peak real-world output of Power One Aurora PVI-3.6-OUTD-UK

[Graddie]

Hi

I have a comprehensive reply from Power One.

It appears the answer lies in the tightening of G83 regulation/interpretation - which is that 16 Amps is assumed at a nominal 230 Volts ac. This corresponds to 3.68 Killowatts (kW) on a single-phase supply.
Nominal voltage as stipulated by BS EN 50160 and the Electricity Supply Quality and Continuity Regulations (ESQCR).

So whilst I'm not very happy at this top end limitation; at most it probably means a reduction of 100kwh per annum which at 43p is £43.

I'm interested to know what will happen if all the non 16A limited systems are deemed in breach of regulation eg SMA.

 

[liquidity]

The G83 certificate seems to indicate the inverter can peak at 4000 watts - see http://navitron.org.uk/download_images/download_1280401387_154.pdf

Also interesting to note that some people see 4000 watts from the same inverter - see SMA4000TL or the Fronius3.6TL for a 3.92kWp (16x245w) system advice needed

 

[liquidity]

I find this limitation rather frustrating - Power One appears to have changed the specification of the inverter without telling anyone and it seems they can't be *rsed to update their literature even well after the fact.

 

[liquidity]

To be fair I need to correct the above post - the latest G83 certificate lists the maximum output as 3600 watts - see http://www.power-one.com/sites/power-one.com/files/pvi-3.0_3.6_4.2-outd-s-uk_g83doc_05102011.pdf It's dated 5 Oct 2011.

 

[Fazzathebrave]

So my installers have just put in a Power One Aurora PVI-3.6-OUTD-UK on a 3.91kWp system. Does the G83 certificate and 16A Max output restriction that I see on the nameplate mean that I will lose the extra power at the top end on a sunny day? I thought it was curious when I saw a flat profile one sunny day recently. Should I ask them to fit the 4200?

 

[liquidity]

If the output curve won't go above 3600 or thereabouts then your inverter is holding back the panels. As I understand it PVI-3.6-OUTD-UK inverters with a serial number greater than 621395 are affected this way.

If you ask to have a 4.2 fitted your installer may need to apply under G59 rather than G83. No harm in asking I suppose.

 

[Fazzathebrave]

My Aurora has a much larger serial number wk 47 2011.
I think I'll monitor the situation for a while as it's not often up at 3.6kW at the moment. Hoping for sunny days ahead! I guess when the sun is not at the strongest then I'm still getting the benefit of having a larger system installed, and that is most of the time.

 

[screwdriver]

We aren't quite getting into the right time of year for peak outputs of your panels so I would hold back until it is definitely clear that the inverter is restricting output, I am sure these are clamped at 16amps which depending on your grid voltage could be anywhere around 3680w to 4000W. If you did want to go down the G59 route then you may be able to update the firmware on the inverter via a registered installer so that the 16amp limitation is removed, to be honest I don't think that overall you would notice a worthy increase in annual yield to justify the hassle.
You have to remember that these inverters were brought out specifically for the UK market to allow installers to comply with G83 recommendations and so there will be a slight compromise to reach that as was so with fitting the larger sma inverters and restricting outputs to 16 amps. In my opinion they are really good bits of kit and will easily complement a 4kw system especially if you are dual aspect or have strange shading issues!

 

[liquidity]

Unfortunately the recent versions post the serial number mentioned above are clamped at 16 amps or 3600 watts - whichever is LOWER. Strikes me as a very conservative reading of the G83 spec.

 

[screwdriver]

Nothing a firmware upgrade wouldn't fix.........

 

[bazzaqpc]

Hi, I have a Aurora PVI-3.6-OUTD-UK and mine also only goes to 3608 watts, but the real annoyance is that I have mine on two strings one string (A) with 12 panels (3Kw) and one (B) with 4 panels(1Kw).
The 1Kw string regularly hits 1230 watts DC when my irradiance meter registers .97, with string (A) disconnected, the other string 3Kw hits 3390 watts, when string (B) is disconnected, so adding both together it should be possible to achieve 4Kw regularly.
Below is a row from the Aurora data logger with both strings connected Yellow is DC String (A) and Green is DC String (B) red is AC output, sadly I didn’t log grid voltage but this is still useful info.
This shows String (A) generating 2503.04 watts DC and String (B) generating 1255.11 watts DC.

14:23;2;PVI-3.3-OUTD-UK;D;391.1;6.4;2487.7;117.3;10.7;1231.0;3607.4;

With string (B) disconnected this is the results

14:26;2;PVI-3.3-OUTD-UK;D;406.7;8.3;3368.6;0.0;0.0;0.0;3266.4;

The reason I chose this inverter was because the tech spec (http://www.power-one.com/renewable-energy/products/solar/string-inverters/aurora-uno/pvi-30-pvi-36-pvi-42/series) clearly states it will peak at 4000watts (230VAC – 17.2 Amp) well it don’t.
My next step is to see if I can get my money back and replace with SMA 5000TL because I give up with Power One.

 

[Fazzathebrave]

I share your frustration - I have a 3.91 kWp scheme and when the sun is out the output is regularly limited to 3.6kw. This is due to the type of connection, G83, which specifies what generation you can connect to the mains. To get more output than 16A you would need a G59 connection agreement. I understand that these can take some time to obtain and I guess may cost money to get, unlike the G83 which is essentially plug and play from the installers.

I have decided not to pursue it and accept that I am capped when the a) the sun is out and b) when directly overhead. Most of the time I am not capped.

Let us know how you get on if you decide to change your inverter and by definition your connection agreements....

Hi, I have a Aurora PVI-3.6-OUTD-UK and mine also only goes to 3608 watts, but the real annoyance is that I have mine on two strings one string (A) with 12 panels (3Kw) and one (B) with 4 panels(1Kw).
The 1Kw string regularly hits 1230 watts DC when my irradiance meter registers .97, with string (A) disconnected, the other string 3Kw hits 3390 watts, when string (B) is disconnected, so adding both together it should be possible to achieve 4Kw regularly.
Below is a row from the Aurora data logger with both strings connected Yellow is DC String (A) and Green is DC String (B) red is AC output, sadly I didn’t log grid voltage but this is still useful info.
This shows String (A) generating 2503.04 watts DC and String (B) generating 1255.11 watts DC.

14:23;2;PVI-3.3-OUTD-UK;D;391.1;6.4;2487.7;117.3;10.7;1231.0;3607.4;

With string (B) disconnected this is the results

14:26;2;PVI-3.3-OUTD-UK;D;406.7;8.3;3368.6;0.0;0.0;0.0;3266.4;

The reason I chose this inverter was because the tech spec (http://www.power-one.com/renewable-energy/products/solar/string-inverters/aurora-uno/pvi-30-pvi-36-pvi-42/series) clearly states it will peak at 4000watts (230VAC – 17.2 Amp) well it don’t.
My next step is to see if I can get my money back and replace with SMA 5000TL because I give up with Power One.

 

[bazzaqpc]

Hi, Yes just ordred a SMA Sunny Boy 4000TL its still G83, if it don`t get to 4Kw guy said he would change to 5000TL at no extra cost he was so confident 4000TL would be ok.

I,ll let you know.

 

[GaryM]

I'm lead to believe it's how the 4000TL is set-up initially. If you're G83 then it should be set to G83 and be capped to a 16A output, if you're G59 then it's not capped.

 

[bazzaqpc]

Thanks, I`ll check with the guy who is installing it,before i pay out any more dosh.