Renewables: "talking 'bout my generation"

EricMears

I too have had a great day with 28.61 kWh

Alas, been out for most of day but managed my usual rainwater pumping session and put on a load of washing as we left. And of course 750W of immersion heater will have been running much of time.

Would have been nice to have seen a peak nearer 4kW though; max recorded was 3.3kW

sly_dog_jonah

csh wrote: »

reading of 14.5 kWh or 7.25 O's today. Highest ever, you know of the last 5 days I have been reading the meter

2 loads washing and drying, slow cooker, hoovering all free

Scorching day here today with not a cloud in the sky all day and no wind.
I've noticed a few say wind/ breeze helps. Why is this?

The breeze helps to keep the panels cool. The more solar radiation they convert, the hotter they get and as the panel temperature increases the output drops off. A breeze helps to keep the panels cooler and hence improve efficiency.

Your 7.25 O's surpasses anything our system has done since October 2011, but there's hope yet!

Oscargrouch

Not too good today either, only 7.36 O's...
No doubt Shafeeq will have beaten me today; I was in Dewsbury all day and the weather there was great... Not too far from Sheffield is it ??...

jimjames

Oscargrouch wrote: »

Not too good today either, only 7.36 O's...
No doubt Shafeeq will have beaten me today; I was in Dewsbury all day and the weather there was great... Not too far from Sheffield is it ??...

That must be approaching the maximum that is possible in the UK unless the temperature drops to near zero.

Looks like we are all doing very well from the cooler temperatures this year!

Martyn1981

csh wrote: »

I've noticed a few say wind/ breeze helps. Why is this?

Hiya csh, as SDJ said, heat reduces PV performance. Different panels will vary, but roughly you'll find a drop of about 0.4% for each 1C rise above their rated temp, which is normally @ 25C. Googling panel type and clicking on data sheet should give you this info.

Flipping that around gives a 1% drop for each 2.5C rise, or 10% drop for each 25C rise. Next think how hot (and how quickly) these panels will get in direct sunlight, so forget ambient air temp, think touching a car that is in direct sunlight.

So colder air, and a nice wind, will help supply more cooling to panels, than warm still air allowing a hot bubble.

I'm seeing generation of around 3kW to 3.2kW at the mo, from my 3.6 ESE. In still, hot air, I've seen it sitting at around 2.4kW to 2.6kW, but of course the boost comes from long, long generation periods compared to say cooler April/October. So now getting a double boost of cold air and long generation ..... :cool:

Mart.

Martyn1981

jimjames wrote: »

That must be approaching the maximum that is possible in the UK unless the temperature drops to near zero.

Looks like we are all doing very well from the cooler temperatures this year!

With an E/W split, I think my theoretical is about 6.5 O's, but requires cold air temp.

Anyone else jealous of 8.12 O's from a 3+yr old system?

http://www.navitron.org.uk/forum/index.php/topic,20278.0.html

Mart.

sly_dog_jonah

In addition to Martin's points, the panels will also heat themselves due to the current flowing through them. It's not unheard of for panels to reach in excess of 50C in full sunlight so the losses on a windless day can be significant.

John_Pierpoint

John_Pierpoint wrote: »

3.6 kWp "Aurora" inverter North side of Thames estuary facing SE on 30 degree roof

Today I am "enjoying" a massive haze of vapour trails, mainly aiming a Stansted airport.

kWh Oscarz
26.12 7.26 04/06 Tuesday

Was it the reflection from the ice crystals, the cool temperature, or the "pruning" I did two weeks to a couple of fast growing conifers?

Martyn1981 wrote: »

Anyone else jealous of 8.12 O's from a 3+yr old system?

http://www.navitron.org.uk/forum/index.php/topic,20278.0.html

Mart.

Property seems to be on a marsh, which probably means wide open "Constable" skies. That is good for generation and probably cooling too.

I note that the poster is quoting his inverter, which might have an inflated opinion of itself, not the generation meter, which is the acid test.

[It is a bit like cars and MPG figures ?]

3.6 kWp "Aurora" inverter North side of Thames estuary facing SE on 30 degree roof

KevinG

Martyn1981 wrote: »

Anyone else jealous of 8.12 O's from a 3+yr old system?

Wow. I don't think I'll ever get 7 now, have only got over 6.5 once. I'd probably do it if I didn't have a not very good slightly under-rated inverter.

Wh05apk

Best day so far (only had the system 4 weeks!) but got 27.54 or 7.48 "o's" very impressed, couldn't use enough power during the day though! must get aircon for my south facing office - seems an ideal way to use power, as only needed when hot and sunny, which will be when we are producing, looking good again today.