Which Inverter To Use?

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KrisWragg

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Looking to get a solar power system installed and the company originally quoted us with an Afore HNS3600TL. I couldn't find much on these other than they're a reasonable Chinese brand with long warranties.

They have also offered the following models instead:

Solarworld Sunplug 3.6 TL1i

Aurora Power One PVI-3.6-OUTD

GoodWE GW3600DS

Afore HNS3600TL

Which would be best to go with 16 x Solarworld Plus 250w black?

 
Good inverters:-

Power One  - I have this myself

SMA - very German and ecellent service when needed

Not familiar with solarworld sunplug, sounds like a rebranded inverter, solarworld make panels, very good panels.

Stecca, 3.6TL - most efficient small inverter, should work with your 16 solarworlds - my favourite.

Fronius - Austrian, built like preverbal outhouse.

GoodWe - crap

Afore - never heard of, probably Chinese crap

Chinese stuff - only make I use is Samil for commercial installations. Chinese build quaility tends to be a bit iffy, they give long warranties as a selling point, but don't expect them to last 20+ years. SMA are designed for 25 years. Don't be fooled by A rating of inveters, you want AA or AAA - everything works at High Irradiance, but the quality stuff is good at medium and low irradiance which is where the extra As come from and boosts performanace on cloudy days and mid-winter.

How much are they charging you for the system? I can fit 4kW with Solarworld, SMA and German frame (Schletter) for less than £6k on a straight forward roof. Most companies offer good panels, but make a quick buck by using cheap inverters. The inverter is more important than the panels, it does the hard work, bit ideally you want good panels and inverter to make a good system. Try to avoid inverter in attic - they get too hot which eventually shortens its life and reduces efficiency in summer.

Incidentally, if your array isn't hghly visible ie front roof of house, don't bother with all black, they are more prone to overheating in summer and lose about 1-3% efficiency on the system. Do look nicer! The counter argument is that they warm up quicker in winter, but I've never been able to prove that argument either way.

just checked, the Sunplug is a re-branded Stecca

 
Thanks for your thorough feedback!

I just read that the Solarworld is a rebranded Stecca so I'm tempted to go with that one.

Where do you install if not the loft? I would have thought you'd want it as close to the panels to keep the losses down on the DC current?

 
Myth, we can get away with using 2.5mm cable for the DC, but I never saw the point when the panels are wired in 4mm. Using 4mm, we can run over 90m before infringing on the 1% volt drop allowed, so in most domestic properties we see a volt drop of around 0.3% max, which is better than 2.5mm on a shorter run. Best place for the inverter is a garage or somewhere else cool with plenty of air movement to allow the inverter to cool itself by convection. That particular Stecca isn't suitable for mounting externally - a north facing wall is good or side of house, but ideally not on south facing frontage in full sun, though that is better than attic. If attic is only choice, then adding a few extra roof vents helps. Inverter must be mounted on a non-flammable surface, like end cable wall. Inverters will work upto 50degC these days, but even then, a hot inverter is less efficient and derates itself as self preservation measure, so longer cable run is worth it!

I've been fitting solar for over 4 years, with 500,000kW fitted to date, I detest bullshitter companies and sales rep types, PV is really good stuff except when the double glazing types get involved....

 I can also bore/ educate you to death on the subject :slap

 
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Do yourself a favour and check what the turn around is in event of failure. As an installer I have had to replace 3 units. 1 Stecca, 2 Fronius. Both replaced in 2 days. My own system has an Aurora which has been down for 6 weeks and have been told end of june for next shipment. This will cost me in the region of £500 in lost FIT on top of energy saving !!! Have looked at compensation rates - they are pathetic. BEWARE.

 
I've had failures on all makes except Stecca, and I've fitted quite few becuase they are the most efficient small inverter according to Photon International, and I've seen the best outputs from system using these, and Power One. Also seen excellent results form a Solaredge system we fitted, but there wasn't any shading and we did use LG Neon panels which are expensive and beautiful as panels go. That system was unusal and expensive at £7k for just over 2.2 kW, but that's what the customer wanted. Will be interesting to see how it performs over the years to come.

Service from SMA and Fronius is excellent. Power One ( now ABB) not quite as good, but far better than the cheapo crap that's knocking around. Fronius is my favourite in that they automatically pay me to replace the unit £70 no questions asked, no having to apply for the money. Which is nice!

have you ever fitted Solarworld Sunplugs paddler?

 
Just out of interest, i posted on another thread about moving some controls for PV. The inverter  that has failed is in a hot loft .

2015-05-13 15.57.19.jpg

Are these any good ?

Customer keeps asking me but i dont do PV. Looking it up on line its £1k and should have a 5 year warrantee but the installer is proving difficult to get

And it failed within one year.

 
Mastervolt - OK ish, got quite a long history. £1k is excessive, SMA3600TL comes in around £780+ VAT wholesale. Warranty will be honoured, but it does seem silly to re-fit the same item. I would only do this is you add some roof vents to allow heat dissipation

 
we struck lucky with some Schuco units IP rated, but rust. They were in fact re-badged Kaco units, anyway after much hassle the screens failed and a replacement unit was not available, so after much more hassle we got the customer an SMA 3000TL model and found the 2,75kWp Sharp panels would max out at over 3kW - well over tolerance. 4 things I have lean't from this:-

1/ decent Japanese panels tend to deliver more than promised - Panasonic especially, but that's another story.

2/ undesizing inverters is probably a mistake - it was fashionable a few years ago to undersize the inverter to 80% of array size 'to be more efficient', hence we had fitted 2.5kW units. Inverters have moved on a lot since then in efficency terms

3/ PV-Sol can be wrong if using decent panles

4/ threaten legal action to get a result and make a big enough nuisance of yourself to get a better one :innocent

 
following on from the Schuco saga, we also fitted a Schuco inverter for the clients parents, 2.85kWp using Schott Panels. This inverter has also failed, and been replaced with an SMA 3000TL. This system is also overunning at 3.0 kW for a couple  hours per day on good sunny day. Incidentally Schuco are Kaco inverters re-badged, the rust being down to a decorative trim Schuco fit which is suppossed to be stainless steel, but clearly is a very proor grade if it is!

Part of the argument for fitting smaller inverters is the winter performance ie it's suppossed to be more efficient when the panels aren't working at full tilt, hence we fit 4kW of panels on a 3.6kW inverter aswell. Unfortunately we are going to have to wait for winter to resolve that argument now, but I am increasingly of the opinion that the C&G course teachings is wrong. Even if the winter argument is correct, ultimately for a system to pay for itself summer is when the most FiT is generated and that's what makes the system viable investments.

 
TBH, and you know I don't "do" solar.

However, I have experience of inverter drives from an internal standpoint.

The technology is pretty similar to the active front end we used, it has to be.

Now these things will, be full of electrolytics and they don't like heat, and it shortens their lifespan, as does overloading, so to under-rate the inverter does not make sense to me.

 
that is also part of my reasoning to avoid undersizing inverters Sidey, its also why I don't like putting inverters in hot spaces like attics. Some inverters have designed out electrolytic capacitors, many haven't, but either way if you want electronic equipment to last a long time and be more efficient, then driving it hard is a mistake. I'm expecting solar repair work to be an important part of business going forward......

 
Not my own stuff, cheeky boy :pray   Doing a fair bit already - leaky roofs, failed inverters, systems shut down for no apparent reason

 
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