Has anyone used Frameless Flexible Solar Panels and attached them directly to the surface of the coach roof?
There are several YouTube channels that show this system, but the results are not the best. Most ended up removing the panels and going to good quality rigid panels. There are several companies out there that have reliable systems. Another site you might want to check is: www.solarinstalled.blogspot.com/
Maybe they have improved, but the twelve 100 watt Renolgy flexible panels I bought about 6 or 7 years ago, lasted a year before they started to cloud up and discolor and production started to drop. Easy to install with VHB tape though. When I bought mine, they were about twice the price of regular framed glass panels.
View the one year review below. They seem to be a plastic surface that scratches and that with the cupping could be a problem. Ours are about 10 years old and with the glass surface, have no marks/scratches. We don't tilt ours so that's not a factor on our coach. Holes in the roof are not a big deal as there are well over one hundred holes as it is for vents, skylights, etc. Making a nice neat wiring harness is also a factor. I pretty much agree with this guy on the pros and cons. My choice would be the heavy duty commercial panes with the aluminum frame. Ours weight almost 70 lbs each but still look like new even though we go through a lot of low hanging branches in many campsites.
https://www.youtube.com/watch?v=_mFgMfKRRLI
Something to think about is heat. Solar panels get hot when the sun is shining on them. Electrical output decreases with increased temperature. Panels in a frame are usually mounted so that air can pass underneath and cool them a bit. Also less chance of the heat passing directly into the coach with a gap between the roof and panel. It's also possible the gelcoat may crack underneath glued down flexible panels. Much less drag going down the road with flexible panels though. My 2 cents.
Good points Jerry. That's why I included a 1 1/2" gap between the roof and the bottom of the panels. The top glass surface is probably another inch and and half above that. I also wanted to use flex electrical conduit to run the solar panel wires in to keep it factory neat and to minimize branches catching on the wires and the 1 1/2" gap is perfect to run the conduit under.
In summer sun, dark panels will get hot and not only decrease the output but increase the thermal load on the coach. The top Fiberglas is very thin and glued to wood making a .400" thick surface. Cracking could occur with high temps. Storing the coach outside can easily crack the roof also. I would think the higher temps would shorten panel life too especially if they have a plastic coating.
The ACs, vents/skylights/antennas are much higher than the panels so I didn't worry about drag.
Pierce
I am not sure you are going to notice any increase in aerodynamic drag due to adding solar panels on your roof. We have two panels side by side at the front and we hear a bit more wind noise. There is nothing aerodynamic about these coaches.
I have to agree with Roger. Nothing aerodynamic about my 320. I guess it would need to look more like a Lear Jet for that, but the DW says no. :o
Larry
Image below of what a Unicoach looks like traveling down the road...note similarity to a brick.
Unihomes, on the other hand, slip silently through the air without making the slightest ripple. 8)
Ya, what Chuck said.. 💨🚈
I have installed 3 160 watt Renogy flexible panels on my coach using eterna bond tape. I had two of them on a previous travel trailer because I didn't want to put holes in the roof, and I wanted something low profile. When I bought my FT coach (2002 U270 36'), I installed them since I already had them and bought another to bring me to 480 watts. So far they have performed well and there hasn't been any yellowing, but they aren't a year old yet.
Are you interested in frameless semi-flexible panels? I put six 320 watt panels on my U270 from eBay. They were:
- raised 4 inches above roof
- optical glass
- high-quality
- conform to U270 roof
- cheap: $.70/watt
That said, I HIGHLY recommend Sunpower panels for ALL RVs since they will produce 2x the power from the same footprint, over their lifetime. It still gets 8MPG: no difference in MPG.
Chuck's UniHome is just about as much of an aerodynamic brick as the UniCoach. Really. But you can believe what you want.
Flex panel warranties are usually only 5-10 years as opposed to a rigid panel which has a 25 year warranty. There's a good reason for that, they won't last!
Not only that but check out the #^%$ wiring in the video. Looks like a 10 year old glued down the panels and had no thought about organizing the wiring.
Pierce
Ya pretty sloppy. And then the guy is standing on the panels after worrying about scratching them wiping the dirt off .But then many people who really have no expertise will post anything on YouTube just to get followers and make some money. Watch with care.
Yes, four inches of air gap is needed under any solar panel to provide cooling. I made and installed 15 aluminum brackets per 320 watt frameless semi-flexible panel and used 3M VHB tape to fasten the brackets. So far, so good.
My solar system passed the wind test with about 120 MPH relative wind hitting the panels when a truck passed by on a two-lane road.
I only have about 1 1/2 inch in the middle of the panel and maybe 2 inches clearance from the roof on the outside of my panels. [320 watt]. Shot the ceiling inside with ir gun, with good sun, and found the areas underneath the panels actually cooler than the non panel areas. But mine are the framed type. Am only using VHB bonded unistrut for securing panels.
4 inches seems really excessive to me. My ceiling never gets even slightly warm at 1 1/2". I've got 3 brackets down each side the commercial panels screwed into the roof. I'm ten years down the road and no movement with the output staying the same. At 68 lbs each, the Chinese panels are built like tanks. I push through a lot of low branches without a thought other than going slow. The 1 1/2 inches to the roof is just right to use electrical flex conduit to keep the wires out of sight and make it look factory.
Pierce
In a worst-case scenario, you could fry an egg on those panels in AZ in the summer. It's the panels that get hot, not the rig's ceiling. Heat is causes the electrical output to decline. During 120 degree days in the Arizona summer, your panels would benefit from four inches of ventilation to help them:
- Produce more power.
- Reduce chance of self-destruction: One leaf blocking a cell can cause cheap chinese panels to get a "Hot Spot", because the electrical power is dissipated is the rest if the panel.
- Cooler panels degrade less over time
So, the more ventilation, the better.
I have 10 year old "cheap panels" on my house, even they came with bypass diodes, which prevents hot spots by diverting around affected cells. You may lose some production by shading but don't believe any damage would occur. I buy my panels off a local grid tie installer. He buys directly from Chinese manufacturers by the pallet. He said he has not seen a panel without bypass diodes in a long time.
What is a bypass diode? | CivicSolar (https://www.civicsolar.com/support/installer/questions/what-bypass-diode)
Does Yingli even still exist? Not much value to a warranty if the company disappears.
Do I detect a bias against Chinese products? :D Yes, Yingli is still one of the largest solar panel producers in the world, producing more than 85 million panels. Here is their website: Solar Panels | Yingli Solar (http://www.yinglisolar.com/en/products/solar-modules/)
When I was looking for panels, I just happened to be looking on Craigslist and noticed an ad for the Yingli panels. I had no horse I was betting on so I called my friend for advice on the quality of the panel. The seller stated that his crew had just finished installing 80,000 panels at a new solar farm in the Mojave Desert and he had a few hundred extra from the installation. They were $160 for a 285 watt panel, cheap at that time so I bought 4. People were arriving with trailers from other states to pick up as many as they could carry.
Before any company invests the mega millions a huge solar farm requires, they check the company's reputation, history, etc. I don't think any savvy business CEO would commit millions of $$$ without making sure they were going to be around many years in the future in case of warranty issues.
Even though Germany is a very small country, they are always in the top three in the world for exports. Countries on the other side of the world may have a hydroelectric project scheduled completion ten or twenty years in the future. They order the German generators because of the quality, the assurance that the product will be delivered on time, that the currency used is stable with a low inflation rate low so there will be no cost overruns and that they have minimum work stoppages because of labor disputes. It's the same for solar farm projects. Make sure the product is delivered on time for the contracted price and most important, that it will be within specifications many years down the road. It's all about reputation!
Hey, I would have gone with several other brands but this one came up, I did my research and it's worked out great. If I had it to do today, I don't think I would change anything in any of the components or design. Again, nothing like spending time doing weeks of research if necessary before jumping in something new.
Pierce
Yingli is still around and is a large producer. They are in some financial problems now because of expansion, market forcesand management decisions. Not uncommon. Warranties are probably best in the first year or so. Once past that a good panel will last a long time. Ten years out it is probably easier to just replace a panel than try to make a claim in any case.
A BIG Thank You.
Your insight to solar has given me plenty of food for thought.
Thank You
Tim
See the first minute of my Youtube video about frameless solar panels at: https://www.youtube.com/watch?v=-s1Vx2z8x0M
Pros and cons of frameless panels are:
PROS
- Less drag
- Esthestically more pleasing
- Lighter weight
- Sheds water, ice and dirt due to slight curves
CONS
- Edges not protected