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Wednesday, August 29, 2018

Time For New Solar Panels! - Even More Efficient And New Material!

    Yup, I went and did it. Couldn't leave well enough alone. I located some new, more efficient solar panels with a new technology twist that are even smaller than the last set! At $192 each with 6 year warranty from Amazon, how could I resist. Of course actually getting the old ones off and new ones installed wasn't fun at all. The concept of semi-flexible panels adhered to the roof and matching the contours is great! Putting them on isn't really hard at all. Getting them OFF, however...is. I managed...it wasn't easy nor pleasant, but I got the new ones installed. Wow!! 

The old set (my Third!) was advertised as 100W panels. I had six of them giving me 600 watts of power. They were, in truth, a little bit better than 100 Watts...maybe 110 watts each, so I had plenty of power. The install on those required trimming the edges to fit in the small spaces I had available on my roof. The new ones required ZERO trimming as they were about 2 inches smaller in width and length. Have you heard the old joke about the successful electronics manufacturing company? They moved into a smaller space! Well this is a perfect illustration of that.

Aside from the size, the new twist is a material named ETFE (Ethylene-Tetra-Fluoro-Ethylene.) It is much more durable and resistant to UV light than the old panels. Their top layer was made from PET (Polyethylene terephalate.) That's what they make water bottles from. ETFE is harder, stronger and allows for a bit more light transmission. All good, but the real trick was the addition of a surface texture to the panels. It's designed to act as mini-lenses to focus more photons (light) onto the electricity generating portions of the cells.

Sounds good in theory. Since they are not smooth any longer, cleaning debris and dust may be more difficult. A paper towel will just shred itself if used on the surface. However, the instructions do say that you can rinse them with a hose...I'd be wary of too much pressure though. Just paranoid I guess.  I am sure there is a cleaning/dusting device that will work. I have a bunch of micro-dusters I'll try, but I believe I'll need something with a bit of force. Perhaps a lightweight paintbrush with soft bristles. One I can get wet... I'll try a few different ones until it succeeds.

The Major P.I.T.A. Rearmost Panel
The hardest part of this install was removing the old set of panels. The 3M 760 Paralastic adhesive really does work incredibly well! When applied it stays on tenaciously! Since it was applied to the entire area of the back of the panel and held down with weights (sandbags) until dry, the removal required getting underneath and slicing through the adhesive. A thin wire attached to two dowels (used as handles) made quick work of most of the panels, but not all! The one on the rearmost section of the roof was especially stubborn. It required using an oscillating multitool and had to be "rolled" as it was removed, destroying the panel. Well, at least they came off without damage to the roof.

Cleaning up the remaining adhesive took a while, but a combination of the oscillating multitool, some alcohol and a scrubbing pad got rid of the residue. This time around I used a different technique for bonding the panels to the roof. The "thin layer all over the back" works well, but if there is an air gap surrounded by adhesive, the trapped air can become super-heated and expand to the point of cracking the rather delicate silicon wafers used in the panel's construction. This is bad and can ruin a solar panel very quickly. They get HOT. I mean, they are sitting in the sun...that's the whole idea!

This time, I applied 10mm beads across the panel about 4 inches apart leaving a 6 inch gap for air to escape. No matter where the air is, it has a path to exit from under the panel. I have zero fear that the panels won't stay attached, but I also used some strategically placed Eternabond tape to hold down the wires and a tiny bit of the front of the panels. Remember to NOT block any gaps you created for air to escape!! The tape will keep the wires from flopping around in the wind and reduce wear on them (and my nerves!). It will also serve to protect the black wires from additional UV damage along the way.

So, after all was rewired and the fuses put back in, how is the performance? No idea! I am parked in my driveway until tonight. I'll know after my trip. So far, the readings have been favorable. I have no doubt they will perform at least as well as the previous set. All this while being a tad smaller. That's a good thing!

Be Seeing You...Down The Road,

Rich "The Wanderman"
www.thewanderman.com

18 comments:

  1. Could you provide a link to this product? Thank you.

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    1. Cheri,
      If you do a seach for "BougeRV 100W" you will find vendors for the panels. I bought them on Amazon.

      Rich "The Wanderman"

      Delete
  2. Excellent! I glued one of those type panels over the top of an old dead one because I wanted air space. That 3M adhesive is amazing.

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    1. 2oldman,
      That air gap is mandatory! Will definitely extend the life of semi flexible panels.

      Rich "The Wanderman"

      Delete
  3. Sounds great. What brand are they? Where did you get the panels? Did they connect to your existing equipment? I have a truck camper with a single 160 watt panel. This may allow me to add more panels (I have room for a max of 3 plugs).
    Thanks, HT

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    Replies
    1. HT and Myra,
      The were "BougeRV 100W" a search will locate a few vendors. I bought them through Amazon and took the Square extended warranty as well...just in case.

      All my Solar is hard wired, so I didn't use any of the supplied connectors.

      Rich "The Wanderman"

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  4. Rich, I always enjoy reading your article. Since I am getting close to adding solar to my RV, I was particularly interested in the output power per panel (still 100W?) and the brand of the ETFE panel you chose? I searched a bit on Amazon and did not immediately find one meeting your $192/panel and 6-year warranty? Will you be kind enough to let me and other readers know the brand and size you chose?
    I'll also be watching for your follow-up about your new panels' performance. Thanks. And, keep up the great work passing along your knowledge and experience.
    J.E. Stine

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    Replies
    1. Unknown/J.E.,
      Thank you! tell your friends about them :)The Panels were/are BougeRV ETFE panels. 182.00 each with around 10/panel for the extended warranty through Amazon/Square. Looks like in good sun (remember no tilt!) I am getting about 212 Watts per pair of panels. This was not under ideal conditions, but is indicative of real world output. I am still in the testing phase an will likely see a small increase as I tweak the controller/battery programming.

      Remember, you can only take in the maximum your battery will receive. It's difficult to test based on partly full batteries. Eventually, I will switch to LiFePO3 and will be able to charge much faster at a higher amperage for much longer time periods, unlike traditional Lead Acid tech.

      Rich "The Wanderman"

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  5. Rich, what are your thoughts on framed panels (with a gap underneath) vs stick-on? My stick-on panels (Unisolar) seem to heat up the coach quite a bit. I hate the idea of debris gathering under the frames, but I sure would like to cool down my coach in hot weather.
    Greg Illes

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    1. Unknown/Greg,
      I do not have much experience with the Unisolar panels (rolls), but the ones I have (on my white roof) do noyt heat up the interior too much, perhaps a few degrees. Framed panels with glass are much, much heavier and more difficult to mount safely without resorting to screws through your roof! framing a semi-flexible panel is not recommended as the air gap and subsequent flexing would likely destroy the panel.

      Rich "The Wanderman"

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    2. OK, interesting. Now the second question: do you run your panels at 12V or 24V? Reason I ask is that my wiring is set for about 30A (10ga), and if I increase wattage, I'll need to configure for 24V (new controller) or re-wire (UGH!!). A 24V config would require a combination of series 12V panels, plus parallel pairs, hopefully that makes sense.
      Lastly -- I've been running LFP for several years, and it's absolutely AWESOME -- soaks up all the power I can give it.
      Greg

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    3. Greg,
      Since I am running an MPPT controller AND CRAZY oversized duplex wire my drop to the controller is very low. Originally, the first set of panels, ran at around 28V however the MPPT controller is more efficient as it gets closer to charging voltage. I am running each string of two panels parallel (18V) then each pair of panels "home run" wired to the controller through 3 fuses. I MAY decide to series wire each set of two and see if that gets me additional power in early morning or later day sunlight. It will, however, reduce the efficiency of the controller MPPT conversion. the question is do I get more than the loss and more overall? Only testing can answer that question.

      Rich "The Wanderman"

      Delete
    4. Rich,
      I realize the air gap is important to reduce heat on the aluminum RV roof I have, so I am thinking of gluing the flexible panel to an aluminum sheet and make a frame panel with ribs below the panel and glue the aluminum substrate to aluminum ribs below the panel and held to the frame. The idea is to dramatically reduce or eliminate any flexing but still have an air gap. The frame could be tilted either direction or the panel removed to another location if the coach is in shade. Your thoughts?

      Larry Forman (larry@forman.net)

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    5. Larry,
      I believe you have an interesting idea. That being said, it's a lot of fabrication work to get to the point of a factory built "traditional panel. Tilt mechanisms are great, but add complexity and use time to change tilt. Both of which I can do without based upon my severe lack of free time. I would follow the K.I.S.S. rule and take the slight wattage loss "hit" and add another couple of panels to make up for it.

      Rich "The Wanderman"

      Delete
  6. I prefer the idea of non-installed solar panels... Saves all those installation/deinstallation issues Rich is having. Lol. Also, more portable if i trade my rig. But most "fun" is that its pretty easy to mount panels on slow moving gimble servos and make them auto tracking for the best possible production.

    As for removing 3 generations of panels, I'd have been tempted to just keep adding, but I have more roof space than your van... I think 4KW of solar is perfectly reasonable, don't you? Who cares about roof heating if you can turn on your AC from battery? LOL...

    ReplyDelete
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    1. Wolfe,
      4KW! Wow that would run my A/C...well mostly. You're right my RV (It's NOT a van, but an actual Class A Motorhome :)) just doesn't have any space left on the roof. MAYBE I could fit one or two more somehow...a lot easier if they keep getting smaller.

      Rich "The Wanderman"

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  7. "Lead me not into temptation; I know the way myself..."

    I did a little international research on AE, and found 200W/18V flexible panels for $150... They list a 2000W package for $1500, so i bet you could get another discount.

    A decent 60A 12-48V (2800W max) MPPT controller is $75...

    2000W solar for $1600ish (plus whatever install supplies)? Way too tempting...

    ReplyDelete
    Replies
    1. Wolfe,
      Go for it! I don't have the roof real estate, but I'll wager you do!

      Rich "The Wanderman"

      Delete

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