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Tesla brought solar batteries to the forefront of home energy technology with the launch of the Powerwall in 2015. A year later, Elon Musk announced the new and improved Tesla Powerwall 2, an industry-leading product that takes solar-plus-storage to the next level. The Powerwall 2 offers a few much-needed improvements over the original Powerwall product, including a larger storage capacity, a lower per-kilowatt hour cost, and a built-in inverter.
The new Tesla Powerwall 2 comes in an updated, more versatile package
When you compare the Powerwall 2.0 side-by-side with the original Powerwall, one of the most noticeable changes is the difference in shape. The first generation Powerwall had a smooth shape with tapered edges, reflective of Tesla’s stylized, futuristic design. However, that shape meant that you had to mount the Powerwall on a wall in order to install it – a seemingly simple requirement that could quickly complicate the installation process due to the battery’s weight.
The shell of the new Powerwall 2.0 has square edges that make it possible to rest the battery on the ground. In addition to opening up more locations for installation, the square edges of the Powerwall 2.0 make it easier to install multiple Powerwalls in a small space.
Tesla Powerwall 2 has twice the storage of the original Powerwall
Home batteries have many useful functions. They make it possible to store your excess solar power at home, rather than send it back to the grid. If your utility has demand charges or time-of-use (TOU) rates, they can help you save money on your energy bills by reducing your electricity use from the grid. However, the primary reason that many homeowners want home energy storage is for backup power in case of emergency – one of the primary areas where the new Powerwall 2 beats out its predecessor.
An average American home uses approximately 30 kWh of electricity each day. The original Powerwall offered 6.4 kWh of electricity storage, which is enough to supply approximately 20 percent of one’s daily electricity use. A single Powerwall 2 battery, by comparison, has 13.5 kWh of energy storage – more than double the original Powerwall, and enough to supply nearly half of your home’s electricity use for the day. While that still isn’t enough to take you off the grid, it is a significant improvement over the first generation Powerwall technology.
The cost of a Powerwall 2 is the lowest on the market per kilowatt-hour of storage
The best way to make a true apples-to-apples comparison between home batteries is to compare their prices relative to the amount of storage they contain. The more kilowatt-hours of storage you get per dollars spent, the better deal you’re getting. In this category, the Tesla Powerwall 2.0 excels, offering twice as much energy storage for roughly the same price as the original Powerwall. Here’s how the numbers break down:
According to the Tesla website, the total cost of buying and installing a Powerwall 2 is approximately $7,600 all in. It has 13.5 kWh of storage capacity, which means that the Powerwall 2 offers a price of about $563 per kWh ($7,600 ÷ 13.5 kWh).
By comparison, the first-generation Tesla Powerwall offered 6.4 kWh of storage capacity, and came with a $3,000 price tag. However, the battery also required additional equipment that needed to be purchased separately (more below). Tesla did not offer information on expected total costs, but industry analysts estimate that the total cost would be roughly double the listed price of the Powerwall. Assuming that the all-in cost of equipment and installation was $6,000, the original Powerwall offered a price of $938 per kWh ($6,000 ÷ 6.4 kWh).
New Powerwall 2.0 includes a built-in inverter
Every home battery needs to be paired with an inverter that can manage the flow of electricity to and from the battery itself. To install a first-generation Powerwall, you also had to purchase and install a special inverter that was compatible with the battery. However, the new Powerwall 2.0 comes equipped with an inverter built right into the product.
That being said, if you are connecting the battery to a solar panel system, you will need only one inverter for your solar panels and battery. In that case, Tesla also produces versions of the Powerwall 2 that don’t come with an integrated inverter. Both options make the installation process simpler and more cost-effective.
Tesla’s warranty for the Powerwall 2: an improvement over the previous generation
The Powerwall 2 comes with an unlimited 10-year warranty that assumes your battery is used for daily charging and draining. Unlike its previous generation, the new Powerwall also comes with a capacity warranty as of mid-2017. Tesla ensures that the Powerwall 2.0 will retain at least 70 percent of its capacity during its 10-year warranty 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 will lose some of its ability to hold a charge.
Tesla’s battery life 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, whether it’s an electric vehicle battery, a home energy battery, or a rechargeable AA battery. Capacity warranties, both for the Powerwall 2.0 and other solar batteries, help protect homeowners against unreasonable amounts of deterioration.
Now is a great time to consider a solar-plus-storage system for your home
The new Tesla Powerwall 2.0 is an exciting low-cost option for home energy storage, and companies are already starting to install them across the country. Homeowners in Hawaii and California, as well as reduced net metering states like Arizona and Nevada, are already positioned to benefit from solar batteries – and the cost might be less than you think. You can get customized offers from qualified pre-vetted installers in your area by joining the EnergySage Solar Marketplace. Many solar companies on EnergySage can offer you a home battery bundled into your solar installation; simply indicate upon registration that you’re interested in solar battery options.