A E Micro Inverters

[Sidecar Man]

Hi not been on here for ages. Decided to put some solar panels on my house and was going to use some A E micro inverters. Does anyone have any experience with them?

 

[sgt_woulds]

I've not come across them before. Cannot see any G83/2 certification unless I'm looking in the wrong place.

Is the roof you plan to put them on easily accessible for future replacement?

Have you considered Solar Edge instead?

JA smart panels with embedded SE optimisers seem to be a real snip at the moment and compare very favorably with Enphase micros. Not suitable for less than 6 panels though (and that is pushing it)

If you are after Poly you could try Jinko Maxim Smart Modules which you can use with any inverter - I cannot vouch for them as we've not used them yet.

What is the shading on your house like?

 

[Sidecar Man]

Hi thanks for reply. Already got my panels as I brought them from an auction. Got 12 Benq 333watt panels and was planning on using 6 inverter with two panels in parallel on the recommendations of the manufacturer.
Can find a G83/1 certificate for them or will that not comply now?

 

[sgt_woulds]

No, will need to be G83/2.

Do you absolutely need micro's? Our experience is on an un-shaded roof you will get maybe 5-10% extra per year but you have to weigh that against the extra costs (and the cost of replacing inverters which will fail 1 by 1).

A heavily shaded roof (one that is too small for an SE system) is the only time I would touch them.

We have used Enphase, ABB and Renesolar micros. Enphase are the only ones with a less than 2% failure rate on our jobs and we only fit on single storey or easily accessible flat roofs. ABB had a 17% failure rate and Renesolar had a 89% failure rate. Any other manufacturer is pot luck.

If you do fit micro's I strongly advise that you fit an SPD as they are very susceptible to transient surges.

There are plenty of good quality duel tracker inverters out there that I would consider first. I know that the Samil SolarRiver 3600TL-21 will work with the BenQ 300W panels probably - ok for the 333W but you'd need to check.

 

[Sidecar Man]

That's interesting to know. I thought with the guarantee on micro.s been a lot longer than conventional I presumed they would be a lot better.
My roof is not overly shaded but is easy to get on to as it's a bungalow.
Next question is then about sizing up a normal inverter?

 

[Sidecar Man]

Found out they are G83/2 compliant.

 

[sgt_woulds]

The guarantee only covers the inverter, not the cost of scaffolding and labour.

And with multiple inverters comes multiple failure opportunities - even with big name and honest suppliers.

So far Enphase are the most reliable ones we have found.

Remember a guarantee isn't worth the paper it is written on if the company ceases to trade in the next 20 years. Or is like Renesolar, pulls out of the UK market and ignores all contact.

A good string inverter will last for 8 - 14 years (average from our installs) and the difference in performance on an un-shaded roof with single orientation will be very small compared to micro's. If you are electrically capable you can change the inverter yourself when the time comes. This is important as PV is long term investment - you want to keep things as simple as possible and plan for your dotage!

Having a string inverter also makes it easier to fit battery storage (when the price becomes sensible) and who knows what other new gadgets in the future...

Have you priced up the cables and connectors required with these AE micros? This can add significant cost. Also (not wanting to slate AE as I've not seen the product) the connectors used by AE seem to be a familiar type - ones that have not proved to be weather tight or secure from my experience. Ask them to confirm the IP rating - and check that it does not apply to vertical installation of the connector only - just sayin'...

P.S. when I say 'good inverters' that takes no account of company size or brand recognition. We've had Jinglong inverters fitted for over 6 years now without issue (and who new of them when we started installing?) Fronius and Mastervolt inverters have all failed after 4 to 5 years. All of them. Long term experience is very important with installers in this game.

As with anything, buyer beware!

 

[Sidecar Man]

Sgt Woulds thanks very much for the information. Access is not a problem as it's on a bungalow. I have been thinking about battery storage and wiring. I have plenty of wiring experience as I'm 2391 commercial sparky. What would you recommend, I was looking at the sunny boy energy but not sure.
Thanks Phil

 

[sgt_woulds]

SMA - good, perform well great back-up but will only talk to installers.

Solar Edge - all the benefits of micros, a bit cheaper to implement. Good support. Should be less to go wrong vs
micro's

ABB - very expensive lots of good features, but if things go wrong expect to wait up to 10 weeks for replacement

Ginlong - good basic inverters

Samil - Ditto

Zeversolar - basically cut price SMA without all the bells and whistles. (Think Skoda / VW) See SMA comments

You should be able to find design tools online for most of them, or speak to Segen / BayWa etc...

Duel MPP trackers are a good compromise and - on un-shaded roofs with positive tolerance panels - should work very well.

Not got much experience with the BenQ's as we've only done 4 commercial jobs with them so far - not enough data to comment. Be careful on installation though, they scratch easily on the glass.