Your Solar PV Readings - Discussions

celerity

Cheers, that makes sense. It also explains why I'm sure I've seen 3.7kW+ on my Sunny Beam, but that hasn't been logged.

/\dam

stoozey

Well weird things happening this morning. We had a heavy rains storm where i was lucky to produce 100w now its cleared up and when the sun comes out from behind the clouds I am making 4KW from my 3.885 system!

zeupater

stoozey wrote: »

Well weird things happening this morning. We had a heavy rains storm where i was lucky to produce 100w now its cleared up and when the sun comes out from behind the clouds I am making 4KW from my 3.885 system!

Hi

This would be quite normal in those conditions ....

Your panels are output rated at 25C which will deteriorate by about 0.5% per degree C above that, and increase by the same amount in cooler conditions. Normal temperatures in full continuous sun will be somewhere around/above 45C(ish), so around a 10% loss in performance.

The shade of the cloud and rainfall will have cooled the panels .... when the sun pops out the panels will therefore be more efficient for a while. Very heavy rainfall in thunderstorm type conditions is usually extremely cold, that's why you often see it as hail, so it's possible to increase performance by around 10%, however, your inverter will then limit the AC power ...

By the way, your panel pack could also average over nominal output due to manufacturing tolerances ....

HTH
Z

stoozey

that is very interesting, i didnt realise there was such a gain to be had from running them at a low temp. Will have to start thinking about a cooling system...

celerity

I have another question about my array (spec for which is post #4 in the Readings Thread).

Today at around noon, it started kicking out consistently more than 4kW (it is rated at 3.91kWp), for example, it was generating 4200W for a fair bit of time when I was watching the monitor. It is quite windy today and I understand that this is expected behaviour due to cooling etc.
I've just checked the Sunny Beam again though, and my daily graph is distorted as it thinks it peaked at about 22kW(!) earlier today. Obviously it didn't, but what could be the reason that the inverter / Sunny Beam got confused and logged this value?

Thanks,

/\dam

free_juice?

celerity wrote: »

what could be the reason that the inverter / Sunny Beam got confused and logged this value?
/\dam

Because the software has bugs? My 3kW Sunny has been playing similar - though not so extreme - tricks.

celerity

Thanks free juice, and I have to say I am most jealous of your Sunny Webbox setup. I have live monitoring of my system on a public webpage too, but had to use a clamp meter to get it working so it's not 100% accurate.

/\dam

free_juice?

celerity wrote: »

Thanks free juice, and I have to say I am most jealous of your Sunny Webbox setup. I have live monitoring of my system on a public webpage too, but had to use a clamp meter to get it working so it's not 100% accurate.

/\dam

The webbox was an extravagance which provides a bit of fun and convenience but will never earn its keep. It's not 100% accurate either as the generation meter consistently reads 1.12% higher.

celerity

free_juice? wrote: »

The webbox was an extravagance which provides a bit of fun and convenience but will never earn its keep. It's not 100% accurate either as the generation meter consistently reads 1.12% higher.

Yes, I feel the same way about my Sunny Beam, and the webbox is much pricier than that - still, all good fun as you say .

It's interesting your webbox and meter don't agree, although 1% is maybe within expected tolerances? I've just checked and my Sunny Beam reports 407kWh in total and my generation meter reads 406kWh, which is close enough for me not to be worried.

/\dam

free_juice?

celerity wrote: »

Yes, I feel the same way about my Sunny Beam, and the webbox is much pricier than that - still, all good fun as you say .

It's interesting your webbox and meter don't agree, although 1% is maybe within expected tolerances? I've just checked and my Sunny Beam reports 407kWh in total and my generation meter reads 406kWh, which is close enough for me not to be worried.

/\dam

The webbox merely relays the inverter's internal data. Does your Sunny Boy report the same as you get from the inverter’s LCD? (Tap it sharply to get it to spring into life.) I expect it does, in which case it’s the inverter tolerances which vary.

It feels much better to be paid more FIT than the inverter says I am due. I think I might feel cheated if it was the other way around.