Peak generation lower today but smooth pv curve?

Ok so firstly this is not a givenergy issue. But as we all have solar one of you might know.

So today there has not been a cloud in the sky. Pretty much perfect solar curve. However My peak generation is much lower than yesterday, amps are a lot lower and I have no idea why. Data below, possible ideas welcome.

For information PPV2 is monitoring a 8kw solis inverter with 8x 295w panels on string1 and 11x440w panels string2 total 6760w. Also I have myenergi monitoring too and confirms the same data peaks. 6800w yesterday and 5786w today. Today is the better weather day!

Todays data. Notice peak power on PPV2 is 5786w IPV2(A) 23.9.

Yesterdays data. PPV2 peak 6800w IPV2 27.9

Todays curve (ignoring this mornings missing data) Suggests 1 tiny cloud around 9:40, a big cloud at 11:45 and a medium cloud at 2:15pm lol

String 1 looks to be the culprit. Check IPV1 against IPV2 both days. Its current seems to be performing well out of synch with string 2. Are they on the same apsect? Also, whilst today appears to be the 'better day', the sky here has more haze than yesterday and the wind has disappeared so there is no cooling air movement to keep the panels performing at max. Still, even accounting for that I would be investigating string 1.

THALL

For context, here is my Monday vs today, I am seeing almost like for like generation (better today as there was no clouds vs yesterday morning lots of clouds here in West Sussex)

cluelesscris pv2 is an East facing pv system, pv1 is west facing. Later in the day pv1 starts up :-) But maybe it is haze, I wasn't at home to see the sky. Might be nothing then.

Shame, I am eager to see what my max day generation is. Had a couple of 48kw already. Wondering if I will see a 60+ this year.

THALL I noticed the same thing. We had a clear day today so I expected to max out the inverter at 6kW (which we have seen many times in the last few days), but instead we only just exceeded 5kW. My assumption was that it was to do with high cloud/haze or perhaps dust/sand in the atmosphere.

This is normal. Peak generation will be higher with scattered cloud than on a clear day. With scattered cloud you can get direct sunlight and reflected light from clouds. This can result in PV power levels in excess of STC. Of course you also get cloud shade

Solar cells are not very sensitive to blue, but more sensitive to red and near IR. You get more generation when the sum shines through a gap in white cloud than from sun in a clear blue sky.
Altermatt's lectures explain all!... https://pvlighthouse.com.au/cms/lectures/altermatt/solar_spectrum

Also, with sustained sun the panels will heat up and be less efficient. But since the air is still quite cool and the sun is still far from its highest in the sky I wouldn't expect to see much of an effect from that at this time of year.