Solaredge - Waste of Money

[MCS Renewables]

Next week we are removing a solar edge system that has been on test for just over a year alongside an SMA inverter with an identical system.

The Solar edge solution promises "25% more energy" yet delivers less and costs more.

Thankfully we have none of this product out with our customer base as we have always opted for Enphase as we liked the no single point of failure and better warranties.


A similar thread is here :-
http://www.electriciansforums.co.uk...lar-edge-vs-string-inverters-performance.html


Enphase v Solaredge here :-
https://www.youtube.com/watch?v=q17vH1mNpDQ

 

[SolarCity]

Thanks for the link.

Out of interest, how much more power did the SMA system produce?

 

[Gavin A]

I agree with the sentiments re solaredge, but am a bit confused why you then make the leap to enphase.

for information, I had some discussions with enphase which resulted in them admitting that they had effectively rigged their side by side comparison tests by comparing with an old low efficiency SMA 3300 inverter rather than comparing against latest generation higher efficiency string inverters with optimal string voltages etc.

We will use enphase in some limited situations, but have found that the SMA & Power-one dual tracking string inverters with the full scan shading functions enabled offer very similar performance in shaded conditions on a correctly designed installation at a much lower cost.

Enphase make a lot of their shade performance, but in reality due to their voltage range they can only function with a single bypass diode operated, so as soon as they have shading on a 2nd string of cells within the panel they can't bypass it, and will end up with the panel performing at the output of the shaded cells instead. The SMA or powerone with full scan function enabled will bypass all shaded sections and allow the rest of the array to function at full power, so I'm really not convinced about the benefits of enphase either, and deeply suspicious of their need to use a 10-15 year old string inverter as their comparison rather than doing a fair comparison with the latest generation of string inverters.

I do like the portal side of things though, just wish we could get some actual reliable performance comparisons as opposed to the obviously biased data they supply.

I'm aware that BRE are doing comparative tests for enphase, unfortunately I'd expect that the results will only be released if they are favorable to enphase - if no results are released this year, then I'll be working on the basis that the tests didn't prove very favorable for them.

- - - Updated - - -

ps this thread is crying out for graphs please

 

[telectrix]

OOPs. wrong sort of graff. :90:

 

[BruceB]

I have done a handful of Solar Edge (SE) installs and been pleased with them. Sadly I do not have good comparative performance data that will settle the argument one way or the other. But the SE solution seems particularly good where individual panels at a time get taken out by a shading obstacle or where you have multiple inclinations/orientations.

I do not trust the video linked to above. Seems rather typical American style advertising where you knock the opposition. There are many misleading points made in it.

Also, I read the side by side comparision report on the Metgen website and do not trust that. It looks like the SE arrays were set up with the minimum and the maximum number of optimisers so they were operating at the boundaries of their permissable range rather than a more typical mid-range where efficiencies peak.

I did consider micro-inverters on the last SE installation I did before Christmas, but as the number of panels increased (beyond say 8 or 9) then the micro-inverter solution became uneconomic compared to SE.

Long term, I am concerned having all the electronic complexity on the roof with micro-inverters, certainly if access is restricted. A power optimiser is much simpler and to my mind less likely to fail over say 25 years. Having the inverter inside in a more environmentally stable place seems a good idea to me.

 

[SolarCity]

Long term, I am concerned having all the electronic complexity on the roof with micro-inverters, certainly if access is restricted. A power optimiser is much simpler and to my mind less likely to fail over say 25 years. Having the inverter inside in a more environmentally stable place seems a good idea to me.

I share your concern over the points of failure on a roof over 25 years but I'm surprised that you believe a power optimiser is more likely to last than a MI. The Enphase MI are encased in resin, as I understand it, something which the SE optimisers are not. Enphase seem to think this will give them better reliability.

And to be fair to Enphase, they do seem to back this up with their warranty. Enphase will send a guy out to repair any MI which fails in the first 5 years; still not as good as I'd expect, but better than SE (although they are improving this aspect this year)

 

[BruceB]

Unless there is better evidence, then optimiser is half the price and under half the weight of micro-inverter, so probably has about half the number of electrical components, so probably is twice as reliable.

I am glad Enphase are putting their money where their mouth is. I hope it turns out to be a good product. I am not making specific criticisms of it as I have not used it. I was a bit irritated by the video as that and all the contacts/marketing over the last year seem a typical American style assault on the market with the aim of denigrating/wiping out the opposition and then cornering the market at leisure.

 

[whinmoor]

We've used Solar Edge a few times and have been happy. No failures yet and the monitoring is great. Support from SE has been good whenever we've contacted them. We use it on jobs with panels on 3 or more roof surfaces. None of the jobs we've used SE on would have been possible with one string inverter. We don't use it to overcome shading issues.

Here are SE's videos promoting their product.

A comparison between SolarEdge power optimizers and microinverters - North America Version - YouTube
Enphase VS SolarEdge on Vimeo

 

[whinmoor]

Also, I read the side by side comparision report on the Metgen website and do not trust that. It looks like the SE arrays were set up with the minimum and the maximum number of optimisers so they were operating at the boundaries of their permissable range rather than a more typical mid-range where efficiencies peak.

They used 240w panels which wouldn't favour SE and are almost impossible to source (except Panasonic) in this country. A 250w panel would have been preferable.

They also only used 8 panels with a SE3000 which isn't great matching. Better to either use 12 panels or go for the SE2200.

Totally biased and unreliable report.

 

[SRE]

Apart from the technical arguments, the warranty and monitoring almost make the extra cost worth it anyway. We've done quite a bit of SE because most of our jobs are on multiple roofs or have shading that's a bit more complex than a twin tracker can cope with. It's not something we recommend for bog standard installations but for the others it seems a reasonable compromise.

We're looking at Enphase too but it always seems to come out that bit extra and we're still a bit nervous about increasing the price too much.

 

[Gavin A]

This graph from solar edge's test document demonstrates the problem I referred to with the microinverters in that they can't properly track situations where more than 1/3 of the panel is shaded due to their operating voltage range.

 

[SolarCity]

That's an interesting point in SE's favour. I wonder how much difference this actually makes in annual yield. I would guess not a huge amount.

 

[Gavin A]

That's an interesting point in SE's favour. I wonder how much difference this actually makes in annual yield. I would guess not a huge amount.

not just solar edge, it also works in favour of string inverters as long as the MPPT tracking can cope with bypassing multiple strings of cells at once - ie it needs either to have a wide standard MPPT range, or a full scan function every few minutes to track for the true peak and avoid getting stuck on a false peak.

About the only thing micro inverters have going for them is that they will allow for generation from fully shaded panels, whereas string inverters functioning correctly will bypass the entire panel.

As the output from fully shaded panels is going to be in the region of 10% of the output from unshaded panels, it's of fairly marginal benefit.

And this is why neither enphase nor Solar Edge will actually run fair comparison tests between their systems and dual tracking SMA 4000TL-21 or Aurora Power-One 3.6 Out-D inverters with the full scan function enabled, and actual shading tracking across the arrays as it would in reality. They have to rig the tests in their favor by not using a dual tracking inverter in order to demonstrate the supposed superiority of their technology.

 

[SolarEdge1]

Have you seen the video at the top of this thread? Microinverters vs. DC Optimisers - click here for the true story: http://www.solaredge.com/files/pdfs/microinverters_vs_optimisers_the_true_story.pdf

 

[SibertSolar]

Do all micro inverters use electrolytic capacitors?