Its sleek design, modern features, and incredible dependability make it worth buying.
However, buyers should remember that there are plenty of other excellent battery options on the market. The major Tesla alternatives include brand names like Q Cells, Pansonic and Enphase, and are definitely worth considering.
To get 3 free quotes for a solar and battery system, head to our online quote request form.
Good to see the other options but Powerwall still seems to be the most attractive in terms of features, if not price. I note that all the options are essentially “off the shelf” type and you haven’t considered a “build a system” option using stackable batteries combined with a separate inverter. As an alternative to a Powerwall I quite like the idea of batteries such as the SOK combined with a Victron multiplus 2 inverter with Victron’s ESS system. The price would appear to be similar or marginally cheaper than the Powerwall for a similar or slightly larger capacity. Not as pretty of course 🙂