Microgeneration 6kwh limit

graememk wrote: »

So I currently have 20 longi 360w. On a dual string solis 6kw inverter.

Could that be pushed to 24 or even 28 panels?
12 or 14 on each string?

It's on low angle roof (walkable), split 50:50 north east/south west.

You can push it to 24 panels - 12 per string, but no more than that. Open circuit voltage is 40.8.

40.8x13x1.15 is 610V. Too high.

Doing it the hard way, for that panel type, temperature coefficient is 0.27% per degree. You have to allow 45 degrees between test conditions of 25c and lowest air temperature of -20c. Tolerance on Voc is 3%.

Worst scenario at -20 degrees is 40.8 x 13panel x 1.1215 temp coeff x 1.03 tolerance = 612V

The voltage is fairly steady - it is mostly current that is affected by light intensity.

No idea if this is for real but on Irish solar Facebook group I've seen 2-3 people claim the 6kWh limit is going to be reduced. No idea if its true or if this is yet another scare tactic from some dodgy installers to push people into signing up! One mentioned may is the deadline? Anyone else heard this ?

UPDATE: thought i'd email ESBN about export limiting like mp3guy did and before i did i found this:

Micro-Generators (esbnetworks.ie)

Information note in relation to Microgeneration units which exceed the defined 25A limit

It has recently come to our attention that some Microgeneration units are being installed which have output currents in excess of the 25A limit allowable as per the ESB Networks document Conditions Governing the Connection and Operation of Micro-Generation (esbnetworks.ie). 

We acknowledge that units may have been inadvertently purchased and installed based on manufacturers model references as opposed to specific data sheet information. In order to address the issue in a reasonable manner and ensure there is absolute clarity, we are now highlighting that we will continue to accept applications for units referenced as 6kW, but with an output current of up to a maximum of 28A single phase, until 31st May 2023, however from that date on any units with an output current over 25A will not be eligible for connection under the NC6 Microgeneration connection application route.

Also reading more I expect mp3guy getting permission is unusual based on ESBN own documentation!

Conditions Governing the Connection and Operation of Micro-Generation (esbnetworks.ie)

This is literally in the foreword of that document !

Any installations with inverter capacity greater than Micro-Generation (6/11 kVA) are classified as MiniGeneration (up to 50kVA installed inverter capacity). There are no active Export Limitation Schemes available under the Micro-Generation ‘Inform and Fit’ process, as the inverter capacity itself, which shall be within the allowed Micro-Generation limits, is used to determine the export limits.

Active Export Limiting Schemes are, however, available under the Mini-Generation connection process.

I wonder how many will be caught out by installer not submitting the paperwork. Mine has still not been done (went from 1.2 to 6 last year) and chasing the installer again. ESBN suggested I get the completed form from them and send it on myself!

Here's the page on that the guy gave me https://www.esbnetworks.ie/help-centre/help-faq/generator-step-by-step-guide/step-2---make-an-application

"Email the completed form to NetworkServicesBureau@esb.ie or post it to:

ESB Networks DAC

NC6 Microgen Notifications

New Connections

Sarsfield Road

Wilton

Cork

T12E 367"

Once you are not exporting more than 6kW peak ever - especially if you have a smart meter - you will never get caught on this. Strictly speaking having 3 inverters with potential export of combined greater than 6kW is breaking the rules and you should be under NC7 instead of NC6.

Reality though, if you're like a lot of folk on here with lots of storage and dump loads etc you will never export near 6kW anyway so nothing to worry about.

No SEAI grant in my case. Would have been great, but house doesn't qualify for it.

What size and make are both of your inverters. Is only one of them a hybrid?

I currently have a sofar hybrid and when set up with export limit it drops it's production to make sure that combined there is never more than 6kw exporting. If turn on something with large load and it is a sunny day it will ramp up production whilst maintaining max 6kw exporting and ramp down when power is not required if producing more than 6kw.

I previously had a solis 5g hybrid and it also did the same. Are both of your inverters going through the same main consumer unit?