Discuss 3KW peak on 4kwh system in this Sunny weather..is there a fault? in the Solar PV Forum | Solar Panels Forum area at ElectriciansForums.net

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loser123

today and tommorow the weather will be glorious not cloud in the sky today and my system has only been peaking 3kwh in the past week
last month it went to the 4kw peak all though it was only for half an hour in this weather surely it has to go up to 4 kw but hasnt gone there

i thinking maybe some of panels may not be connected.... if there is a break from panels how can you tell?

last month my system kept tripping off every morning and i had to wake up to put it back on - i called the engineers out and they repaired it but am wondering as he messed up something else

location ..middlesbrough NE England
sunny roo 4200TL invertor
panels aiming towards south and south west
 
The heat affects the panels and they produce less power when they get hot.
If your able to spray some water on them with a hose you should see the power increase as they cool down.
Our 2.88kw system was peaking around 2.7 to 2.8kw but for the past week it's only reached about 2.4kw in this hotter weather.
If you have a look on pvoutput.org you'll be able to see how similar sized systems in your area are performing compared to yours.
 
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Three things going on:

1.
The weather is hot, which is reducing the efficiency of solar panels.

2.
Some makes of solar panels cope better with hot weather than others. Take a look at the temperature coefficient.

3.
SouthEast and SouthWest systems are now in perfect alignment with the sun in the morning or afternoon.
It may be that the full force of the sun is just making them too hot.
I'm noticing on my 3.75kWp SE-facing panels that their output hits a "glass ceiling" in recent days and will not go above about 3kW - and I suspect this is because the sun is perfectly angled at the panels but it's so intense that it's adding to the overheating.
It's especially interesting because the output of my system plateau's at 3kW for several hours at the monent (from about 9am to about 1pm), whereas a few weeks ago it was making a nice bell-shaped curve, with a distinct peak around 11am of about 3.6kW and being at or above 3kW from about 9.30 to about 12.30 (when the sun was out).
 
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We've had a few calls from people about the problem.

Yes, to go with the handful of recent postings, I thought that there'd be quite a few customers phoning their installers to say "my system's broken - help!".:shocked:
 
we highlight this in our user manuals for each system, and so far we've not had anyone coming back to us questioning the outputs in this weather this year - that I know of anyway.
 
Weather in March was exceptional, very sunny and cold giving ideal conditions. we regularly saw systems banging the 3.6kW limits on their inverters. Now the weather is hotter panel performance is dropping and proves the value of derating inverters, as we always do, as you will rarely actually exceed 3.6kW on a 4kW system. Inverters are now optimising performance. As the systems age this will become even more pronounced.

It also proves the benefit of using decent quality panels whose heat characteristics are better. A cheap system may appear attractive, but ultimately it may well cost you money.
 
my 4kw too is peaking 3kw no more facing south, was thinking this morning uumm!!!but realised i could only get a 3000hf inverter at the time i installed it but its still performing well since 2nd march to now its done 996kwh. so im happy :p
 
My 2.5 kw system picked at 3499w. I have found that's fronius 30 ig plus is actualy 3600w max from panels. System In hot climate of oz and carib.
 
Although sunshine levels exactly the same over the last two days, todays output slightly lower overall than yesterday when the wind from the east was keeping the panels slightly cooler I guess. Seems to reinforce the issue over panel temp and rated output
 
Some graphs to show the performance of my system. I have a 3.6kWp SunPower system matched with a 3000HF inverter where it peaks at 3kW output.


3KW peak on 4kwh system in this Sunny weather..is there a fault? Without Wind.JPG - EletriciansForums.net
Earlier this week on a hot still day

3KW peak on 4kwh system in this Sunny weather..is there a fault? With Wind.JPG - EletriciansForums.net


Yesterday where there was a strong wind
 
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Indeed we have recieved a call from a customer, I'm going to take a down load on Monday to analyse. I've said before the joke about our weather (viability of solar), but places nearer the equator will have increased losses due to temperature. Would like to see the performance of a 4 kWp in africa to analyse the increase irradiance yields against temp losess with a northern Europe array !!
 
Well its over 30deg here in sunny/cloudy Cheshire today and the system is peaking higher today, then in the past few days, so i just think its not that much to do with temperatures, but more to do with the actual irradiation from the Sun
 
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Well its over 30deg here in sunny/cloudy Cheshire today and the system is peaking higher today, then in the past few days, so i just think its not that much to do with temperatures, but more to do with the actual irradiation from the Sun

Blimey! 30'C in Cheshire.
It's only about 26'C here in Cambridgeshire, which goes to show just how dull, wet and cold spring we had here that still appears to be spoiling the weather (cool, wet ground still coolng the air and causing mist which blocks the sun); we're normally one of the warmer, sunnier, drier parts of the country. It's usually so mild and sunny that figs and grapes usually grow well outdoors here. But this year is a shockingly bad one.
 
Blimey! 30'C in Cheshire.
It's only about 26'C here in Cambridgeshire, which goes to show just how dull, wet and cold spring we had here that still appears to be spoiling the weather (cool, wet ground still coolng the air and causing mist which blocks the sun); we're normally one of the warmer, sunnier, drier parts of the country. It's usually so mild and sunny that figs and grapes usually grow well outdoors here. But this year is a shockingly bad one.

You see mist everywhere-sure your glasses don't need cleaning? LOL
 
Well I knew I shouldnt of said that last comment ( edging my bets ) as at lunchtime the weather went to pot, the clouds appeared everywhere and now seems ready for a real down pour .....
 
I was concerned about this as well - max 3.2kw peaks with our 4kw system.

However PVOutput put my mind at rest - if i look at a number of similar sized systems local to us they are all peaking at between 3.1 and 3.4kw, even the sanyo ones which typically peak at @200kw more, as expected.

e.g 26th May (Sat) - our 4kwp system peaked at 3240w. Nearby sanyo 4kwp system peaked at 3468w
 
I washed my panels on saturday, the guy up the road had been cutting flag stones with a stihl saw, so they were covered in dust. 3.57 kWp system, producing 2.9 kW at midday, after rinsing with cold water the power output went up to 3.1 kW, which then settled back down to 2.9 kW within about 5 mins.

So, the layer of dust on the panels made little difference, but cooling the panels did!
 

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