diy solar

diy solar

10,000 watts of solar

P

pcfriend

New Member
Joined
Jun 26, 2022
Messages
28
I have 10,000 watts of solar panels roughly, all panels are in 3 strings. In sunny Arizona.

String 1 = (11) 360W Longi 3,960 watts

String 2 = (8) 370W Bi-facial Aptos which are brand new 2,960 watts

String 3 = (8) 370W Bi-facial Aptos which are brand new 2,960 watts

My problem is the strings hover around 6,300 watts peak from 12 noon - 1pm which is the peak production time of the day.
Why only am I getting 50% to 60% output.

I purchased 1 EG4 6000xp and later purchased another.

Fact #1 With the 1 inverter I was getting almost 100% out of the array at peak time 6000 watts out of 6600 rated watts. (2 months ago)

Then added the second inverter which gave me problems because in parallel they would not produce over 6000 watts. EG4 solved the issue because it was something on the back end with the paralleling of the inverters.

After the parallel setup I noticed that I started to receive at peak performance no more than 5000 watts, but I just thought that the production is what it was.

Now I ordered the Aptos Bi-facial reconfigured my strings and removed some older panels.

With roughly 10,000 watts of solar and and production of around 6300 watts during peak time buying 16 bi-facial panels is not producing any benefit. So in the back of my mind there is still a problem with inverter configuration. I turned off the PV disconnect on the slave inverter and the main inverter jumped to 7700 watts of generated power but it only stayed at that wattage for about 15 seconds then dropped to about 4800 watts.

Has anyone experienced this behavior?
 
So you have two strings on the master and one string on the slave?

Is the battery low enough in SOC to accept the full output?
 
Brucey said:
So you have two strings on the master and one string on the slave?

Is the battery low enough in SOC to accept the full output?
Click to expand...
Yes 2 strings on master and 1 on the slave, my batteries is at 68% SOC and I tested the load with my EV charging to see if PV would increase.
 
Easy enough to test the MPPT's Pull the strings one at a time during peak. My guess is you don't have anywhere to send the power. I'm htting just under 14K with about 17500.
 
The 10,000 watt rating is at 77 degrees cell temperature. The output at high temperatures can be as much as 25% less.
 
ksmithaz1 said:
Easy enough to test the MPPT's Pull the strings one at a time during peak. My guess is you don't have anywhere to send the power. I'm htting just under 14K with about 17500.
Click to expand...
Well I starting charging my EV to increase the load which I dropped the amperage on the charge to 16Amps, I can charge at 48 Amps but I'm sure that would the system into overload. I turned off the PV on the slave inverter and the main inverter jumped to 7700 watts for about 15 seconds which I thought was weird, however I got excited for 15 seconds.
 
ksmithaz1 said:
Easy enough to test the MPPT's Pull the strings one at a time during peak. My guess is you don't have anywhere to send the power. I'm htting just under 14K with about 17500.
Click to expand...
I plugged my EV in to increase the load, the PV load sensing didn't change it just pulled from the energy that was already being generated.
 
ksmithaz1 said:
Easy enough to test the MPPT's Pull the strings one at a time during peak. My guess is you don't have anywhere to send the power. I'm htting just under 14K with about 17500.
Click to expand...
Are you suggestion to pull one string at a time under load? If so that's dangerous, I connected panels in the daylight and as soon as I made the connection it just sizzled and the mc4 connector was burned to a crisp and went to solar heaven. So I would never play around with it under load I make any changes to my panels at night time.
 
Once my 4 x 100 watt HQST panels actually output 400 watts. Was a Texas cold morning in the mid-40F, full sun and a decent breeze to chill my golf cart panels. In the usual 95F Texas heat I never saw more than 300-320 watts.

Not surprised by your output at 107F. Sprinkle with a hose and observe the output.
 
pcfriend said:
Are you suggestion to pull one string at a time under load? If so that's dangerous, I connected panels in the daylight and as soon as I made the connection it just sizzled and the mc4 connector was burned to a crisp and went to solar heaven. So I would never play around with it under load I make any changes to my panels at night time.
Click to expand...

Really people?
Perhaps you should re-think the DIY aspect of messing with electricity in general if we are not smart enough to work with it without blowing sh*t up. For example:

Step 1) Turn off the inverters / place it in standby / shut the breakers off ... (doh!)
Step 2) Turn PV disconnect switch (on the inverter or elsewhere if you were smart enough to put one in, see also RSD).
Step 3) Remove one string cap the wire temporarily (You can pull just one of the two)
Step 4) Turn PV disconnect on
Step 5) Turn on the inverters
Step 6) Check PV input values

Lather rinse repeat rotating the string pairs, three possibilities.
compare the input from each set of two over 5 minute intervals. with similar sunshine. Compare this to when all three are connected. If the input from each of the two sets are as expected but lower with three it is likely the inverter thinks it has no where to put the power. If the power is lower with a particular string attached, repeat the above but shuffle the problem string to the other inverter or other MPPT input.

I have a breakered disconnect for each string independent of the inverter. If you happen to have an EVSE or a clothes dryrer, toaster oven, or other high draw devices with a plug, I would suggest turning them off before unplugging them or you might get a spark and some noise.

Mercy Me.
 
NIFE said:
The 10,000 watt rating is at 77 degrees cell temperature. The output at high temperatures can be as much as 25% less.
Click to expand...
Perhaps, but this not my experience The most likely scenario is there is no place to put the power... Blue is PV show us the battery charge and load
1717682542677.png
 
ksmithaz1 said:
Really people?
Perhaps you should re-think the DIY aspect of messing with electricity in general if we are not smart enough to work with it without blowing sh*t up. For example:

Step 1) Turn off the inverters / place it in standby / shut the breakers off ... (doh!)
Step 2) Turn PV disconnect switch (on the inverter or elsewhere if you were smart enough to put one in, see also RSD).
Step 3) Remove one string cap the wire temporarily (You can pull just one of the two)
Step 4) Turn PV disconnect on
Step 5) Turn on the inverters
Step 6) Check PV input values

Lather rinse repeat rotating the string pairs, three possibilities.
compare the input from each set of two over 5 minute intervals. with similar sunshine. Compare this to when all three are connected. If the input from each of the two sets are as expected but lower with three it is likely the inverter thinks it has no where to put the power. If the power is lower with a particular string attached, repeat the above but shuffle the problem string to the other inverter or other MPPT input.

I have a breakered disconnect for each string independent of the inverter. If you happen to have an EVSE or a clothes dryrer, toaster oven, or other high draw devices with a plug, I would suggest turning them off before unplugging them or you might get a spark and some noise.

Mercy Me.
Click to expand...

Sounds like troubleshooting 101 to me. You start by elimination of what you suspect isn’t the problem first
 
1717683413575.png
A/B PV3 strings (blue) are old CS/250 panels. PV1/2 strings (4) are 3640W ea (8 x 455w x 4) mounted flat on a 2/12 pitch mostly south slightly east facing roof , probably with a good bid of dust and bird poop. Currently peaking about 75-79% of rated. (2800-2900/3640). Batteries full around 1330, plugged in the EV at 1630, PV ramps back up. Make sure your batteries can take / are set to allow a higher charge rate. PV production falls off if you have no place to put the power.

On the two blue CS250 strings, I did have a bad panel that was causing strange production drop-offs It took a while to isolate the bad panel. Probably the connectors, but it's currently not in a string. The two strings are laying around sort of west facing some just propped on block. Just take your time, you'll figure it out. Quick check would simply add load (space heater or something) to see if it boosts solar production during the time you feel it's too low.
 
v_green57 said:
The temperature that NIFE referred to is the CELL temperature, not the 107 AMBIENT. Cell temps. in Arizona regularly run 150 deg. F +.
Click to expand...
Should bring a temp gun out for shots and goggles. Should hit a buck-ten+ today (112 or something). I can also say I've never seen a string hit 100% for any length of time. Cloud edge effect has popped it over briefly here and there. Looking across both inverters, my best sustained hour was this spring on one of the PV2 strings.

myhouse=> select max(i18_pv2_power) from i18_hour_view;
max
--------
3191.9
(1 row)

That is 87%, but I've never seen over 90% (6000/6600). I think the sunshine /temp is actually optimal here in the spring. OTOH 60% seems very low.

myhouse=> select i18_hour,i18_pv1_power,i18_pv2_power,i18_pv3_power from i18_hour_view where i18_pv2_power = 3191.9;
i18_hour | i18_pv1_power | i18_pv2_power | i18_pv3_power
------------------------+---------------+---------------+---------------
2024-04-06 12:00:00-07 | 3185.2 | 3191.9 | 1391.9
(1 row)

April 6 high noon. About 12% lower production at present. Might get a point or two back if I cleaned the panels. As good as it gets for me was April, I have almost a year of data.

1717686926661.png
 
I used my FLIR to obtain mine. Still have the shots somewhere...

LIttle hard to do when panels are on the roof at 51 degrees and 20 of that is the roof itself (have to lay on your back in the middle of the day in summer), but temps. I saw were definitely in the realm of "Yowza!".

To get an accurate read, you have to place a piece of black tape on the back (or front) so that you'll have a .95 emissivity target. Need to take it off ASAP or the adhesive melts and makes a helluva a mess.
 
ksmithaz1 said:
Should bring a temp gun out for shots and goggles. Should hit a buck-ten+ today (112 or something). I can also say I've never seen a string hit 100% for any length of time. Cloud edge effect has popped it over briefly here and there. Looking across both inverters, my best sustained hour was this spring on one of the PV2 strings.

myhouse=> select max(i18_pv2_power) from i18_hour_view;
max
--------
3191.9
(1 row)

That is 87%, but I've never seen over 90% (6000/6600). I think the sunshine /temp is actually optimal here in the spring. OTOH 60% seems very low.

myhouse=> select i18_hour,i18_pv1_power,i18_pv2_power,i18_pv3_power from i18_hour_view where i18_pv2_power = 3191.9;
i18_hour | i18_pv1_power | i18_pv2_power | i18_pv3_power
------------------------+---------------+---------------+---------------
2024-04-06 12:00:00-07 | 3185.2 | 3191.9 | 1391.9
(1 row)

April 6 high noon. About 12% lower production at present. Might get a point or two back if I cleaned the panels. As good as it gets for me was April, I have almost a year of data.

View attachment 220122
Click to expand...
That string was hitting about 90% which I still have the panels, those panels are used 260 Rec panels along with Longi panels. Replaced the Rec panels with 16 370 bi-facial panels (Aptos) for 1300 watts increase in production and 60% output. However EG4 is going to take a look at the inverters.
 
ksmithaz1 said:
Should bring a temp gun out for shots and goggles. Should hit a buck-ten+ today (112 or something). I can also say I've never seen a string hit 100% for any length of time. Cloud edge effect has popped it over briefly here and there. Looking across both inverters, my best sustained hour was this spring on one of the PV2 strings.

myhouse=> select max(i18_pv2_power) from i18_hour_view;
max
--------
3191.9
(1 row)

That is 87%, but I've never seen over 90% (6000/6600). I think the sunshine /temp is actually optimal here in the spring. OTOH 60% seems very low.

myhouse=> select i18_hour,i18_pv1_power,i18_pv2_power,i18_pv3_power from i18_hour_view where i18_pv2_power = 3191.9;
i18_hour | i18_pv1_power | i18_pv2_power | i18_pv3_power
------------------------+---------------+---------------+---------------
2024-04-06 12:00:00-07 | 3185.2 | 3191.9 | 1391.9
(1 row)

April 6 high noon. About 12% lower production at present. Might get a point or two back if I cleaned the panels. As good as it gets for me was April, I have almost a year of data.

View attachment 220122
Click to expand...
That string was hitting about 90% with a single EG4 6000xp, so that made purchase another EG4 6000xp and that's when the issues began.
 
It's 10:37am and I'm getting 60 Percent output 6053 watts. Yesterday reached 6300 watts and would not go above that.
 

Attachments

  • Screenshot (25).png
    Screenshot (25).png
    727.3 KB · Views: 6
You must log in or register to reply here.

Similar threads

flowrider
Moving around large solar panels
2
Replies
39
Views
1K
Hedges
Hedges
D
Still trying to figure out how to wire four solar panels into my Delta Pro and DP Extra Battery
Replies
2
Views
140
Mattb4
Mattb4
Mkgough
What panels and how many you using on your Eco-Worthy Tracker?
Replies
6
Views
252
Mkgough
Mkgough
D
Odd behavior this morning from optimized string of 9 panels
Replies
2
Views
192
dfw_dude
D
N
Less than 50 pounds solar panels near 450 watt range possible?
Replies
2
Views
349
Tulex
Tulex

diy solar

diy solar
Back
Top