Solar generation in rain/cloudy conditions

denmendez65 said:
It’s the principal. You can find panels in that price range and cost per kWh all over the place. This was an example.

To each their own though. I would never buy a second hand phone, inverter, battery etc. Cars only if there is a warranty left and single owner with full history. But like I said that’s just me.

Didn’t your guy on YT have issues with second hand panels?
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Only because he didn't test them with an mppt before purchasing. Sorry, I can't afford R25k for a phone.
 
wingnut771 said:
iphone only or gtfo :P
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I guess its true that once you go apple you cant go back lol. I'm still rocking the Iphone SE 3. 4 years old now and got the battery replaced at apple for 700 rand equivalent. Zero issues with the phone and still new updates.

I do buy new but once every 5 or 7 years. Previous phone I had for 7 years. Got too slow.
 
denmendez65 said:
Some things I just would never buy second hand. That’s just me. Is saving 350 rand to get the same equivalent to this worth it?

I do buy cheap but I get new. My Panels, Inverters and Batteries all new but cheap. I have a thing against second hand stuff like Phones, Solar stuff etc. That’s a me problem though.

View attachment 1927862
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I'm actually not buying I was just posting that the price per watt on those second hand panels are pretty good. Yes space will be the issue generally when someone considers this but price per watt is very very good.
 
cavedog said:
I'm actually not buying I was just posting that the price per watt on those second hand panels are pretty good. Yes space will be the issue generally when someone considers this but price per watt is very very good.
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From that perspective yeah, the price per kw is good as Wingnut calculated. Typically those get replaced during upgrades as the efficiency per square meter isnt that good as modern panels and hard to match panels when you want to upgrade later on. I suspect thats why they are being sold and those funny sizes (270W)
 
denmendez65 said:
I guess its true that once you go apple you cant go back lol. I'm still rocking the Iphone SE 3. 4 years old now and got the battery replaced at apple for 700 rand equivalent. Zero issues with the phone and still new updates.

I do buy new but once every 5 or 7 years. Previous phone I had for 7 years. Got too slow.
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When I still had a job, I started with iphone 4 on contract, then 5, then a 6, then became poor and kept 6 for 5 years until ios stopped updating, then bought the 11 off bobshop for R4k 3 years ago.
 
cavedog said:
I'm actually not buying I was just posting that the price per watt on those second hand panels are pretty good. Yes space will be the issue generally when someone considers this but price per watt is very very good.
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Let me piss off @wingnut771 :p .

Here is what you must do, buy this controller and 3 or 4 of those panels.

All your battery, lack of solar issues all go away. You will fully charge perfectly fine in summer, no need for more battery, panels, nothing after that.

3100 plus 1600 for 4 270W panels (just check the VOC). 3 would work fine also. Add another 2k max for extras like a small DB etc.

Screenshot 2026-08-07 143618.jpg
 
denmendez65 said:
Let me piss off @wingnut771 :p .

Here is what you must do, buy this controller and 3 or 4 of those panels.

All your battery, lack of solar issues all go away. You will fully charge perfectly fine in summer, no need for more battery, panels, nothing after that.

3100 plus 1600 for 4 270W panels (just check the VOC). 3 would work fine also. Add another 2k max for extras like a small DB etc.

View attachment 1927890
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4 panels is 1kW.
1786099762943.png
 
denmendez65 said:
Let me piss off @wingnut771 :p .

Here is what you must do, buy this controller and 3 or 4 of those panels.

All your battery, lack of solar issues all go away. You will fully charge perfectly fine in summer, no need for more battery, panels, nothing after that.

3100 plus 1600 for 4 270W panels (just check the VOC). 3 would work fine also. Add another 2k max for extras like a small DB etc.

View attachment 1927890
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but right back at ya :P

You've converted me when one compares ROI costs for this compared to HP.
 
wingnut771 said:
4 panels is 1kW.
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I have 4x340W which is only 1360W and the guys at geysertech said I only needed 3. Maybe DC is more efficient who knows but it hits 70 early. Around 3 in June (the worst I saw) and summer around 1pm.

Others use just 2 high voltage panels typically 760W in total. This is the actual recommendation they gave me but I didnt have faith in it so went with 4. It was going to work I am sure now.

What they said is voltage matters more than current/power rating.
 
I'm sorely tempted to go grab some of those panels, 18-20 (assuming they are 45-50v ish) would max out my system nicely.
Why the negativity?
I can't think of much that can break on a panel?

Or would it make more sense (the generator was this years upgrade) to go with my original plan of next year getting some larger ones and just let the inverters clip the extra amps?

It would cost a lot more than these...
 
Düber said:
I'm sorely tempted to go grab some of those panels, 18-20 (assuming they are 45-50v ish) would max out my system nicely.
Why the negativity?
I can't think of much that can break on a panel?

Or would it make more sense (the generator was this years upgrade) to go with my original plan of next year getting some larger ones and just let the inverters clip the extra amps?

It would cost a lot more than these...
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Not really negativity. Just different preferences. I doubt your will get 18 to 20. Worth enquiring but won't be surprised they might have 2 or 10 who knows.

Main issue is efficiency though, if you have the space then yeah, but these smaller panels typically suck at efficiency. My 650W are not that much bigger than the 340W I have. Where the 4x340W are fitted I could easily have put 4x650W. It's just that the application didn't require it and the 340W where 900-rand vs 1600 for the 650W. Cost per kW was better though on the 650W and the kW per m2 was also better with the 650W.

If I was upgrading, I would get 16 of these for my place. 26% efficiency. Then can have the North facing roof and south facing of the house have panels. Would have done it when the 5kW packed up and probably gotten a dual MPPT inverter. That would be an extra 11.5kWp of panels.

The current 5.2kWp made up of the 650W would sit on a second inverter. I don't think I would have any issues with generation sitting with some 17kWp of panels regardless of how much load I wind up having.

Screenshot 2026-08-08 095610.jpg
 
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denmendez65 said:
Not really negativity. Just different preferences. I doubt your will get 18 to 20. Worth enquiring but won't be surprised they might have 2 or 10 who knows.

Main issue is efficiency though, if you have the space then yeah, but these smaller panels typically suck at efficiency. My 650W are not that much bigger than the 340W I have. Where the 4x340W are fitted I could easily have put 4x650W. It's just that the application didn't require it and the 340W where 900-rand vs 1600 for the 650W. Cost per kW was better though on the 650W and the kW per m2 was also better with the 650W.

If I was upgrading, I would get 16 of these for my place. 26% efficiency. Then can have the North facing roof and south facing of the house have panels. Would have done it when the 5kW packed up and probably gotten a dual MPPT inverter. That would be an extra 11.5kWp of panels.

The current 5.2kWp made up of the 650W would sit on a second inverter. I don't think I would have any issues with generation sitting with some 17kWp of panels regardless of how much load I wind up having.

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I hear you.
One of the concerns with larger panels is getting the minimum startup voltage. The Deye wants 150v ish .
The other issue is staying within the max wattage (6500W per inverter) stated on the sideplate.
I have 3 mppt's open with about 1.5kWp capacity left each.

So the tricky part is getting the balance right unless I throw caution to the wind and let the inverters clip amp's but I've read mixed opinions on that...

(Although it's a bit of a moot point since a promised payment from a client for yesterday wasn't done, so unless it's a real bargain to use credit for I probably won't.. and I'm in two minds about it anyway.)
 
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Damn that was what I paid for the navasolar 200ah.
 
Right so in PTA it looks like a mostly utility day. Can't really complain we had a good 3 weeks or so.

1000207078.jpg
 
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