New affordable sonnenCore battery gives Tesla a run for its money

Updated

new sonnencore battery paired with roofftop solar panels
The sonnenCore is sonnen’s brand-new, affordable home storage system. Image source: sonnen

Just one week after Tesla raised its Powerwall prices, sonnen announced its brand-new home solar battery, the sonnenCore. 

The German battery manufacturer is best-known for its luxury solar battery backup products, the eco and ecoLinx. The keyword here being “luxury” - as the installation of these batteries can run over $30,000.

However, the sonnenCore is substantially cheaper than its predecessors. Coming in at just $9,500, sonnen’s new battery is now competitive with other all-in-one backup systems, like the Tesla Powerwall

In this article, we’ll take a closer look at the sonnenCore, including its features and how it compares to the Tesla Powerwall. 

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    What is the sonnenCore battery?

    The sonnenCore is a 10 kilowatt hour (kWh) lithium-iron-phosphate battery, composed of new sonnenModules, that has the ability to provide 4.8 kilowatts (kW) of continuous power output. 

    It has a built-in solar inverter and a warranty of 10,000 cycles or 10 years, whichever comes first. Homeowners can connect their solar panel system to the built-in sonnenInverter (a 6 kW solar inverter) in order to power their home with solar power 24 hours a day, 7 days a week. 

    sonnenCore solar battery

    Although it is much cheaper than the eco and ecoLinx, the sonnenCore still offers a similar look, as well as advanced features. Image source: sonnen

    It also includes a backup power mode - which the battery will automatically switch to in the event of a grid outage. It does this to keep your home’s power going when the rest of the neighborhood’s lights are out. 

    The sonnenCore also offers a time-of-use load shifting application so you can reduce the amount of energy you take from the grid during expensive peak consumption hours. This is extremely helpful if you live in a state that utilizes a time-of-use rate billing structure, like California.

    All of these features can be controlled directly through the sonnen app. 

    How much does the sonnenCore battery cost?

    The sonnenCore battery costs $9,500 before installation. This is almost four times cheaper than the sonnen ecoLinx battery! Finally, homeowners can afford a high-quality sonnen battery, without having to pay the equivalent of a college tuition for it. 

    Plus, when paired with solar panels, the sonnenCore can be eligible for the 26% federal tax credit. Although we don’t know the exact cost of installing a sonnenCore battery, we can estimate it to be somewhere around $4,000, which brings the total cost to about $13,500. 

    After the tax credit, that price would fall to about $9,900. Not bad! 

    How does the sonnenCore compare to the Tesla Powerwall?

    Let’s lay out the specs to get a better idea of how the sonnenCore stacks up against the Tesla Powerwall.

    Compared: sonnenCore vs. Tesla Powerwall
    Specification sonnenCore Tesla Powerwall
    Price (without installation) $9,500 $8,500
    Chemistry Lithium Iron Phosphate (LFP) Lithium Nickel Manganese Cobalt (NMC)
    Usable power capacity 10 kWh 13.5 kWh
    Continuous power output 4.8 kW 5 kW
    Depth of Discharge (DoD) 100% 100%
    Round-trip efficiency >85% 90%
    Warranty 10 years 10 years
    Operating modes Time-of-use, solar self-consumption, emergency backup Time-of-use, solar self-consumption, emergency backup
    Dimensions 68” L x 27” W x  11” D 45.3” L x 29.6” W X 5.75’ D
    Weight 348 lbs 251.3 lbs

    Price

    If you have a tight budget, the Powerwall comes out on top in terms of price. The Tesla Powerwall and Gateway management system cost $8,000, whereas the sonnenCore costs $9,500. 

    But, when you factor in installation, the Tesla Powerwall actually costs $12,000. While sonnen does not provide an estimated installation cost, we can assume that the total installed cost of a sonnenCore will still be slightly higher than the Powerwall.

    Also keep in mind that despite Tesla claiming that Powerwall prices will drop in the next three years, Powerwall prices have actually increased twice.

    Chemistry

    The chemistry of your battery is more important than you think. In fact, it impacts every aspect of how your battery operates. Even though it does raise the price, the sonnenCore’s battery chemistry beats that of the Tesla Powerwall. 

    The main thing to note about their chemistry is that the sonnenCore does not contain cobalt, therefore making it more stable and safer than the Tesla Powerwall. Don’t be confused - the Tesla Powerwall is still a perfectly safe battery to install. 

    Tesla does have a patented technology that is supposed to prevent thermal runaway (AKA catching on fire), but they’ve kept it tightly under wraps, so there’s no way to make a judgement on that. All we can compare is the chemistry, and sonnen’s is more stable. 

    Batteries that contain cobalt, like the Powerwall, are less stable in extreme conditions or if not properly handled, meaning they are more susceptible to thermal runaway. Although the conditions that would cause thermal runaway are unlikely, it is still something to consider.

    Batteries containing cobalt also produce more hazardous waste during the production and disposal of the battery. So, the lithium iron phosphate (LFP) sonnenCore is safer both from an installation standpoint and an environmental one. 

    Power capacity and output

    The Tesla Powerwall has both a greater capacity and power output. This means that the Tesla Powerwall is able to store more energy and release more energy than the sonnenCore. 

    However, the power output ratings for both batteries are extremely close, so the difference in what each battery can power continuously is very slight. 

    The capacity difference is more significant. The Tesla Powerwall can store 13.5 kWh of electricity, while the sonnenCore can only hold 10 kWh. So when you buy a Powerwall, you pay less for it and you get to store more energy. 

    Find out which battery storage solution is best for your specific home

    Warranty

    Both the sonnenCore battery and the Tesla Powerwall come with a 10-year limited warranty guaranteeing that after 10 years, the battery will operate at 70% of its capacity at time of installation. 

    But when you look a little closer at the two warranties, it’s a little more complex than that. 

    The sonnenCore comes with a cycle life of 10,000 cycles. Tesla also includes a cycle life for the Powerwall - unlimited cycles! But, that’s only if the battery is operated in solar self-consumption mode or backup mode only. 

    If a Powerwall uses any other combination of operating modes, it will operate at 70% of its original capacity after releasing 37.8 megawatt hours (MWh) of power. So how does that compare to the sonnenCore? sonnen’s warranty states that the sonnenCore will operate at 70% of its capacity after releasing an estimated 58 MWh of power. 

    This means that even though both batteries have the same 10-year warranty, the sonnenCore has the ability to release more energy than the Powerwall over time, with less of an impact on the battery capacity

    What does the sonnenCore mean for the future of energy storage?

    The sonnenCore is one of the first batteries that seems like it can really compete with the Tesla Powerwall. The sonnenCore offers a competitive price, increased safety and stability, and a better warranty than the Powerwall, while still offering state-of-the-art operating modes and battery management technology. 

    That’s not to say the sonnenCore will run Powerwall off the road. Tesla’s brand recognition and the fact that the Powerwall has a larger capacity at a lower price will go a long way. But the sonnenCore will at least give homeowners who are looking for an all-in-one battery storage solution with advanced features some more options. 

    This is a great time for sonnen to be introducing an affordable all-in-one battery to the storage market. With the increases in wildfires and hurricanes, and many people being stuck in their homes due to the coronavirus pandemic, having access to reliable power is more important than ever. 

    It only makes sense that as more people choose to install solar and storage that sonnen would want to expand their reach beyond luxury builds and make a product for the average homeowner. 

    Depending on the success of the sonnenCore, we may see more LFP batteries emerge, which would lead to increased safety across the board for solar storage installations. It seems like the sonnenCore will not only have a positive impact on the company, but on the battery storage industry as a whole. 

    How much can you save by installing solar + battery storage?

    Key takeaways

    • German battery manufacturer sonnen recently unveiled the sonnenCore, their newest home solar battery.
    • The sonnenCore costs $9,500, not including installation.
    • The sonnenCore can hold 10 kWh of electricity and has a continuous power output of 4.8 kW and a 10-year warranty.
    • The sonnenCore seems like it could be a big competitor for the Tesla Powerwall.
    • Even though the sonnenCore holds less energy than the Powerwall and is slightly more expensive, its battery chemistry is less susceptible to fires, doesn’t contain hazardous cobalt, and has a better performance warranty.
     - Author of Solar Reviews

    Catherine Lane

    SolarReviews Blog Author

    Catherine is a researcher and content specialist at SolarReviews. She has strong interests in issues related to climate and sustainability which led her to pursue a degree in environmental science at Ramapo College of New Jersey.

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