One inverter or two?

[dive-elec]

I have an east/west split system to design, the east face will have 6 x Sanyo HIT N240WSE10 panels[FONT=&quot][/FONT] and the west face 8 x Sanyo HIT N240WSE10 panels, no other panel will give me as big an output as its a hip roof. I've read several articles that say 1 inverter with 2 strings and one mpp tracker is the most efficient, but I've also read that strings must be of equal size. The SMA design software advises a SB1200 for the east side and SB2000HF for the west, my questions are:-

• Is it adviseable to connect different inverters into the same meter
• Can anyone suggest a single inverter that would do the job - and I dont want some cheap Chinese make that no ones heard of
• Has anyone got any other solutions

 

[BruceB]

The newest version of Sunny Design says the SB3000TL-21 will do that setup nicely. It has a twin mppt.
I have not run the numbers but I am pretty certain the Power-One PVI-3.0-OUTD will do just fine also. It also has twin mppt.
Different inverters can go into the same meter, but I see no reason to in this case. One will be cheaper and probably more efficient
Regards
Bruce

 

[daytona600]

kostal piko 3.6 2xmmpt trackers

 

[SpitfireW'sale]

By connecting two unequal strings to one inverter (1 MPP Tracker), you are going to have two different Vmp and both strings are operating at loss. The MPP tracker is cable of finding the Pmax point of the system. Because of the fact that there are strings connected in parallel, each string's operating voltage MUST be identical. This means that either the tracker chooses the operating voltage of the small string resulting in the increase of the current of the large string, or it keeps the operating voltage of the large string forcing the small one and thus the modules to produce more current (based on I-V curve of the modules). In both cases, this unequal number of modules per string results in power losses of your system.

It's not a problem to use two different inverters connected into the same meter. The output of the inverters is based on the same grid voltage and they have got the same frequency (50Hz).

By using an inverter with two MPP Trackers, you are able to connect two unbalanced strings to one inverter because each tracker is an indepentent circuit. SMA SB3000TL- 21 has two independent MPPTs as BruceB mentioned before.

SolarMax is a swiss company which supplies MCS certified inverters to the UK taking into account the 16Amps AC Current limitation under G83/1 Stage 1 as well.

It's hoped that my answer helps you.

Kind Regards

SpitfireWholesale