New solar install....

[Perry J]

Originally Posted by Jane P.

I suppose it makes sense that these panels are designed to withstand hail.

How about low hanging branches?

I had pine needles in the solar panel mounting brackets from going into one of my favorite out of the way places in the Sierras earlier this summer.
No damage to the panel from the low branches.
John

[Ron F]

Originally Posted by Jane P.

I suppose it makes sense that these panels are designed to withstand hail.

How about low hanging branches?

Low hanging "anything" can be a problem. I once tried to go through a bank drive-through with my bicycle on the roof. Fortunately, it only stripped the bike computer off the handlebar. On the egg, the Maxair vent cover is higher than the panels, so I'd expect that to be the first contact.

[honda03842]

I've decided to add two 40 watt flexible solar panels to our roof. We have an uncluttered roof, no air conditioner or Maxx Air vent, and the thinnes appeals to me..

These panels are about a 1/10th of an inch thick. Our plan is to attach them to the roof with an adhesive or tape. In addition to being thin, they weigh less than 5 lbs apiece.

They come in a number of different wattages. Information follows on the product.

Sunflex Solar and Alternative/Renewable Energy - About us

[cpaharley2008]

Norm,
I'm not sure I'd attach solar panels flat against your roof, I always heard that air was needed to prevent deterioration underneath, does the manufacturer recommend a permanent attachment to a fiberglass surface, what about heat generated underneath, may crack the fiberglass.

[honda03842]

I'm not sure I'd attach solar panels flat against your roof, I always heard that air was needed to prevent deterioration underneath.

Jim,

I've sent the manufacturer an email about mounting the panel. They show them mounted to fiberglass boats in their ads though I admit to being a little concerned.

We've had traditional panels on a painted white, aluminum trailer roof and they did get hot. It would get up to 150F in the air gap under these panels

Initially I'm going to purchase a single 40 watter and experiment with it before attaching it (semi) permanently. The panel is about 2.5x1.5 feet.

I assume the air between the panel and roof is for cooling.

I haven't purchased a solar panel yet. I bought a Tire Pressure Measurement System for the trailer and car this month, don't want to bust the budget. When it arrives I'll report on it. I'm always concerned about tires.

[cpaharley2008]

I like those panels but not sure about taping them direct. I thought of using suction cup clamps, they sell them at Sears- Craftsmen- they have little clamps that will hold like 3 lbs. Anyway, 4 should hold these panels on the side/front of the trailer and you can move it with the sun. Not permanent but portable does have it's benefits and you could attach the clamps to roof if you are going to be gone and worry about theft. Course you would need a ladder.

[Carol H]

Originally Posted by Jane P.

Actually, I had a similar problem with my furnace (a faulty thermostat). The blower would not turn off, and it drained the battery.

So, your second 50 W panel gives you piece of mind? How so? If you have an appliance problem which drains the battery won't your battery still drain?

Mostly I dry camp in the Winter, so I can have several days without sun. I haven't really measured my daily energy consumption, but I would be surprised if it is above 25-30 W.

I am trying to wrap my head around cost/benefit ratio of going above 50 W.


As I am reading this thread ...

1. Ramsond is the manufacturer of choice
2. Want to get 50w or greater solar panel(s)
3. Anything over 80-85 W is "overkill"

And ... GET LED LIGHTING

You have asked a good question - one I'm also wondering about. I think it has to do with where and when you camp.

I have a 15w panel for a number of years and have gone up to 5 straight days without power and this summer went about 15 days but had 3 days of towing in there where the car was charging. I was most of the time in the sun if not I moved the panel over to the sun. The battery recharged full each day with that one little panel. Being carefull with the use of power I have never had the battery go down to 60%. I use LED's and have the fridge on propane so the only thing using the power are the Fantasitic Fan and the water pump. If I read well into the night I use a little head lamp. I do recharge phones each day and camera battery - on the recent trip the fan was only used in late afternoons - it was in the high 90's but it cooled off a lot at night so not needed to sleep. An hour or less a day to download photos to computer..... Radio is a portable battery so its no need for power.

Having said that I am considering upgrading my panel as the prices have come so far down from when I purchased mine. If I was to do it again I would not get anything less than a 30 watt - if I was camping where I did not need to run a fan all day and night or run the furnace. If I was camping where I need to run the furnace and or the fan all night I would for sure go for more power - 60 watts or more. I can also see where if the panels where mounted on the roof you would also need more power again as you would not be mounted to the correct angle to the sun or may not be in the sun at all.

[honda03842]

Jim, My first real concern is your earlier comment about temperature of the panels on the roof.

I would like a solution that allows me to attach the panels, but also to remove them at a later date without damaging the roof. I'm looking for an adhesive that will allow this. I like the vacuum hold downs but would be unsure about their travelability.

We don't carry a ladder, that limits our solar panel placement options. As well we are not the type to move our panels for maximum Sun. Generally our rule is to minimize setup components.

We are like most fiberglass campers, low electricity users. We have all LED lighting, probably the most important single improvement for minimizing electricity usage. We have the ability to charge phones and computers when driving with an Inverter in the tow vehicle. As well we have the ability to charge our trailer battery from the tow vehicle.

I hope to do a test this month to see how much power our electric blanket draws, wondering if we can do an overnight with the e-blanket on.

As to theft, it's something we don't worry about; it almost seems that the low frequency of theft is not worth the worry.

Jim, thank you for all your thoughts.

[cpaharley2008]

Another option is a second battery and a 15 watt portable solar to keep it full, that is what I have had success with, the 15 watt panel keeps both my batteries @ 100%. Well you can figure it out what is best for you, good luck.

[Night Sailor]

Originally Posted by honda03842

I've decided to add two 40 watt flexible solar panels to our roof. We have an uncluttered roof, no air conditioner or Maxx Air vent, and the thinnes appeals to me..

These panels are about a 1/10th of an inch thick. Our plan is to attach them to the roof with an adhesive or tape. In addition to being thin, they weigh less than 5 lbs apiece.

They come in a number of different wattages. Information follows on the product.

Sunflex Solar and Alternative/Renewable Energy - About us

I have used Solar panels on many of the boats I've skippered. I liked them all. One had 10 110 Watt panels which ran DC Fridge, auto pilot, and a water maker. This was a 62' catamaran. On the other end of the spectrum, I've seen single flexible panels on deck that I never thought woukd hold up. They take a beating, literallt pwople walk on them unconcerned about damage and never seen one fail--just a small steady charging current and no need for a charge controller. I became a believer in these thing. I agree with Norm on taping them down with double sided tape. Less wind drag ane only a small hit in performance due to lack of an underlying cooling space.

For me, I tend to use a lot of power and would rather go larger on a panel. The ideal set up is a smooth fairing on the leading and trailing edges with ventaltion from side to side. It woukd be relatively easy to custom make a mount that would allow a flush mount on the fore and aft axis for maximum efficiency. However if you dont mind the wind drag any old mounting solution will do. The most important factor is to have at least one panel--that give you energy independence.

I have to admit the cost of these panels seem very low. The market must be weak for these now. Grab these deals whike you can.

One final note. A new technology, not yet perfected and it might be very long before it is, places a carbon nanotube in the center of each cell for a three fold or more increase in efficiency--up to 70% efficiency compared to 17% with current technology. The nabotube acts like a resonant antenna for light. However there is no way to place them where the need to be. We can look forward to much higher efficiencies in the future.

[honda03842]

Thank you Night Sailor.

I looked up solar panel efficiency. In summary a typical panel loses 0.5% power for each degree above 25C. Assuming a top solar panel temperature of 70C (about 158F), you'd lose about 20% of your rated power.

[Night Sailor]

Originally Posted by honda03842

Thank you Night Sailor.

I looked up solar panel efficiency. In summary a typical panel loses 0.5% power for each degree above 25C. Assuming a top solar panel temperature of 70C (about 158F), you'd lose about 20% of your rated power.

I am not sure what you are thanking me for, but you are welcome. I hope I did not disuade you from the flexible panels--they are wonderful. I think your taping idea is fantastic, unless you decide to go bigger with a raised mount. I would not worry about cooling or the perfect angle--just get nore of them, wire it up and forget about them.

Any solution you chose will psy for itself over time in frer energy. I am such a believer in these things, I am thinking about putting an array on the roof of the house.

Excuse all the typos. Small phone keyboard means I often hit the wrong keys.

[Andy B]

Originally Posted by honda03842

I looked up solar panel efficiency. In summary a typical panel loses 0.5% power for each degree above 25C. Assuming a top solar panel temperature of 70C (about 158F), you'd lose about 20% of your rated power.

The mono and poly crystalline panels loose power at elevated temperatures, however the amorphous type panels work much better at high temperatures. They also work better in partial shade and low light situations and when not at the optimum angle towards the sun as stick on panels would be on the roof of a camper. The only trade off is that the require a bigger area for the same wattage, but there is usually plenty of space on top of a camper.
Amazon.com: Uni-Solar PVL-68 PowerBond PVL 68 Watt 12 Volt 112-Inch x 15.5-Inch Flexible Solar Panel: Patio, Lawn & Garden

The manufacture shows that they are available in a shorter length as well.

[honda03842]

amorphous type panels

I favored the amorphous panel however they are long and thin. At least the 68 watter is too long for our roof's central section. As well it's too wide for the side section, lower section.

[Andy B]

Originally Posted by honda03842

amorphous type panels

I favored the amorphous panel however they are long and thin. At least the 68 watter is too long for our roof's central section. As well it's too wide for the side section, lower section.

There are some other sizes that are shorter than the 112 inch long 68 watt panels. The 62 watt panel is 103" and the 31 watt size is 55.5 inches long. A couple of the 31 watt size panels might fit side by side. The 31 watt panels are 6 volt and would need to be used in pairs.

http://www.sunwize.com/info_center/p...%20RoofLam.pdf

http://www.solarcellsales.com/techin...l-saleslit.pdf

[Sharon G]

Could you mount a layer of Reflectix underneath the flexible panels and prevent heat buildup underneath?

[cpaharley2008]

I think that is a disaster waiting to happen. Fiberglass is porous to an extent and sealing it under this will probably cause damage. Maybe to a piece of aluminum or fiberglass sheet and then elevate the whole thing like a conventional panel would work? This would allow ventilation and keep heat to a minimum.

[Sharon G]

Oh, dear. Another "brilliant" idea shot down. I'm so glad, though, because I would probably have tried it! Thanks!

Originally Posted by cpaharley2008

I think that is a disaster waiting to happen.

[cpaharley2008]

Originally Posted by Sharon G

Oh, dear. Another "brilliant" idea shot down. I'm so glad, though, because I would probably have tried it! Thanks!

Please do not ever take any of my comments personal. I did not intend to make you feel shot down. Do not disparage, it may work but I think there are better solutions. Maybe there was a better way I could have expressed myself.
"Necessity is the mother of invention" or is that the other way around?
.

[Sharon G]

Oh, no! I didn't feel personally shot down at all! I was making fun of myself!!!

I'm delighted I got a good answer to my question!!!

Originally Posted by cpaharley2008

Please do not ever take any of my comments personal. I did not intend to make you feel shot down. Do not disparage, it may work but I think there are better solutions. Maybe there was a better way I could have expressed myself.
"Necessity is the mother of invention" or is that the other way around?
.