Inverter Choice: SolarEdge, SMA SB3600TL or SMA SB4000TL?

[danesol]

The SolarEdge has a 12 year warranty which is another consideration. I have just had a SolarEdge SE4000 fitted with 12 x SunPower E20 333

SMA also have an excellent 'out of warranty' 300euro Inverter exchange scheme from their Milton Keynes factory, that should always be considered

 

[finewine]

Based on your original post I would cast my vote for the 4000TL as you shouldnt imho design your system to limit your output to the max 3.6KW.

I purchased a 4KW system last June and the various software packages predicted an annual output of around 3000KWh/pa

I have a more or less East facing roof in Cambs and my total for the year was 3600KWh -on cool sunny days peak output hits 4KW

I am sure I have gained an extra 5% at least by not limiting the output to 3.6KW

Depending on the panel spec tolerances you could in theory end up with say a 4.20KW system (some panels are up to +5% output spec)
Dont know the yingli spec but again another reason not to cap the potential of your system.

If you are south of me in the uk I would expect a well designed south facing system to outperform mine by perhaps 10-20%
So the 3600 would hold you back certainly more than the £100 difference or 1-2% inverter efficieny differences
I have a 19 panel Schuco system split 10+9 on each mppt with no shading issues.
Sunny Explorer is all you need for monitoring and there is also additional software for android and such -the sunny beam again imho is
not really needed.

Hope this helps

90% of the time that my SMA 3600tl is running with optimum sun angle etc I see a figure between 3840w and 3960w and occasionally just over 4000w. It doesn't sit at 3680w even though its capped to this. Perhaps our local voltage is lower and the inverter caps at 16A rather than wattage. When it is clear all day the panels generally get hot and the panels can only output 3300 w - 3500 w anyway so I would hazard that the performance difference is tiny. That said, if we lived a climate that had plenty of sunny cool days such as the winters in the south west states then I think a measurable difference could be shown. Unfortunately cool days in the UK are generally cloudy or the sun is too week during winter months to approach peak output anyway.