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 ?