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48V recommended for home 10+k Watts?

voon

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May 11, 2021
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Please be kind to a few sort of noobish questions :) Also, this is in Europe, so 230Vish, no split phase etc.

1. Is it a good idea to do y DIY battery with a Jikong BMS and EVE Cells and use some sort of 10kw hybrid for 48V? DO most 48V Hybrids even work with soemthing like a Jikong? Is the only advantage of this, that you can build very cheap (mainly a cheap battery), but lose a few watts in the conversion from 50 to 220V and/or the 1000V of an inverter (and well, not kill yourself due to 48V and not HV)?

2. Would you forget 50V for residential and just go HV? Sadly, battery prices there still are .. let's say, not to my liking. They're still somewhere in the 500ish$/kW, while DIY seems to be around 150ish/kW.

3. Which 3-Phase inverter would you recommend (one phase is only allowed up to 3k here .. not sure about when you run three in parallel, though .. maybe then the max diff in phase can be 3k)?

In general, the choice of 3P 10+kw hybrid inverters for 48V seems to be extremely limited, especially since some models are never locally available (Deye, MPP SOalr etc) where I live. Wherever I look, it seems it mostly comes down to the MPP Solar MPI 10k ... which is probably good but also a very old design .. I wonder why there's not more on the market? HV on the other hand has 10 million choices (Huawei, Growatt, Goodwe, Solax, Fronius, SMA, Kaco, Kostal, SolarEdge, Sungrow...) full of modern designs, with nice BT apps or good LCDs etc. The 48V world looks like something from the dinosaur times. I love the idea of DIY, especially if it means cheap battery and the fun of building one (yes, I know the dangers).
 
Stuff gets ineffecient and pricey when its gets above 100amp, and ironically stuff get even more expensive if you wanna use HV dc equipment thats plenty available.

Best bet is to import from china via alibaba i say and maybe settle for 5kw max? :/

I myself use two seperate singlephase 2000watt and 1500watt with diy 48v and simply dont use microwave oven at same time as coffe machine :p I got 5kw PV in to charge battery and two 230v inverters. 2kw and 1.5kw

Epever have good cheap stuff as long as you dont push them past their rated power. You cant oversize PV 1.5x. It will kill solarchargecontrollers if the sun goes behind clouds and then pops out to fast.
 
Thanks. The problem here is I need 3phase. They do not like onephase inverters grid tied at all, besides very weak ones. I can't use a 5k onephased inverter. And I'd like to fill the roof with panels .. in an installation, more panels are only helping with amortization, since they're not tat much fo a cost issue compared to the entire thing.

HV is kind of inverse to LV: The inverters cost nothing .. I can easily buy a good HV Hybrid 10 kW for 1500$, like a Huawei etc. The problem is, that HV Batteries are ridiculously priced .. they're still around 500$/kW and much more around here. Which is bad for amortization again and I want a PV system to be economically viable and amoritzed within 10 years .. not 25 or more. If HV batteries had sane prices, I'd just go with some BYD box, since it's easier and has a lot of choices.

It's just annoying :p
 
Thanks. The problem here is I need 3phase. They do not like onephase inverters grid tied at all, besides very weak ones. I can't use a 5k onephased inverter. And I'd like to fill the roof with panels .. in an installation, more panels are only helping with amortization, since they're not tat much fo a cost issue compared to the entire thing.

HV is kind of inverse to LV: The inverters cost nothing .. I can easily buy a good HV Hybrid 10 kW for 1500$, like a Huawei etc. The problem is, that HV Batteries are ridiculously priced .. they're still around 500$/kW and much more around here. Which is bad for amortization again and I want a PV system to be economically viable and amoritzed within 10 years .. not 25 or more. If HV batteries had sane prices, I'd just go with some BYD box, since it's easier and has a lot of choices.

It's just annoying :p
you can, but you'll need 3 of them...
MPP solar ( voltronics/voltacon e.o.), Deye/Sunsynk all make 3 phase inverters... i believe starting from 8 Kw though
 
In theory .. the laws and controlling people however are irritating .. they won't accept three onephase inverters in conjunction as a threephased one, even if it'll work the same. Laws are funn. But then I'm back at 10+k anyway and prefer less hassle with just 1 machine. It's a bit of a nightmare :p MPP Solar and Deye are impossible to get around here and cost twice the money of a HV inverter and I'm wary of shelling that money over to china with nonexistant service or high costs afterwards.
 
In theory .. the laws and controlling people however are irritating .. they won't accept three onephase inverters in conjunction as a threephased one, even if it'll work the same. Laws are funn. But then I'm back at 10+k anyway and prefer less hassle with just 1 machine. It's a bit of a nightmare :p MPP Solar and Deye are impossible to get around here and cost twice the money of a HV inverter and I'm wary of shelling that money over to china with nonexistant service or high costs afterwards.
define "here"
 
The (somewhat) Neutral Country :)
lol, there quite a few of those :)

Deye can be bought from france or austria
Mpp-solar from italy

if you are in the neutral country in my mind ( Swiss), those should be doable
 
Yes, the one and only, of course .. Switzerland :p I googled for them a bit but ended up fairly horrified with the prices .. I'm not sure what an imported one would en up from China, but the ones around here are all over 3000 Euros for the big one. From HV, I was used to 1500-2500 Euros. And I ended up thinking that 3000+ is a bit much for an inefficient 48V fun project .. then I can throw the difference into a BYD battery and just go HV. It's a bit of a mind project since a year since I'm still looking for a house :p
 
Thanks. The problem here is I need 3phase. They do not like onephase inverters grid tied at all, besides very weak ones. I can't use a 5k onephased inverter. And I'd like to fill the roof with panels .. in an installation, more panels are only helping with amortization, since they're not tat much fo a cost issue compared to the entire thing.

HV is kind of inverse to LV: The inverters cost nothing .. I can easily buy a good HV Hybrid 10 kW for 1500$, like a Huawei etc. The problem is, that HV Batteries are ridiculously priced .. they're still around 500$/kW and much more around here. Which is bad for amortization again and I want a PV system to be economically viable and amoritzed within 10 years .. not 25 or more. If HV batteries had sane prices, I'd just go with some BYD box, since it's easier and has a lot of choices.

It's just annoying :p

whats stopping you from building your own hv battery with cheap lifepo4 cells?
 
did you figure out anything? :) I'm in a similar situation now and I'm wondering why are the HV batteries so expensive compared to the LV ones? it seems that if one had the courage then one could DIY a HV battery out of the lifepo4 cells themselves. but it seems bizzare to me that these are not available on the market already at reasonable prices, when the raw component prices are so much lower (~$0.1/w for DIY solution vs $0.3/w for a commercial solution)
 
Not really .. it doesn't seem to exist. Maybe the HV BMS are not available or the ones that are, do not talk to the broadly available HV hybrid inverters. Also, you'd need small cells I guess if they're still just 3.6V. Otherwise, if your target is soemthing like a 300ish V Battery, you'd have an insanely huge thing :)
 
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