My Panels Not performing as well as neighbour

[Gary K]

Soem of my panels are bluish and some of them are blackish, should I paint them all the same colour? :13:

Try white -they will be so much more efficient as they will reflect the heat and run cooler LOL

 

[Gavin A]

I'm not sure if I've missed something but I don't understand what all the fuss is about. Sanyo panels are sold on the basis that they will generate around 10% more than "normal" poly or mono panels. If they are only producing around 6-7% more then I'd be jumping for joy at the fact that I hadn't paid out all that extra cash just to get 6-7% extra.

You'd be madder than a Mad Hatter at a Tea party to want to change over panels and pay the extra.

who sells them on that basis?

We've always worked on around 5% performance advantage over the year in the UK from the better high temperature and low light performance, though actually I don't think there's any difference in the low light performance between them and the best poly panels, or even the better mono panels like the Yingli Panda, or others using the same cell type.

 

[Vegelen]

In exceptionally overcast / rainy years, they can underperform inexpensive, good quality monocrystaline panels, due to their unimpressive performance in low light conditions
(like happened in 2012 in North West England).
In sunnier parts of the UK i.e Cambridge, Cornwall etc outperformance of 5-10% is possible annually, due to their excellent performance in bright sunlight.
In Northwest England, Sanyo 250 HITS typically outperform Suntech STP250S-Wd+ by 5-7% in bright sunny weather / clear skies, but persistently underperform in low light.
How much bright sunny weather v overcast weather dictates the level of outperformance / underperformance between a high quality, expensive panel and a far cheaper, good quality panel.

 

[Berneray]

Have a look at your original SAP2009 projection which you would have received from your installer at that time........

Is your system performing in line with that projection. If so then be happy with it as that is one of the criteria you based your buying decision on.

 

[zeljuga]

Citat:

Originally Posted by Vegelen He'll probably start to profit from his panel choice 18-20 years down the line.
At that point he'll most probably be dead or have moved.



'If that happens, pop round and swap them over while they are sorting the probate out, but don't tell anyone....'

Naah , Just swap DC cables overnight. Easy one.

 

[Gavin A]

In exceptionally overcast / rainy years, they can underperform inexpensive, good quality monocrystaline panels, due to their unimpressive performance in low light conditions.

I don't think that's right.

It's not the low light performance that's having that affect - the low light performance is better than the vast majority of mono panels at 25 deg panel temps.

What I'd expect s happening there is that in colder weather the high temperature advantage of the panels works in reverse, so the mono panels improve their output at 0.45%/deg C below 25 deg C vs 0.3%/deg C for the Panasonic HIT.

So the effect my well be as you describe, but let's get the cause of it assigned properly.

I reckon it'd be interesting to actually monitor the panel temperatures through the year to see what proportion of the generation is produced above and below 25 degrees panel temperatures in the UK. Unfortunately this is a bit hard to achieve on a working system as any probe attached to the front of the panel would cause shading and output loss on the panel, and the rear of the panel is a lot cooler than the front in full sunlight. I might have a go at this though as we've got a solar water heating monitoring system running on our house which has spare sensor channels I could use.

 

[Vegelen]

A few points of curiosity.

How do solar panel temperatures fluctuate in different parts of the UK, at different locations and latitudes?
How does temperature affect solar panels and their ability to generate, with differing temperature coefficients?
Is a solar panels power temperature coefficient constant or does it change with temperature?
How does wind and rain affect panel generation ability?
How does temperature affect solar inverter longevity and its ability to generate?

 

[SolarCity]

Vegelen's data on Sanya vs other panels doesn't correlate with data that we have. Sanyo panels seem to outperform nearly all other panels we have installed in ALL conditions.

I'd be interested to see some data from other installers.

Linuo panels appear to be doing really well but from what I can make out, they don't necessarily do any better in colder temps than Sanyo.

 

[zeljuga]

I have small test set up Sanyo 250 side by side with Schoot thin film over the last year. On dull cloudy days thin film Schoot panels regularly equals or slightly outperform Sanyo.In wp per wp comperesment . Elevation 35`: S SW.

 

[Gavin A]

I have small test set up Sanyo 250 side by side with Schoot thin film over the last year. On dull cloudy days thin film Schoot panels regularly equals or slightly outperform Sanyo.In wp per wp comperesment . Elevation 35`: S SW.

to be expected, as that's what thin film is designed to do, and the reason Sanyo / Panasonic are good in low light conditions is that they have 2 x thin film layers.