Solar Edge Power Optimiser - sounds too good to be true?!

bigmacburgers · Post by **bigmacburgers** » 21 Dec 2016, 19:29

Hi

I've just had a call from a company called Solar Plants who sell Solar Edge Power Optimisers for solar panels and also Solar Edge Invertors.

One thing that the sales person said that surprised me was that the technology can change the panels from being in series to being in parallel - just by fitting something to each panel. Even more surprising was the fact that he said that if there is shade on one panel then other panels will produce less electricity. I got a bit annoyed by this statement and said that this couldn't possibly be the case. He replied by saying that it was like a set of old-style Christmas tree lights - if one doesn't work then none of the others work. I then said that this wasn't the same as saying that leaves or shading on one panel would cause other panels to produce less electricity. He reiterated that one panel producing less electricity would mean that other panels in the series would also produce less electricity - note that he was saying that each panel would produce less electricity rather than the total produced across the series would be less because of the poor-performing panel.

Surely this can't be right? I ended up getting his boss on the phone and he said exactly the same thing. The quote is, "If one is shaded then all other panels in the series will be affected and will produce less electricity." When I asked him to confirm this and made it obvious that I was writing this down he qualified to say that other factors like leaves could also cause the same effect - again saying that one panel producing less would make others produce less. (Sorry, I know I'm flogging that a bit but want to highlight the fact that he said that each individual panel other than the shaded panel would also produce less elctricity.) My understanding of the panels was that they were more like batteries and so one producing a lower voltage wouldn't mean that others would produce less?

Also the quote about series/parallel sounded dodgy, "[It changes the panels] from being wired in series to being in parallel." This is the Power Optimiser that is fitted to each panel - ever heard of this magical device? If so, how does it do this?

Many thanks - I carried on listening as I reasoned that it was a long time ago that I did my Physics A-Level so some of the fundamental laws of the universe may well have been upgraded. Someone is coming round to explain the magic tomorrow but I'd be really interested to hear thoughts about any of the above before then.

If I'm being a plonker please feel free to tell me

Have a great Xmas

BMB

Post by **clv101** » 21 Dec 2016, 20:31

Sounds like they are talking about microinverters:
https://en.wikipedia.org/wiki/Solar_micro-inverter

bigmacburgers · Post by **bigmacburgers** » 21 Dec 2016, 20:46

Thanks very much for the link - I was looking at a few pages online but couldn't really get my head around the concepts!
Reading from the link and thinking about what they said on the phone, it looks like it's the power optimisers rather than the microinverters that they're talking about which are also covered in the link you provided.
From that reading and the reading I've done already it looks like I need to eat some humble pie! It seems counter-intuitive to me that shading on one panel would mean that the other panels will be limited in what they can put onto the system but, if I understand what I've read correctly, that is exactly how it works.
I will have to get the rep tomorrow to explain it all to me.
Do you happen to know if power optimisers have proven worthwhile when considering the cost of installation versus increased/improved output? (I realise that's a very general question but am really looking to understand if some have benefitted or if it's more a gimic).
Thanks for the help

BMB

RenewableCandy · Post by **RenewableCandy** » 17 May 2017, 15:32

I've heard the thing about the shading, from the guys who installed the system here at Chateau Renewable. The shaded panels (iirc) don't conduct current through, so block power from the others.

As a result, our system has 2 'blocks', so that when part of one is in shade, the whole of the other still works.

My guess is that reconfiguring your system would only be worth the cost if you have any overshadowing.

Peter1010 · Post by **Peter1010** » 18 May 2017, 07:29

We have two parallel sets of 8 series panels. The invertor takes two feeds and shows power produce by each. Our neighbour made a comment about shading as some of the fence posts do cast shadows on some of the panels at certain times of the day. They are mounted at ground level. So as an experiment I monitored the outputs from the two sets with one set having one panel with some shading. It made very little difference as far as I could tell to power output of that set. So I doubt any saving by creating more parallel sets will exceed the cost of converting. It should be noted though, there is an optimum electrical loading for each panel to extract maximum power (i.e. a curve of power out versus load applied by invertor). So the more in series the less likely the optimum loading for all panels is possible.I can see it being a problem if one of the panels was duff or mismatched in some way.

Post by **kenneal - lagger** » 21 Oct 2017, 13:52

Don't most modern panels have internal wiring which bypasses duff or shaded cells to give at least some output from a shaded or damaged panel?