Mike's (non-Sunsynk) System

furpile said:
I have 16x 460W panels, so 7.36 kWp. Although I have half facing East and half facing West due to my roof layout, so not ideal. In summer the PV power would usually peak around 6.4 kW, now it barely gets over 4kW. In terms of production, max in summer was 47 kWh in a day (but you really need to try and use all that energy), in winter about 22 kWh is the max for a day.
Click to expand...
Yeah, that layout suffers with the low angle of winter sun.
 
Mike Hoxbig said:
Depends on the season, in winter the angle of the sun is lower.

With 6.3 kW installed, it typically peaks at about 6 kW in summer and 4.7 - 4.8 kW in winter.

How much you generate per day depends on whether you have enough load to draw power continuously. The panels can't produce what isn't being asked of them. Running them flat out, in summer the most I've generated was 41 kWh and in winter this drops to around 24.

Plan to add 6 more panels in August to take it to 9.1 kWp, and after that I'm done with solar upgrades...
Click to expand...
Thanks. Wow, 95% of peak capacity in summer sounds great and would be useful if Aircons are essential load. About 75% in winter is not too bad.
 
surface said:
Thanks. Wow, 95% of peak capacity in summer sounds great and would be useful if Aircons are essential load. About 75% in winter is not too bad.
Click to expand...
I have 12 455 JA.

In summer I sometimes get over 6kw/h from like 12 to 2. That's over 100%

In winter 4.3-4.6kw/h

My daily production is slightly lower
34kw- summer
28kw - winter

On full sunny days.

However I haven't cleaned my panels in over 6 months. Doing that today.
 
BadBoyGP said:
I have 12 455 JA.

In summer I sometimes get over 6kw/h from like 12 to 2. That's over 100%
Click to expand...
How is this possible ? 12 x 455 = 5460 so you should not be getting above 5.46kw/h ? Eish - I don't know how this works now.
 
surface said:
Thanks, will read up on it.
Click to expand...
Basically, when the sun is behind a cloud, the panels cool down (panels increase power when cooler, the spec is at 25c) then when the sun appears, there is like a lens effect from the cloud and you have cooler panels causing the power generation to spike. It doesn't last long though.

This is why you need to give yourself a 10% buffer with your Vmax as those clear cold winter -1c mornings will push the PV voltage up quite a bit, so you need enough headroom so you don't exceed the MPPT controller max volts spec. You see the values on the panel spec, it tells you the watts volts per temp c.
 
Last edited:
wingnut771 said:
Basically, when the sun is behind a cloud, the panels cool down (panels increase power when cooler, the spec is at 25c) then when the sun appears, there is like a lens effect from the cloud and you have cooler panels causing the power generation to spike. It doesn't last long though.

This is why you need to give yourself a 10% buffer with your Vmax as those clear cold winter -1c mornings will push the PV voltage up quite a bit, so you need enough headroom so you don't exceed the MPPT controller max volts spec. You see the values on the panel spec, it tells you the watts volts per temp c.
Click to expand...
this is super interesting. thanks for posting!
 
Mike Hoxbig said:
So this happened on Tuesday night.

View attachment 1566986

Installer came out today to replace the breaker but will now have to look at replacing it with proper 60A ones on both the Eskom and inverter sides...
Click to expand...
Eish, ek kak in my broek.
What do you mean by proper 60A ones? How many A's are these ones or are you referring to a different brand?
 
abudabi said:
Melty Melty. Breaker fault or wiring fault?
Click to expand...
Wiring was fine. They ran a multimeter across all the inputs and outputs and double checked the correct size wires were used everywhere.

Hard to say what caused it but it definitely happened under load. Load was at 7.6 kW on Tuesday night when it tripped, and wouldn't run with the changeover switched to inverter. Had to change it to Eskom and run on grid the past 2 days.

Probably a combination of faulty/underspecced breaker.
W@P said:
Eish, ek kak in my broek.
What do you mean by proper 60A ones? How many A's are these ones or are you referring to a different brand?
Click to expand...
The Eskom input is 50A and inverter output is 40A. Which seems a bit low to me. So any load over 9-ish kW including passthrough would be pushing it. Maybe I need someone like @Speedster to test my line of thinking...
 
Mike Hoxbig said:
Wiring was fine. They ran a multimeter across all the inputs and outputs and double checked the correct size wires were used everywhere.

Hard to say what caused it but it definitely happened under load. Load was at 7.6 kW on Tuesday night when it tripped, and wouldn't run with the changeover switched to inverter. Had to change it to Eskom and run on grid the past 2 days.

Probably a combination of faulty/underspecced breaker.

The Eskom input is 50A and inverter output is 40A. Which seems a bit low to me. So any load over 9-ish kW including passthrough would be pushing it. Maybe I need someone like @Speedster to test my line of thinking...
Click to expand...

The 8kw inverter will allow for 50A pass-through so 40A output breaker is too small. Although looking at the picture it seems the wires were damaged, so you might want to check the wiring size. Alternatively it could have been a loose connection which caused the wires to overheat.
 
Interesting, so when i did my COC recently they actually changed my inverter breaker from 60A down to 40A.
The reason was to "protect my cables" when I asked.
In my mind the higher the better...

I have a 8kw.
 
Deanoblado said:
Interesting, so when i did my COC recently they actually changed my inverter breaker from 60A down to 40A.
The reason was to "protect my cables" when I asked.
In my mind the higher the better...

I have a 8kw.
Click to expand...
You want the MCB to trip before the wires overheat, hence the smaller MCB. Ideally you'd want a 50A breaker and cables to match on the 8kw output
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X