Solar - Flexible (Peel And Stick) Solar Panel Vs. Conventional Polly Crystalline Panels

[CeesHofman]

I am new here and I am looking to hook up solar to a 1989 Odyssey that I just bought. We are hoping to do some serious boondocking in this rig and want to be as 'off-grid' as we can.

As I have been trying to learn about different solar units that I can hook up permanently on the roof, I have come across these peel and stick (made by Unisolar). For me there are a few appeals to the peel and stick. Installation seems MUCH easier and straight forward. There are not mounting holes. It just seems pretty nice to peel and stick. Also, it seems like this would be MUCH more "wind resistance friendly". I can only imagine that there is a big difference in the aerodynamics going on.

BUT, I don't really know what I am talking about! I want to ask you!

What is the difference? What are the pros? The cons? How does this compare to other models? What do you recommend for what we have going?

Thanks for the help!

Here are links to products that I have been looking at:

Standard panels:

http://www.ebay.com/itm/30W-50W-70W-80W-100W-Watt-Poly-Crystalline-Solar-Panel-PV-18V-RV-Motorhome-Boat-/321018505264?pt=LH_DefaultDomain_0&var=&hash=item4abe31a830

Flexible (peel and stick) panels:

http://www.amazon.com/Unisolar-Flexible-Solar-Panel-Laminate/dp/B006EP6MCU/ref=sr_1_1?s=automotive&ie=UTF8&qid=1415303023&sr=1-1&keywords=unisolar+solar+panel

[Derek up North]

Have you looked on your roof to see if you have a clear area 18ft x 16"?

[CeesHofman]

Have you looked on your roof to see if you have a clear area 18ft x 16"?

I actually haven't. I am out of town and will get to measure the roof on Saturday. Besides possible length issues, is there much of a difference?

[Derek up North]

I don't have solar so am only going by what I remember others saying.

I believe the flexible panels output less watts/sq ft than the rigid panels. Also, I'm guessing that the roof would have to be pretty smooth for the adhesive to stick to.

[zero]

As I have been trying to learn about different solar units that I can hook up permanently on the roof, I have come across these peel and stick (made by Unisolar).

The flexible Unisolars have less watts per square inch then most conventional panels which I not a huge deal. The heat is what would concern me. Solar panels usually rely on air flow underneath them to cooling and longevity. Those Unisolars are only rated to sustain a certain max high temp. I don't know how many have failed when used on RV roof-tops, but I can say this. Several RV companies tried offering them for options for a year or so and then stopped. I assume they had a reason. All solar panels I see offered now for the roofs of RVs are conventional with some air space underneath. The Unisolars use 23 square inches of space for every 1 watt of power they make (at max rating). A conventional panel will use 11 square inches to make 1 watt.

[snail powered]

Unisolar company history. The cost of the panels had been subsidized so that they were competitive in Europe but when that subsidy went away their company started failing. Then they got a big subsidy payout check from the US federal government and the business shut down within a very short time after getting that money. All the assets were sold off including the remaining inventory. Any Unisolar panels you see on Ebay came out of the auction sales of big lots of pallets of the panels after the closing of Unisolar. Quality is not guaranteed and there is no warranty on them. You will have no way to know if you are getting a grade A panel or one that was rated as substandard during the original quality control inspection. This all happened several years ago so if you purchase them be aware that you will be buying old stock made by a company that is no longer in business.

[Pete1122]

There is a middle ground here, its called semi flexible solar panels. Super light weight and easy to mount, check the link below.

http://www.ebay.com/itm/Semi-Flexible-100-Watt-Solar-Panel-12V-High-Efficiency-Sunpower-Marine-Rated-/141374996655?pt=CPUs&hash=item20ea9b40af

[Totem]

Put your money into rigid panels and a good controller as JDE suggested, cooling is key. Peel n stick fail, Karin is right.

[CeesHofman]

This is awesome, guys! Thanks for the info.

What ridged panels would you recommend?

[YoungSage]

Yes. I have the same question. What rigid panels are currently seen as "the best"?

[YoungSage]

How about this kit?

http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Kits/c1_272/p2752/12-Volt-280-Watt-Solar-Panel-Kit-with-FREE-SHIPPING/product_info.html

[BobBeery]

Also, how many watts should we be looking for? I use a CPAP that takes about half the house battery each night.

[WME]

Without a bunch of details...... Lets say your battery is 100 ah and your using 50 ah a night powering the CPAP. That means you need more than 50ah to recharge things.

So a 100w panel would do about 7 amps x 10 hours of sunlight would get you 70ah. Right!! Ain't never gonna happen.

You MIGHT get 10 hours of good light on the equator, but not likely here. Thumb nail numbers would be around 1/2 rated amps for 6-8 hr.

So your needing a 175w + setup to keep your CPAP happy.

To fall on the safe side of things with my wife's CPAP I have a 210ah battery bank and a 200w panel.

[zero]

A 100 watt panel might provide 4-5 amps for 4-5 hours on a good day. A little more in some prime areas in the southwest. Nowhere near 7 amps for 10 hours. There is no where in the USA that has more then 6 hours of peak solar-sun in a 24 hour day. 4 1/2 is the average. In New York - during the best summer days - a 120 watt panel makes an average of 5 amps for 4 hours. That's on a good bright sunny day. If you carefully do the math on the little bit of output you get from solar panels - it can be a little depressing. My house runs on solar. I have 27 two-hundred watt panels on the roof. On average, each 200 watt panel puts out 1.2 amps per hour @ 12 volts over a 365 day year. You've got to keep in mind that a solar panel does most of its output in 4-6 hours and that leaves 20 - 18 hours of a day when it does nearly nothing.

As to differences in quality? I don't know of ANY substantial differences when it comes to real world use. Just about all solar panels made in the past 10 years have similar output per square inch. The key factor is that most if not all have "blocking" diodes built into them so a partially shaded panel can still make power. Every panel I've ever bought came with the same basic 20 or 25 year warranty. Solar panels don't go bad. They just slowly degrade and they are repairable when damaged. A solar panel is a bunch of separate solar cells wired together and protected with many diodes. So individual cells can cause problems as can failed diodes. Rare, but when it happens they can be repaired - if desired.

I've got a pair of 100 amp panels on the roof of my Toyota Minicuiser. Both are 12 volts (nominal voltage around 18 volts) and are wired in parallel. Highest output I've ever seen, in total, was 9 amps @ 13 volts on one August day around noon.

[jmowrey]

We use a 100watt regular solar panel. It measures about 2 x 3 ft. Instead of mounting it on the roof, I have place I can hang it on the wall inside the bathroom. When we get where we are going, I can hook it up with extension cables (that coil up and ride inside the compartment where the land line cord is stored). That way I can position the panel to access the most sun and the best angle throughout the day.

Since the goal usually is to find shade to camp in, the panel won't provide anywhere near the maximum output if it is permanently mounted on the roof. It may not always be pointed in the correct direction, either. I have enough extension cable to be able to position the panel up to fifty feet from the Dolphin to get out from under any shade trees and into the sun.

I use a dual battery controller, which also allows me to use the solar panel to charge the truck battery if need be. I trickle charge both batteries during the winter and during times of storage using this system. The dual controller allows me to regulate how much juice goes to each battery. When we are boon docking, I set it for maximum charging of the coach battery.

It's been a very effective system for us. By maximizing the panel's access to the sun, we are almost always able to charge our coach battery back to full by noon or so every day. It even gives us some charge on cloudy days, though obviously not as much. But much more than a panel permanently mounted on the roof that could be in the shade and at the exact wrong angle, even when the sun is out.

Joe