Sunpower system, which is best? Opinions?

[Wortle]

I have a small roof and to get a 4kw system wiil need to use the Sunpower E20/327 system. I have narrowed it down to 2 installers who seem competent etc.

One wishes to put the panels with a PowerOne 3.5 inverter, the other installer would use a Samil 3680[FONT=&quot][/FONT]. Both inverters have 10 year warranties.

Please forgive my ignorance but does the inverter monitor the generation or is there a separate piece of kit to do this?

Does one system seem better than the other?

Thanks for reading.

 

[whinmoor]

Do you mean Power One 3.6? That's a decent inverter. We have a case study on our website of a 3.0 model (baby brother) we installed recently in a garage: 4kWp South Leeds

If we had put all 16 on the same roof, we would have upgraded the inverter to the 3.6 but the 3.0 seemed a better choice for a split arrangement.

With hindsight, the customer wished he had opted for more panels (with the 3.6 inverter) and dropped into the next lower FiT band.

Worcester has also posted an image of the 3.6 in a recent post by Smidgen:

http://www.electriciansforums.co.uk...974-inverters-good-performers-4kw-system.html

The inverter does monitor the output but, depending on its location, is probably not the most convenient way of doing it. There are lots of monitoring devices on the market but it's difficult to recommend the best solution as it will depend on your circumstances and personal preferences.

 

[Wortle]

Yes, I mean 3.6, sorry. What would be justified in terms of price to have the Power one over the Samil?

 

[SpitfireW'sale]

I think it is fair to say that most distributors and installers would say the Power One is a more trusted brand. The Samil is Chinese and until very recently Chinese inverters were generally not recommended. This is changing but mainly because there is so much pressure on prices to be low from customers. Unless the Samil price is much lower I'd rather have a Power One if it were my house.

Generation is officially measured by an Ofgem approved generation meter which will be fitted with the system. This meter reading only is used as the figure to submit to your FIT provider for payments. As whinmoors post above, the inverter can record generation figures, but there will likely be a small variation between the reading on the inverter and generation meter. You should not submit inverter readings to your FIT provider.

Sunpower make great modules so you won't go far wrong there.

 

[Gavin A]

tbf we've had no fault reports from any samils we've installed to date, though that's only about a dozen or so.

 

[Earthstore]

You are thinking of buying the "best" and probably the most expensive panels and considering having a "cheap" inverter???

Would you buy a Ferrari and put budget tyres on it, Would you buy an expensive diamond and have it set in a plastic necklace??

I do hope you get my point here?

 

[Wortle]

You are thinking of buying the "best" and probably the most expensive panels and considering having a "cheap" inverter???

I'm not designing the system here! Its what has been suggested in the quotes and is exactly why I am asking the question.

This is what I have been offered. I chose the panels as they will fit on one elevation and not be stuck like a patchwork on every angle, but give me a 4kw system

Thanks for the pms from other contributors. I am only allowed 3 so my inbox is full BTW and I cant respond without deleting.

 

[SolarCity]

To be fair, I think the Ferrari analogy is a clumsy one. I haven't seen anything to suggest that a Power One inverter is any better than a Samil inverter.

For the record, we have had three faulty Power One inverters since we have been installing and have had no faulty Samil inverters. We have only installed around 20 Samil inverters and around 50 Power Ones. From what I gather, our experience with Power One inverters hasn't been shared by other installers so it is more than likely just an anomaly.

We've not had to deal with Samil's technical support nor had to have an inverter replaced yet so can't comment on that side of their company, however Power One have been pretty good. Although their response to some ongoing problems with monitoring problems has been very disappointing.

There is a lingering sinophobia in Britain and the idea that all Chinese stuff is sub-standard is entirely outdated.

 

[Wortle]

I think that is a fair point Solarcity. I think its probably not all about where its being manufactured but the standard of quality control in place. That said I will buy anything under a fiver wherever it is made to give it a go, but this is slightly higher risk. I am trying to be cautious all round to make an informed decision.

Given that both are offered with a 10 year warranty and word on the street has it they will need to be replaced in 10 years anyway would it be better to save money there and look to replace with better technology in 10 years anyway?

 

[Wortle]

I would be interested to know what the difference in price between these 2 inverters is as well. Thanks

 

[SpitfireW'sale]

Good point Chris - but I think to say it's a "lingering sinophobia" implies an irrational fear? I agree it is outdated to say all Chinese manufacturing is poor, but the country is miles away from having the reputation earned over time by, for example: German industrial processes, British engineering or Swiss precision quality. There have been several major incidents related to products made in China in the last 5 years alone and IMO that (unfortunately) tars other manufacturers with the same brush.

 

[Earthstore]

So as not to sound so clumsy, however this may confuse the Op?

I remember when Sanyo had a problem with some inverters that kept "dropping out" and one of the members on here worked out the problem, the problem was that high performing panels can change voltage quickly so the inverter was searching in the wrong voltage width causing it to shut down.

The remedy was to switch on optitrac so it constantly searched different voltage widths.

My point here is: Is a Samil inverter technical enough to work with these panels?
Of course it may work, and may be reliable, but will it return the same output as something a little better.

Having gained many years experience in the motor trade, my analogy may not be so clumsy after all, a budget tyre would be fine on a Ferrari, but if it were tested to it's limits would it's performance be up to a Michelin?

 

[Gavin A]

My point here is: Is a Samil inverter technical enough to work with these panels?

good point, and the answer is no it isn't, there's no full scan feature on those inverters.

 

[ExtremePV]

I'd definitely go with the PowerOne 3.6 over Samil.

Have u got any possible shading? If so.. make sure they enable the wide sweep on the PowerOne, or better still go for an SMA 3600TL with optitrac enabled.

Ken

 

[jason121]

I was told that Samil have been bought out by SMA. True or false ?

 

[ExtremePV]

False!

 

[Gavin A]

I was told that Samil have been bought out by SMA. True or false ?

think that was eversolar, but may be wrong.

 

[jason121]

Has the Samil inverter been copied from the SMA TL -21? and been given a face lift ?

 

[Berneray]

To be fair, I think the Ferrari analogy is a clumsy one. I haven't seen anything to suggest that a Power One inverter is any better than a Samil inverter.

For the record, we have had three faulty Power One inverters since we have been installing and have had no faulty Samil inverters. We have only installed around 20 Samil inverters and around 50 Power Ones. From what I gather, our experience with Power One inverters hasn't been shared by other installers so it is more than likely just an anomaly.

We've not had to deal with Samil's technical support nor had to have an inverter replaced yet so can't comment on that side of their company, however Power One have been pretty good. Although their response to some ongoing problems with monitoring problems has been very disappointing.

There is a lingering sinophobia in Britain and the idea that all Chinese stuff is sub-standard is entirely outdated.

Agree entirely with SolarCity here. We have been using Samill for 14 months...and not one call back so far. Bet I'm tempting the gods here!

 

[Wortle]

I'd definitely go with the PowerOne 3.6 over Samil.

Have u got any possible shading? If so.. make sure they enable the wide sweep on the PowerOne, or better still go for an SMA 3600TL with optitrac enabled.

Ken

Minimal shading by trees til about 9am at this time of year and again about 5.30pm,probably less than that for 4 months of the year when the sun is higher in the sky.

The Samil system is being quoted £350 less than the Power one is that really the difference to the end user?

Thanks for your help everyone.

 

[Wortle]

Still wondering if anyone can enlighten me on the price difference I should be paying between the samil,power one or even if I ask the two installers to requote for the SMA....although I think they both stated independently that SMA werent worth the "extra money"

 

[SolarCity]

I would say the difference would be around £100.

 

[whinmoor]

Why not ask the Samil guy to re-quote with a Power One?

There must be more to base your decision on than just the price. Which one did you trust more? Which did the better survey and produced the clearest paperwork?

 

[whinmoor]

I would say the difference would be around £100.

It may well be more than £100 if they both have a 10 year warranty.

(Note to OP - different installers will have different opinions.)

 

[Wortle]

Which one did you trust more? Which did the better survey and produced the clearest paperwork?

I felt both were trustworthy.

Both were thorough on survey.
Samil guy was a bit tardier on producing paperwork, but I felt had more experience.
Two younger guys came from the other company and were much quicker on responses, and I felt they were a bit more involved/dedicated/interested. Bottom line is I am looking at the price to try and help on the decision! If they both offered the same price and the same equipment it would be even worse! Head says older guy will be around longer. heart says younger ones will do a good job and would like to give them the work as they probably need it more......aaaargh.

 

[Gavin A]

ask to be put in touch with a previous customer in the area, that'll help find out what they're really like as a company.

 

[Wortle]

Thanks to everyone who helped me out both here and with PM's. I have weighed it all up and made a decision finally,bit of a relief. Expect a flurry of posts on 24th!

 

[SibertSolar]

Good for you, well done! I hope it all goes well.

 

[Earthstore]

Thanks to everyone who helped me out both here and with PM's. I have weighed it all up and made a decision finally,bit of a relief. Expect a flurry of posts on 24th!

Just curious, which choice did you make?

 

[John Barsby]

I was under the impression these panels needed special earthing arrangements as when we fitted the Benq Sun Forte panels we were advised to use an Eltek inverter configured for positive grounding.

 

[jason121]

I believe so. The BEN Q panel requires a transformer type inverter. Eltek offer a High efficiency inverter, comes with a neat display

 

[Gavin A]

no longer an issue

 

[jason121]

no longer an issue

Have they altered the panel

 

[SibertSolar]

Jason - I could be wrong but I believe their official stance was that if you wanted to get optimum performance out of their previous Sun Forte panels, then they recommend that the +ve branch of the DC string is earthed. For this reason they dictated that you should NOT use a TL inverter when choosing to do that. However, apparently their new (not sure if available yet) modules do not need to be +ve grounded and, therefore, the use of TL inverters is not prohibited.

That's my take on it anyway, I'm sure others who are sourcing/using these BenQ modules will clarify.

 

[Gavin A]

Have they altered the panel

I assume so. As of the latest shipment, there's no need to ground positive and can use TL inverters, where the reverse applied to the previous shipments.

So check with suppliers, as some will still have old stock I'd assume.

 

[Wortle]

Just curious, which choice did you make?

I am going with the younger guys. A forum member from up north very kindly looked at both guys quotes and told me which one he would choose from the paperwork. So thank you to my "independent solar advisor",

Powerone inverter, but now you have worried me about the earthing.

 

[Worcester]

If they are the 'latest' PM096B00 modules, grounding / earthing /bonding is not necessary when using a TL inverter , subject to the PV Guide

Latest Installation instructions attached, see para 4.4 p 15 (2013 Vn 1.1)

Comply with the local regulations for earthing the modules and the PV array.

View attachment InstallationGuide_en.pdf

 

[Worcester]

Update for you... Just spent today up at Waxman's Training centre - they've got a good set up there, everything from Biomass to PV.

Main reason for update: the old and the new:

Waxman are stocking and selling the NEW BenQ panels that are OK with TL inverters.

They claim that the Sungift stocks are the OLD panels that have the earthing/grounding requirement and can;t be used with TL inverters.

 

[jason121]

I did some of my training there when Simon was teaching. Do they still have that solar thermal panel slung on the wall

 

[Worcester]

I did some of my training there when Simon was teaching. Do they still have that solar thermal panel slung on the wall

Yep!

Seems like I have to have more than six letters in my reply...

 

[jason121]

Nice pub 10min drive away where the premier inn is located

 

[Earthstore]

Yep!

Seems like I have to have more than six letters in my reply...

Yep!!!

 

[Gavin A]

Update for you... Just spent today up at Waxman's Training centre - they've got a good set up there, everything from Biomass to PV.

Main reason for update: the old and the new:

Waxman are stocking and selling the NEW BenQ panels that are OK with TL inverters.

They claim that the Sungift stocks are the OLD panels that have the earthing/grounding requirement and can;t be used with TL inverters.

cheeky gits.

It's sungift I got this info from.

 

[jason121]

Don't see a problem with the grounding, not with the ELTEK HE-T. Very good inverter.

 

[Wortle]

Hi guys,

Having a 'mare here.

Still not installed and they started Wednesday. The planets are not aligned for me!

Is a sunpower 3.6 inverter better than the powerone? The same, badged up?

Thanks

 

[Worcester]

Possibly, post a photo and we'll tell you, also post a photo of the serial number plate / sticker that should be on the right hand side.

Also if has been rebadged, it may not be configured internally for the strings in the same way that a UK standard Power-One PVI-3.6OUTD is.

 

[SibertSolar]

Sunpower is Taiwanese

 

[whinmoor]

Hi guys,

Having a 'mare here.

Still not installed and they started Wednesday. The planets are not aligned for me!

Is a sunpower 3.6 inverter better than the powerone? The same, badged up?

Thanks

What's the problem? Are the panels on the roof ok? A Power One 3.6 looked ideal for the job. These are available off the shelf at several of the big PV distributors.

Don't let them take the scaffold away until you're 100% convinced it's working fine.

 

[Wortle]

Guys came Weds as forecast not good, got all wiring in place and rails, readyn for Thursday delivery.
Thurs they turned up and waited all day but no delivery as M5 closed.
fri they turn up again and wait til 2 pm for "first drop", 26 ton lorry gets stuck in lanes (they warned them not to use it) Towed out, then try to get through an ancient bridge with a sharp turn and 6'6" width restriction.Panels arrived but too windy to take up on roof. Then discover no earth on whole system and have to get Western Power out. They have now fitted the different inverter to the wall. WP have beeen out and done some voodoo in the dark.....etc etc etc.

Will photograph inverterr in the morning.



Aaaaaagh

 

[Energetic]

I'm amazed at the lack on Sunpower knowledge on this forum, Their inverters are the same as the normal Power Ones except for some snazzy sunpower branding and a 10 year warranty as standard. They cost about £300 more than a Samil.

Sunpower partners are chosen by Sunpower to represent them and have to pass rigorous conditions imposed by Sunpower so i wouldn't start worrying yet, sounds like the installers will be just as annoyed as you that they have not been able to finish the job!