Solar output much lower than should be

[justinm001]

I just finished my install of 5040 watts of solar and since Thursday I've been boondocking at the Indy500 with zero shading but yet still not getting the results I expect. I'm facing west, maybe a bit north west.

Drivers solar 2s3p Renogy 320w vmp 33v (rng320-d) panels 1920 watts. Max voltage is 76.2V max power 1333W. 69.42%

Passenger solar 2s3p Renogy 320w vmp 33v (rng320-d) panels 1920 watts. Max voltage is 74.72V max power 1244W. 64.79%

Middle solar 5s2p Ecoworthy 100w bifacial panels 1000w. Max voltage 106V max power 896w. 89.6%

The middle panels are flat while the drivers and passengers are tilted in opposite directions. Before when I had 18x100w panels tilted I was easily able to get 1800w+ at times.

On the way here I filled up at a truck stop and was stuck there for about 2 hours at the pump (starter wire issue) The front 2/3 was covered under the roof and i was getting 400-500w from drivers, 200w from middle but 0 from passenger. I'm wondering if I have a string on both the passenger and drivers disconnected which explains why I'm only getting 2/3 max wattage. Unfortunately the combiner boxes are under the panels and everything's secured down. I also can't find a clamp meter anyways to check.

Any tips on how else I could find if a sting is dead or issues? Its definitely possible I damaged a couple panels when drilling holes to put bolts in, A few times I touched the glass with the drill

 

[Aussieguy]

what controllers and voltages are you using?
signature says you have 12 and 48 volt systems
what panels to to what controllers

 

[HarryN]

I envy you being at the Indy 500 - but have fun.

One possible approach is if you can isolate off each array and check the panel array voltage each at a time.

Another possible approach is to put a blanket over each array, one at a time and see what happens.

Depending on the array design, it "might" be possible to just cover 1 or 2 panels in the parallel strings to get a feel for what is going on.

 

[justinm001]

what controllers and voltages are you using?
signature says you have 12 and 48 volt systems
what panels to to what controllers

48 volt system
drivers/pass are 150/100 Victron MPPT vecan
Middle is 150/35 Victron MPPT

12 volt system
front renogy 2x100w panels in series. 100/30 Victron MPPT max voltage 46.32 max power 209watts. (these are on front)

 

[HarryN]

I am assuming that you have some method of cutting off the solar power coming into each controller ?

Perhaps try isolate off each one ?

If you have access to a volt meter, then it might be possible to measure the solar panel voltage coming into the controllers by just measuring the screw terminal.

Keep in mind that chargers have some cross talk - having 3 controllers in parallel - can easily interfere with each other in terms of total output.

Just throwing out some ideas to play with.

 

[HarryN]

Looking at the photo, the shadows are very soft vs hard edged.

This is an indication of slight overcast vs perfectly clear skies.

 

[justinm001]

I am assuming that you have some method of cutting off the solar power coming into each controller ?

Perhaps try isolate off each one ?

If you have access to a volt meter, then it might be possible to measure the solar panel voltage coming into the controllers by just measuring the screw terminal.

Keep in mind that chargers have some cross talk - having 3 controllers in parallel - can easily interfere with each other in terms of total output.

Just throwing out some ideas to play with.

They're all going into ecoworthy combiner boxes with fuses and these are in the roof under the panels I really should have checked this but RV stays under trees so just assumed poor wattage was from this

 

[justinm001]

Looking at the photo, the shadows are very soft vs hard edged.

This is an indication of slight overcast vs perfectly clear skies.

I'm on day 3 here and have had clear, overcast and yesterday storms. Its possible the panels are dirty as they were left outside for like a year.

Ecoworthy middle ones hit 963w which is great. I figured the bifacials wouldn't be great, especially since almost touching 6 ACs.

Have been using genny to keep charge and keep cool so everything's been in bulk the whole time

 

[HarryN]

They're all going into ecoworthy combiner boxes with fuses and these are in the roof under the panels I really should have checked this but RV stays under trees so just assumed poor wattage was from this

Well - learning experiences hits us all - especially when on vacation.

I am still thinking that it should be possible to do at least some partial isolation of the arrays.

For instance, the drivers side is 2S3P - feeding a combiner box, then down to the Victron solar controller.

If you can put a blanket over just one of those panels, then it should dramatically cut off that 2S string.

Repeat for each of the other 3P strings.

You should see a fairly significant "change" in the output of the total solar power.

You will need to turn off the generator to do the measurements.

 

[0truck0]

How are you measuring?
I assume you know that if batteries are full or near full then the controller will not be puting out max output? It only puts out max during the Bulk charging phase, not Float charging.
Are you measuring the panels or the controller(s) output?

Yes, shade any very small part of a panel and the output goes closer to zero than 100.
Dirt from one year? Yes, probably this will be an issue. Of course clean it.

 

[justinm001]

How are you measuring?
I assume you know that if batteries are full or near full then the controller will not be puting out max output? It only puts out max during the Bulk charging phase, not Float charging.
Are you measuring the panels or the controller(s) output?

Yes, shade any very small part of a panel and the output goes closer to zero than 100.
Dirt from one year? Yes, probably this will be an issue. Of course clean it.

From the mppts and they're in bulk entire time. I cleaned them just not super well.

 

[Bluedog225]

Check your mppt settings?