I like your setup.
I started thinking in a similar direction, one for HA, one for media-oriented containers, and one for security-oriented containers. Taking into account that they are all DC-powered, UPS functionality can be made without the device that needs a set of new VRLA batteries every 2-3 years.
IMO way too many computers. Depending on the specs of the NUCs, you could either run everything as a VM or docker container or both. I personally think, that going for one higher-power PC instead of multiple lower-powered PCĀ“s could save energy.
When I used my old office pc from 2006 as HA server, I had no issues also using it as samba server. Maybe it was a bit slower, but it was perfectly fine back then. My new server, which is my old gaming rig, became then my server where I run everything on. Host OS is ubuntu server 20.04 LTS, HA runs as supervised (i dont care about official support, im a tinkerer anyways), some addons are also used, then some additional docker containers, also samba server, it acts as my backup repo and my backup softwares server relies on windows, so it runs in a win10 vm. No problems at all, I believe I could also add some AI things.
Since I had to lend my servers PSU to a friend and staying in a temporary apartment, I use my old NUC as server lite, means only HA again as supervised under ubuntu server 20.04 LTS, some addons and some other containers, which still runs fine. Ok, it doesnt run a VM and doesnt do file serving, but still its enough to handle my automation needs while still not consuming much power.
If youāre simply running HA, most NUCs are overpowered. And the low end NUCs have a lower passmark score. Unless youāre going to do some video processing or share the box with another service.
It all depends on the needs, and the location of a particular user I suppose.
I finally got the first NUC yesterday. It is based on i3-6100u. It does not have stellar performance, but at 90eur, I would rather have 2-3 of those and have some redundancy if one fails than have one machine running everything, costing 4-5x as much as this one, and losing everything if the machine should die unexpectedly.
My primary pc gets sold off for about 60-70% of its initial value after 4-5 years of use (not the whole device, just the set mb+proc+memory). And I always value that when the time comes for some components to die, it happens in someone elseās ownership. After having a 3yr warrantied power supply die after less than 4yr twice I have learned that it is more practical to buy a 5, 7, or 10 yr warrantied supply, sell it off with a warranty going another year, and buy a new one than waiting for it to die in my care.
Now when I have a working NUC to play around I will install Proxmox, a few servers, and HA also and see how everything works. Learn the nuances of Proxmox and containers, and at some point, if I like the experience add another NUC for other containers. Then I will have the opportunity to power off my main pc when it is not used. This will in the end bring the power consumption down.
glad to find this thread, had just opened this myself:
running a mini PC with Celeron for 2 days now (upgraded form RPI4 which started to struggle), in doubt whether I should upgrade a bit further, maybe I3 indeedā¦ but also considering power, which I dont see mentioned here?
But, this conflicts with:
You missed the point of why I have three NUCs.
I did not want to learn Docker, Proxmox, Containers, etc. I wanted the simplicity of one NUC running only HAOS. One NUC running Plex and one NUC for random Linux purposes.
If my HAOS NUC bites, I can quickly repurpose my Ubuntu NUC by flashing HAOS on another M.2 drive. (Yes, I bought a spare M.2 drive for precisely this kind of redundancy.) My downtime would be an hour or two. Yes, I could run everything in a NUC i5 and have horsepower left over, but the complexity of containers is not my idea of fun.
I have a NUC Intel(R) Coreā¢ i7-8705G 3.10 GHz, Kaby Lake, 32GB RAM, 512GB SSD, Windows 11.
It runs HAOS on a VM (VirtualBox). The VM has 2 processors, 12GB RAM and 32GB IDE allocated.
It is up for almost 3 years and I havenāt had a single problem.
The NUC also acts as a media server.
Easy to do backup by copying the vhdx image.
Cheers,
us
I agree that my two statements are somewhat conflicting. The point is that I cannot really make a judgment about Proxmox without having used it for some time, and I never had spare hardware to run it (because it is a bare-metal hypervisor it cannot really shine inside a VM). Now I have the NUC to try it out. I know a bit about docker having it run in a Linux VM in Windows. Not a production-level knowledge, but bits and pieces here and there. When I have gained experience I can choose whether I like Proxmox or not. I am generally curious about the tech and want that learning experience.
But, on the other hand, when my instance of HA gets to be an important part of my home it should be on a production-ready platform. I might come to the conclusion that Proxmox is good for it, or that it is not, but I do not think that gained knowledge will go in vain even if I conclude that I do not want my HA virtualized.
At the moment I do not have the means to buy multiple NUCs, so the means will follow the learning process, and in autumn I will probably have either means for another NUC or enough knowledge, to add HA permanently to the Proxmox.
Usually, when I fall, I do not fall because of the lack of knowledge of some of the software solutions on top of Linux, but my limited knowledge of Linux itself.
After a few days I got almost nowhere with Proxmox, but have not given up yet.
I think that I read somewhere that an i3 NUC takes about 20% more power than Raspberry Pi, after the NUC has fully booted. The exact values were 12W for Rpi and 15W for the NUC, but at the moment I do not remember where I have read it.
I do not really care much about power at the moment, because the whole NUC experience should help me reduce the number of regular PCs running permanently. So, in the end, I will reduce power usage, whatever option I choose.
The i3 NUC maybe take a little more power from your outlet, but gives way more power to your system.
Once I swapped the Pi for an Intel machine for my HA instance, I never looked back.
The Pi still does a wonderful job as a Volumio music center, but HA runs much smoother on a PC 
(I run HA supervised on Debian, no WMās involved.)
Most pi projects are not writing to the SD card quite as much HA.
As an example of players, picoreplayer runs entirely in RAM, and only settings have any lasting effect. No worries to run something like that long term.
Iāve been thinking about this for the longest time as well. Iāve been throwing around the idea of a NUC, or a Blue, or other custom hardwareā¦
FInally purchased myself a Lenovo M900 micro PC (i5-6500T, 16GB RAM, 480GB SSD) for 260 euros and its going to be the best thing for HA.
I agree with the sentiment of a few in here, NUCs are great (Really they are!), but there are many GREAT options out there.
There have been comments thatās wasting a NUC and you should run other things off of itā¦ but I have an i3 and thatās all I run on it is HAā¦ itās a powerhouse for that. Raspberry Piās are great for some things but for thisā¦ no. I have it running a different project [which I wonāt name as the last time I did someone tagged my post, ugh].
At any rateā¦ I came home Friday and we had a black or power surge of some kind because my system was down and wouldnāt come back up so I wiped the drive reinstalled HAOS on then did a restoreā¦ I was up within 30 minutesā¦
I love the NUC it has all the power and no lagā¦
Absolutely, Iām running HASSOS on my Lenovo M900 for a few weeks now, and its the best.
Anyone that says its overkill for just HA, I would say that HASSOS allows you to run many docker containers alongside HA as its a supervised host OS.
So you can run a video platform like Blue Iris, or have full Visual Studio Code container, as well as full local DB access, as well as other things like Grafana and other hungry systems.
The whole point is that on a NUC-like system, you can run a lot more.
Just my advice, but I would give unRAID a go, as I have 2 unRAID servers at home to run VMs, dockers, many other things and its much easier and better for my uses than Proxmox, even though I know Proxmox to do many more advanced things.
Also the unRAID community and forums I find to be a very lively and helpful place.
For the record, I recently migrated my unRAID-VM to my Lenovo M900 a few weeks ago, but I ran HASSOS for years as a VM on unRAID with zero issues. I might even put unRAID on my M900 and host HASSOS on there as a VM in the future, as I can better use the M900 hardware (VM-enabled i5-6500T, 16GB RAM, 480GB SSD) for more things.
As it is though, I can run things as supervised containers within HASSOS just fine directly on that hardware.
Thatās why I did it. Iāve run other things on Piās but they just didnāt have the power for that and it was a LOT smaller then HAā¦ couldnāt do videoā¦ it was choppy at best. So Yes I am using an older NUC and VERY happy with the results!!! Rarely do I get lag in anything!
does Blue Iris run in container?
yes, there are working containerised versions of Blue Iris, some windows containers and some Linux containers running WINE, a google search will easily get you there. 
how well does it work?
I am about to commission a new home server and would like to hear more about your setup.