Should you buy the Kohler Power Reserve solar battery?
Individual panel prices
Prices of DIY kits
Installed system prices
Editor's note: As of January 2023, the Kohler Power Reserve solar battery has been discontinued. For more home battery options, check out our list of the best solar batteries.
If you own a home (or ever lived in one, really), the name Kohler probably rings a bell. Kohler has made everything from sinks, to toilets, and even cabinets. But what you might not realize is that Kohler isn’t just a leader in plumbing equipment, but in power generation, as well.
In fact, Kohler built the first modern-day generator back in 1920, and it’s still a trusted name in backup power today. Despite that, even a 100-year-old company can still experience some “firsts”. Having seen the importance that clean energy plays in having a sustainable future, Kohler Power released its first residential solar battery - the Kohler Power Reserve.
But does the Kohler Power Reserve energy storage system live up to the company’s high quality standards and outstanding legacy? And being that it’s offered at a higher price point than competitors like the sonnenCore and Tesla Powerwall, is it worth the extra cost?
The Kohler Power Reserve is a lithium-ion solar battery (more specifically, it’s a lithium iron phosphate, or LFP battery, that stores the excess solar energy a solar system produces.
The stored power can then be used to run the house at a later time when the solar panels can’t meet the home’s energy needs, like when the sun goes down. It can even power your appliances during a power outage.
When you add a solar battery to your home solar system, you then have what is known as a “hybrid solar system”.
Watch the below video to get a better understanding of how solar panels and batteries work together to power homes:
Homeowners can choose between four different operating modes for the Power Reserve:
Kohler offers their solar battery backup system in three different sizes, so they have three different starting prices:
|Battery size||Starting cost*|
*Starting cost not including installation or incentives
These prices are a bit higher than what you pay for some other leading solar batteries on the market. The 10 kWh sonnenCore battery, for example, costs around $9,500 before installation or incentives, while the 13.5 kWh Tesla Powerwall costs $8,500 before incentives or installation.
Yes, the Kohler Power Reserve qualifies for the 30% federal solar tax credit. The tax credit can reduce the cost of installing a Power Reserve battery by between $4,600 and $8,000.
Let’s say you purchase the 10 kWh Power Reserve. The installation costs an additional $2,000, bringing the total cost to $15,325. The federal solar tax credit would drop the price down to about $10,727.
Another thing to take note of is the fact that the Power Reserve is OpenADR compliant, so it can participate in energy storage aggregation programs where available, which means your utility will pay you for access to the energy you have stored within your battery.
So, the Power Reserve could actually wind up earning you a little extra money from your utility if your utility has one of these programs, or is planning one in the future.
Keep in mind, installation costs will vary greatly depending on the battery model, where you live, the design of the system, and the installer you choose.
|Specification||DC model||AC model (10 kWh)|
|Usable capacity||10, 15, 20 kWh||10, 15, 20 kWh|
|Continuous power output||7.6 kW||5.12 kW - 7.6 kW|
|Peak power output (60 seconds)||9.12 kW||5.76 kW - 8.64 kW|
The Kohler Power Reserve comes in three different sizes: 10 kWh, 15 kWh, and 20 kWh. The battery capacity tells you how much electricity the battery will store, and how long it will be able to run your appliances. Offering a variety of sizes gives homeowners the opportunity to choose what size is best for their lifestyle.
The higher your home’s energy usage, the bigger the battery you’ll need. If you use a lot of electricity, a 20 kWh model may be the best choice for your home. However, most homeowners can get by just fine with the 10 kWh or 15 kWh batteries.
Aside from a variety of sizes, Kohler also offers their batteries in both AC and DC models, again giving homeowners more control over their battery system.
An AC-coupled battery is best paired with an existing home solar system. The battery has its own inverter, so it can be easily connected on the AC side of the existing solar inverter.
A DC-coupled battery is the better choice when you’re installing your solar panels and battery at the same time. The DC battery can be installed before the solar inverter and charged directly with the electricity produced by the solar panels, making them more efficient.
Learn more: AC vs DC-coupled batteries
Depending on the model you choose, the Power Reserve will release anywhere between 5.12 kW and 7.6 kW of continuous power. “Continuous power output” describes how much electricity a battery can release over an extended period of time, giving you an idea of what appliances it can run.
Most solar batteries today have a continuous power output of 5 kW. So, if you’re looking to run more power-hungry appliances, like a central air conditioner, the Kohler Power Reserve is a good choice.
While continuous power output measures how much power a battery can release over a sustained period of time, peak power output is the maximum amount of power a battery can release for a very short amount of time.
Peak power output is important because many appliances require more power when they turn on, and then draw less once they’re up and running. So, you need your battery to be able to release the amount of energy necessary to turn on your appliances, not just run them.
In the case of the Kohler Power Reserve, the battery will release between 5.76 kW and 9.12 kW of power for 60 seconds, depending on the model. Most batteries on the market today have a peak power output of around 7 kW for just 10 seconds.
If you’re looking to run something like a sump pump or an air conditioner that needs a lot of electricity to power up, any of the Kohler models besides the 10 kWh AC would work best for you.
When power is sent to a battery, some of that electricity is used to facilitate the storing process, which means all of the electricity your panels produce won’t be stored for you to use. The round-trip efficiency of a battery gives you an idea of how much electricity is lost to that storing process.
The higher the efficiency rating, the better. Most batteries today have an efficiency rating of at least 90%, with a lot of them coming in around 95%. The Kohler Power Reserve has a round-trip efficiency of 96.6%, which is good in our book.
The Kohler Power Reserve is a lithium-ion battery. More specifically, it’s a lithium iron phosphate, or LFP, battery. LFP batteries are able to remain stable at high temperatures, making them less likely to overheat and catch on fire than other types of lithium-ion chemistries, like nickel manganese cadmium (NMC)-based batteries.
Don’t get us wrong, NMC batteries like the Tesla Powerwall and LG Chem RESU are still perfectly safe to install in your home, so long as they are handled correctly. But, if you want a little more peace of mind, an LFP battery like the Kohler Power Reserve could be the one to go with.
The Kohler Power Reserve comes with two different warranties: a product defect warranty and a capacity warranty.
Under the product defect warranty, Kohler will cover qualifying defects of its energy storage system for either of the following warranty terms, whichever comes first:
This is pretty standard for product defect warranties. Anything less than 10 years should serve as a red flag.
Solar batteries, just like the batteries in your phone or laptop, lose the ability to hold a charge as time goes on. The capacity warranty gives you some insight into how long the solar battery will last as it is used.
Kohler’s capacity warranty is close to what you’ll see from most solar battery manufacturers. Kohler states that the Power Reserve will operate at a minimum of 70% of its initial capacity during the first 10 years of operation, or until the battery has released 3 megawatt-hours (MWh) per kWh of storage capacity, whichever comes first.
Battery warranty language can be a bit confusing, so let’s simplify this by using the 10 kWh Power Reserve as an example. Based on the warranty terms, the 10 kWh Power Reserve would be able to release 30 MWh (or 30,000 kWh) of electricity before falling below 70% of its original capacity.
But, will you pass the 30 MWh threshold before you reach 10 years? Well, it depends on how the battery is used. If the battery is completely discharged every single day from the initial installation date, you would reach 30 MWh after about 8.22 years, meaning the battery wouldn’t be covered by the warranty for a full 10 years.
In order to actually reach the 10-year mark and maximize the amount of time that your battery is covered by the warranty, you could only use about 82% of the power stored in your battery daily. However, this is the case for most lithium-ion batteries for sale today.
Yes, you can go off-grid with the Kohler Power Reserve. This also means that the battery does not require connection to the grid to operate, making it a great choice for those with a cabin in the woods or a home in a rural area without reliable utility grid access.
The Kohler Power Reserve is a great battery. It has impressive specifications like high power output, a decent warranty, and it comes in a variety of capacities so you can choose what size best meets your needs. Not only that, it can be monitored and controlled right from your phone.
The biggest downside to the Kohler Power Reserve is the price. At $13,325 for a 10 kWh battery before installation costs are considered, it is on the pricier side. But, the purchase does include an inverter, and you get all those great features we mentioned earlier. Plus, Kohler is a reputable brand so you can trust that the company will be able to honor their warranty and provide customer support for the lifetime of the battery, should you need it.
But, we have to be honest with you, whether it's the Kohler Power Reserve or not, most homeowners don’t need to get a solar battery. Batteries will add upwards of $13,000 to your solar installation without providing you very much (if any) additional electric bill savings, unless:
If none of these scenarios apply to you, investing in a solar battery doesn’t make a whole lot of sense.
With that said, if you are definitely in the market for a solar battery and value a good warranty and company reliability, the Kohler Power Reserve is worth buying.
What does make financial sense for most American homeowners is switching to solar. To get an estimate of how much you can save with a solar power system, check out our free and easy-to-use solar panel cost and savings calculator. By using the calculator, you can also see how much adding solar batteries will add to your solar panel installation and how it will impact your payback period.