If your goal in going solar is to reduce your reliance on the electric grid, you’ll be needing to include battery storage that can step in when the sun isn’t out. Battery storage is how you can use excess energy generated throughout the day that your home isn’t able to use immediately. It can also help you generate more credits from net metering as it allows you to sell energy back to the grid from your batteries at peak times of use.
Let’s explore these two options, arguably the most popular choices for large scale battery storage on the market today: the Generac Pwrcell and the Tesla Powerwall.
For homeowners looking to go completely off the grid, these batteries won’t line up with your needs. Neither the Tesla Powerwall nor the Generac Pwrcell are intended for off-grid use. These large scale home battery systems are intended for grid-tied homes as a backup that lets you keep the lights on at night and offers an insurance against outages from storms and other disturbances.
You never know when something could go wrong, although many Powerwall and Pwrcell users haven’t experienced any issues, it’s good to know how the warranties stack up.
Tesla Powerwall: 10-year warranty, and a guaranteed end-of-warranty capacity of 70%. Batteries ability to hold a charge diminishes over time, but very slowly, so 70% after 10 years is pretty good considering batteries are often charged and discharged daily.
Generac Pwrcell: 10-year warranty also, but there are no guarantees on the capacity of the battery when it reaches the 10 year mark. They do have a throughput warranty though, which refers to how much energy in total has been circulated through the system. In this case, the warranty is 10 years OR a set amount of energy based on the size of your battery.
PWRCell model 9: 22.6 MWh
PWRCell model 12: 30.2 MWh
PWRCell model 15: 37.8 MWh
PWRCell model 17: 45.3 MWh
Both companies have their own monitoring app to see how much energy you have and how much you’ve used. You can also control how much you use and how much you’re paying by managing your energy use.
Tesla Powerwall App: If you have a Tesla electric car, this may be an enticing feature—you can control both your Powerwall and the battery in your car through the same app. However, you will have to mind two apps if you also have one for your solar panels. Tesla will not integrate with other systems.
Generac Pwrcell App: You can monitor your usage and production, with detailed bill tracking and the ability to predict your energy use and future bills. Depending on the solar panels you choose to go with, you might be able to monitor all of your system from one app.
Let’s get to it, right? How much are we talking about?
Tesla Powerwall Costs start at $6,500 with another $1,100 in hardware needed to secure the battery. Installation, permits and other costs not included. And many customers find they need two units to fully support their system, bringing your investment to anywhere from $15,000 - $25,000 or more.
Generac Pwrcell’s smallest unit starts at around $10,000, but are very flexible and allow you to add more later.