Hi guys, I just installed my first pv system at home after doing the pv and battery course and have seem to encountered a problem! I've installed 6 Canadian solar 550w panels south facing and it's not producing consistently. When the sun is directly over the panels it would produce close to peak but soon as the sun is on the east or west with clear skies and sun hitting the panels it would only produce between 0.5 to 1kw in total. Surely the panels should be producing more than 15% with clear sky and full sun even though the sun is not directly over it. Today midday the panels were producing 2.5kw and have suddenly dropped to 0.6kw for the past 2 hours which doesn't make sense. What tests can I do to diagnose the issue?
New panels not performing
- Thread starter dipesh
- Start date
Help Support Talk Electrician Forum:
Clouds passing over ?
generally speaking, if it hits peak, it's working properly. What's the roof pitch, obviously angle to the sun makes a big difference.
Will double check inverter side tomorrow hopefully I find something there. Can you recommend a way to test for faults or the panels? The solar pv course only taught a fraction of what you can learn online!
No clouds, today was clear sky 29c and I was averaging 0.6kw after midday and then 1.5kw at 5pm for an hour
It's only hit peak once for a very short period of time yesterday, I was expecting it to be close to peak throughout today as it was the best weather conditions since I've installed. Panels are 35 degrees south facing
Overheating panels, hence when it gets late in the day and temperature cools off, performance improves.
There's no real way of testing panels for useful stuff like continuity of the cct, it's bugged me for years. About all you can look at is panel output and insulation.
Ucatchmydrift
Well-known member
Doesnt sound right to me.. I have ~3kw of panels, 2 strings, east and west facing, sunny all day yesterday, see the picture below for solar output during the day. Notice the drop in production after about 11:30am, this was the inverter limiting the solar output as the battery banks were getting full. Going into absorbsion, if you have battery storage, that could be the reason, that they were getting full? Other than that, i dont have the experience to help, sorry.. (the solar Production spiked back up at 4:00pm as the 1.5kw immersion heater came on and was able to use the available solar..)
- Joined
- Dec 23, 2021
- Messages
- 270
- Reaction score
- 75
Is there any shading ?
Even the shadow of a power cable or telephone line can reduce output.
Even the shadow of a power cable or telephone line can reduce output.
Ucatchmydrift
Well-known member
Also, my inverter is not grid tied, so any extra solar produced has no where to go, if you have grid tied, then presumably it sould be being sent to the grid resulting in no drop in production. Unless of course, some of your inverter settings are not setup correctly, which may well be the case, especially with diy lifepo4 battery storage, as there are many many setting to get right.
I think you're right about battery capacity! I'm checking the production graphs and as the battery got full the pv production dropped to close to the house usage as I've set export to grid to 0kw. I've now changed the export limit on the inverter and hopefully the production continues when the battery is fully charged. But still don't understand why the panels were only producing around 1.5kw max (while charging low battery SOC) with great weather, its only produced peak 3.3kw for 5mins twice in the last few days. With clear sky, 0 obstructions and full sun I expected the panels to produce close to peak minus the temp deficiencies etc.
Ucatchmydrift
Well-known member
Yes id expect them to produce a bit more than 1.5kw from about 11am to 2pm roughly, being new panels? - and south facing. Maybe they suffer from heat issues more than my jinko panels? - mine are second hand from a german solar farm and probably 10 years old also. They do seem to produce a few hundred watts less after summer solstice compared to pre summer solstice for some reason. (maybe as mine are east and west facing?) And also they will peak higher in certain cloudy conditions, up to just over 3kw, where as in full sun they peak at about 2.2 - 2.5kw around may-june.
Also, check your charge voltage (boost and float) you may want to increase the boost voltage, that may limit peak output if too low? And also if your inverter goes into float too soon, that could bring the charge voltage down (so check the float voltage also) too quickly. - im not sure how that would interact with a grid tie inverter as i dont have one..
But when building my setup, when i got dissapointed, it was usually due to me having a wrong setting somewhere on the inverter. I found the only way to sort any problems is to learn and truly understand what every setting does and how it interacts with other settings, which can be a big headache at times.. Not easy this diy solar and lifepo4 storage stuff as i found out myself!..
You will rarely see peak outputs in any weather. Despite what may look like clear skies, there's usually moisture in the air, dust, and a little bit of dirt on the panels. You get the best outputs during the spring and autumn, just after rain. Rain clears the air and washes the panels clean, plus the panels will be cooler. Chances are you also have greasy finger prints on the panels from installing them. All these little things knock back performance.
Ucatchmydrift
Well-known member
I think the typical output is only about 60%-70% of the quoted panel output. So a 100w panel would only produce around 60-70w in normal sunny conditions in the summer. Bit dissapointing when i found this out also, but 1.5kw from 3kw of panels does sound a bit low tbh. Im often wrong though lol.
bladerunnerpv
Well-known member
dipesh:-
Hi, what's the panel specs and the inverter specs pls?
Where is the inverter, could that be overheating?
Hi, what's the panel specs and the inverter specs pls?
Where is the inverter, could that be overheating?
it's not that bad!
California test panels using a different method that is suppossed to rate panels in a more 'real world' way. Their test results are always interesting, I used to look up panels on this listing to see which are the best, ie those that come closest to STC numbers.
https://solarequipment.energy.ca.gov/Home/PVModuleList
Ucatchmydrift
Well-known member
What i said was based on memory!
- but also, to be fair, i think it was based on my particular setup now thinking about it, which is east and west facing. Which supposedly gives you about 20% less output than a south facing array. And in my case i get about 2kw peak output on a sunny day at the moment from 2880w of panels, which is around 68% roughly. Wondering what the total production on a sunny day is for dipesh?, as im at about 15kw/h on a sunny day atm, so he shoud be 20% or so more than that...(also not taking into account any shading, which i have a bit first thing in the morning, and your panels are new and probably more efficient than mine)
Last edited:
Panels: Canadian Solar HiKu6 MONO 550W x6 (8 more panels to install)
Inverter + battery: Fox Ess H1 6kw + 5kw battery
Inverter is in an outbuilding with ambient temps, inverter and battery are within operating range so that's not the issue. Today its been rainy with thunderstorms in London so I haven't really produced much but I think @Ucatchmydrift is right the inverter clips the production as there isn't any export to the grid and batteries are full however I'm still concerned about the inconsistent production and will need to monitor over a longer period with good weather. Sometimes I'm producing only 400w 8am and another day with same weather I'm producing 1.2kw. It's my first experience with solar panels so not too sure what is normal and how sensitive the panels can be.
it's only been 4 days I've installed and I've produced 10kw on a sunny day and the panels have no shading. With today's poor weather I've done 6.9kw; I guess I won't be able to tell the total daily production until I start exporting to the grid so the inverter doesn't clip the production.What i said was based on memory!
(also not taking into account any shading, which i have a bit first thing in the morning, and your panels are new and probably more efficient than mine)
bladerunnerpv
Well-known member
this panel ?
https://bimblesolar.com/docs/Canadian-Solar-HiKu6_CS6W-MS-EN_525-550w.pdf
for STC,
- Isc 14A,
- Voc 49.6V
- Imp 13.2A,
+0.05% temperature coeffcient Isc"
This inverter ?
https://www.tradesparky.com/solarsparky/battery-storage/fox-ess/hybrid/fox-h1-60-hybrid-inverter-6kw
- max input current of 13.5 A,
- max short circuit current 15A,
- rated input voltage 360V
- max input voltage 600V
I'd like to understand this overheating phenomenon better,
Does temperature coefficient apply to Imp ?
If so a panel temp of about 70deg would make Imp reach 13.5A, the max input current of the inverter.
Is that how it then starts to affects things ?
https://bimblesolar.com/docs/Canadian-Solar-HiKu6_CS6W-MS-EN_525-550w.pdf
for STC,
- Isc 14A,
- Voc 49.6V
- Imp 13.2A,
+0.05% temperature coeffcient Isc"
This inverter ?
https://www.tradesparky.com/solarsparky/battery-storage/fox-ess/hybrid/fox-h1-60-hybrid-inverter-6kw
- max input current of 13.5 A,
- max short circuit current 15A,
- rated input voltage 360V
- max input voltage 600V
I'd like to understand this overheating phenomenon better,
Does temperature coefficient apply to Imp ?
If so a panel temp of about 70deg would make Imp reach 13.5A, the max input current of the inverter.
Is that how it then starts to affects things ?
