Hi Folks,
I trust I have posted this in the correct section : It says there is no such thing as a silly question in the Topic description but I may actually be the exception that proves the rule 😀

Long and short I am exploring options and doing as much reading and research as I can to best educate myself into what i require as some stage in the future regarding a solar experience. I have my head wrapped around the invertors and the brands and the pro's and con's as well as expansion capabilities and whatnot....

 

But panels ... to get a theorised output of x from an array (assume 3000 watts) would 10 x 300W panels be better than 3 x 1000 watt units?
To be honest I don't know if you get 1000W panels but it is more a thought experiment. Fewer large versus many smaller.

So things like scale of economy; multiple redundancies (10 v 3 panels) , less wiring , etc ,etc ,etc - What is the general consensus on this ?

 

Thanks in advance 

Bryan
 

I think less hardware is all there is to it. Smaller panels might fit the jigsaw pattern on an odd shaped roof or space better. If you're working alone, 660 watt panels may be too heavy. Let's see what others have to say.

Edited February 14, 20233 yr by Mako
comma

Now we get technical. If the 10 panels fit side by side in series then it is only the last panel that needs to be wired to the start point as adjacent panels have long enough leads to the next one. So I would ignore wiring cost if you look at the total system cost. 

Erection is the major extra expense for 10 as well as mounting hardware. If you DIY try going to the gym beforehand unless you are 2 people. 

Come a difficult roof for 2.1+m long panels and the small ones might fit in a landscape portrait in a better way than large ones. 

Just my thoughts. 

Edited February 14, 20233 yr by Scorp007

I went for 20 x 365W panels instead of 16 x 455W panels because it was easier to fit them in due to their smaller size.

Another factor to consider that is often overlooked is that panels that produce higher Watts do so by supplying higer Amps at slightly lower Volts (compared to smaller Watt panels). 

Higher Amps leads to higher temperatures in the wires which might increasing loss in the wires. 

Another drawback to this is that if you connect then in paralell you will likely be far out of the Amp range of most MPPT controllers leading to significant loss in actual capacity (compared to potential capacity). You don't have this problem with lower Watt panels.

To add to the question and the last reply, in regards to the mppt limits. If a pannel is rated 18.5 amps on 1000W/m2 but 15A on 800W/m2. Would this be safe on a max18A mppt, or would it be better to go with higher volt lower amp pannels(seems this is the case as anyway)?

6 hours ago, mbzn said:

To add to the question and the last reply, in regards to the mppt limits. If a pannel is rated 18.5 amps on 1000W/m2 but 15A on 800W/m2. Would this be safe on a max18A mppt, or would it be better to go with higher volt lower amp pannels(seems this is the case as anyway)?

Normally it is safe as the MPPT will just limit the current it can use. Some MPPTs will also allow higher than spec for a few minutes before they throttle. 

It is the Voc that you must stay clear of and also allow for higher Voc at decreasing temp on cold days from the spec 25 degrees C.