Flexible Solar panels... Opinions?

[gypsydad]

Originally Posted by mefly2

Zamp has a nice foldable unit. Let me know if you like as we have a spare... got the solar option on the new EB.

Will do. Heading for Glacier in a couple weeks...will try the unit out and report.

[gandttimes]

Ok,so now I have my Trimetric TM2030 hooked up,SC2030 in place and ready,and it's time to get off the pot and get the panels.Have definitely decided on flexible panels,so here's the question.
AM is now touting it's flex panels(Grape) because they are 5mm thick and not 3. at $349. Go Power has theirs at about $549 (ouch) and Renogy has the same thing at about $199. They are all so close in specs that it doesn't really matter.Anyone out there with experience with Renogy? They seem reputable as far as I can gather from the net.Are they all from China? Does it really matter?
George

[Tincampers]

Renogy sells Bosch hard panels. Didn't know they sold flexible.

[gandttimes]

Yup, 100w mono panels according to their site.


George

[lewster]

Originally Posted by gmeikle

Ok,so now I have my Trimetric TM2030 hooked up,SC2030 in place and ready,and it's time to get off the pot and get the panels.Have definitely decided on flexible panels,so here's the question.
AM is now touting it's flex panels(Grape) because they are 5mm thick and not 3. at $349. Go Power has theirs at about $549 (ouch) and Renogy has the same thing at about $199. They are all so close in specs that it doesn't really matter.Anyone out there with experience with Renogy? They seem reputable as far as I can gather from the net.Are they all from China? Does it really matter?
George

I'm about to begin a beta test of the new Photo Flex panels from AM Solar and a pair of 100 amp/hour lithium batteries (LiFePO-4). The 5 GS-100 panels that I just removed from my Sprinter roof weighed around 20 lbs. each with mounting hardware and the Lifeline GPL-6CT batteries (6VDC @300 amp/hours) were close to 200 lbs. And if anyone thinks that the VHB tape method that we use for mounting the panel feet to a smooth, hard roof doesn't work, it took half a day to get the tape residue off the roof after cutting the mounting feet off at the tape line. They would not budge otherwise.

The new arrangement will have about 20 lbs/ total on the roof and 65 lbs for the batteries. These new formulation lithiums are can be drawn to 80% depth of discharge providing a total of 160 amp/hours of usable capacity. The Lifelines could be drawn to 50% yielding 150 amp/hours.

The lithiums MUST NOT be discharged below 80% as damage will occur. They also require very specific constant voltage /constant current charging to very precise voltage points, which look to be 14.3 VDC for charging and 13.7 for maintenance. We are still playing with the lower number.

The new flex panels look promising as they will not cup due to their heavier backing, but there are still considerations. They are still covered in plastic which will scratch (that's one thing that Go Power neglected to mention in their video showing the couple dancing on their panels If they had actually PAID almost $600 per panel, I can assure you that they would NOT be dancing on them!!) and they appear to have less sensitivity to solar radiance at low light situations like early morning, late afternoon and overcast skies.

I'll be looking at the charge that I get from the new panels and will be comparing it to the results that I have had over the last 3 years with the hard panels. They have exactly the same cell structure and voltage specifications at STC as the GS series has. We'll see how much they loose to low light situations and heat inefficiencies.

More to come.............

[RVDreamer]

Sounds great!

I'll be looking forward to what you find out.

[gypsydad]

[QUOTE=gypsydad;1488875]Will do. Heading for Glacier in a couple weeks...will try the unit out and report./

We spent 5 days in Glacier. Found the water pump on DC would not work unless 10+ registered on factory information display in kitchen. Also, bathroom and under cabinet lights barely lit....hooked up Go Power portable to batteries and with in 30 min, had 10.2 V and everything was fine...ran radio, lights, pump as needed and disconnected panels after dark and put away. Morning, had same issues. Connected panel and immediate 11 V reading and everything worked again...not sure what is happening; any one else notice water pump and dim lights under cabinets when below 10v reading? Also, why would the solar jump from 9V to 10 so quick after connecting the solar? I have the deep cycle Interstate batteries which came with my 2014 25' FC...when charging on shore power, I get up to 13V reading...any help is appreciated....

[lewster]

Sounds like a severe case if voltage drop. Your solar panels in bright sun should be putting out 14.2 +/- VDC to your batteries on bulk/absorption charge.

You should check the voltage readings with a multi-meter at the array input and then the controller output. This might give you an indication of whether you have a problem with the panels, the charge controller or both.

In addition, most items that use 12 VDC on the trailer will not work properly below 10.5 VDC.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[VintageRV]

I know that GoPower's warranty is 10 years for defects in materials and workmanship....and that they are readily available to honor it. Be sure to compare that to all other brands you are considering.

[lewster]

Here are some installation photos from yesterday, when I placed the 5 100 watt Photo-Flex panels from AM Solar on my Sprinter roof. And if anyone doubts the tenacious holding capabilities of VHB tape.......it took me 3 hours to remove the mounting feet from my old hard panels. That's 20 1" X 2" sections (from 5 panels with 4 feet each). They were bonded to the roof and did not want to come off....which is a very good thing!

Anyway, the first shot is the first, forward panel, these are laying on the raised ribs of the roof and are bonded with SikaFlex 221 only. It will be interesting to see how mounting these on the raised rails of the roof with the accompanying air flow under them will impact the overheating possibilities of these panels when they are mounted flat to the roof. The full 5 are shown in the next shot. Final wiring and connections to the combiner box, solar charge controller (Blue Sky 3024iX) and finally to the new lithium batteries will be later in the week.

These panels weigh around 2-3 lbs. (didn't have a scale) and are slightly domed on the roof, following the slight arch of the Sprinter's roof line. Now that the SikaFlex has cured, they have become a semi-permanent part of the roof. Also note that these panels are covered by a 10 year warranty as opposed to the 25 year warranty for hard panels (for those of you that have any doubts) and are backed by AM Solar, who have been in the RV solar business for 27 years. Not only have they been in business for a long while, they are honest, caring folks!

Stay tuned................

[ghaynes755]

Lew would be interested in what your are going to use for an inverter/charger, if in fact you are going to install one? Good to hear that Bluesky has a charger that works with the LiFo4 batteries. Is that a new model?

[lewster]

I have a Magnum MS 2812 but I rely exclusively on solar for battery charging, so there is no shore line. All of the newer Magnum ME-RC remotes have a constant current/constant voltage charge setting that works well with the lithiums.

I'll be tracking the charge amperage to see how these flex panels compare to the 5 GS 100s that I just removed.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[Safari Tim]

I think you'll be pleased Lew. My 400w of GoPower panels are pumping out over 20amps. You can't even see them when you are standing near the trailer.

They kept me charged up for a week w/o a converter with a family of 4 using power without any conservation efforts in place. Even when it was well over 100F.

[gandttimes]

Lew, the only question I have is if you are testing these panels to see how they react to heat, shouldn't you be doing a test with them placed flat on a roof as they would be in a real life situation on an Airstream roof?


George

[lewster]

Originally Posted by gmeikle

Lew, the only question I have is if you are testing these panels to see how they react to heat, shouldn't you be doing a test with them placed flat on a roof as they would be in a real life situation on an Airstream roof?


George

Yep! But unfortunately that's not possible if you look at the layout of my Sprinter's roof. There are still enough contact points on the raised ribs to get a good idea, and I also have a single panel mounted on an aluminum sheet that I'll be watching for a comparison.

[gandttimes]

Not exactly scientific unless you have that sheet directly touching everywhere.
When will you be able to do a real test as it was you who adamantly said that that was the problem with the panels, so I'm sure there are others out there who are just as interested as I am.


George

[lewster]

We already know that there are 'problems' with these panels when compared to the glass/aluminum framed GS-100 series hard panels. The version 1 of these panels had a thinner backing which cupped when heated by solar radiation, collecting dirt over center of each cell. These new flex panels have a much heavier backing that reduces the cupping, but the cells are still not optically flat like the ones found in the glass panels, even though they use the very same cells.

They also had reduced amperage amperage when compared to raised, hard panels, more than likely due to the higher operating temperatures that come with flush mounting directly to the roof. They still scratch as the top layer is plastic, not glass, even though some folks like to Cha-Cha on theirs. Maybe I would too if I was sponsored by the solar company!

They both have the same ratings in laboratory STC, or Standard Test Conditions. I don't need to re-invent the wheel for exact lab conditions, rather, I want to see what kind of amperage they give me in the real world.

The flex panels are not as sensitive to low light conditions when compared to hard glass panels. Probably the lower light transmissivity of the plastic top when compared to the glass. I've already had 3 years with the hard panels so I have a ton of charging data. The flex panels will provide more data, and they will both be compared.

If you want a totally rigid, scientifically based test, I suggest that you purchase one of each panel, mount then side by side with identical charge controllers and battery banks using identical loads and keep an hourly log of what is going in/out of the panels and batteries with accurate battery monitor systems. Only then will you have the type of accuracy that you seek. Unfortunately, my work schedule will not allow for this amount of data keeping time.

I'll stick to my bulk data and observations, thanks! I still won't recommend the flex panels until I see that their output is satisfactory in my situation when compared to the rigid panels.

[gandttimes]

Ok out there, I have read everything I can find on the Renogy 100w flexible Panels ($199 each plus shipping) and there are a lot of positive comments, but I can't find much on the Go Power 100w Solar Flex ($400) yet as they are newer. I am prepared to pay more for quality but really have nothing more to go on other than advertised specs, and manufacturers comments, and they are so close as to be the same.These are the only 2 types of panels I am interested in after my research. Does anyone have any useful info on either?
Thanks.


George

[Safari Tim]

GoPower warranty is 10 years. Renogy is 5.


Sent from my iPhone using Airstream Forums

[gandttimes]

Originally Posted by Safari Tim

GoPower warranty is 10 years. Renogy is 5.


Sent from my iPhone using Airstream Forums

Well, you have to be careful with that. Trying to read the fine print, it basically says that the modules are guaranteed to work for 10 years and that a gradual decline in efficiency is not a warrantable claim. They also say that if there is the slightest bit of damage even to an eyelet that the claim can be denied. So I am guessing that taping or gluing it to your roof would constitute damage that would void any warranty.
I am trying to get clarification from them as 10 would certainly be better than 5, but at double the price?????


George