SMA Sunny Boy capabilities
- Thread starter bteigrob
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ArtDeco
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Yes.
The SI is a battery inverter/charger. You will need a BMS. REC is expensive but has a good reputation.
The SI is also a grid forming inverter. Which is important for an ac coupled off grid or backup system that has grid tie inverters. My 2 SI plus the sunny boys can provide 24kw to the house when the sun is shining.
If you use separate DC charge controllers (and you can) I'm a little fuzzy on how the BMS works.
My system will use about 1kw of the panels through a DC charger for a couple reasons. That charger will not receive BMS info and will not fully charge the batteries.
It's more of a "helper".
AC coupling has quite a few advantages, flexibility being one, it's easy to add on to. couple drawbacks like the black start problem if you mismanage your battery charge level.
SI SB is not so great if you are under restriction of how much AC you can send to the grid. All the excess production is either all going to the grid or none( off grid).
The SI internal transfer switch is undersized, I power the whole house either from the grid or via a backfed interlocked breaker. This is not automatic.
How I imagined it to work: SI to make its own network (off grid) the battery would be a forklift (acid) 800+ah,some other dc controllers to charge the battery directly from the PV system,or SB to SI connect...actually, it is absolutely irrelevant to me whether it will be SB(ac) or some other dc controller? Or I didn't think it through well? my small farm has to have electricity 24/7...!
You have it right.
No BMS required for lead acid either.
SI doesn't care if it charges the battery from SB, or if another charger does as long as the charge and discharge current pass through the ( external) shunt.
My point was I guess that an off grid ac coupled system can handle higher loads when the sun is out. May or may not matter to you.
Hedges
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"Дакле, имате на располагању електричну енергију. Урадите мало математике о цени по кВх током животног века ПВ, инвертера, батерија. Можете димензионирати систем за критична оптерећења током нестанка струје, или величину за снабдевање 100% свега. ПВ је релативно јефтин, тако да превелика величина помаже у лошим временским приликама и смањује величину батерије која је потребна за једну ноћ држећи корак са оптерећењем касније током дана.
Можете да изградите систем ван мреже или резервну мрежу са СМА или другим брендовима. Највеће софтверске разлике мислим да ће бити одабир времена за извлачење из мреже у односу на батерију, за неке се можда неће моћи конфигурисати.
Буџет енергије, дневни у односу на ноћ, омогућиће вам да га ефикасно одредите. Резервни генератор је јефтинији начин да прођете кроз повремене више дана без сунца.
Системи могу коштати само $1000 или чак $20к+, разлике у величини и квалитету. Чини се да већ имате јефтин мали резервни систем."
Did I say that?
Hedges
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You could have 2x Sunny Boy 6kW with one Sunny Island 8.0H, 12kW can pass through to grid (or be used off-grid.)
Sunny Island will disconnect from utility grid when it goes down and make an "island" grid.
Internal transfer switch isn't so undersize for the European model, because 50A at 220V is more power than we get at 120V. I use 4x SI wired 2p2s on account of that.
With AC coupled Sunny Boy, Sunny Island can adjust Sunny Boy's output to hit a target charge rate, (e.g. 0.12C if appropriate for FLA), and request more current from Sunny Boy when used by loads.
DC coupled charge controllers will put as much current as they can into the battery, unless they use battery shunt to throttle back power. Sunny Island used to tell SCC what target voltage, don't know if it does with these new models (assuming Sunny Island Charger, or Midnight Classic with a data interface.) Sunny Island does not command SCC's charge current.
If you mix DC coupled (not too much for battery) and AC coupled, Sunny Island will adjust AC coupled power production so that plus DC coupled (as measured by shunt) hits target charge rate.
I think SI communicating with BMS will adjust charging from AC coupled PV as requested. Don't think it can do anything with DC coupled except change target voltage, and then only if it communicates with BMS.
I recommend Sunny Boys. Also a "load shed" relay or two, which would disconnect loads at certain state of charge.
I have US model 5048US, 6048US, several model Sunny Boys, and Sunny Island Charger SIC-40. Also Sunny TriPower.
I've never used the new European model 8.0H, or the newer Sunny Boy -40 or -41.
It is good to keep the grid, because you can avoid cycling the lead-acid forklift battery except when grid is down. Or does FLA need to by cycled, to keep it stirred? Also, if battery large enough for 3 days autonomy without sun, would only cycle 15% at night, should be able to last 20 years. In my case of undersized AGM (cycles 70% at night), I want to keep it at float.
Diagrams?
I find some, but now I'm questioning whether 8.0H can do grid-backup without an external relay. You're going to have to figure that out yourself, I'm afraid.
Sunny Island 4.4M / 6.0H / 8.0H | SMA Solar
Did I understand correctly or not? The recommendation is SB and SI? That combination seems to give me the least headaches. A little later I will go to take a picture of the battery. I saw it on the link, but I try to avoid the diesel generator, and the city network is almost non-existent.....the idea is off gridYou could have 2x Sunny Boy 6kW with one Sunny Island 8.0H, 12kW can pass through to grid (or be used off-grid.)
Sunny Island will disconnect from utility grid when it goes down and make an "island" grid.
Internal transfer switch isn't so undersize for the European model, because 50A at 220V is more power than we get at 120V. I use 4x SI wired 2p2s on account of that.
With AC coupled Sunny Boy, Sunny Island can adjust Sunny Boy's output to hit a target charge rate, (e.g. 0.12C if appropriate for FLA), and request more current from Sunny Boy when used by loads.
DC coupled charge controllers will put as much current as they can into the battery, unless they use battery shunt to throttle back power. Sunny Island used to tell SCC what target voltage, don't know if it does with these new models (assuming Sunny Island Charger, or Midnight Classic with a data interface.) Sunny Island does not command SCC's charge current.
If you mix DC coupled (not too much for battery) and AC coupled, Sunny Island will adjust AC coupled power production so that plus DC coupled (as measured by shunt) hits target charge rate.
I think SI communicating with BMS will adjust charging from AC coupled PV as requested. Don't think it can do anything with DC coupled except change target voltage, and then only if it communicates with BMS.
I recommend Sunny Boys. Also a "load shed" relay or two, which would disconnect loads at certain state of charge.
I have US model 5048US, 6048US, several model Sunny Boys, and Sunny Island Charger SIC-40. Also Sunny TriPower.
I've never used the new European model 8.0H, or the newer Sunny Boy -40 or -41.
It is good to keep the grid, because you can avoid cycling the lead-acid forklift battery except when grid is down. Or does FLA need to by cycled, to keep it stirred? Also, if battery large enough for 3 days autonomy without sun, would only cycle 15% at night, should be able to last 20 years. In my case of undersized AGM (cycles 70% at night), I want to keep it at float.
Diagrams?
I find some, but now I'm questioning whether 8.0H can do grid-backup without an external relay. You're going to have to figure that out yourself, I'm afraid.
Sunny Island 4.4M / 6.0H / 8.0H | SMA Solar
www.sma.de
Sure. I have two Victron MultiPlus-II 3000VA inverters running in combined 240v mode. I also have a couple of victron autotransformers providing 120v output.
I power one of the inverters with 120v from my generator during power outages. This provides some of the power; I have a limit on the victron so that no more than 14 amps @120v is pulled from the generator. If more than that is needed then the Victron inverters pull from the batteries to provide the "boost" needed to cover the demand. During periods of lower power demand the generator provides enough power to slowly charge the batteries back up.
The batteries are 48v E-Bike batteries. I have about 9600kWh of battery. I would recommend going with LifePO4 batteries instead though. The batteries are the most expensive part of the system.
Hedges
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Yes, SB with SI works well.
I'm not certain the European 8.0H model works for backfeed of utility grid by itself, might need an external transfer switch? But for offgrid, and generator backup, should do all you need.
I recommend also a load-shed relay, to disconnect loads but keep SB connected if battery gets low.
| SI-LS100-48 | Load Shed Contactor 3 Pole 100A (non inductive) 48V DC Coil | £95.15 |
Thank you very much, the return of the utility network is not a problem, I also have a charger from a forkliftYes, SB with SI works well.
I'm not certain the European 8.0H model works for backfeed of utility grid by itself, might need an external transfer switch? But for offgrid, and generator backup, should do all you need.
I recommend also a load-shed relay, to disconnect loads but keep SB connected if battery gets low.
SI-LS100-48 Load Shed Contactor 3 Pole 100A (non inductive) 48V DC Coil £95.15
. All I need for my farm to work is: SB-SI and battery (I have uploaded pictures) I have two such batteries.......If I understood correctly: SB would provide power for SI network and battery charging, the rest is not important.
Hedges
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Thank you very much, the return of the utility network is not a problem, I also have a charger from a forklift
If you DC couple another source (forklift battery charger) to battery, use a shunt so SI knows how many amp-hours.
If this was lithium with BMS talking to SI, that should take care of current measurement (but I don't know this for certain.)
Hedges
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Sunny Island should be able to manage any GT PV inverter which does frequency-watts as part of Rule 21 or UL-1741-SA. The frequency range of power ramp-down is something like 60.5 Hz to 61 Hz. The must-remain-connected range is 58.5 Hz to 60.5 Hz (lower than previous 59.3 Hz of UL-1741.) I think the immediate disconnect max frequency is 61 Hz, not sure if with frequency-watts it can just sit at zero output waiting for it to drop back down.
Sunny Boys in off-grid or backup mode by default do frequency-watts rampdown from 61 Hz to 62 Hz, and remain connected up to about 64 Hz. Mixing these with later model Sunny Boys or other brands could mean that when SI ramps frequency up to curtail output from the last older Sunny Boy, other models would disconnect and remain offline for 5 minutes. You might want to adjust frequency settings so all inverters remain connected through the frequency where the last one disconnects. SI overshoots frequency a little bit, so an extra 0.3 to 0.5 Hz could be beneficial.
Sunny TriPower also works with Sunny Island. I have one of those set up. Some of the models require neutral as well in 277/480Y, while the STP 30000TL-US I have also works with no neutral, 480 delta.
Voltages of course need to be converted from 120/208Y by means of transformer. Right now I have some wired up as auto-transformers boosting 120V to 260V (close enough.) Later I want to replace with 240/480 to 120/240, which will take each 120V leg an make one side of 480 delta. I plan to generate a neutral on the isolated delta with another transformer (for a couple reasons; protection of STP from 480V relative to neutral in event of a fault is one, 277/480Y loads is another.)
Sunny Island 3-phase system will work with 120V single phase grid input, generating the missing phases. That's what I have now. TriPower will not work without all three phases, so can't be put on a single-phase Sunny Island system.
Sunny TriPower supposedly supports UL-1741-SA. Mine does have settings of frequency-watts, but only UL-1741 not UL-1741-SA so disconnects at a frequency below where frequency-watts occurs. I entered custom wider frequencies and it now works on my Sunny Island 3-phase system. Maybe a firmware update would give more options.
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