FIT and panel replacement

Chris_Type_R

QrizB said:

Have you seen this document?

Thanks for that. 

> 6.6 You must notify your FIT licensee if you extend or reduce the (Total Installed Capacity) TIC of the accredited

installation.

> 6.16. When carrying out such works, if your installation:
> - was accredited under MCS-FIT, you should only notify your FIT licensee of the modifications to the accredited installation.

It does seem to suggest the possibility of replacement, provided one can secure confirmation from the licensee in advance. 

I believe my inverter supports two strings, so in theory I could replace 3 x 225s with 2 x 330s on a different string and remain within TIC.



For some added context, this is my generation today on a cold/wet & cloudy day. 

What's of interest is that A9, A8, A1 would have been the panels most affected by tree shading in the past - the tree was removed last December. A6 and A5 see early morning building shading. It's as if they're suffering from "shading memory" .The panels themselves are clean. These have diodes which should have, to a lessor degree, mitigated shading. 

It will be interesting to see if the same pattern persists should we ever see a sunny day again. 

Martyn1981

Will the reduced number of panels on strings still meet the minimum voltage requirements of the inverter and the MPPT, or doesn't that matter with the optimisers?

Chris_Type_R

Good question.

Chris_Type_R

QrizB said:

Have you seen this document?

https://www.ofgem.gov.uk/publications/feed-tariffs-guidance-renewable-installations-version-16

Chapter 6 concerns modifications. In particular paras 6.14 to 6.17 seem to cover your situation.

Thread revival. I'm looking at this again as I have a number of 405W panels looking for a 'home' and the best aspect is where my existing FIT array is installed. 

Thanks for posting the document link at the time. The linked document is up to v17 now. The document was amended at that time to include the OFGEN 2021 decisions  - https://www.ofgem.gov.uk/sites/default/files/2021-12/Feed in Tariffs_Consultation on the treatment of replacement generating equipment_Decision_13122021.pdf

>> 6.16. You may repair or replace all or some generating equipment without affecting the compliance of an accredited installation, provided that the installation continues to meet the scheme rules. ...
>> 6.18. When carrying out such works, if your installation:
>>    - was accredited under MCS-FIT, you should only notify your FIT licensee of the modifications to the accredited installation.

My understanding of the revised FIT document is that it is okay to change the generating equipment now - with the requirement to notify the FIT licensee.

My plan would be to neither increase or decrease the kWp rating, as I can neatly replace 9 x 225 with 5 x 405 - freeing up space for another 6 or 7 panels - ultimately to be used on a battery system when these become cheaper.

I have emailed Ovo which have taken over my FIT from SSE for clarification/reassurance - it remains to be seen if the email will be answered. 

Chris_Type_R

Martyn1981 said:

Will the reduced number of panels on strings still meet the minimum voltage requirements of the inverter and the MPPT, or doesn't that matter with the optimisers?

The answer to that good question is a 'yes'

matty_bram

You are unable to change the output of your system if it's connected to a FIT - and any changes you make yourself won't be MCS certified so it will mean your FIT will cancel. You can update the system to include more modern equipment but not the power output - it's best to install a system alongside the original if you want to keep the FIT – the new system can be connected to an SEG https://solarfast.co.uk/blog/feed-in-tariff/

Martyn1981

Hi, actually it's fine to increase the power, you just need to notify your FiT provider so that they can apportion the generation accordingly.

More detail (but my posts are extremely boring) on this thread:

Expanding Existing Solar System and adding battery and keeping fits payments

Chris_Type_R

As Martyn says, it's fine to increase generation as this will be pro-rated by FIT provider - but they need to be made aware of the change. The latest guidance supports this.

I would rather not do this personally - I want to replace 9 225W panels with 5 * 405W or 4 * 500W. The replacements will be located in the best positions shade wise, which would be a slightly better outcome than pro-rating.

Additionally, I want to add a hybrid inverter as well as additional panels in other elevations, which seems easier to keep DC, rather than DC->AC->DC.