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Can anybody let me know what is the maximum output (in percentage terms) they see from their system ? I'm only seeing a maximum of 85/86%.
Thanks.0 -
HeyRevolver wrote: »Can anybody let me know what is the maximum output (in percentage terms) they see from their system ? I'm only seeing a maximum of 85/86%.
Thanks.
If you mean how does the highest ever Kw reading compare with the declared Kwp of the system, then I really did get a peak reading of 4.02Kw over the weekend which is fractionally above 100%. Several people have claimed figures of around 110% on these pages.
But you really need to give more details of your system - for instance if you had half the panels facing due E & other half due W then you'd never hope to get anywhere near 100%NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50 -
Wow...
It's just the SAP calc is:
0.8 x kWp x S x Zpv = esitmated kWh/year
The 0.8 (or 80%) factor is used because there will always be losses from the solar irradiance hitting the modules to the AC electricity used. As a rough guide, the estimated 20% losses arise from: 4% reflection, 1/2% arrangement, 2.5% dust on modules, 4-8% temperature, 1% DC cable losses. (Module conversion efficiency is accounted for in kWp).
I have a South facing roof, 40-45% orientation, no shading. I don't have the most expensive panels but... seems like something wrong to me if you got max 100% over the weekend and I got only 86%.
I'm thinking a panel or two is not working properly...
Any ideas anyone ?0 -
ps. I have my invertor in the garage so it's a few meters from the array - don't know if this makes much difference.0
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What's the size of your array and maximum output of your inverter?
For example, I have a 4kWp array (16 x 250W) and a 3.68kW inverter (G83) with a maximum output of 3.8kW though it has peaked at 3.813kW.16 x 250W JA Solar Panels (JAM6-60-250) : Fronius IG TL 3.6 Inverter : South Facing : 28 Degree Pitch : No Shading : Manchester M460 -
HeyRevolver wrote: »Wow...
It's just the SAP calc is:
0.8 x kWp x S x Zpv = esitmated kWh/year
The 0.8 (or 80%) factor is used because there will always be losses from the solar irradiance hitting the modules to the AC electricity used. As a rough guide, the estimated 20% losses arise from: 4% reflection, 1/2% arrangement, 2.5% dust on modules, 4-8% temperature, 1% DC cable losses. (Module conversion efficiency is accounted for in kWp).
I have a South facing roof, 40-45% orientation, no shading. I don't have the most expensive panels but... seems like something wrong to me if you got max 100% over the weekend and I got only 86%.
I'm thinking a panel or two is not working properly...
Any ideas anyone ?
Could well be a faulty panel - although that might drag the whole installation down even more.
Your 45 deg slope is a touch too steep for best performance this week - but OTOH my slope is always too shallow.
Could even be a mis-match between SPs & inverter. e.g. perhaps when all panels are supplying their maximum output the inverter is overloased ?
Or . . . . . !!
Probably your best course of action is to ask installer to come back and investigate.
Just hit 4.07Kw. But it's fluctuating wildly between 3.8 & 4.0 (and a cloud is fast approaching !)NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50 -
HeyRevolver wrote: »ps. I have my invertor in the garage so it's a few meters from the array - don't know if this makes much difference.
Won't be a problem if the correct sized DC cable has been used to take into account volt drop though the standard size of 4mm2 will be fine for most domestic properties with the inverter in the garage.16 x 250W JA Solar Panels (JAM6-60-250) : Fronius IG TL 3.6 Inverter : South Facing : 28 Degree Pitch : No Shading : Manchester M460 -
HeyRevolver wrote: »Wow...
It's just the SAP calc is:
0.8 x kWp x S x Zpv = esitmated kWh/year
The 0.8 (or 80%) factor is used because there will always be losses from the solar irradiance hitting the modules to the AC electricity used. As a rough guide, the estimated 20% losses arise from: 4% reflection, 1/2% arrangement, 2.5% dust on modules, 4-8% temperature, 1% DC cable losses. (Module conversion efficiency is accounted for in kWp).
I have a South facing roof, 40-45% orientation, no shading. I don't have the most expensive panels but... seems like something wrong to me if you got max 100% over the weekend and I got only 86%.
I'm thinking a panel or two is not working properly...
Any ideas anyone ?
Do you sit in-front of the inverter or remote monotor watching for momentary peaks, or are you looking at output averaged over a period of time (5 minutes ?) .... it make quite a difference to what you're asking ....
When some/most refer to their peak being above nominal this will usually be for a very short time when the panels are cool, the sun is near-perpendicular to the plane of the panels and there is a partially cloudy sky which introduces 'cloud edge effect' to what is seen. Over a period of time of clear sky conditions the panels will warm and generation efficiency will fall by ~0.5%/degreeC rise above 25C, so with normal full sun panel temperatures expect somewhere around a 10% loss in generation ...
The nominal rating of your panels is based on lab test conditions with 1000W/sqm of sun-spectrum light delivered. Although 1000W/sqm is possible under very clear-sky conditions, it is normal for high altitude water-particles to reflect a considerable proportion of the available light back into space which reduces your generation potential ..... you can usually judge how much moisture there is in the atmosphere by looking at how blue the sky is ... the darker blue the better it will be for your panels ...
HTH
Z"We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle0 -
I have a 3.5kWp array (14 x 250W).
The invertor is an SMA Sunny Boy 3000HF which I've just checked with google.. not very good with this technical stuff but... it says Max. Input DC power 3150W and Rated Output AC power
3000W. Also Max. efficiency of 96.3%.
So I guess the invertor is capping it at 3kW ?
I'm told if one of the panels wasn't working the whole array wouldn't be working....0 -
Hi
Do you sit in-front of the inverter or remote monotor watching for momentary peaks, or are you looking at output averaged over a period of time (5 minutes ?) .... it make quite a difference to what you're asking ....
Certainly does ! I reported a momentary peak of 4.07 at 11:39 ; the 5m average for then was only 3.5 (which is indeed around 85% of Kwp)NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50
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