Solar Panel Guide Discussion

zeupater

Hi

In respect to Q3 ....

It's pretty well accepted that there is a significant reduction in efficiency early on, then the panels degrade on an almost linear basis. If you look at the specs for most panel manufacturers they show the performance having step changes, this really only reflects their performance guarantee, however, there are some manufacturers who try to gain a marketing advantage by claiming their panels are different because they degrade on a linear basis and modify their performance guarantee to support this. I'd guess that there's very little difference between any panel cell degradation in reality with the difference in glass reflectivity and ability to self clean being far more important.

HTH
Z

Lck_2

I had solar panels fitted on Friday, the installation went online around 3 pm and since then the panels have produced 4.3 kw on the meter (that's as at 12 noon today so 45 hours from installation). That doesnt sound like much to me. I know it's cloudy but that's not a lot of electric. It's supposed to be nearly 4 kw or whatever the units are for the panels - sorry not a very techy person! But is this what you would expect? The panels are arranged east and west on a roof and I'm sure there is no shade.

zeupater

Lck wrote: »

I had solar panels fitted on Friday, the installation went online around 3 pm and since then the panels have produced 4.3 kw on the meter (that's as at 12 noon today so 45 hours from installation). That doesnt sound like much to me. I know it's cloudy but that's not a lot of electric. It's supposed to be nearly 4 kw or whatever the units are for the panels - sorry not a very techy person! But is this what you would expect? The panels are arranged east and west on a roof and I'm sure there is no shade.

Hi

Don't panic .... you'll very rarely get anywhere near the maximum power generation capacity of your system. To get an idea of what to expect on a daily basis feed your details into the PVGIS system (http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php) ... you'll find that somewhere around 1.6kWh.d/kWp will be in the right ballpark as a target for October, so on cloudy days expect less and sunny days more.

HTH
Z

pr_giles

If it's any consolation, we only got 4.6 kW for yesterday (grey and overcast most of the day). Our best day so far since installation (about 20 days), 15.05 kW, so a huge variation is to be expected.

Paul

bjohnson

Hate to be pedantic but kW is just the amount of electricity being generated at a particular time. What you need is the kWh (kilowatt hours) figure which is how much electricity was produced over a period of time. For example if you had 0.5kW produced for ten hours that would be 5kWh.

BornAtTheRightTime

pr_giles wrote: »

If it's any consolation, we only got 4.6 kW for yesterday (grey and overcast most of the day). Our best day so far since installation (about 20 days), 15.05 kW, so a huge variation is to be expected.

Paul

Agree on the huge variation - our best since installation is 19kWh. It seems we had ours installed at the same time so will be interesting to look back in 11 1/2 months' time to compare results. I'm a little more East and South of you, in eastern Essex.

BornAtTheRightTime

bjohnson wrote: »

Hate to be pedantic but kW is just the amount of electricity being generated at a particular time. What you need is the kWh (kilowatt hours) figure which is how much electricity was produced over a period of time. For example if you had 0.5kW produced for ten hours that would be 5kWh.

:rotfl:pretty sure LCK and Paul just dropped the 'h' from their figures (as generating 15.05kW on a 4kWp system would be cause for CERN to get interested...!)

TrickyDicky101

bjohnson wrote: »

Hate to be pedantic but kW is just the amount of electricity being generated at a particular time. What you need is the kWh (kilowatt hours) figure which is how much electricity was produced over a period of time. For example if you had 0.5kW produced for ten hours that would be 5kWh.

That wasn't pedancy: that has sorted a few things out for me Many thanks!

I'm sure at one time I knew all this (kWh = kW * hr) etc but time appears to have atrophied certain cerebral pathways

Caerhendy

Thanks for the explanations TD & Z.
I've had my first quote:-
2.45kWp at £10,450
Total Income £1060

Disappointed with 10yr payback.
Hope the others are better.
Rob

Hungerdunger

TrickyDicky101 wrote: »

That wasn't pedancy

Just being pedantic myself: I agree it certainly wasn't pedancy; arguably it may have been pedantry.