Under performing solar panel.

SauRoNZA said:
Because he’ll struggle more to get the minimums pushed through the system to get it ticking over properly wouldn’t he?

But I see now it’s all PWM and not MPPT on a small 12V setup so none of it is ideal.
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That's why he's getting 200W.
 
wingnut771 said:
That's why he's getting 200W.
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That and it's April and probably not pointing the right way!

It's not just clouds is that impact production. It's because the sun is not directly overhead. Sheesh, it's like people don't understand what Summer and Winter are!
 
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SauRoNZA said:
Wait, are you only running 1 panel?

That more than likely in itself is causing some issues.
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Not really many of these low voltage systems can't handle much more than that

ie this model has 50A controller so lets work on lowest voltage the battery will go 10v so with max 50A 500w is the most you can push through it
 
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BBSA said:
Canadian
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giphy.gif
 
So it's down to the inverter, and the solar curve. For those too lazy to follow the links at the start.

The 480W is using an MPPT at 1000W/m2 irradiance top right corner of the graph. With a PWM you'll only get the battery voltage, so it will be that times about 40A maximum.
 

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richjdavies said:
So as I understand it: that panel should be making 460W when there is the 'name plate' radiation landing - - believe this is 1000W/m2. So that depends on 2 things:
1. Weather
2. Angle of panel
(and 3 the power electronics... MPPT vs PWM and there being enough load to use it!)

Looking here https://en.tutiempo.net/solar-radiation/pretoria.html recent weather hasn't got to 1000. No wonder, it IS April!
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No quite the 460w is under standard test conditions
At 25c (ie module is at 25c)

When it is baking in the sun at higher temp
You get less out of the panels as the voltage decreases, and the inverse too hence why we have to under spec the panels to avoid max voc limit of charge controllers in record cold temps

the panel spec sheet you will see 2 test results the stc (standard test conditions)
And NMOT normal module operating temperature

Now yes in SA we get more because we have higher irradiance than the test conditions bringing us closer to STC rating

We have a cold day today so i actually got 3600w from my 3600w array and even spiked to over 4000w when some cloud rolled over allowing panels to cool more and then when sun popped out you get a higher output than Normal

Some call it cloud edge

When in fact it should be called cloud cooling imo
 
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I still have another inverter, so maybe I could return this inverter and get an MPPT controller for my 12v 100Ah lithium battery.

What controller would you guys recommend?
I only use the inverter for a 50w koi pond pump in the evenings?
 
BBSA said:
I still have another inverter, so maybe I could return this inverter and get an MPPT controller for my 12v 100Ah lithium battery.

What controller would you guys recommend?
I only use the inverter for a 50w koi pond pump in the evenings?
Click to expand...
1713113464918.png
 
BBSA said:
I still have another inverter, so maybe I could return this inverter and get an MPPT controller for my 12v 100Ah lithium battery.

What controller would you guys recommend?
I only use the inverter for a 50w koi pond pump in the evenings?
Click to expand...
If you are only using 50W in the evenings (50W x 12 hours = 600Wh) then what is the problem? You have 200W x 5 hours of sun = 1000Wh, more than what the koi pond uses.

With the MPPT controller, your battery will be charged before 10am but I guess will perform much better in cloudy weather.
 
wingnut771 said:
If you are only using 50W in the evenings (50W x 12 hours = 600Wh) then what is the problem? You have 200W x 5 hours of sun = 1000Wh, more than what the koi pond uses.

With the MPPT controller, your battery will be charged before 10am but I guess will perform much better in cloudy weather.
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The 50w is only for the pump but the inverter also use about 25w. I also only get 200w for about 2 hours.

I checked my other inverter and it only have a 5w overhead.

I think I'm going to get the controller you recommend but I'm considering spending a bit more and get the 100/20 one.
 
BBSA said:
The 50w is only for the pump but the inverter also use about 25w. I also only get 200w for about 2 hours.

I checked my other inverter and it only have a 5w overhead.

I think I'm going to get the controller you recommend but I'm concedering spending a bit more and the 100/20 one.
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I doubt it would make any difference as the bottleneck is the PV panel.
 
I see the 75/15 is limited to 220W on 12V:
1713115809688.png

and 290W on the 100/20 controller @ 12V.
1713115870624.png
 
BBSA said:
That is at 34.8v.

The controller will charge at about 14v, so the max should be 32A (460w/14v)
Click to expand...
MPPT stands for Maximum Power Point Tracking. So the MPPT controller will try max out the amps when possible.
 
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