Solar Panel chat

[Bossrox]

What's your system using?

Want to show off your array? Embed a youtube for us to see.

My new system will consist of 6 - 320 watt 40 volt slightly used Jinko polycrystalline panels @ about 40"x76" each, I got for $200 a piece which aren't yet wired into the system as I'm still gathering stuff to put it together.

Update: Just got them put up today & here they are & as you see, covers about a 20 ft x 6 1/2 ft area. Got them wired later into the controller & batteries on a day it rained all day with no sun & to my surprise the panels were kicking out enough juice to charge my batteries.

Update 2: Plunked out some more green for another 6 panels for an output of almost 4kw to be added later.

They're producing power from sun up to sundown & even cloudy with rain altho much weaker at those times & as soon as I get the time, will test the panels watt output levels early morning, near sunset & cloudy days just to see what they can crank out in low light & get that info posted for anyone curious.

My setup before moving to my new place.




My new setup at my new property. The other panel on the right side of the pole is my solar water heater.



A new array set up for 6 panels is in the works. I'll be removing the 2nd set of panels off the shed roof to be replaced later with a new set of 6 panels & putting them on a pivoting 20 ft steel pipe hooked to a winch so I can track the sun from then on.

It should give much better power in the morning & late afternoon & I'll have a report on the results & a pic when finished then a video later on of the whole system set up. It will be most intresting with all the gadgetry I have automating the system so stay tuned.

Output update: Today it's totally overcast in the middle of the day & I'm getting a 25 amp charge going to my batteries from my 12 panels. Pretty remarkable to me!

After taking the 6 panels off the shed roof & mounting them on the new pivoting frame, my output at 8am went from 300 watts to 1000. I had a shadow running across the panels in the morning from the power pole I didn't realize was robbing a considerable amount of output from them.

[Bossrox]

Monocrystalline vs. Polycrystalline

From just what I've read, there's pro's & con's to both. If you have a location that's not subject to the panels getting even partially shadowed, mono's seem to be the best choice & reportedly more efficient & smaller in size per watt output to their poly counterpart.

But if there's any likelihood of a shadowing potential, the poly's appear to be the way to go. It's my understanding that when part of a mono panel gets shaded, it'll kill the whole panels output & if it's in series with another panel even tho it might not be shaded, it'll be killed as well but poly's don't seem to be affected other than diminishing output depending on the degree of shading to my understanding.

When I got my panels, I had no idea what I was buying & was relieved when I discovered they were poly's 'cuz I definitely have a shading issue certain parts of the day as you can see the power pole shadow on the above pic.

Update: I had seen some video's on youtube of a demonstration of shading both poly & mono with no appreciable difference but what I didn't pick up on was that the test was done reading panel voltage. Come to find out, the voltage stays pretty much the same during shading but the amps/watts is a whole different story.

until I set up my new pivoting panels with no shading issues, I never understood why I wasn't getting good wattage until after lunch. Well up until then, my panels were partially shaded by a power pole. It didn't shade very much so I didn't think it was much of a problem, but I was up doing a roof coat on the shed 1 day & had a small 2x2 ft platform to sit the paint bucket on over a panel, & just out of curiosity I checked the panel output with the platform on a panel & then off.

That little 2x2 ft board covering the panel robbed 100 watts & the power pole during the morning tho just a sliver of shading, spans all the way across 6 panels gradually diminishing til after lunch & that's why I had such weak output in the morning.

As further evidence, my new pivoting array does start to get shaded real late in the afternoon from some trees & today I saw a significant drop just as soon as the tree shadow started creeping onto just 1 panel. Man, all the power I could've had & pissed away 'cuz I didn't know any better, grrrr.

[Bossrox]

Solar panel amps conversion mystery can be confusing

With my charge controller putting out its max current of 100 amps, I was taking some amp readings off the panels, measuring each of the 4 strings of 3 panels wired in series at 8 amps with the total from the panels being 32 amps.

Being my electrical math was pretty rusty, I was thinking I should be seeing more, with each panel doing about 8 amp times 12 panels, I figured that should give me about 100 amps but was just 32 going into the controller & 100 out to the batteries. It wasn't making sense to me knowing when you down convert 120 to 24 volts, it should multiple the amps by about 5.

Here's where I was getting confused, I forgot when you put amps in series, it doesn't change, only the voltage multiples. I would only get 100 amps if all the panels were in parallel.

So with a panel output of 40 volts @ 8 amps of 3 panels in series, times 4 sets should = 120 volts @ 32 amps & was, then down converting it to 24 volts should be a bit better than 100 amps but being the chargers max output is 100 amps, there ends up a bit of untapped power not getting utilized.

A little understanding for those who aren't quite electrical savvy or rusty as I was.

[Bossrox]

New pivoting panel array on the way

With my power requirements higher than I can produce with fixed panels, I was thinking if I could find a way for the panels to be moved to track the sun, I should be able to squeeze out some more power. How much more is still a mystery til my new pivoting array is finished & an expensive experiment to find out if it'll make a notable difference.

My plan is to build a box to hold 6 panels balanced on a 2" 20ft steel pipe pivoting on 4x6's at each end. Then 2 winches mounted on each side of a 4x4 center support to hold the array steady from gusty winds & guy wiring the 4x6's to each other along with ground anchors to keep everything steady.

My guess is the panels & the wood frame is going to clock in somewhere around 1000 lbs so I'm not taking any chances with wimpy hardware. Guy wires along with just about all the other hardware will be heavy grade stainless steel.

I'll post some pics soon in it's stages of progress & eventually a video so stay tuned.

Update: Now that I've got them up, it's rather spooky how much weight is pivoting on those 4x6's. Not that they can't support it, but now that I've thought about it some more, 2 eye lag bolts are at the top of each 4x6 to pull them together, otherwise the weight would force them apart & to the ground it all would come. There's a chance the stress on those eye lags could be enough to rip them out of the posts & I should have used eye bolts going all the way thru each post so I'm going to add that to what I already have for more insurance but I wish I had thought it out a 'lil better.

The cradle frame done & guy wired.



Frame to hold the panels roughed in.



Winches strapped to both sides of the frame to hold it steady.& obviously to pivot it.



There ya go, all done & didn't come crashing down, & instead of the 270 watts I was getting @ 8am, now it's doing 1000 watts. My best power total from my inverter on a good solar day was 12.9kw, today with the last 3 hours of solar potential lost to total overcast, I did 14.7kw. It looks like I could get about 17-18kw on a strong solar day & I guessed right, had a day my panel output was the highest I've seen it so far at a bit over 18kw. Anyways, it turned out a worthwhile experiment. BTW, I have another 6 panels that are fixed position in case you were wondering how I was getting all that power.



What did it cost to build this contraption you ask? I didn't keep tabs on it but I'd say it seemed like it was around $500. Eventually I'm planning to come up with a scheme to motorize it to automatically track the sun.

[Bossrox]

Best day I've seen yet from the panels!

Since I got a set of my panels up on the new pivoting array, my panel output has improved a bunch but we've had 1 of the wettest, cloudiest summers I ever remember so til today, I could never know how much I could get out of my panels.

Well today, a miracle happened, it stay sunny all day with hardly a cloud to be seen & the assholes out spraying our sky's with those damned chemtrails weren't out either.

The highest I ever saw coming off the panels for a day was 18kw. For the 1st time today, the panels cranked out 22kw & the usable energy I got from the inverter was 17.5kw where previously the best I got was 14.7kw.

So now I know what my best potential is, which means I need more panels 'cuz I use about 24kw a day for my normal summer demand. Another 6 panels are on the horizon & that'll pretty much take care of most of my energy needs.

[Bossrox]

12 more panels added to the system

I'm working towards a 48 volt system & getting all that's needed before ordering the 48v inverter. My charger is already maxed out with the existing 12 panels running at 24v so these new panels can't be hooked up directly without overloading the charger but.......

I schemed a way to utilize them to give me extra power during low sunlight. I built another 2 sun intensity switches you can find out more about in my gadgets thread, hooked the new panels to it & when the suns intensity falls below a set threshold, they are staggered so1 of them kicks in half the extra panels at 1 level, then the 2nd switch kicks in the rest at another level & back off when the sun returns.

The reason for staggering the set points is to regulate the maximum amount of power going to the charger to keep it from getting overloaded during changing solar intensity.

This way I'm gaining extra power lost during low solar intensity as a temporary measure til I switch to 48v. Once I make the switch, the charger will then accept double the panel power & the intensity switches will no longer be needed where I can hook all of them together permanently which will be about what the charger can then accept.

Eventually I'll add another charger for the extra panels & those switches will no longer be needed but to make enough power on overcast days to run my normal load with enough extra to charge the batteries will require doubling my 24 panels, so those intensity switches won't end up as useless gadgets. When I find a steal on more panels, they'll get recommissioned again to do what they're doing now.

With 24 panels, that should get me up to 7kw output or around 200 amps for charging in full sun but here's the power I'm getting on overcast conditions. About 50 - 70 amps in light overcast, 25 - 50 in medium overcast & 10 - 25 amps in heavy overcast. Without the added 12 panels, it would be half that.

18 stationary panels & 6 trackable panels

[Bossrox]

Buying used solar panels? This you should know before you do.

I just recently got some used 270 watt panels & was real disappointed in their appearance. They had what looked like blotchy rainbow discoloration under the glass & the backing was splitting. I'd guess they were in extreme heat conditions & not ventilated properly.

My gut said these are in bad shape & if I hadn't traveled pretty far, I would've likely left empty handed & waited on something better but I took an amp probe with me for testing the output of each panel & got some with decent output.

This is an essential tool to have if buying used panels. Testing the voltage output only tells part of the story, the amps output is the most important value.

To test the amps, 1st, buy them only when it's a full sunny day, then take the 2 wires & plug them together. Clamp the amp probe on the loop & be sure you are using an amprobe that reads DC current, not all of them do. If the amp output is close to the label rating, you got a good panel but the best reading will be when the sun is at the highest point of the day. If your testing early or late in the day, your reading could be misleading & also if those criminal bastards have been chemtrailing the sky's that day & how thick they lay it down.

Anyways, I found a few panels with bad output so I tested all that were there to get the best panels out of the bunch.

You want to look for a difference of no more than half an amp to get good performance 'cuz if you string several panels together in series & have a panel that's substantially weaker than the others, that panel will drag down the whole string. That's not much of an issue tho if all your panels are in parallel.

If the used panels you get vary more than half an amp & you're making a series string, pick the panels for that string that are closest to each other in amp output.

If you're buying used panels online, 1st I'd try to verify their reputation, then I'd get in writing the output of each panel being sent to you & a guarantee if they aren't up to snuff they'll replace any at their expense including shipping.

[Bossrox]

Solar panels with blocking diodes, what they do & why you want them

I just discovered something I never knew of. I don't know if blocking diodes are a standard on most panels made these days but here's why having them is an important consideration when buying panels.

I had the preconception that polycrystaline panels were less affected by partial shading than mono's but that's not the case & found out the hard way when I moved some of my panels out of the shadow of a power pole during the morning into full exposure & raised my output from 300 watts to 1000 getting that pole shadow off the panels.

With further testing & I found just a sliver of shading on a panel will just about kill it dead & if it's in a series string, it'll kill the whole string.

So here's why panels with blocking diodes are so much better. As I understand it, when a panel see's a shadow with these diode panels, the diode short circuits the area getting shaded & bridges the area that is getting sun thru it. So instead of losing a whole panel or a string, it's output just drops to the degree of how much the panel is shaded resulting in an increased in output over a panel with no diodes.

What really sux tho is I don't have diode panels & now I want to replace mine that I have so much invested in so far. But I guess I can find a buyer for my old panels to offset the cost.

[Bossrox]

A now video up going thru the build construction of my pivoting panel array.

[Bossrox]

My new solar paneled roof carport now with a total of 36 panels in the system.