In October 2016, Tesla announced its new home battery, Powerwall 2, with installations to begin in January 2017. This latest clean-energy innovation from Elon Musk promises to provide a complete home energy solution, maintenance-free, at an excellent price.
It sounds like a great deal, and it might be, but here's why you might not want to jump to the Tesla site, credit card in hand, just yet.
Tesla Powerwall 2: What it is and how it works
The problem with solar power is that the majority of homes use electricity in the evenings when the solar panels are not working. Therefore, you need a battery to store energy created during peak periods in order to use it when the sun is down or there are stormy skies overhead.
The Powerwall is, in essence, a battery large enough to power your home. It works with solar panels, storing the energy gathered during the day for use in evenings and as a supplement in peak periods when the solar panels cannot handle the load alone.
The Powerwall 1 is a rechargeable lithium-ion battery that integrated with existing solar systems, using their inverter to convert energy from DC, which the solar panels generate, to AC, which your home can use.
The Powerwall 2 is also lithium-ion, but it's made to work best with Tesla’s solar roofs and contains its own inverter. It offers twice the capacity of the Powerwall 1, with 13.5 kilowatt hours of storage and an output of 7kW at peak use and 5kW continuous. If that’s not enough for the demands of your home (or small business), you can scale up to nine Powerwalls per system.
Why wait to order the Powerwall 2?
As any early adopter knows, there are always bugs in new technologies. While this can be an annoyance with your cell phone, it can have serious consequences when dealing with the power system for your house.
There have been few complaints about Tesla’s Powerwall 1, but the overall customer acceptance was not as strong as expected. In fact, Tesla stopped selling its 10kW-capacity Powerwall 1, citing a lack of interest from customers, yet the Powerwall 2 is even larger. There have also been some complaints of noise from the battery. While the Powerwall 1 claims to be indoor or outdoor rated, some reviews have recommended against outdoor placement for certain climates. These discoveries, while not as disastrous as a phone catching fire, illustrate the practicality of waiting to purchase.
Another consideration is that the Powerwall 2 contains its own inverter. If you already have solar panels, you will need to bypass the inverter. Our research did not uncover any literature about the potential success of adapting the Powerwall 2 to an existing system.
Will the Powerwall 2 work as well as the Powerwall 1? Tesla’s reputation indicates it will, but if you’re not willing to bet your house on it, waiting a few months for the kinks to be worked out and the reviews to come in is a prudent move.
Another consideration is cost. Customers have found the savings have not truly met their expectations. Even those who are seeing significant decreases in their electric bills say it’s in part to changing habits, such as running appliances in the day when the solar panels take the load. The savings also depend on the area where you live. The average person with a Powerwall 1 will pay off the system in 16 years – six years after the warranty expires. The Powerwall 2 is nearly twice as expensive.
If you don’t have panels yet, then you have that additional expense to consider as well.
Finally, Tesla’s innovations will drive down the price point for the technology as a whole as competitors strive to secure their place in the market. Tesla excels in marketing and packaging, but it’s not the only reliable home solar battery available. Trusted companies like Samsung, Panasonic and LG are working on similar devices.
Tesla is slated to begin installing the Powerwall 2 soon, and shortly thereafter we will be hearing about the effectiveness and gremlins of the system. If you’re not in a rush to get off the grid, then waiting a few months for the customer and expert reviews could help you make a more informed purchase.