I've had my 6.4kWp system for a few months now. Mostly happy apart from they're installed on a flat roof too close together causing self shading in December and January. So I get even less power than expected in those months. However now it's April and it's sunny and according to the GE dashboard I'm apparently getting more than the expected peak power. How can this be? I was expecting to reach 6.4kW at midday in June, July, or am I missing something?
Peak solar generation is always in spring as the temperatures are lower. More is generated in the summer due to the longer days though. Wait until it gets hotter and you will see your peak kw will drop a little bit.
I have an Emporia system to measure the Solar power. This shows my 6Kw Solaredge system clips at pretty much 6Kw now we are getting enough sun whereas the Givenergy is showing 6.3Kw. I don't think the Givenergy meter is that accurate. I need to measure all 3 meters at the same time when it's clipping but unfortunately the sun seems to have disappeared today!
I suspect its due to tollerances and what not, I've got a 3.6kWp array (10*360) but have seen it peak up to 4kwh according to the reported figures... again, take wiht a pinch of salt i guess.
TimI Its because the temperature of the PV cell is lower than 25C.
You'd have to look at the datasheet for your panels but here's a quick worked example...
Power temperature coefficient = -0.38%/C
So lets say at 25C the panels produce a maximum of 1000W from an irradiation input of 1kW/m2
Now we drop the cell temperature to 10C (ie reduce it by 15C). The negatives cancel so we get 0.38 x 15 = 5.7
The panels cells now produce 5.7% more power than they did at 25C, so they produce 1057W instead of 1000W.
Is the quoted figure really based on an irradiation input of 1kW/m2? I thought that was what you get at midday on the equator.
We are beating our quoted rating on a less than optimal roof slope of 25 degrees not long after the equinox. The air temperature is less than 25C but I doubt the panels are when it is sunny.
I always took it that the figures quoted for panels woudl be their absolute peak under perfect conditions with everything "going right" etc (thats normally the case with things... never an average / under case)