Inexpensive 100W flexible solar panel install, part 1

[autumnbreeze27]

I bought these panels right before we sold the house. I wish I would have waited, because they're $199/ea now with a white plastic back versus these shiny aluminum backed panels.

Lensun Panels - 100W Flexible Panels cost me $247.50/ea for 4
Description:
Highly efficient monocrystalline cells
Laminated for weather resistance
laminated with oxide aluminum + EVA + Silicon cell + EVA + Tedlar
Size: 1240,570,2.5mm
peak(Wp): 100w
Open circuit voltage(Voc): 21V
Optimum power voltage(VMP):18V
Short circuit current(Isc): 6.11
Max operating current(IMP): 5.56
torrence:+_5%
weight: 4kgs
one year manufacturer warranty

Morningstar TS-MPPT-60 is connected via 12# wire (I wasted $130 on fancy solar wiring that was never delivered, but that's in the other thread)

I set my solar panels on the new hard bimini and wired up half of them in series. I put a terminal under the bimini to connect everything, so I can switch it to parallel if needed.

I've got the shore power battery charger turned off, so the 12v is running off the batteries/solar.

Yesterday I checked the output in the late afternoon:
Array Voltage 33.41V, current 2.9A, Sweep Vmp 33.41V Sweet Voc 41.53V Sweep Pmax 98W

Yesterday data log shows:
Max array voltage 41.64V, Amp hours 29, Watt Hours 380

The boat is facing south, the 2 connected panels are on the starboard side. They are shaded in the AM by the boom and sail (stack pack is being repaired), mast, signal halyards, stays, etc.

I'm going to setup a camera and do a time lapse to see how the output compares to the shading, and then switch the wiring to parallel and see what the difference is.

[chuckg5]

very interesting. please keep us informed!

[travellerw]

Thats the nicest wire stripper warmer I have ever seen...

[JK n Smitty]

If you have them in series and you have partial shading on one or two you are affecting your total output significantly. I would rewire them in parallel.

Also, what kind of house load did you have going and how charged were the batteries when you started the test?

On face value you got 29 amps from 4 panels that should have produced closer to 100 amps. So this test doesn't make me want to dive into these panels.

Did you do any testing of the panels before you mounted them? MaineSail has recommended making an easel and testing each panel separately to make sure they are putting out consistent power. One of the big issues noted with the solbian-knockoffs is the consistency of construction.

I am going through this evaluation and just trying to get some real world data on these panels.

Thanks,

Jesse

[NahanniV]

I would really appreciate seeing some more pictures of your Bimini as I am in the process of designing one for our boat.

Cheers,
JM.

[4arch]

Originally Posted by JK n Smitty

On face value you got 29 amps from 4 panels that should have produced closer to 100 amps. So this test doesn't make me want to dive into these panels.

The OP mentioned having only 2 panels connected but even so I would have expected double that 29 amp output and with all four panels easily over 100 amps. I agree wiring them in parallel might improve the situation.

[PleiadesC36]

With partial shading, the BEST way to get the MOST out of your four modules is to have a smaller MPPT controller on each module.

The ultimate way to do MPPT charging is on each solar module. That's why so many grid tie solar systems are going to micro inverters or DC optimizers on each module.

The next best way is to parallel two on either side of the boom and have a controller for each pair.

If you have to keep the TS60, then run the 4 modules in parallel and get whatever you get.

Regarding the current you should get: At peak sun, assuming no shading, IF you were to get about 90% out of your array, you should see about 360W X .96( controller efficiency/wire losses) = 345 watts, now take that 345 watts and divide it by your average battery voltage during charge which lets say is 13.3 (we know it will go up to 14+ volts at the end of charge), which will be about 26 amps. As your battery voltage rises your current out of the controller will drop. (P=IE). You will see the most current when the battery voltage is low.

These guys that were talking about 100 amps must have been thinking about amphours???

I hope this helps...

Mike

[d design]

what about the efficiency of the battery?

[PleiadesC36]

In the above thread I think we were just talking about getting the most current out of the solar modules.

Battery efficiency is typically considered more when you are designing a solar system that has a known load that you are trying to supply with a PV array.
It is always a factor in the amount of energy you can get out of a battery, and typically changes with the age of the battery and type of battery, temperature, and charge and discharge rates.

If your load is 100 amphours per day, then for example, you might design a solar array that could produce 110 amphours, given the many design factors such as insolation data, tilt angle, soiling, temps, etc that you would use in your design.

Even though the sun may be up 10-14 hours a day, the equivalent "peak sun hours" from the whole day, depending on location, tilt angle, and season, could be anywhere from 2-7 hours.

Cheers,
Mike

[autumnbreeze27]

I brought a 3rd panel online yesterday, and re-wired everything for parallel.

I haven't been able to find the last solar panel connector, so I may have to replace it or rewire it so I can connect the last panel.

At 9am, if looking at the panels from port to starboard, #1 is in full sun, #2 is disconnected, #3 is 75% shaded, #4 is 100% shaded

I charged the batteries last night to 100%, then shut it off this morning about 8am.

Current stats from my MPPT: (9am)
Array voltage = 17.35V
Array Current = 0.5A
Sweep Vmp = 17.35V
Sweep Pmax = 10W

It says it's putting 0.9A into the battery.

I bought all this stuff too long ago to return, I thought I'd have a hard time dealing with shipping once we moved aboard.

[Target9000]

If the batteries are full then the controller should be scaling back the current output to the batteries. Drain your batteries down a bit then take a measurement.

[Stu Jackson]

Originally Posted by Target9000

If the batteries are full then the controller should be scaling back the current output to the batteries. Drain your batteries down a bit then take a measurement.

+1,000

Battery acceptance will diminish your input from the solar panels.

[donradcliffe]

You can't determine your solar capacity unless your batteries are discharged enough to accept it. If you need more out of your solar, swing your boom out so it doesn't shade the panels.

[Maine Sail]

Originally Posted by autumnbreeze27

I

I charged the batteries last night to 100%, then shut it off this morning about 8am.

Current stats from my MPPT: (9am)
Array voltage = 17.35V
Array Current = 0.5A
Sweep Vmp = 17.35V
Sweep Pmax = 10W

It says it's putting 0.9A into the battery.

I bought all this stuff too long ago to return, I thought I'd have a hard time dealing with shipping once we moved aboard.

You can only stuff so many clowns into a VW Bug...... The batteries are FULL and this is what the system is telling you.

If you want to see the performance of the system whack the batteries with a large inverter load that exceeds what the panels can put out...

[Schrewsburyduo]

The picture looks great but i can't help thinking how are you going to sail with that sheet being prevented from being tight by the solar panel? I am dealing with the same issue and because I have end boom sheeting it means I can't have a bimini. I am curious if you are going to be re-doing the main sheet, or is there something else I am missing? As it looks right now in your picture, it's one gybe away from the bimini ending up in the drink.

The bimini looks great and I always thought why don't people do that -- use the solar panels as shading for the bimini itself... It looks so cool.