Solar-thread

[Anonymous No.2903345]

Essentially, pic-related is everything I need to know, but I'd like to talk about it anyways.
How can I keep it legal? (I'm in Germoney, so I can only do a "Balkonkraftwerk" without involving the power company, meaning I can at max have 800W flowing into the grid. Of course, I'd rather not have anything flowing into the grid, using it all myself, so that means batteries, but that is either expensive, or I'm not sure if my electrians-skills are good enough for that.
tl;dr:
What do you have on your roof and how did you put it up there?

[Anonymous No.2903435]

>>2903345
>I'd rather not have anything flowing into the grid
That's not always desirable since, solar panels being cheap, you'd usually want to oversize the system - provided you're not limited on space. Conversely batteries being somewhat expensive, you usually wouldn't want to buy a battery big enough to store enormous amounts of excess.
I saw someone posting a $1k-ish literal balcony setup sold in Germany with a "solar generator" managing everything, and for that price, and being plug&play, it was a decent deal.
Total /diy/ of a battery is not hard at all, but it is very dangerous to fuck up. In current year and current market, buying a complete battery parts kit with everything except cells, including a JK-BMS, and then plopping in 280-300Ah A-grade cells from nkon would be the way to go.
>What do you have on your roof and how did you put it up there?
~5kWp in 410Wp cells all roof mounted, had a company do a complete install. Will be semi/diy/ expanding by another 8kWp this year on another roof, plus in a different location doing a full /diy/ install for a ~4kWp initial set, possibly ground mount, and another 4kWp roof mount later.

[Anonymous No.2903569]

>>2903345
>What do you have on your roof and how did you put it up there?
Some panels, screws

[Anonymous No.2903700]

>>2903345
what do you guys recommend to affixing solar panels to the ground? currently i am in the process of buying a terrain next to mine and i need to put temporarily the panels in the fence between our terrains, upper side in the fence, the other in the ground. I dont want to do anything permanent, as i hope it wont be there for more than a year.
would camping stakes be a good idea?

[Anonymous No.2903701]

>>2903700
I haven't used ground screws, but they seem fairly easy to install and remove. Alternatively find some bricks or concrete blocks and do weighed panels.

[Anonymous No.2903711]

>>2903345
>What do you have on your roof and how did you put it up there?

Am i doing it right?

Only two on the actual roof, however a quick count has 50 of various sizes attached to the building.

>Idiot has those two on the side

The two 100w panels on the side are to boost the system in the winter, on clear days they put out around 50% more than the two identical ones on the pivoting mount when it is pointed perfectly at the sun. Reflected light from the snow makes them better than ones that are angled 'right'

[Anonymous No.2903716]

>>2903711
Same guy. Full baka off grid lit up like Christmas tips:

>Whenever possible use independent systems for the lights, solar barn/security lights ect
>Get cheap solar yard lights from end of season sales at dollar stores or yard sales, like $0.50-0.25 each
>But those suck and the ones from yard sales all have dead batteries!
>Which is why you replace the Ni-Cds with bulk Amazon Lithiums
>Yard sale barn/security light doesn't work because of dead battery?
>Buy all the 'dead' power tools at the yard sale or scrounge 'dead' tool batteries from people you know, at least half of them have perfectly fine 18650s in them the charging circuit board is fried

[Anonymous No.2903795]

>>2903569
It was absolutely pissing it down all day and got a pretty poor result out of it.
The bank was also precharged to ~90% but this didn't fill it so I'm not sure what is going on there

[Anonymous No.2903796]

Also I wanted to know if anyone has experience with copper tube bus bars?
For the charger wiring I just shoved 2AWG wire in the open tube and smashed the thing with plyers to crimp it.
Should I solder it? I have strong concern that it is not a good enough connection for 100 amps.

I am also aware that running this many batteries in parallel is dangerous, I don't give a shit.

[Anonymous No.2903812]

>>2903711
I'd almost guess it's Wayne's, except the house itself looks too decent for that.
>>2903796
All of these connections have to be crimped properly, buy a hydraulic crimper off chinks. I don't think paralleling the batteries is bad if they're lithium, maybe more so if they're not. You should definitely unfuck the connectors and definitely cover up at least one of the bus bars, so that the first wrench you drop on it doesn't immediately do a dead short on a 1000Ah battery.

[Anonymous No.2903860]

>>2903345
The solar batteries are easy man. I'm retarded and built my own 280ah, you can easily do it.

[Anonymous No.2903873]

>>2903812
I think the perceived danger is that the string is capable of 2500 amps in a dead short, so people say to limit it to four at most because the current is less.
Meh a hydraulic or more likely a hammer punch crimp is designed for a proper connector and not a piece of water pipe, I don't think it will work.
I could I guess put proper termination lugs on it and bolt it down to one of the batteries on top of the bus. Kinda starting to have concerns about distribution though, but I should be safe because the max amps is equal to the max control of any one battery so safety wise it's ok

[Anonymous No.2903881]

>>2903711
>Reflected light from the snow makes them better than ones that are angled 'right'
sounds like a use case for bifacial panels

[Anonymous No.2903890]

>>2903873
A 48V big guy battery can do 20kA+ in a dead short so 2.5kA isn't so bad. The hydraulic crimper could cold weld the pipe just fine, provided you choose the right size terminal for the cross section. You should have a high breaking current fuse on the battery side of the wiring, at least on positive, and then have the thing enclosed. Each battery can give out 100A, totaling at 1000A, while your wiring is sized to 100A. The copper pipe and everything leading to the fuse should ideally be sized to handle 1000A peaks for a few seconds, until the 100A fuse gives. Either way the worst part by far is that the bars are in open air with nothing covering them.

[Anonymous No.2903917]

>>2903881
It really is, if i put any on that metal roof i'm absolutely using them.

[Anonymous No.2904038]

>>2903890
Ehh I bought all of the batteries because I was going to put them in series and make 120v dc.
I bought a special charge controller and everything for it. But then I realized that if one of the bms ever opens up from temperature, low voltage, high voltage, ect, it would instantly kill itself big time and maybe go on fire.
I tried ordering a 40s bms and the transaction went pretty bad and I refunded it. Now I'm stuck not sure what to do at this point so I just made it 12v for now.


The 120v battery voltage is cool because I found a lot of my electronics just plug in and work fine on DC. I even modified my oven to work on either. But no proper bms is super sketch

[Anonymous No.2904064]

>>2904038
i think some bms could be put in series, but dont take my word on it
desu i dont know why systems that can be directly inverted to mains are not more common, it lowers the complexity a ton, needs way less copper.
it is not that unsafe

[Anonymous No.2904067]

>>2904064
400-600V batteries exist, which are more closely aligned to solar string voltage. Only that they cost a fuckton. But "it's not that unsafe" doesn't cut it with electrical code.

[Anonymous No.2904069]

>>2904067
its more you need an actual electrician to sign for it, not that it cannot be used by code
which i get, but its bullshit that only because of that companies barely do equipment for it
every fucking mains installation need the electricians signature already, why industry act like this is a big deal

[Anonymous No.2904112]

>>2904064
>>2904038
>>2904069
Any reason you can't wire two BMS next to each other? If the parameters are the same they should just ignore each other unless one fails.

[Anonymous No.2904127]

>>2904112
that is what i said, and there is bms for huge series batteries, seems like regular bms acting as slaves of a master controller, but they are kinda expensive

[Anonymous No.2904136]

>>2904112
>Any reason you can't wire two BMS next to each other
Yes, there is a reason.
Bms use a mosfet or multiple mosfets to disconnect the cells from the terminals in order to protect the battery.
The mosfet is a piece of silicon, it has a maximum voltage limit of 60v or something.
If you have a 128v nominal string of batteries, and any load at all, if any bms opens, there will be 128v between the mosfet now and it will rapidly start emitting fire and burn down your fucking house is what I was told.

I was going to get around this by bypassing the mosfet and instead using the mosfet output to keep a giant contacter closed but meh I want something not quite so jank and I'd still need to balance everything

[Anonymous No.2904138]

>>2904136
you are getting it wrong, you need to split the bank
example you put a 60v bms in a 60v section of the bank, which is in series with another section like that to get the 120v

[Anonymous No.2904160]

>>2904138
Read what I posted

[Anonymous No.2904178]

>>2904160
you need to check how bms work dude

[Anonymous No.2904200]

>>2904136
>>2904138
>>2904127
Use a controller and a really big active pizeo switch as the BMS. If something fails it will automatically disconnect.

[Anonymous No.2904227]

>>2904178
Oh you're right, that's so cool, I hope one day you give it a try

[Anonymous No.2904439]

thanks for asking! nothings up there yet but I scored a bunch of free old modules and similarly decrepit microinverters yesterday. which is great and i cant wait to carry them onto my roof but now i need racking and permits and shit so hopefully i actually do it before winter... whole system is maybe 4kw at best but how can i say no to such a passive economic buff?
does anyone know of any charge controllers that work with higher voltages? everything seems to be 12/24V. I have big panels with diodes so is it retarded to think i can attach news leads near the diode for half the voltage and then terminate it in parallel?

[Anonymous No.2904459]

>>2904439
Most big panels that have diodes can be setup to half the voltage yeah, you actually just install two jumpers usually.
What are the permits for? I guess if you grid tie but I can't think of a single thing more cuckold than giving away your power for nearly 0 dollars

[Anonymous No.2904525]

>>2904459
really was keen on doing non permitted work but i'm already grid tied and cucked as fuck so we're more interested in KWh credits than outright selling. seems most utilities are moving towards time of use billing as a counter to residential solar anyway. ill see if i can get a manageable voltage out of one of these modules for some off grid larp tho.

[Anonymous No.2904528]

>>2904525
Actually could not be me ever. Fuck grid so much. My house is solar only, no grid or poles or anything, fuuuuck that shit.

[Anonymous No.2904551]

>>2904439
>everything seems to be 12/24V
Where are you looking? I'm more surprised you can find a 4kW charge controller that only takes 24V DC from the panels. Even 24VDC battery is relatively rare, let alone panels. Also why are you talking about charge controllers if you want to be on-grid? On-grid takes an on-grid inverter, no charge controller, no battery. You should probably keep rereading the rentry until you understand terminology and basic components.

[Anonymous No.2904611]

>>2904551
Pwm controllers will pull the panel down to battery voltage, so if he's trying to use one (literally why) then it will be doing that and so you want to optimize the panel voltage a little for it

[Anonymous No.2904692]

>>2904528
you must be smart to have achieved such status and maintain it. maybe if i had made different choices id be living in a solar powered van by the river. actually dont think i need permits at least because it depends on the cost of the work in my state. not sure how that works with getting permission to operate tho so maybe i will just export to grid and see what happens.
>>2904551
sorry i confused you, the 4KWDC system with the micro inverters i mentioned is grid interactive so it wont work when the power goes down. I also have other different separate panels with Voc's ranging 36-56 VDC. most of the charge controller i see on amazon, ebay, alibaba take 12 or 24VDC input, so i think maybe i can figure something out by asking retards retarded questions on an autistic honeypot weaving forum.
>>2904611
>literally why
fuck around to find out? if one works, than more than one might work better or maybe i dont need any. so i could gain the experience and decide whether to scale up or abandon the project without investing too much.

[Anonymous No.2904693]

>>2904692
Those cheapo charge controllers take 12V or 24V battery input, the solar input is usually 25 and 45V, respectively. This isn't even "read the rentry", this is "read the specs".

[Anonymous No.2904883]

>>2904692
>most of the charge controller i see on amazon, ebay, alibaba
You have to go absolutely out of your way to get a charge controller that ISN'T mppt now. What are you doing differently?

[Anonymous No.2904889]

>>2904883
unless it changed recently the low end of mppt controlers are not actually mppts... and you find them in hardware stores

[Anonymous No.2904927]

>>2904889
Idk about that, I got this cheep chinesium one and it is definitely mppt and tanks my 185v VOC. https://www.amazon.com/gp/aw/d/B0DHZN8Q82

[Anonymous No.2904930]

>>2904927
that is not low end
i mean the 10/20/30a 12/24v that you see for really cheap

[Anonymous No.2905035]

>>2904930
You're in the wrong hobby

[Anonymous No.2905039]

>>2905035
i dont use those,just say that they exist,
i got a victron one for the price of a chink one

[Anonymous No.2905040]

>>2905039
Victron is chink

[Anonymous No.2905043]

>>2905040
not their prices or support