3.6kw on sma 400tl ?

[will547]

Hi All,

just had customer inform me he,s gone with a 3.6KW system with SMA 4000TL, 15 x 240w panels.

does this sound right, checked SMS software which suggests no inverter suitable for 15 panels

not sour grapes about not getting job, but from what i,ve been led to believe, over rated for system and sma software suggests not suitable.

thoughts ?

 

[SolarCity]

Do you know which panels he had quoted for?

 

[will547]

15 x ET Solar ET-P660240

 

[SolarCity]

I haven't run it through Sunny Design because I don't have access to my laptop. From my sums, however, I haven't found any reason why this system couldn't be run on two strings.

I agree that the inverter does seem a little oversized. The SMA range are not, in my opinion, ideal at or around the 3.8kWp size. The 4000TL inverter is often oversized and the next smaller option (in the TL range) is the 3000TL - too small. SMA are plugging this gap with the release of the 3600TL but at the moment, those installers that are relying purely on Sunny Design for systems of this size are missing out on some vital options which could increase their yield significantly.

Most well designed systems using a 4000TL will also require prior permission from the DNO - in my experience this can take weeks rather than days - I am beginning to suspect that a lot of installers are simply ignoring this and notifying the DNO at a later date.

 

[will547]

thanks for reply, SMA design suggests only conditionally compatible, noticed from his quote it showed fully compatible but was an older version of software, guess that the customer may loose out on yield.

 

[dansk]

View attachment ET240.doc

Run through PV sol, south facing on birmingham and seems ok.

 

[PeteFT]

I haven't run it through Sunny Design because I don't have access to my laptop. From my sums, however, I haven't found any reason why this system couldn't be run on two strings.

I agree that the inverter does seem a little oversized. The SMA range are not, in my opinion, ideal at or around the 3.8kWp size. The 4000TL inverter is often oversized and the next smaller option (in the TL range) is the 3000TL - too small. SMA are plugging this gap with the release of the 3600TL but at the moment, those installers that are relying purely on Sunny Design for systems of this size are missing out on some vital options which could increase their yield significantly.

Most well designed systems using a 4000TL will also require prior permission from the DNO - in my experience this can take weeks rather than days - I am beginning to suspect that a lot of installers are simply ignoring this and notifying the DNO at a later date.

Why does a 4000TL require prior permission from the DNO? I had one fitted last week and the installer did not mention this!!

 

[BruceB]

Why does a 4000TL require prior permission from the DNO? I had one fitted last week and the installer did not mention this!!

Because its maximum output is 22A per phase which is over the 16A per phase G83/1-1 limit.
There may be a reason your installer has not got prior permission, if for instance you do not have enough panels to ever get the output above 16A.

If you want a well reasoned opinion on here then say what panels you have in what configuration and also what has been put on the MCS and DNO documentation if you have it.

Regards
Bruce

 

[PeteFT]

Because its maximum output is 22A per phase which is over the 16A per phase G83/1-1 limit.
There may be a reason your installer has not got prior permission, if for instance you do not have enough panels to ever get the output above 16A.

If you want a well reasoned opinion on here then say what panels you have in what configuration and also what has been put on the MCS and DNO documentation if you have it.
Regards
Bruce

I have 21 Schott 190 panels in threee strings. The MCS certificate says
Estimated Annual Generation: 3425kW
Declared Net Capacity: 3.90

 

[BruceB]

I have seen your other posts now. In my opinion, assuming the array is south facing, your system is over 16A per phase and needs to be a G83/1-1 Stage 2 connection (in other words prior permission). Your installer may have got permission from the DNO without your knowledge. Alternatively he may have under-declared the system in the DNO documentation he submitted after commissioning. What you have quoted from is the MCS certificate not the DNO documentation. The DNC is OK. If it is south facing then unless you are well up north then I would expect you to do better than that in terms of annual generation, which I hope is pleasant news. You should ask the installer about the DNO side. Around here the DNO(s) either send the client direct a 'parallel connection agreement' or send to me a letter acknowledging commissioning and giving permission for the connection, which I pass onto the client.
Regards
Bruce

 

[PeteFT]

I do not know what DNO stands for, but i assume in my case it is EON. The form sent to them states: Installed capacity 3.990kW, Declared net capacity 3.136kW. Did query the 3.136kW figure, and thegot an apology and the explanation that " I had accredited you on SAP 2009 & not the revised" if that makes sense. I live in Surrey, the panels are on my roof at C.30Deg and the roof faces SSE.
Kind regards
Pete

 

[BruceB]

DNO is Distribution Network Operator. It is the company that runs the electricity network in your area (either Scottish and Southern Energy or UK Power Networks, not sure their exact borders in relation to Surrey). Your supplier is who you pay for your electricity. EON is who you have applied to for your FIT payments. EON is probably the same company that you buy your electricity from (your supplier), but you could have gone to a different company for your FIT if you had wanted to. It sounds like you have not seen any DNO documentation - as I suggested earlier you should ask. 30 degrees and SSE affect the figures a bit, but do not change my view.

Regards
Bruce

 

[PeteFT]

Bruce many thanks for this. My DNO apparently is Seeboard, aka the French Goverment. I will chase my installer for DNO documentation, to see waht has been submitted.
Once again many thanks.
Pete

 

[BruceB]

Seeboard is long since dead. Look at the map half way down this page or look at your mpan number to find your DNO. It will be one of the two I mentioned earlier.
Meter Point Administration Number - Wikipedia, the free encyclopedia
Regards
Bruce