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Topic: Flexible Solar Panels ??? (Read 861 times) previous topic - next topic

Flexible Solar Panels ???

Initially I was dead set on installing flexible solar panels, however, the more I read I'm starting to second guess if that would be the right way to go.  According to what I have read volts start dropping when panels reach a temp of 77 degrees.  Living and storing the coach in South Florida I can see where the panels by being adhered directly to the roof surface could easily reach temps of 125 plus degrees.  Not sure what the voltage drop would be but sort of think it would be significant.  Also, been told flexible panels only have a 3 to 5 year life expectancy with heat being a major cause of deterioration.

With rigged panels the inch or two clearance from the roof would go a long way in allowing heat to escape. 

The purpose for installing solar is mainly to keep house and chassis batteries charged so I figure about 300 watts should do it.  Knowing very little about solar I'm not very comfortable with making decisions from what I have been reading.  For esthetic I would prefer the flexible panels but it would be cost prohibitive for us if we would have to replace every 3-5 years.

Would very much appreciate solar advice/recommendations/experience from flexible panel install coach owners on how to proceed.  Looking to use either a Blue Sky or Tracer MPPT controller.

Thank you...Gary

Re: Flexible Solar Panels ???

Reply #1 –
Gary,

Have you read the article on solar that Technomadia posted a few weeks ago?  They were also originally thinking flexible but opted for rigid for many of the reasons you cite.

Zephyr is Solar Powered! ? 800 Watt RV Bus Roof Solar Install | Technomadia

Not shown (done earlier in preparation) in the article is their Victron boosting inverter Boosted Electrons: The Victron MultiPlus Inverter | Technomadia  .  I recall Don (acousticart) has purchased a Magnum hybrid inverter which does the same basic thing MSH-M Series Inverter/Charger - Magnum Energy, Inc. in preparation for his solar projects.

Re: Flexible Solar Panels ???

Reply #2 –
Thank you Michelle for the information on the articles.  Just finished reading the Technomadia article and rigged panels is what it will be.  The challenge will be to place them so not to distract from the coach appearance.  Thanks again...Gary

Re: Flexible Solar Panels ???

Reply #3 –
As one who has already invested in flexible solar panels yet to be installed (not the type referenced in the Technomadia article by the way), I would be interested in where you got your information about the voltage drop and bout the short lifespan. Any links would be appreciated. The ones I have from the bankrupt company UniSolar, had a 20 year warranty at 80% output (of course, the warranty is now meaningless except for a statement of the design intent). As far as I can determine, the company's chapter 11 had nothing to due with the quality of the panels or warranty issues with same.
Attached is a PDF of the specs, which in my limited testing, seems to be credible to me.
Don

Quote from: GFM –
Initially I was dead set on installing flexible solar panels, however, the more I read I'm starting to second guess if that would be the right way to go.  According to what I have read volts start dropping when panels reach a temp of 77 degrees.  Living and storing the coach in South Florida I can see where the panels by being adhered directly to the roof surface could easily reach temps of 125 plus degrees.  Not sure what the voltage drop would be but sort of think it would be significant.  Also, been told flexible panels only have a 3 to 5 year life expectancy with heat being a major cause of deterioration.

With rigged panels the inch or two clearance from the roof would go a long way in allowing heat to escape. 

The purpose for installing solar is mainly to keep house and chassis batteries charged so I figure about 300 watts should do it.  Knowing very little about solar I'm not very comfortable with making decisions from what I have been reading.  For esthetic I would prefer the flexible panels but it would be cost prohibitive for us if we would have to replace every 3-5 years.

Would very much appreciate solar advice/recommendations/experience from flexible panel install coach owners on how to proceed.  Looking to use either a Blue Sky or Tracer MPPT controller.

Thank you...Gary

Re: Flexible Solar Panels ???

Reply #4 –
Don...when I googled flexible solar panels the sites I went to talked about the adverse effect heat has on solar and even more so with flexible panel output.  On the solarstik.com site they talk about heat and flexible panel durability.  They mention 3 year serviceability and when I went to one of the companies they recommend, Global Solar ( declared bankruptcy in 2012) they warranted panels for only 5 years.  Most rigged panels have at least 20 year warranty.  On amsolar.com site I had read voltage drop off startied at 77 degrees and this happens to be the company referred to in the Technomadia Article.  After reading the article where they talk about deterioration of flexible panels I do not have any confidence in performance.  However, I am going to check out the Unisolar panels and see if I can find some reviews. 

Gary

Re: Flexible Solar Panels ???

Reply #5 –
I have two unipolar 136w panels and twi Global Solar 90w panels on my roof. So far I am satisfied. Yes, the power is reduced when the outside temperature is above 110 degrees, but I expected as much.

I'll be in Quartzsite in January for a real cool weather low sun angle test.
 

Re: Flexible Solar Panels ???

Reply #6 –
I have 10 Renogy 100 watt flexible panels on the roof. I run series/parallel so my voltage is fairly high.
There is some degradation of performance in the summer, but if you need more charging capacity, easy to
add more panels. They are relatively small for their output, and mount easily with vhb tape, no need for drilling
holes in the roof. I could probably add another 6 if I needed to. Only downside I can see is cost, generally about
$2 a watt compared to $1 a watt for glass panels.

Jcus