generac pwrcell review

The Generac PWRcell home battery complete review

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In 2019, Generac acquired battery manufacturer Pika Energy, and has since integrated their technology into the launch of their own Generac-branded home storage solution: the Generac PWRcell. Having long been a leader in the backup power space, Generac is now moving into clean energy and energy storage, with the PWRcell line of batteries at the forefront of their new product fleet.

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There’s a lot to talk about when it comes to the PWRcell battery system – skip down to any section here:

How does the Generac PWRcell work?

The Generac PWRcell pairs well with solar panel systems, especially if your utility has reduced or removed net metering, introduced time-of-use rates, or instituted demand charges. Installing a storage solution like the Generac PWRcell with a solar energy system allows you to maintain a sustained power supply during day or night, as long as you store enough power from your solar panels when the sun is shining.

As with many other home battery products, the Generac PWRcell is sized for day-to-day use at your home and is primarily designed to be paired with a solar panel system. 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.

Pika’s original battery solution was designed with two major markets in mind. The first was locations with time-of-use (TOU) electricity rates, such as California, where electricity costs more during the hours of the day when demand is highest, which are often when the sun isn’t shining at its brightest. The second was “zero export” markets, such as Hawaii, where solar system owners are prohibited from exporting their excess solar electricity to the grid. The battery has built-in operating modes that are designed to optimize household energy usage under each of these scenarios. 

How much does the Generac PWRcell cost?

The Generac PWRcell starts at a price of $9,999 and scales up in cost for larger battery models. This price includes the battery itself, but not additional costs like installation and labor. 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.

If you want to install the PWRcell as part of a 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.

That may sound like a lot of money, but installing a solar-plus-storage system can be a worthwhile investment. Whether or not the Generac PWRcell 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.

Key things to know about the Generac PWRcell

Generac describes the PWRcell, which first launched in September 2019 following the acquisition of Pika Energy, as a “truly scalable storage system with unmatched raw power.” As described in greater depth below, the technical specifications of the battery support these claims: the stackable PWRcell has among the most power of any residential battery currently on the market.

Alongside the PWRcell, Generac offers their own energy monitoring system, known as PWRview. Complete with a custom mobile app, PWRview displays detailed electricity bill tracking and forecasting, as well as other useful energy dashboards. You can also set daily and monthly goals on electricity usage within the application.

When evaluating the PWRcell, 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

Size

The Generac PWRcell comes in four different models, based on the number of battery modules: the PWRcell M3, PWRcell M4, PWRcell M5, and PWRcell M6. Two important metrics to keep in mind when comparing the PWRcell 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 PWRcell M6, the largest battery in the lineup, boasts a maximum power rating of 6.7 kW to go along with 18 kWh of usable capacity

Importantly, the PWRcell system is modular, meaning that you can add multiple battery products to your storage setup. For example, you might want to install multiple PWRcell batteries for a home with high energy demands. Generac’s PWRcell spec sheet indicates that you can connect up to two PWRcells to a single PWRcell inverter, so you’ll need to upgrade your supporting hardware to add even more storage capacity beyond the stored energy of two batteries.

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 available energy capacity 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.

Basic functionality

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. The suite of PWRcell hardware and software products are designed to provide both of these services.

Generac offers a solar inverter alongside their PWRcell. This inverter acts as both a battery inverter and a rooftop solar array inverter. This means that, as long as your installer installs the correct components and the PWRcell inverter, your Generac PWRcell battery will be able to provide backup power for your home when the grid goes down, as well as interact with your solar panel system if you have one.

Their monitoring technology is fully built-in to their PWRcell inverter, but Generac also offers their monitoring capabilities with the installation of a device known as PWRview. With the built-in inverter monitoring technology, Generac’s PWRcell batteries and their associated parts can intelligently manage electrical loads throughout your house and appropriately pull energy from the battery when needed.

Performance metrics

Two key ways to evaluate the performance of a solar battery are its depth of discharge and roundtrip efficiency

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 Generac PWRcell boasts a depth of discharge of 84 percent.

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. The Generac PWRcell has a high roundtrip efficiency of 96.5 percent; this means that for every 10 kilowatt-hours (kWh) of electricity you put into the battery, you’ll receive 9.65 kWh of output.

Generac PWRcell warranty coverage

Generac PWRcell warranties


  • Warranty period: 10 years 
  • Throughput warranty: between 22.6 and 45.3 megawatt-hours (MWh), depending on battery size

In most cases, homes with a Generac battery will charge and discharge their battery every day. The PWRcell comes with a 10-year limited warranty. For the different models of the PWRcell, Generac also notes a “throughput warranty”. A throughput warranty is another way to measure when the warranty period on a battery has been reached based not on time but rather on how much energy has been stored and discharged over its lifetime. 

Overall, a PWRcell warranty is valid for either 10 years or the amount of time it takes to cycle the specified amount of energy through the battery, whichever comes first. (This is similar to car warranties – ten years or 100,000 miles, where the throughput of a battery is similar to mileage warranties.) The throughput warranty values for each PWRcell model are below:

PWRcell modelThroughput warranty
M322.6 MWh
M430.2 MWh
M537.8 MWh
M645.3 MWh

Importantly, Generac’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.

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.

Can you go off-grid with the Generac PWRcell?


Installing a solar-plus-storage system at your home is a great way to take control of your electricity bill, but it doesn’t mean that you’re completely disconnected from your utility. Going “off the grid” with solar batteries is actually a more expensive and complicated proposition than you might think. Most home batteries, including the PWRcell, only have enough capacity to store a few hours of electricity. If you want to make sure you can maintain power to your property for days at a time, you’ll need to install several PWRcell batteries together to increase your storage capabilities.

Frequently asked questions about Generac’s battery

There are many, many questions you can (and should) ask about any battery you’re installing. Here are a few more quick hits about the Generac PWRcell:

Where can a PWRcell be installed?

Like the Tesla Powerwall, the Generac PWRcell is properly set up to be installed inside or outside.

Can you power an electric vehicle with a PWRcell?

The largest PWRcell model is 18 kWh, which is much smaller than the batteries in most long-range electric cars. As such, you likely won’t be able to recharge much of your electric car with a Generac PWRcell.

Can a PWRcell back up your whole house?

In short, yes, but not for long. If you want to back up your whole house for an extended period of time, you’ll need a much larger battery bank. Plus, you’ll definitely want to pair your storage system with solar panels. A single PWRcell battery might keep your appliances going for a few hours or so, but don’t expect to stay powered through a long outage with just a single PWRcell battery (even the biggest one available). Check out our article about how many solar batteries you need to see the math.

Where to buy the Generac PWRcell

The Generac PWRcell battery is currently available online through Generac’s website where you can request a quote and through any solar and/or energy storage installation company that is a certified Generac/Pika 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 Generac 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.

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About Jacob Marsh

Jacob is a researcher and content writer at EnergySage, where he focuses primarily on current issues–and new technology!–in the solar industry. With a background in environmental and geological science, Jacob brings an analytical perspective and passion for conservation to help solar shoppers make the right energy choices for their wallet and the environment. Outside of EnergySage, you can find him playing Ultimate Frisbee or learning a new, obscure board game.

48 thoughts on “The Generac PWRcell home battery complete review

  1. Don Viecelli

    I would be interested to know if the system could be installed for use only as a solar backup system instead of installing a gas fed 22 kw generator. I use community solar energy now and don’t plan on installing solar panels on my roof.

    Reply
  2. Axel Detrew

    How much was your total cost at the end .
    Are you able to run the hole house at 100% with that system or you must play with it ?

    Reply
  3. Mike

    What type of battery does the Generac use?
    Lithium Ion
    Lithium Iron Phosphate (like Sonnen)
    or some other

    Reply
    1. Chris

      They state it’s an NMC battery chemistry.. but thru don’t state what format these batteries are in sadly. Still looking for that info

      Reply
  4. Maxx

    What I find so infuriating is that if a person wants to do “anything green” whether it is eating organically or powering sustainably the costs are always so inflated, not due to manufacturing costs of the technology or equipment, but because all of these industries are just plain greedy and dishonest. I have a friend that lives in Norway. He converted over to 95% sustainable years ago with barely a premium over staying on the power grid system. It seems in the U.S. going green is only for the very rich, who actually don’t need it, or people just can’t afford it. Based on cost recovery projections from the industry itself a $20K investment will take over 20 years to recover the initial cost only. Replacement batteries , panels and inverters are barley guaranteed for even 10 years are not included. This makes the conversion not a very reasonable idea at all. Why can foreign countries do so much better? I would guess it has to do with the U.S. policy of allowing businesses “open season” on customers. With all of the advancements and innovation we were promised the costs would decrease. Sadly, for some reason they have not.

    Reply
    1. Paul

      Simple solution to your problem. Become an importer of the “Norway systems” and become mega-rich by providing people the cost effective green technology you claim they are being cheated out of.

      Reply
    2. Jj hagelund

      Thats not true. With power home you can match your solar system bill within 5 years of procurement. Meaning as the utility costs rise a % every year, the solar system plan you have remains and within that 5 year span you actually pay less than your normal utility bill while also losing the power bill thanks to your system upgrade. i have it. 19 panels and a battery with 6 cells. 20 year financed @ 2.9% ez pz. 206 a month. Not to mention federal tax incentives and a bonus for going with them. Gotta love it.

      Reply
    3. Joe Bennett

      Your exactly right. I just installed a 5000 watt solar array and batteries my self for five grand. Americans seem to always get the short end of things. Someday I will have 10000 watts and unplug from the grid.

      Reply
    4. Fred

      For one, US companies generally give us very affordable energy so the “payback” on a solar system is much longer when the cost of energy is so reasonable. 2nd “eating organically” is hard on the environment. It takes way more land, way more water and way more resources to produce food “organically” than it does using technology. What exactly is “green” about wasting resources?

      Reply
  5. Brian Mulligan

    This is over priced considering the advances in power cell technology. LG has a more compact cell that can produce 11 to 13 kw and it’s 3k plus cheaper. I have a generac generator but you’re going to have to do much better if you want my business for power cells.

    Reply
    1. john hagelund

      11 to 13 kw is maybe half a days worth of power for a 1500 sq ft home in the Midwest and without kids or a family involved. I have 4 kids and 1800 sq ft. Average kw usage per day is around 25 to 30kw and my solar system produces 35 to 40 kw per day average. I have literally no power bill now. Went with powerhome and never looked back.

      Reply
  6. gary waller

    I already have solar but I was looking at the power cells can you hook up power shell to an already existing solar system

    Reply
    1. James l. Moore

      Hi Gary my name is Jim iam wanting to get battery storage for my 10kw actually 11 +kw system for my home for a power outage and be able to us my 22kw gentronic generator to charge my battery if it should need more charge than my solar can supply.

      Reply
    2. john hagelund

      With generac you start with 3 cells on a basic system and can advance to 6. Their company is growing with powerhome and a command module cell is coming soon as well.

      Reply

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