Aiko comet panels.

[NoraBatty]

These seem to be the smallest, high powered panels on the market, from what i can see.
Feel free to tell me otherwise or point me to something different.
Max size 2323mm x1134.
Akios do 615 and 625W panels

The blurb states
Cell-level partial shade optimisation.
Doea anyone know what exactly this means.
Does the panel effectively work as its own optimiser?

These will be for my gable end wall. I have spent the day measuring, re measuring, and figuring out what i can put on the wall, to maximise output.

I can fit 5 of these on the wall, and still have the wall look quite nice.
2 vertically either side of the window, 1 vertically to the left of the door and 2 horizontal to the right of the door.
The lower panels will be lower than i ideally wanted, but i think i can just about get away with the low winter sun skipping above the fenceline.
I may need optimisers on these 3 panels though, hence asking if they are built in.

Thanks.

[nowty]

They do not have built in optimisers.

The "cell-level partial shade optimisation" is what practically all new panels are now built like. They are made up of double the amount of half sized cells. In other words they act as two panels in parallel in a single panel. So if in portrait format, if the bottom half is shaded the top half still works so you only lose half the current, but that is still going to bring the power of the whole string down by 50%.

This explains it better than me,
https://www.novergysolar.com/twin-cell- ... echnology/

[Snuggy]

Shouldnt the by pass diodes and the half cell feature help? I am looking at the 625,s abc n types and was told it would be ok with minimal shading????
However NB (that is good init) I wasnt asking about an upright wall.

[NoraBatty]

Ah fooled by marketing again!
Thanks for the explanation Nowty.
Ive not seen that term on panels for sale before, but am well aware of their application.
Optimisers it is then.

[NoraBatty]

Shouldnt the by pass diodes and the half cell feature help? I am looking at the 625,s abc n types and was told it would be ok with minimal shading????
However NB (that is good init) I wasnt asking about an upright wall.

Yes it will help, but it will be a bit more than minimal shading for me at certain times/seasons. After 7pm in summer i can expect almost the entire bottom left panel to be in heavy shade from the gate and fence, and some of the other bottom ones too.
In winter the sun will not get round that far before setting but the fence line then comes into play.
Without optimisers on the string, whatever the panel is reduced to, will affect the output of any panel that is wired after it, in the same fashion.

So if you lost 20% of the first panel, you would lose 20% of every panel in the string despite them being in full sun.

[nowty]

By-pass diodes for shading only work if your inverter does a global peak algorithm. That is the inverter does a scan through a wide voltage range now and again. With some inverters like SMA you can turn it on or off and set the scanning interval as turning it on if you don't have any shading loses a bit of generation whilst its scanning.

Or they help if you have a segment of a panel that has actually failed and gone open circuit.

[Sim_C]

Have you considered the match between the overall panel string voltage and current against the capabilities of the inverter?
The inverter startup voltage needs to be achieved as early as possible in the day even with shading of some of the panels.

My gable wall panels perform well in direct sunlight, but much less well in light cloud conditions. I think because they have limited line of sight of the horizon due to next doors house even with it being about 1m lower than mine.
So far 3 complete months have given 100-108 kWh/month, compared with the PVGIS forecast of around 150 kWh/month, though the weather has been pretty grim this year. My panels only weigh 20 kg each, and they were difficult to hoist up in to position even with a block and tackle setup, so your proposed 32 kg panels will need some sort of lifting system.

Smaller panels such as the Trina Vertex S+ 450W may actually peform better as the bottom row would be higher up the wall so more likely to keep each 1/2 panel unshaded.

Another option to consider would be 1 row acting as a canopy over the door but covering the full width of the house. Cannot tell from the photo how wide the walkway between the wooden fence and the house is to know what sort of slope of panels could be achieved, though some form of guttering would be required to capture the run off when raining. Of course the slope and number of panels would need to be assessed with PVGIS or similar to rate the relative performance over a year.

[NoraBatty]

Hi, thanks for the comments.
The gable faces between SSW and SW
What isnt clear from that photo is the corner plot, with road and parking area beyond, in front of my house.



As the sun swings round, the panels will all be in full sun, before the fence comes into play.
I dont envisage the fence becoming an issue, but i can always cut the wavy top off if it is.

Ive spent all day mocking up what configuration with all sorts of panels would be.
Yes they are lower than i would have liked but should be fine for the majority of the day.
If i stepped down a panel size from 2323 high to 1722 high i would still only be able to fit 5 panels on, but granted these would be a little higher up.
The thought is not lost on me, but I would still have evening sun shining from the gate on the left hand side, over the panel in summer after 7pm. In winter the sun doesnt get anywhere near there before setting.

If i went even smaller still, to 340W i could fit even more on, but to the detriment of asthetics.

If i go with a victron multiplus 5kw, as i think i will, start up voltage is about 180-190v
I assume this is fine given 5x625w panels with a voc of 51-52V

That depends, on if an installer can fit the inverter within my timeframe and what the DNO say.
If not, these panels will be DC connected to the batteries and the roof solar will be on the new hybrid mppts.

Im not worried about mounting or the weights. I have a scaffold tower to safely work from and a winch, with pulleys and more than enough rope. rigging was part of my former job, so i should be fine.

I also dis enquire with planning about any kind of canopy over the door. Its about 1.3m from wall to boundary fence. They said even for a canopy across the door I would have to have planning.
I can have projections on the wall out to 200mm, and be safe, but no canopy without hassle. Otherwise i would have put in for planning and had a full width of the house canopy/covered walkway.

[NoraBatty]

Just found these in the phone.
Taken in november and janurary of 2022 when we moved in, between 11am and 1pm.
Looks like the fence wont be an issue.

[Mart]

These will be for my gable end wall. I have spent the day measuring, re measuring, and figuring out what i can put on the wall, to maximise output.

I can fit 5 of these on the wall, and still have the wall look quite nice.
2 vertically either side of the window, 1 vertically to the left of the door and 2 horizontal to the right of the door.

Hiya. hesitated to ask this, since you stressed the re measuring, but just wondering if there's any chance the two panels to the right of the door can go vertical, just in case the aesthetics of the panels will be improved?

Looks to me as if two by one panels are almost square after allowing for a 20mm panel gap, so Max size 2323mm x1134 gives approx 2323mm by 2288mm for two panels.

Probably not a big issue, but just thinking out loud as some panels can look a bit different when the sun is shining on them and the cells are more evident.

Also, leads to me a second thought where all vertical panels would help - can you install them with a tiny tilt? I think the PP rules are excempt so long as the panels don't protrude more than 100mm (but I may have this wrong). So if the top rails are mounted as close as possible, but the bottom rails are built out, or doubled up (is that a thing?) then the panel top face could be ~50mm (or less) off the walls, whilst the bottoms are ~100mm. Not sure if that makes a huge difference to generation, perhaps +10kWh/kWp per degree, but every little helps.