The graph is from the electric company website showing my usage for a single day last week. It was sunny all last week, so pretty much every day’s usage looks like that graph. The little peaks around 1pm are when I made lunch since I can’t run the electric range from the power station. I could have run things for about 3-4 more hours from the power station, but I like to end the day with it charged to at least 90% in case I need to use it for a power outage.
This is just my trial PV setup with 800W of PV on the south-facing side of the house and another 800W on the west-facing side so I get a pretty continuous 600W throughout the day. I’m currently using an Anker Power Station which is limited to 60V and 600 watts of input, so I’m not getting the most out of my PV panels.
Today I ordered two, big 16 KWh batteries and a 10KW inverter to finally start my “big boy” PV installation (for comparison, that’s 32x the capacity of this power station and 5x the total wattage in addition to supporting 220v split-phase). That will let me take better advantage of the panels since I can put all 8 in series for less losses (partial shading notwithstanding).
I’ve been planning on building this out all winter and am finally seeing it through. Totally unrelated (/s), but my electric rate just got hiked another $0.01/KWh so I wanted to get this in place before A/C season kicks in.
Just yesterday I was thinking about PCs on solar and how it’s wasteful to run the DC power through an inverter and then through a rectifier in the power supply… the solar panels already put out DC so it seems like a DC input PC power supply would be simple to create.
Searching, I found this guy: https://hdplex.com/hdplex-800w-dc-atx-with-12v-63vdc-input.html
I’m not running solar currently (in the gadget shopping stage, obv) but maybe someone has been wondering in the same direction. My idea for a first project would be to put my homelab on a solar battery setup so this or something like this seems like a good way to squeeze a bit more efficiency out of the system.
So sick. I wish I could install solar where I live
I don’t know where you life and what your rules are. But here in EU(NL) is now also possible for renters to put a solar panel on their balcony.
Or avoid all the rules, and use an camping off-grid power system
How do you do the utility transfers? Also of this is only partial, small load for your household, how is that able to be broken out for the graph?
The main things I run from it are all downstairs in the basement and within reach of extension cords: homelab, WFH office, washing machine, etc. Those are lazily run through the drop ceiling to not be trip hazards. I did install a second outlet behind the fridge upstairs and ran romex down to the basement for it. That was from an earlier plan to have a subset of outlets that were on a backup circuit, but I changed my mind and opted for a whole house solution. So I just put a plug on the end of that (basically turning it into a sort of heavy duty extension cord) and hook it into the power station during the day.
To transfer them back and forth, I just switch where they’re plugged in. They’re all on UPSs (including the fridge - long story) so there’s no power interruption. For other stuff (like charging the lawnmower and power tool batteries, etc) I’ll just either run an extension cord out of the basement or plug the tool chargers into it (it’s got 4 outlets and can put out 2,000 W).
The graph depicts the utility usage, and the bit in the middle where it’s low/negligible throughout the day is just those “base” loads missing / not using power.
Nice! I’ve got 19.2kW of panels on my roof with optimizers and two inverters for 17kW A/C. I got them a couple of years ago and love em. They’re south facing and do a pretty good job (far north US). I installed a circuit breaker monitor so I can see how much electricity I’m producing and consuming per circuit. My power utility doesn’t show me nice fairly realtime graphs like yours.
I’ve been wanting to get batteries or a bidirectional EV that can power the home, but I haven’t been able to swing that yet. I’m still tied to the grid. But I’m working toward being grid fault tolerant. I’m jealous of your progress.
Nice!
Back atcha. 19.2 KW would be amazing and probably way more than I need, but I don’t have near enough south-facing roof (sadly, I have plenty of north-facing roof. With these 200W panels I have, my back of the napkin measurements seem to make my limit about 6 KW on the roof. I may check the measurements of the 320W ones and see what that gives me, but I’m thinking it’ll be close enough that it’s not worth the extra cost.
I do have plenty of back yard, though, so after I get this up and running, I may do another string or two as a ground mount setup.
Grid-tie was my original plan, but power company has too many hoops, restrictions, and red-tape to make it worthwhile. Plus, I still need a backup power solution (e.g. a Generac) so I went ahead and got some big batteries right at the start since I was already planning on spending about that same amount for the generator + installation.
Yea, I went big so I could charge an EV or two in the future. I wish I had the yard to put them in instead of roof. I get a lot of snow here and I’d love to be able to easily clean them off. They’re basically useless for half of the year. Even worse when the snow melts it slides down, catches on the gutter and breaks the gutters. It pops the mounts out and I have to pop them back in every spring.
Would you mind sharing order details on the big batteries/inverter you ordered?
Literally these.
Once I get the wiring done and everything settled in, I may pick up another set and have a total of four 16KWh batteries and two inverters for a total of 20KW (the inverters can parallel up to 6 units, and the batteries up to 15).
Nice one.
I’ve no idea on how much you know about PV installation so my advice is research the shit out of it. Join forums, etc, and ask every question you can think of. Then do more research!!
What’s the cyclical wave every ~3 hours or so?
That I’m not sure, but likely various misc/intermittent loads that aren’t running from the power station (bathroom lights/fan, electric range, attic fan, etc). The one right before 8am is probably the coffee machine, and the bump around 1pm is when I made lunch.
The graph is also confusing. Like, I know my homelab runs at about 0.25 KWh continuously but the graph is in half hour increments so shows it as half that.
Someone else suggested fridge/freezer, but electric motors are usually “spikes” for startup. No idea what a smooth wave’s cause would be.
It does kind of match that, energy profile-wise, but fridge was definitely on the power station and isn’t reflected in the graph from 8am to 5pm. I wanted to make sure I could run that from PV alone and after that was confirmed, just kept putting it on PV during the day. That, and the usage graph seems to be averaged over 30 minute intervals, so I don’t think a momentary spike like a motor’s startup draw would show like it would with a realtime graph.
We’ll never know.
Oh, I’m stupid lol. I was only referring to the PV period from 8-5. On the full 24 hour graph, including the times it’s not on PV, that probably is the fridge
Maybe fridge/freezer?
Fridge/freezer is running from the power station, but the huge spike around 6pm is it kicking into its defrost cycle after I took it off the PV.
Could be.
Neat. I’m looking forward in the next few months when I can setup some of the newly legalised balcony solar. Should eat into my bills nicely.
Oh nice! Ive been thinking of doing something similar.
It’s been pretty great even with this little setup I have now.
I’ve been wanting to do this for years, so I finally justified the cost of the big system I just bought by combining it with my need for a backup generator. I could stretch 30 KWh of battery to about 2-3 days even with no sunshine to top them up. I may still get a small generator as a backup backup just to charge the batteries, but I won’t have to spring for a Generac and having that plumbed into the gas and wired in. Plus those don’t seem super reliable as both neighbors who have those always seem to have service techs coming and going.
I would love to know more if/when you get the whole thing set up!
PGE is killing me.
Maybe I can post a parts inventory or something and some highlights from the install.
I’ll definitely be taking pictures as I go if nothing else than for having a reference of what goes where. The PITA part is going to be moving most (all?) of my circuits from the main panel to the new panel I’m putting in on the other side of the basement. The PV inverter(s) will feed that panel and distribute them out. Main panel (too expensive to move) will then just have a few 60A circuits running to the PV inverter(s). I’ll probably also throw in a bypass switch so I can isolate the inverters for maintenance and whatnot.
If grid tie is an option for you, I’d recommend that if you’re just looking to cut your electric bill. It’s technically an option for me, but the electric company makes you jump through so many hoops and red tape that it’s just not worth it. Plus, I also want this to work “off grid” as a backup power solution in lieu of a whole house generator.
Lol yeah…a tiny bit of it is my job. the permits in particular. Its both easy and hard…
That would be awesome! No pressure im just super interested cause I want to make it happen for me too.
Thankfully, unless I’m moving my main panel and/or service connection, I don’t need a permit here. Well, unless I do a ground mount in the backyard because that requires digging a hole, and digging a hole requires a permit for…reasons lol.
Nice! Good to see more people trying to run on there own power more.
Do you have/did you check into a hybrid invertor, or do you manual swap the power around?
The small setup I have now is based on this so I currently have to manually move where things are plugged in, but the 10 KW inverter I just bought is a hybrid one.
It’ll charge, invert, and load balance automatically and there’s configuration you can program to set the cutover levels, charge/discharge limits, whether it should prioritize power the loads or charging the battery, and such. It can also mix utility and inverter power and switch between the two pretty seamlessly (10ms switchover which is comparable to a UPS).*
*According to the data sheets, anyway. I ordered it today and wont’ have it until probably close to end of the month.
Ahh, a power station. I have on of those too for camping and using it at home to let the 3D printer run off-grid on some spare camping solar panels.
For the house I’ve used a hybrid invertor. It can do all of the same functions but can do much more power, and it can also zero the meter (no import and export, since it automatically tries to compensate for your usage, whole house-wide)
Are there any platforms you use to try and outmate things yet? Or integrate it to track power usage?
Are there any platforms you use to try and outmate things yet? Or integrate it to track power usage?
Not yet since I don’t have it yet (should be here toward end of the month), but there are mobile and desktop apps which can interface with it over wifi and serial, respectively.
I’ll definitely be looking to see if there’s a HomeAssistant module or something or if someone has documented the serial protocol so I can write my own software.
Basically I want to be able to change the configuration without having to enter the numeric commands and params on the unit itself. I’m imagining something like a list of preset custom modes I can switch by having a program change the params to a set of predefined values.
Like, I want it to only charge the batteries from the PV most of the time (which is something you can configure), but I’d also want an easy way to tell it to charge from utility in case a big storm is coming or something. Once I have that, I’d like to extend it so that I can watch for severe weather events and if NWS issues a severe storm warning, have it automatically switch to that mode and back once the storm warning has passed.
That’s all down the road, though but definitely something I’ve been thinking about.
Home Assistant is super nice. Worse case if you can’t figure it out to control the power station. You can always use some power plugs to enable/disable grid charging with a switch.
With all the rate hikes, we no longer have cheap power in the PNW. I was recently able to get enough together that I think I can afford it, so I called Signature Solar yesterday and started a dialog and quotes. I watch a youtuber (Jesse Muller) and he recommended them. They seem to use decent quality gear.
How many kWh a month do you use? We use a…lot. I am a systems admin, so I have gear in the homelab I’d like to maintain through any grid outages. I have three potential service goals: essential power, whole house, and finally whole house and shop. I’d rather start on the small side, but want to be able to reuse gear, if at all possible, as I go up in capacity.
Anyhow, just saying another Dull Guy is getting into solar, but I still have much to learn. Any youtube channels you’d recommend? Other resources? Advice?
How many kWh a month do you use?
Depends on the month as everything except my furnace and hot water heater are electric. In March, when the furnace barely ran and didn’t need any ceiling fans, etc, I used 391 KWh and my bill was $105 for the privilege. In July when I have to run the A/C almost constantly, I use close to 1,300 KWh and don’t even want to say what that costs me. I work from home, so I kind of need to keep it comfortable all day as well as run my WFH office gear. (Otherwise, I’d bump the thermostat up until I get home in the evenings)
I’ve also got a homelab, but I’ve downsized it enough over the years that it’s down to ~250W continuous (yay USFF PCs! I used to use old rack servers that were 200W each).
Any youtube channels you’d recommend? Other resources? Advice?
I’m more of a hands-on learner, so mostly I’ve just played with it in different forms for 6 or 7 years and started small or Googled specific questions i had. The main thing I learned is that on a good sunny day, PV is like a waterfall and you often only need a glass of water from it. Unless you’re going grid-tie to absorb the excess, storage (batteries) is important otherwise it’s just wasted. The rest I guess I’ll figure out as I get this one up and running. As far as the electrical work, I grew up helping my grandfather on jobs (he was an electrician) so other than referring to NEC for some specifics, I’m pretty comfortable/confident with that kind of work (doesn’t make it any less of a pain in the ass though haha).
I appreciate the information! Yes, I still have some of the large servers and I don’t see them being retired soon either. We’ve always had higher bills because of it, and that was fine when power was inexpensive. The recent data center cost increases being shoved onto the consumers has solidified my desire for renewables to offset the hikes and I am lucky enough to be able to afford it, atm.
Oh, for sure. If I hadn’t/couldn’t downsize, then I’d just be adding more solar lol.
Yes. I am trying for as much as I can afford. I am also looking towards the highest wattage panels (probably bifacial). Are the newer N-type panels worth buying?
Edit: Yes…They are more efficient which also means more expensive. https://www.electricaltechnology.org/2024/06/p-type-n-type-solar-panel.html
