9 replies to this topic

[wicked1]

I've been wanting to add a modern, lighter and more shade tolerant panel to my older FWC.  Mine came w/ the 100 watt Zamp panel.  Overland's panels look great, but are higher voltage. 
I found Sol-Go, who use the same cells as Overland, and their datasheet lists the specs as basically a match to my existing Zamp panel.  I thought problem solved. 
BUT..  after some investigation and a bunch of emails w/ Sol-Go and the vendors, I have determined both US vendors have an older batch of panels which are a couple volts lower on average than what their datasheet specifies, and so are a couple volts lower than my Zamp panel. 

Sol-Go says their new panels, which are in their warehouse in SoCal, match the datasheet.  But they will only sell pallets of 30 panels. 

 

From what I can tell, the benefits of the Overland panels are mostly due to the new solar cells they're using, so this sol-go should be equivalent.  They're just 115 watt, vs Overland's 160.  But, they match our older FWC's existing panel, so can simply be added in parallel. 

Maybe I'm putting way too much effort into saving my existing Zamp panel..
But basically, I'm wondering if there are others wanting to add panels to an older FWC w/ existing Zamp?  Maybe I could buy the pallet of 30 and organize a group buy.  (I can cover the up-front costs, but would want to know I can sell most of them).  

 

Anyone interested?
https://www.sol-go.c...eet_q3_2020.pdf

I haven't asked for a price for the pallet, but vendors sell the panels for about $200.

 

This shows the actual specs of the older batch of panels which are available from the two US vendors.  (Verified by Sol-Go)

https://cdn.shopify....pg?v=1587959501

 

Edited by wicked1, 26 October 2020 - 11:20 PM.

[Vic Harder]

How about a single new panel that puts out 365W for $257?  No affiliation:

https://unboundsolar...erc-solar-panel

[CougarCouple]

Hi Vic
Looked a specs over 6 feet long and 48 lbs. I’m not sure about the voltage at 35 volts that seems different to mine I think was 17volts. Does the charging controller chop it down.

Thanks Russ

[wicked1]

That one is too high of a voltage for me (My MPPT controller only accepts up to 32v for some reason...). And, my main concern is shade tolerance.. I live in the midwest and will basically always be in the woods.. Always have partial shade. I haven't read up on how they work, but apparently the solar cells in these panels can handle individual cells being shaded while not affecting the rest of the panel. Plus the light weight and low profile of the new panels. (I know that comes w/ the trade-off of maybe not lasting as long, but I will mount them rigidly to a frame). In the end, I'll probably remove my old Zamp panel and just go w/ all new panels. I'm not really expecting many takers on my 'group buy' offer.. but you never know.. 15 of us wanting 2 panels isn't inconceivable. And I did ask the two vendors if there's any chance they could order a new batch of panels from Sol-Go w/ the proper specs, but haven't heard back from them yet. And thanks for the response.. If my rig was a little bigger, I'd definitely have more options available to me. I've just got a little Tacoma w/ flatbed fleet.

[JaSAn]

I didn't see anything in your links that mentioned 'shade tolerance'.  I would want to see lab results.  My understanding is that this is a physics problem that would be difficult and complicated to overcome.

 

I also camp in heavy forest, Northern Minnesota and Black Hills.  Shade greatly reduces the output of my 2 X 100W Renogy panels.  Using a generator for less than an hour in the am and then letting the panels do the slow absorption phase, my 208 AH battery bank is full before the sun goes down.  This has worked well for me for 6 years.  I find I only have to run the inverter/generator (a quiet 1000W Sportsman) every other day for about 20 minutes.

[rando]

I am not seeing or buying the shade tolerance thing either.   The only way to do this would be to put bypass diodes on each and every cell, which there is no mention of.    The Sunpower Maxeon cells used in both the SolGo and Overland solar are pretty standard these days in many of the light weight panels.  I wouldn't limit you search to these brands.    Given how cheap solar panels have become, ditch the old Zamp panel and get two matching panels.   

 

If shade is often a problem, you could consider a portable panel to supplement your current panel.   They are kind of a pain to deploy, but you can hunt out the sunny spots with them.  

[wicked1]

Here's something about the shade tolerance.. According to this the cells are different, but not perfect. And, they also put a few diodes in the panels (although this website isn't about the panels I'm currently looking at). https://www.mcelectr...unpower-review/ Section 2 is about shade. (Apparently the Maxeon cells are what they refer to as X series in the article)

 

I've got a portable panel, which does help. W/out it, I'd definitely slowly drain my battery, but w/ it I'm often OK.

And yeah.. generator. We're not quite in the future yet, I guess. Seems like it's always a day away..

Edited by wicked1, 27 October 2020 - 08:58 PM.

[PaulT]

The first video explains their claims about shade tolerance.

https://www.overland...ave-set-the-bar

These are the panels that FWC to which switched in the recent past.

 

I haven’t seen any independent tests giving actual performance.

 

Paul

[Vic Harder]

Hi Vic
Looked a specs over 6 feet long and 48 lbs. I’m not sure about the voltage at 35 volts that seems different to mine I think was 17volts. Does the charging controller chop it down.

Thanks Russ

My present 330w panel is 6' - it fits either across the front of the 72" Puma (first way I had it mounted) or lengthwise in the drivers' front quadrant of the camper.  And yes, its heavy.  80# roof lifters help with the weight.

 

My Victron 100/30 MPPT can take up to 100V on the input.. so 3 of those in series.  And yes, it cuts it down to what the batteries need at that point (more like it transforms it... power is not thrown away like it would be with a PWM solar controller)

[rando]

With a little more digging, there does seem to be some truth to the claim that SunPower Maxeon cells are slightly more shade tolerant.  The cells have a lower voltage drop across a reverse biased (ie shaded) cell, so instead of the bypass diodes kicking in with one cell shaded, you can continue to produce power until 2 cells are shaded.   The normal 100 - 160W 18-20V style panels have 2 strings of 20 cells each in them.  For a 'normal' panel, if you shade one cell the power output drops by about 50% as you shutdown one out of two strings.   If you were then to shade another cell on the other side of the panel, you would loose two out of two strings. 

With the Maxeon cells, you need to shade 2 cells in a string before it shuts down, meaning you can shade up to 4 cells on a panel before you completely loose power.   I can see this making a difference if your shade is from a leaf blowing onto the panel or from some precision bird bombing, but not in the case of partial shade from being under a tree - which will most likely hit more than 2 cells per strong anyway.    

 

There are also a bunch of manufacturers using Maxeon cells.  It is pretty easy to tell if the panel doesn't have lines on the individual cell, it is a Sunpower Maxeon.    AIMSPower is oner of the cheaper options using Maxeon cells.