3 inveters? Surely not!?

[matt25]

Hi. Can anyone suggest what inverters should be used on a domestic 3.6kwp approx system where the modules are on 3 different aspects of the roof?

 

[dansk]

If there at different angles and all pointing in different directions you may need to use two inverters, one with duel mppt, and one with single mppt. That should do it.

 

[matt25]

Thanks, given the size of the system can you suggest any such inverters for dual mppt please?

 

[mmorse60]

If you can't do it I'm sure there is an installer on here who can, try doing some research. Even google could answer your question for you

 

[matt25]

I wondered if their was a prefered manufacturer or maybe one to steer clear of?

 

[dansk]

There are a number of manufactures that supply duel mppt, take a look at all the leading brands and look through the specification, fronious is one that comes to mind. I'm sorry but I'm able to design the system for you as I don't know what panels they are and I have no idea about the site location, but ask your supplier to help.

 

[matt25]

Thanks for the help, the panels are bp185's. 5 or 6 on a south east with slight shading and 7 or 8 on west no shading

 

[Worcester]

We've just got one similar, 9 on one east aspect at one pitch, 3 on east at another pitch 7 on south clear, and 2 on south with horrendius shading.

No choice, I tried everything I could, nearly 40 permutations, and the only one that actually worked was micro-inverters, even for just going the 9+7 I couldn't find a twin MPP inverter with good enough string match for only 3.04 kWp.

So micro-inverters it is (I knew they had a use!)

 

[Worcester]

14 x 85 = 2.59 kWp - Who does a Twin MPP tracker inverter at that power?

 

[Worcester]

When you use an oversized inverter the biggest problem is usually the higher voltage point before the inverter kicks in.

With a small number of panels you will be nearer the bottom end and when they heat up (hot sunny day) the voltage drops further so then the inverter kicks out on a sunny day as well as low light days and takes longer to kick in on the mornings and shuts off sooner at night, so your losses can mount up.

 

[pvsolaruk]

Hi Matt,

I would suggest a multiple inverter setup in this case.

We are an official Power-One distributor who have a 3.0 & 3.6, both of which have dual MPPT trackers.

I envisage utilising one/two of these would be your best option.

If you wish to discuss your requirement, or have any questions, please feel free to contact me anytime.

Best regards,
Christopher - PV Solar UK Ltd - 0141 642 9949

 

[t4sltd]

StecaGrid2010 2kW twin MPPT is handy for small split systems