Solar array not performing to rated power (not even half)

[chamberwil]

I have 4 175w panels ground mounted in series. This is a potential problem rating of 700w. However, I am getting an average of 275w and peak of 375w on a daily. The panels are not shaded and are at a good angle for the Caribbean sunshine. The run back to my house is about 50-60 feet with 10 gauge wire. I am stumped now because my solar array doesn’t produce no where enough power to recharge my battery bank. I am open to suggestions and tips to get this power rating as close as possible to max rating.

FYI I am using 175w Newpowa panels model NPA175S-12 and a Victron MPPT 100|50 charge controller.

 

[kendive]

I'm not expert but why do you have the panels just about laying flat? Also looks like alot of shading on them. My 1360watt array drops alot also when there is shading. I can walk in front of it and drop the watt output. LOL

I used https://pvwatts.nrel.gov/ to get the ideal tilt for my off grid array which playing with PV Watts it was 30 Deg for max production for the year. Even though I will not have them system on 24/7 matter of fact I can put the array up and take the EcoFlow home with me.

I made my array so I can tilt it just for fun and testing. A friend of mine likes to play and use the paint can trick and try to get every watt of of it when we meet up at my property.

I posted this before but here is my setup. 4 340 Watt Used panels. EcoFlow is limited to 60V and 1000watts in two seperate inputs. So these panels are two separate arrays connected in parallel. These panels are 41VOC so I can't connect in series.

The Ecoflow will be in the cabin later this is still work in progress.

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I know I need to start a separate thread on all my solar toys I play with.


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[DIYrich]

Battery voltage? How are the panels wired to the victron? Have you tested each panel? What voltage are you getting at the victron?

 

[Madcodger]

It does look like the panel is shaded. Even a tiny bit of shading would cause the problem you're noting.

 

[chamberwil]

Battery voltage? How are the panels wired to the victron? Have you tested each panel? What voltage are you getting at the victron?

The battery voltage is 24v. Panels are in series to the charge controller. I have not tested each panel. The voltage to the victron range between 48v on an overcast day to 70v.

 

[chamberwil]

It does look like the panel is shaded. Even a tiny bit of shading would cause the problem you're noting.

It will look so based on the photos but I pruned all the trees around and even when there is no shade in peak sunlight I was getting nothing above 340w and that was briefly after wetting the panels. I have attached a graph to show. On this day in particular I was outside watching the panels and absolutely no shade on the panels and the sun was directly above.

 

[chamberwil]

I'm not expert but why do you have the panels just about laying flat? Also looks like alot of shading on them. My 1360watt array drops alot also when there is shading. I can walk in front of it and drop the watt output. LOL

I used https://pvwatts.nrel.gov/ to get the ideal tilt for my off grid array which playing with PV Watts it was 30 Deg for max production for the year. Even though I will not have them system on 24/7 matter of fact I can put the array up and take the EcoFlow home with me.

I made my array so I can tilt it just for fun and testing. A friend of mine likes to play and use the paint can trick and try to get every watt of of it when we meet up at my property.

I posted this before but here is my setup. 4 340 Watt Used panels. EcoFlow is limited to 60V and 1000watts in two seperate inputs. So these panels are two separate arrays connected in parallel. These panels are 41VOC so I can't connect in series.

The Ecoflow will be in the cabin later this is still work in progress.

.

I know I need to start a separate thread on all my solar toys I play with.


.

I like your rig for your panels. The tilt of my panels is slight and almost would appear flat but due to my location in the Virgin Islands that’s my recommended position.

 

[Madcodger]

If not shaded, it looks like only 2 of your 4 panels are producing. Please share info on how you have these wired. Given your controller, I would assume all 4 in series, but given you production I'd suspect 2S2P, with one string not producing (bad connection)?. You're getting very close to full expected production of 2 panels, which is likely a good clue.

 

[chamberwil]

If not shaded, it looks like only 2 of your 4 panels are producing. Please share info on how you have these wired. Given your controller, I would assume all 4 in series, but given you production I'd suspect 2S2P, with one string not producing (bad connection)?. You're getting very close to full expected production of 2 panels, which is likely a good clue.

They are wired up in series. 4S. I once tried the 2s2p approach but it didn’t yield any real benefits. So I when back to full series connection. This maxed out my panels for 12v but I can technically double but doing a 4s2p config if I had 4 additional panels For 24v.

 

[DIYrich]

Comment on similar panel on Amazon:

not 180Watts, that is the lab theoretical test. in reality you can get 125 out of them. seem to be built decently, the connectors start chalking up almost instantly in any direct sunlight. my set of 4 have been outside for 4 weeks and the one set of connectors that get about 1 hour of sunlight a day are already chalky white. This means I'll need to replace them in a year. I had 2 panels have to be replaced as they ship them with barely any protection via UPS and two arrived broken. Amazon takes care of the returns (do NOT call the maker, deal with it through amazon if you want fast service). they are not tolerant at all to any shading, even a line shadow from a wire will take the panel offline. so make sure there is no chance at all for shadows in your mounting location. 4 of these in the sunshine state and the higest power output I have seen from them is 500 watts total, so that is 125 each. so design accordinly. This is tilted correctly at the sun. I expect even less power from them when they are flat on the roof of the camper.

https://www.amazon.com/Newpowa-Moncrystalline-Solar-Efficiency-Module/dp/B0772PD96K

 

[yodamota]

Any chance one of the setting on your charge controller is off? I can change the amount of current the charge controller outputs. having the same 100/50amp victron. Mine is set to 45amps.

 

[chamberwil]

Any chance one of the setting on your charge controller is off? I can change the amount of current the charge controller outputs. having the same 100/50amp victron. Mine is set to 45amps.

The charge controller is set to

Comment on similar panel on Amazon:

not 180Watts, that is the lab theoretical test. in reality you can get 125 out of them. seem to be built decently, the connectors start chalking up almost instantly in any direct sunlight. my set of 4 have been outside for 4 weeks and the one set of connectors that get about 1 hour of sunlight a day are already chalky white. This means I'll need to replace them in a year. I had 2 panels have to be replaced as they ship them with barely any protection via UPS and two arrived broken. Amazon takes care of the returns (do NOT call the maker, deal with it through amazon if you want fast service). they are not tolerant at all to any shading, even a line shadow from a wire will take the panel offline. so make sure there is no chance at all for shadows in your mounting location. 4 of these in the sunshine state and the higest power output I have seen from them is 500 watts total, so that is 125 each. so design accordinly. This is tilted correctly at the sun. I expect even less power from them when they are flat on the roof of the camper.

https://www.amazon.com/Newpowa-Moncrystalline-Solar-Efficiency-Module/dp/B0772PD96K

Wow, I read the review above and the update to it and the update is even worst. The guy is only getting 100W from the 180W panel. I will do a close visual inspection of my panels to make sure they are not damaged. Thx for the tip.

 

[chamberwil]

Any chance one of the setting on your charge controller is off? I can change the amount of current the charge controller outputs. having the same 100/50amp victron. Mine is set to 45amps.

I only change setting recently for my 24v update and even before it was still performing the same way.

 

[yodamota]

Setting look good. My next test would be to remove each panel and test out three panels. Or test each panel individually. Do any show differing readings?

This is what I see when the panels are plugged into midnight solars calculator. What are you seeing on the victron app? could you take a photo of the victron connect screen?

is this a new issue?

 

[chamberwil]

Setting look good. My next test would be to remove each panel and test out three panels. Or test each panel individually. Do any show differing readings?

This is what I see when the panels are plugged into midnight solars calculator. What are you seeing on the victron app? could you take a photo of the victron connect screen?

is this a new issue?

I will be trying that tomorrow in the peak sunshine to test the panels individually. this is a screenshot of my panel at 3:30pm my time, a few moments ago.

 

[Mattb4]

A possibility that your incoming wattage reading is inaccurate. If you have a DMM and DC clamp on meter you might do some checking. W=VA

You should be getting closer to 500w or more. *( If you have enough load)

 

[chamberwil]

I tested all the panels voltage individually and everything was in range. I clean and put WD40 on each connector. I also thoroughly cleaned and wash each panel spotless. Tomorrow I will see if that helped. I may also change the main MC4 connector back to the house because there was some rust on them. This can be cause to my issue. I will update you all tomorrow.

 

[Hedges]

New or used panels?

Do you have an ammeter able to measure short-circuit current of the panels?
If so, measure each one individually.
Then connect each to a 12V lead-acid battery, and measure the current. See what wattage is indicated. Voltage a bit below Vmp, but should be somewhat close.

Sometimes, Isc looks good, but Imp is reduced due to damage/degradation. 12V battery as a load could approximate Imp. Or an electric space heater of suitable wattage, maybe a couple space heaters in parallel (if you even have such things in a warm climate.)

 

[chamberwil]

New or used panels?

Do you have an ammeter able to measure short-circuit current of the panels?
If so, measure each one individually.
Then connect each to a 12V lead-acid battery, and measure the current. See what wattage is indicated. Voltage a bit below Vmp, but should be somewhat close.

Sometimes, Isc looks good, but Imp is reduced due to damage/degradation. 12V battery as a load could approximate Imp. Or an electric space heater of suitable wattage, maybe a couple space heaters in parallel (if you even have such things in a warm climate.)

I don’t have access to lead acid battery only lithium. Also just to be clear you mean connected each panel individually to the charge controller under load? Just want to be clear.

 

[Warpspeed]

The clue is in the shadows cast by the panels onto the ground.

Direct sun in a clear blue sky casts razor sharp shadows.
Haze, or dust in the air casts a softer shadow, and that is what I am seeing in post #1