Solar PV advice

[Richard77]

Hmmm...

Didn't see that SunSynk did a single phase hybrid inverter between the 8.8kW and the 16kW model... D'oh!

Thought the 10kW and 12kW were only 3 phase.

Installer has already applied for the G99 for the 8.8kW.

I feel like I should have went for the bigger inverter (as one of you suggested earlier in the thread... Sorry!)

Will the DNO tell me the maximum I can have installed or will they just say yes or no on the 8.8kW?

Was thinking... Can I submit a g99 application myself for the 12kW or 16kW? Even though the 8kW application has already been put in?

Cheers.

[sharpener]

Will the DNO tell me the maximum I can have installed or will they just say yes or no on the 8.8kW?

Was thinking... Can I submit a g99 application myself for the 12kW or 16kW? Even though the 8kW application has already been put in?

Cheers.

I don't think they will tell you specifically about anything you have not applied for, though when I recently wanted to up my exports from 16 to 32A NGED just emailed me a Connection Letter with the export limit blank.

Perhaps best to ring yr DNO and ask, they might give you an informal answer over the phone. Bear in mine the fast track process for G99 is limited to 32A anyway so you are already outside that, and if applying formally they might have you withdraw the 8kW application first which you might not want to do.

[Richard77]

Hi All....


Installer got informally told by the DNO today that 12kw inverter should be ok and export probably capped at 6kw.

Will need to resubmit application though, as original application was for the 8.8kw.

Unfortunately the installer got in touch with SunSynk today and they said can only have 14 panels on each MPPT and no more.

SunSynk 12kW:
PV input voltage: 370v (125v-500v)
MPPT range: 150-425v
PV input current: 26A + 26A + 26A
Max PV Isc: 44A + 44A + 44A
Max DC input: 15600w
No of MPPT / Strings per MPPT: 3 / 2+2+2

455w Aiko's:
Voc = 40.79v (+2-3v cold temp) so 44v to be safe.
Isc = 14.22A

So 14x panels (7/7 on each string) would only be 308v (being very conservative at 44v voc) and 28.44A.

Surely more than 14 panels is ok in this case?

18x panels (9/9) would only be 396v. I can't understand why they would say 14 is the max, or am I missing something?

Thanks

[Stinsy]

I agree with you!

[AGT]

Maybe they have included the postcode correction factor and other multiplier. Don’t have paperwork with me it’s in the office

[AGT]

Ps does anyone have a G99 for PV& EESS filled in that they could share some info

What’s the IDC and RC figure? Never come across this in manufacturers data sheets,

[Richard77]

I agree with you!

Phew...

Was thinking I was messing something up. I think I will have to get in touch with SunSynk myself and see what they say.

I was thinking that going for the 12kw with the 3 mppt's (6 strings) would be better for my needs.

MPPT1 (west) 18x panels (9/9) 396v 28.44A
MPPT2 (east) 16x panels (8/8) 352v 28.44A
MPPT3 (south / garage) (6/6) 264v 28.44A



Thought I could get away with no optimisers with that setup, if I took down the chimney stacks down that caused a bit of shading.

Installer suggesting optimisers now too.

[Richard77]

Ps does anyone have a G99 for PV& EESS filled in that they could share some info

What’s the IDC and RC figure? Never come across this in manufacturers data sheets,

I haven't a clue mate sorry.

Edit...

IDC: intrinsic design capacity. Maximum power output that a generating unit can produce.
RC: registered capacity. Maximum power output that a generating unit is registered to export to the grid.

AI generated from my phone! God knows if correct.

[AGT]

Cheers yes got that too, but still not clear what it is, always helpful to see a worked example for guidance.

Ie got 2011 fit 1.7kW
Looking to add 8.8kW hybrid inverter with 30kWh batteries and another 2.2kW of PV on that inverter..

[Stinsy]

I agree with you!

Phew...

Was thinking I was messing something up. I think I will have to get in touch with SunSynk myself and see what they say.

I was thinking that going for the 12kw with the 3 mppt's (6 strings) would be better for my needs.

MPPT1 (west) 18x panels (9/9) 396v 28.44A
MPPT2 (east) 16x panels (8/8) 352v 28.44A
MPPT3 (south / garage) (6/6) 264v 28.44A



Thought I could get away with no optimisers with that setup, if I took down the chimney stacks down that caused a bit of shading.

Installer suggesting optimisers now too.

I’ve got optimisers on a couple of my panels. I’d recommend them. You need to think about how the sun tracks and shades move. You could easily end up with a string crippled because a single panel is shaded…