The number of whole home battery options out there can make your head spin – it’s a real charge to the senses. Everywhere I looked at CES this past January someone had a shocking, modular, whole-home battery solution. Well, I’ve made my decision … or rather, I made my decision a while ago and just recently got out of permitting hell to have it finally installed. I ended up installing an Enphase battery system, but not for the reasons you might think. So why did I go with Enphase? What took so long? And most importantly … is it going to be worth the cost?
This has been a video a long time in the making. I originally thought I might be sharing this near the end of last year, but that plan went out the window pretty fast because of an extremely long delay, some crazy bureaucracy, and all manner of complications. I’ll get to those later, but first I think we should hit on …
What Did I Get?
What you see here in my garage is four of the new Enphase IQ 5P batteries. Each one of these has 3.84 kW of power output (7.68 kW peak) and 5 kWh of storage, as well as a 15-year warranty. What that means for my total system is about 15 kW power output and 20 kWh of storage. For the power output, that’s more than enough to cover my entire house with all the major appliances running and even charging my car.
They’re tied into a 17.2 kW Enphase solar power setup, which is made up of 43 REC Alpha 400 panels. If you want to hear about the details of that setup, I’ve got a full walkthrough video of what I did there and why. Bottom line, though, is that I stayed within one ecosystem for batteries, solar controllers, and inverters. That leads straight into …
Why This Battery … or Any Battery?
Right off the bat, I want to answer the question: is Enphase the best battery on the market? No, not necessarily … but it’s what’s inside that is. That would be lithium iron phosphate (or LFP), which in my opinion is the best battery chemistry you can get for your home today. It doesn’t matter if you’re talking about Enphase, LG, Sonnen, or any other brand — if they’re using LFP batteries, then I think you’re on the right track. They aren’t the most cutting-edge battery technology, but when it comes to longevity, safety, and cost, they’re the ones to beat right now.
For Enphase specifically, I’m kind of a fan of micro-inverters for home energy generation. Instead of having one large inverter that handles all the DC power your solar panels generate, you have a microinverter behind every single solar panel on your roof. That redundancy has pros and cons like anything else, but at the core it means that if one inverter or panel goes bad, your entire string of panels doesn’t go down for the count.
Well, these Enphase batteries are actually using the same microinverters inside the battery chassis. There are six embedded IQD8-BAT microinverters sitting above the LFP battery cell packs. Just like the redundancy on my roof, the same thing happens inside the battery. If one of these inverters goes bad, the battery will keep working, albeit at a slightly diminished capacity. This all means my system will keep chugging along while I wait for a replacement part or service.
Now, yes, there are still energy losses every time you convert energy from DC to AC and back to DC again. If you have solar with a central string inverter, not microinverters, the DC energy from the panels can go straight into the battery as DC. In my case, there’s conversions happening before the energy gets into the battery, so I’m losing about 10% or so there. However, I knew this going in and accounted for that kind of loss when calculating how much solar I wanted installed on my roof. Another factor is how I’m planning to use these, which I’ll get to later.
Because the Enphase IQ 5P comes in smaller component blocks, that means you can really dial in exactly how much storage you want or need and keep the price in check. You’re only jumping in 5 kWh blocks as you add each 5P battery. Other battery systems, like Tesla’s Powerwall, jump in 13.5 kWh blocks. That makes it hard to nail down the perfect cost to storage ratio you might need. But that raises the big question: what did it cost?
What Did it Cost?
There’s no sugar coating it. It was expensive. All in this cost $33K, which is typical for the area where I live. It’s really hard to compare apples to apples here. Before you start furiously commenting “it only cost X dollars where I live,” or, “I did my own battery installation for half that,” remember that location is a huge driver of cost. I’ve talked about this issue before, because it’s relevant to solar panel comparisons, too. Your mileage is absolutely going to vary, so it might cost you much less.
That said, it’s expensive going the route I went. I could have saved a lot of money buying a similarly sized AC capable battery system and tying it into my setup. For instance, if I had bought a similarly sized LFP battery from bigbattery.com, it would have cost between $10K – $15K before shipping and installation. You’re talking about something that would have been half to three quarters the price all in.
That’s a great option, and depending on what your goals are, I might recommend that first. Like I said earlier, LFP is the way to go … regardless of the brand. However, for me there was a perk with the brand angle. It’s one source for all maintenance or warranty claims … and it’s a great 15-year warranty. It also ties into my Span smart electric panel for virtualized critical loads that I can modify on the fly. It’s also a battery supported by the Connected Solutions program, which is a virtual power plant program that operates in my area. None of that would have been possible with the more DIY, bigbattery.com example. For my goals and things I wanted, the all-inclusive Enphase approach made the most sense.
Installing a battery system like I did does qualify for all the solar incentives, which means a 30% tax rebate that I can apply to the federal taxes I owe next year. That makes it more like a $23K battery system after that point. I’m also going to enroll my battery in my utility’s virtual power plant program I mentioned, which will also help recoup some of the cost. I had my Tesla Powerwall at my old house enrolled in the program and I got between $700 – $800 a year for that.
They pay you $275 per kW that you supplied to the grid during each load shedding event during the summer (on average). So, if you were to average a 3 kW power output to the utility when they call for it during those summer months, you’d get cut a check for about $825. My Powerwall had about 5 kW continuous power output capability, so that would be the absolute max for the program. Keep in mind though that your own home’s power use during those events comes first, so you’ll never hit your max kW for the program. And now my new battery system tops out at about 15 kW, so I should get a much bigger check each year. Based on the average paid out by Connected Solutions, that could be $1,500 a year … maybe slightly more.
Extending those figures over five years, which is the length of enrollment, that could add up to $7,500. I’ll need to wait and see how that actually plays out though. If it is $7,500, that means my battery cost is more like $15K. Still a lot, but now we’re in the realm of a whole home generator installation for emergency backups. For me, that’s another reason I wanted a battery system. I wanted to have emergency power that could carry us through any winter storms in addition to all the other perks.
Pros & Cons
What about the pros & cons? Since I’m all in on the Enphase system, I’m using their Enlighten app to manage everything. It’s actually a fantastic app with really great insights into energy usage, generation, historical data, and more. Just like all the major platforms, like Tesla, it has a storm guard mode that will automatically make sure your battery is fully charged and ready for any big storms in your area. In my neck of the woods, there could be high wind events in the summer or blizzards in the winter that might knock down tree limbs and affect power. Just a week or two ago, my system automatically went into a storm event from major high winds and rain that came through the area.
You can also configure the system to be either: Self-Consumption, Savings, or Full Backup. I’m running my system in Self-Consumption mode, which optimizes to use as much of my solar generated power for myself as possible. I’ve also got it set to never dip below 30% as an emergency backup buffer. Any excess solar production beyond that will get sent out into the grid. If I had time of use (TOU) electricity rates, I’d most likely be running in Savings mode. That will store energy to make sure you’re only pulling from the grid when energy is the cheapest (usually at night) and exporting, or using stored energy, when it’s the most expensive. That can save a lot of money. Full Backup should be self explanatory, but it keeps your battery at 100% for emergency backup only.
Enphase also has their own EV charger that ties directly into their controller, which means you can charge your EV only when you have excess solar production. I’m not using their EV charger, but have the same functionality I rolled on my own with some smart controls and my Span smart panel.
That actually leads to some of the cons I’ve experienced. While the Span smart panel ties in directly to Tesla’s system for very accurate tracking of your Powerwall’s charging status, the way it integrates with Enphase is … well … a little fuzzy. Span created something they call the remote meter kit, which allows Span to tie into other systems, like Enphase. It’s not tied into the main controller in the same way as Tesla, so it’s more of a battery charge estimation than an actual number reported by Enphase. It hasn’t been the most accurate reporting so far. There’s a drift that keeps happening with the system.
For instance, while Enphase may show my battery at 35% charge, my Span shows the battery at 27% charge. Span does have a way to recalibrate, which seems to be helping the accuracy over time, but it’s still only an estimation. This is potentially a big deal considering the purpose of the Span is to automatically shed circuits I’ve configured in the app to save power and extend the battery. It will shed some circuits immediately and others once the battery is below 50% charge. If the calibration is way off, that could cause problems. Like I said though, it has been getting much more accurate with each recalibration, so it’s in the ballpark almost all the time now. I just wish it was more tightly integrated and on-the-money accurate.
The other con is something I’ve already mentioned: cost. The one ray of sunshine on that count is a program I was able to take advantage of here in Massachusetts. There’s a 0% interest Heat Loan available to people upgrading their furnaces to something like a heat pump, but it also can work with battery installations. Navigating the application process for this loan was bonkers and slightly maddening, but we got the loan approved. I’m not going to complain too much about a 0% interest rate. Without that option, getting a battery installation like this is out of reach for most people. Batteries only really start to make some financial sense if you have time of use rates or virtual power plant programs available. If you have both, you can make a massive dent in the cost.
What Would I Have Done Differently?
I probably wouldn’t have changed anything, but the timing of us installing a home battery ended up being a little awkward. There are a bunch of different battery technologies hitting the market right now that could be easier to install, like those modular systems I mentioned that are flooding the market right now. For example, there’s the Anker Solix or the Ecoflow Delta Pro Ultra, which you could start very small and literally just stack more units onto over time. I might have opted for something like that if the timing had worked out differently.
However, there’s a crazy permitting requirement in my area for batteries installed inside a residential structure. If I installed over 20kWh of energy storage in my garage, I would have had to install a sprinkler system. That would have cost thousands of dollars. I get that there’s concern over battery fires, but here’s the part that kills me … I have a car with over 60kWh of NCM battery chemistry cells parked in my garage. Do I need a sprinkler system for that? Nope. LFP is extremely safe (much safer than NCM), but the local regulations don’t make any kind of distinction for that. All of those new modular systems would have run into this same issue in my area.
Another thing that I couldn’t have changed, but could have been better prepared for was what I alluded to at the beginning: the delays. The Enphase 5P batteries were launched last summer and based on when your order was placed you fell into the queue. For me that meant a long delay. Since my setup is grid-tied, there’s a lot of permitting hoops you have to jump through with the utility, so I also ended up in a bit of a permitting hell. I know my installer’s heart will sink a little bit when I say that, but it is what it is. I’m not upset by any of those delays, but was just a little frustrated by the whole situation. I also find it hysterical that my utility calls the grid-tied energy storage system’s application process an “expedited application.” A two-month wait for them is “expedited.” With all of the delays together, it took 6 months to get this installed. Still, it all worked out in the end, and my installation team did an awesome job. Hat tip to those guys … they did a great job.
We’ll have to wait and see how the numbers work out with the VPP, but the costs of the system were worth it to my family for our goals. If you have similar goals as I do for home energy generation and storage, then I’d definitely recommend taking a closer look at something like this Enphase system. But depending on your goals, you may have better luck with the more modular systems, so you can start small and build over time. Regardless, it gets me charged up to see so many options available on the market today to make energy storage more accessible.
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