SunPower has always been known for its top-tier solar panels – now, they’re branching into the storage space. In 2019, the company launched their first home solar battery: the Equinox Storage system. This battery and software solution, when paired with a SunPower Equinox solar panel system, enables you to keep your lights on during power outages and manage your home’s electricity use.
How does SunPower’s Equinox Storage system work?
The Equinox Storage system is a great addition to a solar panel system, but not just any solar panel system. You can only pair this battery solution with a SunPower Equinox solar installation. This means that if you’re installing a different type of solar panel system or looking for a standalone storage solution, you’ll want to look into different battery options.
However, if you’re installing a SunPower Equinox solution, including this battery is worth considering, especially if your utility has reduced or removed net metering, introduced time-of-use rates, or instituted demand charges for residential electricity consumers. Installing a SunPower Equinox solar-plus-storage system allows you to maintain a sustained power supply during both day and night, as long as you store enough power from your solar panels when the sun is shining.
As with many other home battery products, SunPower’s Equinox Storage system is sized for day-to-day use at your home. When your solar panels produce more electricity than you can use in your home, you can store the excess electricity in the battery system instead of sending it back into the grid. Later, when your panels aren’t producing enough electricity to meet your home’s needs, you can use the stored energy in your battery instead of having to buy it from your utility company.
Importantly, when you install a SunPower Equniox solar-plus-storage system, your entire system–battery, panels, microinverters, racking– comes from SunPower. This means that, unlike most solar panel systems, all of the individual components will be warranted by the same company.
Key things to know about the SunPower Equinox storage system
Each Equniox system comes with two main components: the battery and the Hub+. The Hub+ is the connected energy management system that allows you to control how much energy you store, determine how much energy to use, and switch to backup power mode.
Similar to other storage solutions, SunPower provides a companion app for their battery. With their software, you can view real-time energy production and usage from your mobile device, as well as manage that energy remotely.
When evaluating the Equinox Storage solution, there are various important metrics and technical specifications to keep in mind. Among the most important are the size of the battery (power and capacity), its depth of discharge, and roundtrip efficiency.
Two important metrics to keep in mind when comparing the Equinox battery to other home storage options are power and usable capacity. Power (measured in kilowatts, or kW) determines the maximum amount of electricity that can be output at a single time, while usable capacity (measured in kilowatt-hours, or kWh) is a measure of the maximum amount of electricity stored in your battery on a full charge. The Equinox storage system comes in two sizes: one with a maximum power rating of 4.2 kW and 6.5 kWh of usable capacity, and a larger option with a maximum power rating of 6.8 kWh and 13.5 kWh of usable capacity.
Think of your battery like water running through a pipe. The usable energy capacity is the amount of water available to push through the pipe, while power is the size of the pipe itself. Larger pipes allow more water to flow through at once, which depletes the water faster. Similarly, a battery with a high power rating can deliver more electricity at one time, but will burn through its stored energy faster too.
A battery’s power determines the number of appliances you can run from the battery concurrently, while usable capacity determines how long those appliances can be run. Batteries with a higher power rating are capable of powering more, bigger appliances (i.e., your HVAC system) or many appliances at once, while batteries with a higher usable capacity can store more total energy and thus can run your appliances for longer periods of time without needing to recharge.
The functionality of one solar battery next to another can vary; some batteries have excellent off-grid capabilities, while others offer software solutions specific to rate arbitrage. SunPower’s Equinox solar-plus-storage system can provide both of these services and more.
Two key ways to evaluate the performance of a solar battery are its roundtrip efficiency and depth of discharge.
Roundtrip efficiency is a measure of electrical losses involved with charging and discharging a battery. The higher the efficiency percentage, the more efficiently the battery is able to convert incoming electricity into stored electricity and then back into usable electricity. Unfortunately, SunPower does not list the roundtrip efficiency of the Equinox Storage solution on its spec sheet.
Depth of discharge (DoD) indicates the percentage of a battery’s energy that has been discharged relative to the overall capacity of the battery. Because the useful life of a battery decreases each time you charge, discharge, and re-charge–or cycle–your battery, many battery manufacturers specify a maximum DoD level for optimal battery performance. In general, batteries with a higher depth of discharge are considered better quality products. The Equinox Storage solution has a favorable depth of discharge of 98 percent.
SunPower Equinox Storage warranty coverage
Warranty period: 10 years
The SunPower Equinox battery line is backed by 10-year product and performance warranties that cover the product in the case of faulty parts or defects, as well as the actual performance of the battery.
Importantly, SunPower’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 starts to lose some of its ability to hold a charge.
Warranty, capacity, and power are three of the most important metrics you should consider when comparing home battery options. If you’re curious to learn more about the best way to perform your own battery comparisons, check out our video explaining how to evaluate your home energy storage options:
If you want to compare individual battery models side-by-side, our battery Buyer’s Guide lets you select products and compare them based on efficiency, capacity, power, and more.
How much does the SunPower’s Equinox Storage system cost?
The cost of installing a battery isn’t as straightforward as looking up the list price for an individual component–i.e., your battery. In fact, depending on your electrical setup, installation costs can vary widely. While there isn’t exact pricing for the Equinox Storage system available online, similar battery options typically cost anywhere between $8,000 and $20,000.
If you want to install an Equinox solar-plus-storage system, battery costs are just one piece of the equation. A 5 kilowatt (kW) solar energy system costs anywhere from $9,000 to $15,000 depending on where you live and the type of equipment you choose; because SunPower offers premium, high-efficiency products, they typically end up on the higher end of cost ranges.
That may sound like a lot of money, but installing a solar-plus-storage system can be a worthwhile investment. Whether or not the SunPower Equinox system makes sense for you is determined by the way that your electric utility structures its rates, as well as your reasons for installing a solar battery.
In some cases, depending on where you live, you may have access to financial incentives that can reduce your home energy storage installation costs. For instance, if you live in California, you could get a cash rebate that covers most of your home battery costs through the Self-Generation Incentive Program (SGIP). Other states (such as Massachusetts) are in the early stages of evaluating battery storage performance incentives as well, and several states already provide cash rebates.
Where to buy the SunPower Equinox Storage system
SunPower plans to roll out the Equinox storage solution nationwide throughout 2020. In order to install the Equinox Storage system, you need to go solar with a certified SunPower installer. Adding energy storage technology to your home is a complicated process that requires electrical expertise, certifications, and knowledge of the best practices required to install a solar-plus-storage system correctly.
A qualified EnergySage-approved company can give you the best recommendation about the SunPower’s home battery system and other energy storage options available to homeowners today. If you are interested in receiving competing installation quotes for solar and energy storage options from local installers near you, simply join the EnergySage Solar Marketplace today and indicate what products you’re interested in your profile’s preferences section.