Which inverter SB 3800V or SB 4000TL

[MrBod]

Hi.

We are being quoted at the moment for a 4kW PV install, with 16 x Sanyo HIT250 panels. Roof is approx 45 degrees and south facing. Location is North Hampshire. Partial shading of some of the panels in the morning and some others in the afternoon.

The installer is recommending a SB 3800V inverter with 2 strings of 8 panels. Both obviously going to the single MPPT. S

unny Design seems to indicate (as far as I can tell) that a SB 4000TL with 1 string going to each of the MPPTs would give a greater output. I would also expect this would better handle the partial shading issues. The installer is willing to fit this if I insist, but believes that it will be less efficient. I believe that the startup voltage is lower on the 4000TL, so this would mean that it would be generating quicker at the start of the day?

A possible issue with the 4000TL is that the DNO might have objections as it could theoretically produce more than 16A. Does anybody know if Scottish and Southern are likely to be friendly or not regarding this?

If we do have to restrict the 400TL to 3.68kW, I am not sure what effect this would have on the predicted production figures as I have not been able to model this in Sunny Design.

I welcome opinions on which inverter I should specify.

 

[SolarCity]

I think the 4000TL would be the better option. It will certainly help with the shading issues and it is more efficient than the SB3800V. It IS a little oversized but I still consider it a better option in this instance.

 

[MrBod]

I think the 4000TL would be the better option. It will certainly help with the shading issues and it is more efficient than the SB3800V. It IS a little oversized but I still consider it a better option in this instance.

Thanks BiggsSolar. You are confirming what I thought. As I have only been researching this for just over a week, I did not feel that confident going against my (potential) installers advice without a second opinion. Still waiting for other quotes to come in, but if I do go with this one, I will probably specify the 4000TL.

 

[Markc]

Try to check with your DNO to see if they would accept the installation as a G83? Otherwise you will only find out AFTER installation by which time you would of paid for it.

The 4000TL is a big grey area. Our DNO still will not give me a written answer to this and it depends on which voltage you use, 230V or 240V. (16A 230V = 3.68kW, 16A 240V = 3.84kW) UK Power Networks own advice. Use what voltage you like!

 

[Worcester]

Is the SB3800V actually out there in the wild?

I know it's on SMA's web site, however we couldn't track one down a couple of months ago when we wanted one.

 

[MrBod]

Is the SB3800V actually out there in the wild?

I know it's on SMA's web site, however we couldn't track one down a couple of months ago when we wanted one.

My installer was offering it, so I assume that he expects to be able to source it.

 

[Worcester]

My installer was offering it, so I assume that he expects to be able to source it.

Not nescessarily!

It's on a few distributors price lists, and was a while ago, but rocking horse manure was easier to come by when we looked.

 

[saint]

We haven't had an installation over 3.68kWp but under 4kWp refused by SSE yet. Not to say we wont though. The 3800V is available. We installed one today.