Hi All I have an AC3 and a 9.5 battery connected to my existing setup. I am considering adding a second array (which may not be with a givenergy inverter). I was wondering whether the AC3 can still handle that? Will it work fine with the existing monitoring (ie does it rely on looking at the main house feed to balance load between solar and battery) or would an extra CT clamp or something required for the second array?
Incoming mains monitoring should be fine.
Solar monitoring - probably need an extra CT for that. Believe the AC can support grid monitoring and two solar inputs.
My solaredge solar inverter doesn't use a CT clamp. I can monitor the true solar gen in the solaredge monitoring which is coming direct from the inverter to their cloud, and see the GE version of the solar gen through their portal/app (which comes via CT).
pacemaker how does the GE unit know about the solar if it's AC connected?
Is there an API connection between the solar edge and GivEnergy?
TX200 thanks. That’s helpful.
Boffinboy I think it may be of benefit if you say exactly what today's set up is and what the considered new array is going to be, There may be other considerations to take into account.
TX200 No idea tbh... I assumed the CT was somehow seeing excess wattage and therefore "detecting" solar... I see small solar noise throughout the night (0-15w) when the solar inverter is asleep, so I assume its inferring it rather than seeing it directly...
SilverArt thanks Silverart. I have an existing array on a 3.68 inverter (non Givenergy). I recently added an AC3 and 9.5kWh battery. I’m looking to add a new array on a different roof orientation that is more westerly (maybe using GE, maybe using other manufacturer), and wanted to ensure that the current AC setup will still function. It sounds like I likely need to get someone to add an extra CT clamp otherwise won’t be able to monitor the extra solar array within the GE app.
I am unsure if there is any advantage in an additional array using a GE inverter? I know that there are some issues with “plant” setups?
I realise the battery and inverter won’t be enough to capture all excess, but that’s not necessarily the main objective. Adding more battery capacity could be useful, but that likely means either using a hybrid inverter (and then potentially creating issues of charging back and forth between AC and the hybrid battery) or adding a second AC3 which I understand doesn’t work well currently.
Apparently 1x hybrid inverter and battery+ 1x AC connected and battery play nicely, they don't cross charge.
Mentioned elsewhere in the forum.
So, are you on a FIT tariff with the existing or are you 'free' to do whatever you please? What DNO approval are you going to need for your proposed setup? What is the panel split going to be,, both in terms of power and number?
Ah, good to know hybrid works OK with the AC coupled.
SilverArt no FiT. I will need DNO approval, I assume - G99 fast track since new array will be under 3.68, but ultimately the installer needs to figure that out! I need to make sure I can get the export payments or it becomes unviable.
The new array would be slightly North of West - so not optimal in any way - but if priced right will work out well give nice generation in the peak hours (not in winter of course) and I can export for a good rate if it’s not being used. It will complement a well orientated SE array which trails off earlier in the day and re-top up the battery which helps smooth things out.
Unrelated, but due to a frustrating installer situation current array is massively oversized (like 50%) vs 3.68 - I think they didn’t want to bother with G99 and when I got it installed I didn’t know better, but switching out the inverter for a bigger one would probably cost more than the benefit. In fairness, modeling in the installer software (which I verified myself too independently, as did someone else) shows a bigger inverter would only give 5% extra generation over the year and most of that in the middle of the day. I assume this is because on dull days the inverter is more efficient by hitting start up voltage earlier and therefore getting more generation on the “shoulders” of the day and in overcast conditions. This is more valuable that excess exported in the middle of the day.
What will the total potential export be when you have the new system? Guess both systems will have to be capped unless you get a better export limit on your new application?
Presumably the solar generates more in the morning as the panels are cooler, then when it gets warm, not so efficient, so perhaps whilst it does increase it doesn't go too far over the limit, as you say, not enough to swap out the inverter.
Currently figuring out how many panels fit on the other orientation. I’m guessing total potential export would be 6-7kW, assuming I didn’t change the existing inverter. Not sure what likely limit would be with DNO here - need to get installer to check - as if I can’t get export payments for one array it won’t be worth it (unless also getting a hybrid with battery on new array).
Boffinboy if your two arrays face in different directions, it’s unlikely that both will be generating (much) at the same time. If your existing inverter has two MPPTs, you could connect the new array to the second MPPT. Alternatively a new hybrid with attached battery would give you greater storage capacity and greater supply from the two battery-attached inverters for heavy loads.
Tim definitely agree, they won’t overlap much, which is why I am keen to do it, even though it would be closer to north. Will definitely need an additional inverter, so all going to come down to what price I can get for an install as to whether it’s viable. I quite like the idea of a hybrid with second battery, which would expand storage capacity as well, whilst saving VAT.
Does anyone know how the app sees / handles an AC coupled with battery plus another giv hybrid with battery?
Boffinboy worst case scenario is that you have multiple accounts and login. Best case is that the two inverters show up in the same portal as two hybrids currently do. The summations may well be wrong but the individual inverter data should be correct as logged (at least it is for our dual hybrids). In any event, as long as they are performing in the way you want them to, they will be delivering the benefits you’re looking for; it’s just the data collation that would need a bit of manumatic work.
Boffinboy My EW split is skewed the opposite to yours, the mean being a little SE. Last year it was 7.1kWp in an 8E/10W split into an GE AC3 + GE 5.2 battery (with a Growatt 6kW dual mppt inverter). This month I added a GE 9.5 battery and a couple of extra panels making a 10/10 split, 7.9kWp total.
My observations: Last year the June/July/Aug normal generation daily (09:00 to 19:00) levels went from 1kW to just over 4kW (dependant on weather and time of day) with some high periods at 5.6kW. There were a few peaks which were clipped at 6kW, they were never sustained and probably due to reflection.
Overcast days just evened the per panel generation out i.e. if I was getting 1kW from the West string I'be be getting approx. 800w from the east string, morning or afternoon.
With the addition of the two extra panels on the east string it is much closer to an even split when overcast but the west string benefits from a slightly more open view of the sky so it has a small watts advantage.
The only other thought if affordable is to add another battery as it would be VAT free.
Not sure if this helps with your deliberations but good luck anyway.
Boffinboy current array is massively oversized (like 50%) vs 3.68
If that's the case, then removing both the (non-FiT) solar inverter and the AC-3 and replacing with an HY5 would enable the full array to be utilised, with the second string on the second MPPT. That would extend your harvesting period each day and during the year and it would reduce losses with conversion to AC and back to DC for battery charging. If you wanted to do the work without a new G98/99 application, you could substitute the HY5 (ie existing two inverters) for a gen2 HY3.6 since, as long as the battery charge rate from PV was limited (so that it could consume most of what would otherwise be clipped output), the inverter could consume most of the full array output by pushing a limited amount to battery, supplying house load and exporting surplus, up to the maximum array output. The HY3.6 can consume a maximum of 4.7kW from PV (so not quite your available output), pushing this to battery (maximum rate of 2.6kW, balance to house/export) or house/export (maximum of 3.6kW, balance to battery). If you plumped for the HY5 and a full G99, the available PV would be clipped. As I understand it, there's very little price difference between the HY5 and HY3.6.
Tim thanks Tim. A helpful suggestion but I don’t think this plan will work as I have two strings already due to panels spread across slightly different roofs and some shade late in the day. So, to add stuff on the other side of the house, I need a new inverter.
Expecting some quotes this week and will go from there! Current thinking is I can switch the current inverter to the new panels (it’s quite a nice SMA, which is why it can take such oversizing), and get a larger inverter for the current array.
Just a thought.
How long left on your FIT payments?
Reason for asking is you could punt for an inverter that would handle your new PV install & you existing FIT enabled setup. That way when your FIT payments end you could combine them into 1 large system.
If you went for a Hybrid then you could add a battery to this either at time of install or down the line.
Boffinboy no FiT
dragon2905 thanks. No FIT, which makes life easier. Main reason I think against that is I’d need more than two strings, plus probably an 7-8kW inverter or so, dependent on size of array on other side.
Sorry my bad about FIT......
We have S/East N/West facing roofs with panels installed on S/East side.
We could install another 6kw Peak on the N/West roof but adding another complete install is beyond our budget atm.
So instead I have been looking for something that will ramp down/up Solar PV on different strings but wasn't able to find anything that is manufactured.
However interestingly I did find this which was built by a chap in the USA who uses a PV combiner box in conjunction with relays and timers to effectively switch of his PV arrays and enable him to continue to use a single inverter. Kinda genius in my opinion.
dragon2905 Some more "out of the box" thinking. Would probably invalidate the inverter warranty but a good work around for the lack of MPPT where the arrays have completely different aspects. I can see why he's doubled up on the relays in series but personally, I'd rather switch both poles and use one to break any load and then two other contactors to connect the desired string to the first contactor (ie string contactors only operate when the "line" contactor is open). Using actual string voltage to control the operation (eg via HA) would also improve operation. One issue with using contactors (or relays) for this sort of project is that the DC rating of the contacts is significantly less than the AC rating due to arcing, hence switching at low/no power is highly desirable. Also, most high current DC contactors/relays are rated for relatively low voltage (<100V), so operation at 500V+ would call for a specialist device, or some informed fettling @hoggy?
Tim if you’re looking to combine strings perhaps a Growatt SP2000 on the DC side a bit like my Goodwe thing would do it cheaply?
I’m yet to pick one of those up (they pop up on eBay constantly as the 1st Gen Growatt batteries have a habit of going out of balance and killing their BMS)
They do however have 3 MPPT trackers and 2 outputs to go out to the Givenergy.
The party trick with these is you can also do 1 way AC charging so no impact on G98/G99.
I just don’t know if I can get it to talk to Pylontech batteries but I’ll try and bag up be on eBay at some point to find out and if so retire the Goodwe…
dragon2905 no worries. That’s pretty much my exact aspects. Since the new array would be North West it really has to make sense cost wise, and DNO allow export to get some SEG payments, as in winter generation will be poor. Seeing the evening sun on that roof is making me want panels there though!
Quite a creative solution that person has used!