Octopus Agile

QrizB

I would say my generation has dropped off by closer to 10% this week

Here's my experience.

• Two months ago, on the 25th of April when it was sunny but relatively cool, my panels made 17.8kWh (6.5 kWh/kWp)
• One month ago, on the 25th of May during the first heatwave when we saw about 30C, that made 15.9kWh (5.8 kWh/kWp)
• Yesterday, where we saw 34C, they made 14.7kWh (5.4 kWh/kWp).

That's a reduction of 18% in June vs. April, despite the June days being somewhat longer.

Peak generation was 2.3, 2.1 and 1.9kW respectively. The generation curves for all three days I've quoted look "perfect", smooth with no dropouts.

debitcardmayhem

https://forums.moneysavingexpert.com/discussion/comment/82047278#Comment_82047278

JUST looked at mine for April too and am seeing much the same 18% ☹️

Scot_39

https://forums.moneysavingexpert.com/discussion/comment/82047278#Comment_82047278

https://www.ecoflow.com/au/blog/effects-of-temperature-on-solar-panel-efficiency

States 0.25-0.5% per degree C above 25 degrees C - cell not ambient.

Other sites talk about ventillation - so wind - or lack of it likely to have an impact on actual cell temps too.

And if those temps are say metoffice - rather than your own - the chances are they are shade temperatures - and your actual panels would be getting considerably warmer - and possible cooling down less without a decent breeze - like say a black / dark car sitting in bright sun - the surface temp likely a lot lot hotter than ambient.

But 18% - would suggest panels getting up to near 65 degrees - assuming more like the nominal 25C.

And this site - says 50-65C actual panel is possible in UK - and 85 C plus in harsher nations 0 but its drop off chart stops at 8% at 50C. So it could well be possibly during this amber red period (but for some reason thought you were further north

https://www.sunsave.energy/solar-panels-advice/how-solar-works/hot-weather

.

QrizB

I wouldn't be at all surprised if the panels on my roof have been at 65C this week. But I'm not planning on going up there to measure them!

debitcardmayhem

https://forums.moneysavingexpert.com/discussion/comment/82047548#Comment_82047548

I am going to check mine soon 🍳just waiting for my sausages and chips

Newbie_John

https://forums.moneysavingexpert.com/discussion/comment/82047548#Comment_82047548

If that helps, my solar thermal showed 142°C today.

QrizB

142C is crazy hot. It illustrates the challenges of putting equipment out in the sun!

Scot_39

https://forums.moneysavingexpert.com/discussion/comment/82047612#Comment_82047612

And thats with a white face.

Google quote a reddit page user suggesting a black car gets around 25C hotter than a white one ?

GingerTim

Negative/under 1p from 11.00-15.00 in London tomorrow. Air con will be on throughout.

Netexporter

A small reward for enduring the horrific rates, at times, this week. Having said that, I'm not sure if I'll be feeling the benefit. A dull morning but looks like at least partially sunny during the plunge period, so probably more than enough solar to meet my needs.