Discuss Voltage output from 15 x Sanyo HIT N235W array in the Solar PV Forum | Solar Panels Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

T

TrickyDicky101

Hi Guys

Need your expert opinions and advice here - I have a solar array installed comprising the 15 panels connected to a Fronius 3.0 IG TL. I just checked the voltage being registered from the array (given it is cloudy and rainy conditions at the moment) and total voltage from the array was 530V.

Now, the N235s are rated at 43.0V per panel. I have them connected in a series on one string of 15 so I was expecting a voltage of

15 x 43.0 = 645V

However, I don't know if conditions affect the voltage (or just affect the current, hence reducing the power output). For information, power output was low at around 200W (so current was 0.35A ish).

I am concerned that maybe not all the panels are connected/functioning - I have been comparing my outputs with another owner with a similar array (but 17 N235s and different Inverter) and, even after allowing for the smaller size of my array, my outputs especially on sunny clear days are significantly smaller than his. I will now monitor what voltage I get on sunny clear days (if we have any more this side of Christmas!) but I haven't done so up to now.

Your thoughts would be appreciated.

Many thanks

Richard
 
Last edited by a moderator:
If you get the data sheet of the N235 there is the typical current/voltage graph on the 2nd page. That graph shows the current/voltage relationship for 5 different irradiance levels. On a cloudy rainy day the bottom graph (200W/m2) is probably what you would expect or maybe even lower. At 200W/m2 the expected voltage would be in the region of 15 x 40V = 600V, anything lower than 200W/m2 then your guess would be as good as mine as to what voltage to expect. I get the 40V from the 200W/m2 graph at the point where the horizontal line starts to drop - known as the knee point of the curve.

In summary the 530V wouldn't worry me for such a 'bad' day - it would worry me if it was brighter!
 
if its generating then that voltage you see on the inverter will be the VMP, which will be lower than VOC which is what i think you have calculated
 
Thanks for the replies :)

Yellowvanman - I completely agree! Where's the sun when you need it? Hopefully it will be a bit brighter tomorrow. It was because of the difference in generation on sunny days (admittedly October sunny days) between the two systems that I was worried. However, we are not in the same part of the country so local weather conditions could well be playing a part. I guess I want reassurance that my £13k has been invested in something that works! :)

mmccx - would you mind explaining the difference? Please treat me as if I'm simple in any reply :)
 
vmpp - voltage at maximum power point, i.e when the modules are operating (basically the optimum voltage to squeeze the most amount of power out of them check the IV curve on the module data sheet)

voc - voltage open circuit, voltage at standard test conditions when not generating, this value will always be higher than the vmpp value. You would use the voc to confirm all modules are connected together but you would have to test the modules when they aren't generating, some inverters also show the voc of the modules during the inverters wait period
 
Hi Richard,
Me again! Mine is pretty poor too although, as you know, is e/w and so I would not expect much when the sun is so low. Today was the pits at 1.36Kw, yesterday was 3.75 and I think the highest I've had since commissioning on 2oth Oct was about 7.5Kw.

I have come to the conclusion that regional weather differences can be huge and also that my system will not perform like a south facing at this time of year. I really hope that when light intensity levels improve and the days get longer, I will have useable power earlier and later but it may not ever reach its potential peak of 3840Kwp.

My installer has given me a sheet from Sanyo suggesting that October only produces about 6.5% of total annual generation and November, only about 3.5, Dec, 2% so sit back, don't worry and look forward to March/April!

You said in an earlier post that you would expect yours to get 7/8ths of my output but, if I remember correctly, you are on the south coast and yours faces south. I am in Herts and although my system is slightly more powerful, the e/w arrangement cuts predicted output by about 15%.

I am just relieved to have got mine done before the **** hit the fan!
 
mmccx - thank you. If I refer to the Sanyo data sheet it shows that the panes should be outputting 41V at low irradiance levels, so this still seems much higher compared to the 35 - 37V I have observed.

Hi Kate - I can well believe that the weather differences have a profound effect. I find the panels generate comparatively little unless they have direct sunlight. I hope shelling out for the expensive Sanyos proves a worthwhile move! I am incredibly glad I got my install when I did!
 
Last edited by a moderator:
Hi,

I too got in before the Fits reduces thanks to one of the senior posters on the forum. I use
PVOutput to compare my array with others around the country as you can see their composition of panels, inverter etc

I'm FrankNKims Powerhouse on there. Hope its of help.

Frank
 
Last edited:

Reply to Voltage output from 15 x Sanyo HIT N235W array in the Solar PV Forum | Solar Panels Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock