inverter help sorry

[funboy57]

Hi all, I have had three quotes for a PV system 10 sanyo 250 on the south facing roof and 5 on the west facing roof, two of the quotes spec one inverter although they just say SMA or equivalent on the quote, one quote from one installers recommends two, one for the south SB2500 and for the west side SB1200, both sides have no shading issues, when questioned he said the west side will impede the performance of the system so want to treat them as two seperate systems, any advice would be welcome.

 

[Noshocks]

Theres nothing wrong with susing two inverters, however duplication of switchgear etc will add cost to yourself, I would use an Aurora 3.6kw dual MPPT invererter or an SMA 4000TL if I had quoted on this, that said I havent seen site so its just my initial thoughts.

 

[MorganPVI]

For 2 different aspects you need a Dual MPPT inverter or 2 of them, any quote that uses 2 inverters or explains the need for 2 inverters has the greater technical knowledge and would be a good a quotation to consider.

 

[SolarCity]

I'd say that using two inverters is not necessary. If the inverter happens to be an SB4000TL then it's more than suitable for the system you have suggested.

The only way I'd ever recommend using two inverters is if it was impossible to match a single inverter to both arrays or if the distance between the arrays was vast.

A 4000TL, due to it's higher efficiency, will yield much more than an SB2500 and an SB1200.

If I were you, I'd question the "one inverter" installers on the inverter they have suggested and ask them why they chose that model.

 

[cal]

Hi, strongly agree that two inverters is not needed, I get the impression you are not up on your solar jargon, so....a twin /dual mppt inverter can "look" at two different banks of panels and treat them seperatley within itself, its kind of like having two inverters in one box, it should be a lot cheaper for you to have one inverter and one set of switchgear/ wiring.

 

[JohnBoyZ]

There could be a case for preferring a dual inverter set up in this situation with only 5 panels on the west side. Even though the SB4000TL has dual MPPT inputs the MPP DC voltage range is 175v-440v, if the Sanyo panel Vmp is about 35v then 5 panels will be about 175v which is a bit tight. The SB1200 MPP DC voltage range is 100v-330v which is a better match for the 5 panels.

 

[cal]

Good point well made about the 5 panels and lower voltage produced by them, well spotted. perhaps two inverters are the way forward? or maybe an inverter with twin mppt and with with low start up voltage, , but still with capacity for ~ 400v input on two strings

 

[SolarCity]

If only there were other inverters on the market apart from the SMA range.....

 

[Worcester]

@BiggsSolar,

We've been using both SMA and Power-One, turn out Power-One are #2 behind SMA, and oftne their efficiencies are better..

I prefer the SMA installer interface, support from bioth is pretty good.

The Power-ones seem in most cases to have a lower startup voltage.

 

[SolarCity]

SMA have the gimmicks and gizmos wrapped up. I linked the one we installed today to the immersion heater so it would come on when the inverter was producing 1500w - an excellent feature. The bluetooth aspect of the SMA inverters is also invaluable.

Power One is more versatile and we are installing more and more of them now. The voltage range on them is really impressive.