iSwannie
Now that's WATT I am Talking About!
Very nice to hear. Looking forward to the picture postings.
I think it is, by several generations of datacom equipment.
I presently have Sunny Web Box connected, which can see and adjust both Sunny Island and Sunny Boy.
Not advisable for internet connection because they gave it a hardwired admin password.
I also have the earlier Sunny Data Control.
Other interfaces are currently marketed by SMA.
[/URL]
You can use DC coupled SCC, but better is AC coupled, e.g. Sunny Boy GT PV.
Like Hedges said, you can DC Couple them like most other off grid inverter systems, but they are capable of AC coupling, which is a better way of going off grid in my opinion.. Not a lot better, but I think AC Coupling has advantages, especially if you're driving loads during the daytime hours.
The problem with the Sunny Islands is that they lack features.. They're designed to do a job and they do it exceptionally well, but they lack all the bells and whistles if you're into that.
Its a $5000 inverter and they equipped it with a 2 line dot matrix display that's 2.5 inches wide and 5/8 inch tall.. LOL
SMA of course made products for Germany and Europe, and because U.S. 120/240V split phase is different (also electric building codes), we get the products later with redesign.
We have an older design Sunny Island, which has been around 15 years. Slightly updated, seems to have improved cooling so 5.75kW continuous vs. 5.0kW, and single large battery cable lug instead of two smaller ones. All use same firmware. It is an indoor model, with SD card slot and mechanical breaker. Also the display you mention and keypad. Convenient to be able to configure it without needing interfaces, PCs, networks.
I noted it was packaged same as the "Opticool" Sunny Boys which are rain tight, and put a silicone sheet over the front panel. With a modification, I can work the breaker through that, but have to remove front cover to use SD card.
The main feature it lacks is time and inverter/charger wattage control to shave usage during peak rates. It is primarily an off-grid or backup inverter and seeks to maintain battery charge, rather than zero export or minimum import/maximum export at some times of day.
Does your "H" series have features like that?
Another big plus for the European models (including previous one just like present US one) is that at double the AC voltage, same 56A relay can handle double the wattage.
So 6kW Sunny Island can have 12kW of Sunny Boy while on grid. We are limited to 6.7kW on-grid (56A x 120V) but can have 12kW for an off-grid only system.
I would expect it to come to the US eventually. For now, guess is they are working through old inventory (DC Solar with $1B to spend bought a lot of them, resulting in liquidation sales that let us buy Sunny Island for 1/2 or 1/4 of retail price, so I'm happy.)
Do you use external relay to pass grid/generator through to load, or internal relay? (Given both, smaller internal relay could have been assigned to generator, but probably firmware doesn't support that.)
I've considered coupling such AC sources to Sunny Island by rectifying them and putting through a Sunny Boy (likely older model with "Constant Voltage" or "Turbine" mode, not using "MPPT" mode.) This would make it a double-conversion UPS, with Sunny Island rather than the source being what establishes voltage and frequency. No dropouts due to switching. No backfeed, either.
I have an almost identical use case. I got the SolArk12K and 6 Trophy heated batteries and a Honda 7000is. Could not be more satisfied. It’s been flawless. I put my batteries in small heated and very well insulated closet. Batteries have never been below 50F event at -30F. My primaryarray is 10kwp. i have only had to use the generator once, but I do top off the batteries if I’m not going to be there.Looking for recommendations for off-grid inverters for a system with these characteristics:
If you have an inverter brand/model recommendation based on your experience, please indicate why you recommend, and pros/cons. I've seen a lot of discussion of issues with certain brands on this forum, but not anything collecting it into one place for my scenario.
- 48V
- un-inspected: off-grid, no building or electrical inspections required
- ~6 KW solar panels expanding to 12-18 KW over time
- PV array would probably settle in at around 400 V, 19 A initially, expanding to multiple arrays
- battery storage (looking at the EG4 batteries at the moment)
- 9100 ft elevation
- many days below freezing, with many also below zero
- ~5-6 KW of inverter capacity initially, expanding if required
- 240 V required
- The cabin will be uninhabited 3-5 days/week
- generator backup, and I have a Honda EU700is generator, currently without autostart
Research so far:
Would appreciate any advice you guys can provide as I embark on my design.
- Sol-Ark 12K: Perhaps not the best for off-grid use. Seems to include features that benefit grid-tie systems that I would not want to pay for. Seems touchy, as a lot of folks have struggled with it shutting down with slight imbalances on the AC legs. Needs an additional autotransformer to overcome this. Pricey.
- Victron Quattro 5000 KVA: Seems straightforward. You buy two to get 240 V. Not UL listed, which does not matter for me. Less pricey than Sol-Ark for two. Reputable brand.
- Growatt 5000W 48V: Price seems too good to be true. Needs an autotransformer to produce 240 V. Relatively high idle watt usage. Reputation of the brand? Reliability? Longevitiy?
There are a lot of features and capabilities the "H" series has, and they all available and configurable via the web GUI.
There is another firmware version (3.30.12.R currently) which I first sampled in 2021 (3.21.04.R). It seems to be code designed for non-multi-cluster systems. I run into some weird issues with it, so I rolled back to 1.4.0.R, which lacked a few features compared to the newer code, but nothing that I missed. 1.4.0.R has been stable since 2020, and all new developments seem to be happening on the 3.x software train.
You're right - grid pass-through is a whopping 11.5kW, and it handles it without any problems.
But assume that if you run it as a split-phase system, you can get 11.5kW out of it, yes?
Not sure I understand what you mean here fully. Please explain a little more.
The key features for us involve knowing time of day when rates are peak, monitoring grid current with a current transformer, and storing power in battery during off-peak to minimize import/maximize export at peak times.
For tax reasons, may want to ensure battery only charges from PV, never from grid (makes eligible for credits; Tesla is careful to do this.)
If we have different rate for import-export (e.g. pay $0.25, get credited $0.03, we want it to adjust its inverter/charger power seeking to maintain zero amps through grid connection.
These features are in other models like Sunny Boy Storage, which can also be set up for grid backup. But those still aren't stackable and don't have same surge capability. Also use high voltage battery. Sunny Island is still the best for larger systems & bigger motors, also DIY or otherwise affordable batteries.
The off-grid limit of GT PV wattage 2x SI wattage I would guess is a fuzzy limit.
Load addition would be limited to surge capability of SI (and whether it was already sourcing or sinking power), and load-dump
I would think battery charge limit (do battery charge limit settings prevent momentary surge higher? Lead-acid would tolerate, but lithium BMS would disconnect unless they have surge programmed in.)
There are also minimum battery size recommendations - 100 Ah per SI, 100 Ah per kW of GT PV. My AGM is 1/3 the recommended size based on PV, seems to be OK with my loads.
AC sources (grid or generator) are normally connected to AC2 input. SI synchronizes to them, then lets them be voltage/frequency source. When disconnecting, there is a drop-out.
My idea is to feed AC source, not into AC2 input, but into a Sunny Boy just as you would from a hydro turbine. Rectify the AC and connect to "PV" input of SB. Needs to be electrically isolated, so use a transformer. Capable of delivering large fault current, so have soft-start mechanism (e.g thermistor, precharge resistor, or transistorized current-limit circuit. Possibly use arc welding transformer, which limits current by inductance.) The nicer way would be a power-factor correction circuit, but rectifier-capacitor is the crude way.
If you have an inverter generator, probably just tap into its DC rail.
What this does is it lets SI be the voltage and frequency source continuously, no glitch on transfer.
So if you have SMA's Energy Meter (EM) and Data Manager (DM), you have a way to tell the SI about grid power. I am not aware of any way to tell the DM about grid tariffs, although this capability is available on the ennexOS portal, which may not be obviously useful for this type of feature requirement.
Have SMA told you whether they can support this feature in their "H" SI inverters at some point in the future?
Right, Tesla do this because they do not market the PowerWall as an off-grid system. SMA's focus is off-grid (even though they do support grid-tied deployments), so their philosophy is quite different from Tesla's.
I think this is something SMA can implement as part of their DM, but you would also need to install their EM and have a DM too. From my system, I don't see this capability today, but I do not see why it cannot be supported as part of a software update.
But again, given SMA really sell themselves as an off-grid vendor, I'm not sure how much appetite they would have for this, especially since not all markets have this from their grid providers (although, to be fair, the U.S. and Australia, which are big SMA markets, do).
The SB Storage also supports Li-Ion batteries only, so this is a limitation for LA installations. It is what comes closest to Tesla's PowerWall, which is why it can support similar grid-tied features.
The SI 8.0-H is 6kW rated, 11.5kW grid pass-through. The 6kW rating from the inverter is governed by other factors such as temperature and conversion losses. However, the 11.5kW pass-through performance is guaranteed under all conditions, as it's just a relay across the SI between loads and the grid.
I'm thinking about whether monitoring grid frequency sag might be better than monitoring voltage sag. Any thoughts?
Hmmh, that is quite the solution, I have to admit . Not sure SMA would be pleased to hear you've turned their Sunny Boy into a rectified DC inverter, but well...
Have you tried monitoring the external grid via other mechanisms so that you give the SI some buffer where it does not have to "surprise" you during a grid/generator outage?
SMA talks about selling power to the spot market. That may be a future thing but not what I'm interested. It could also be related to the communication and control features required by our newer UL-1741-SB
Just time of use for the tariffs is all we would be looking for. If rate is $0.50 from 4:00 to 9:00 PM, $0.35 from 9:00 to Midnight and 3:00 to 4:00 PM, $0.25 from Midnight to 3:00 PM, want to use battery to avoid importing at high rates, even export at high rates. (But then if grid fails at night you're in the dark.)
The US model SI will draw from battery to limit maximum current drawn from grid.
If battery is charged to higher voltage than it wants (by external SCC), then it will export from battery to grid.
I don't think it has any commanded or time based export, or any continuous regulation of export. If we reached in and commanded a low battery voltage I think it would invert at maximum to achieve that. What is desired is analog monitoring of current transformer and inverting to keep that at a target current to grid (like zero.)
SBS and SB, with external meter, offer zero export (and battery storage of what would have been exported.) I don't think US model SI does.
Hopefully H series has command set for battery charge/discharge to accomplish zero/limited export and to take advantage of time based pricing.
I think for SB, output wattage is commanded (something about involving their internet portal, while I think it should only need current transformer.)
I would think 95% to 99% or more of their sales volume is grid tie. Lots of SB on the grid, also MW scale inverters for grid tie. They offer MW scale battery inverters as well, don't know how many are used off-grid vs. grid attached storage.
I think amps pass-through is what is guaranteed. Watts depends on line voltage.
Firmware does what it does, not always what we expect.
I connected 3x SI as 120/208Y 3-phase, with 3-phase TriPower, but connected just one SI AC2 input to the grid.
Power from the AC coupled PV passes through on that one leg, while the other two legs just charge battery. SI on the first leg sees elevated voltage on battery so it inverts and adds that current to grid on its leg.
I did that with 5kW of PV connected, and set (what parameters I could find) for grid current to 8A, about 1kW at 120V. SI went ahead and exported 2400W (the amount of sun available) by inverting from battery, rather than limiting that to the 800W from AC coupling plus just 200W from battery (which would result in battery voltage rising.)
I don't know if it would have limited to 56A, the max setting, or if SI would have added current to TriPower on one leg and exceeded that. I was hoping inverting from battery would limit, charging from AC would limit, AC voltage would rise, and TriPower would reduce wattage collected.
I've imagined CT on SI AC2 to command TriPower, limited export through SI relay. This would be to allow AC coupling in excess of relay capability. (Not such a problem for you because at 230V, pass-though wattage limit same as GT PV wattage limit for SI to manage.) More for my split-phase to 3-phase conversion. Only "Y" with 120 degree phase shift not high-leg delta with 90 degree phase shift settings, so only one SI can connect to split-phase grid.
SI monitors grid for voltage and frequency. Limits are wider under UL-1741-SA. I would think internal monitoring should be sufficient.
Only older models SB have "turbine" setting. SMA dropped Windy Boy. But I use older models.
Nope, was counting on SI doing that. SMA discusses length of dropout vs. grid voltage (or impedance, or something)
Does this seem feasible considering how mature the off-grid/renewable market has become?
It should not be that onerous to implement, but something tells me that SMA's focus is on off-grid deployments.
Well, this is configurable on the "H" series. Is this not flexibly configurable on the US versions?
Well, that is likely because the CC does not support FSPC, yes (which makes sense, since the CC and battery are directly connected via the same DC bus)?
But then again, this would not really apply where Li-Ion is concerned, since the BMS would throttle charge back from a CC, yes?
So the "H" series give you the option to prevent grid export. See attached.
"H" series allows you to disable grid export. It does not allow you to manage all this based on grid tariffs.
PV producion from the SB is managed by FSPC signaling from the SI.
This is not limited to the SB, as other PV inverters that support FSPC can be commanded to ramp-up/ramp-down by the SI via frequency.
For MW-scale, SMA's central PV and battery inverters are typically deployed by grid operators.
Enterprise users looking for MV-scale applications will typically go for other vendors, as SMA currently do not have an MV-scale battery inverter for that market. They do have an MV-scale PV inverter (the Core 1, Core 2, Central and Central UP units), but there are a number of Chinese vendors who are pushing MV-scale hybrid inverters in the 100kW - 600kW range that SMA currently have no answer for.
Are you running LA packs?
Is your external grid only reachable via the one SI?
Technically, as long as the SI and PV inverters are AC-coupled, it should signal to the PV inverters to ramp-down. But that is, ultimately, directed by the battery's BMS.
If you are running LA packs, and assuming you don't have a BMS that sends data back to the SI, have you setup your charging profile in the SI to ramp-down charge current from PV or grid when the battery is at the set charge voltage?
Do you have a DM?
I assumed your PV inverters only get access to the external grid via the SI, but it seems to me that your PV inverters have a more direct path to the external grid. Is that the case?
Hi mvonw, which trophy batteries do you have and on the EU7000is how did you wire it for auto start from the SolArk? did you need an additional module?I got the SolArk12K and 6 Trophy heated batteries and a Honda 7000is.
I have the 120 (listed as 110)AH batteries. I don't think he's selling those any more. I connect my Honda directly to the Grid input of the Sol Ark and set the Grid limit to 75A, so it doesn't overload the generator. I use a remote start to manually control charging, because the I only want to run it at night or very overcast days and not have it controlled by strictly SOC of the batteries. Auto start isn't very useful because of the limited fuel capacity of the Honda. One tank doesn't even completely charge my 720 ah battery bank.Hi mvonw, which trophy batteries do you have and on the EU7000is how did you wire it for auto start from the SolArk? did you need an additional module?
I have that generator already and I'm getting ready to buy an AIO and batteries to update my system.
Thank you for your input.
Pj
This is exactly what I was wondering.I have the 120 (listed as 110)AH batteries. I don't think he's selling those any more. I connect my Honda directly to the Grid input of the Sol Ark and set the Grid limit to 75A, so it doesn't overload the generator. I use a remote start to manually control charging, because the I only want to run it at night or very overcast days and not have it controlled by strictly SOC of the batteries. Auto start isn't very useful because of the limited fuel capacity of the Honda. One tank doesn't even completely charge my 720 ah battery bank.
You always need more.. ..This is exactly what I was wondering.
I have the Genconnex wired remote start on it now, and I could just start it as needed on cloudy days, or when I know we need to run an air compressor or large load.
I am looking at going with two of the Trophy 48V220E-1, this would give me plenty of storage for my little cabin.
primarily used to inflate low tires, clean chainsaws, and in the winter, connect to the plumbing to blow out the water lines; I have a small pancake-style compressor now that works well off the generator.Some inverters can start a decent size air compressor, and may not need generator.
How much air do you need? For me, often just a few seconds of impact wrench.
How about patching in a tiny compressor, share the same big tank?
(Just don't blame me if it burns out its oil-free piston with the run time to fill your 20 gallon tank.)
True, that's why I like the idea of going server rack style.You always need more.. ..
I’ve been looking at the Schneider with the victron inverter- any likes on this combo? Comments?!It’s a good low frequency inverter / charger I don’t think it comes with a charge controller
you have to buy one separately.