Solar Questions

[JHanson]

Longhorn, as Brian mentioned, we had FWC install two 100-watt Global Solar semi-rigid panels on our camper. We wanted the extra capacity to charge camera batteries and run our laptops for working in the field. FWC moved the roof vents on our camper to the center to accommodate the panels:

We're extremely happy with the system - plenty of power, essentially zero wind resistance, and just two holes through the roof. We also used the GS charge controller, which has been operating perfectly.

Solar power is frighteningly expensive to install, but it's a lifetime investment, so it's worth it to do it right the first time. For most applications I think a single 100-watt panel would be sufficient. I think the ultimate setup would be a single GS panel on the roof, plus a portable plug-in panel with a strut that would allow you to park in the shade and run a panel out into the sun (and would also allow you to exploit very early and late sunlight).

Here's a link to the writeup I did on Overland Tech and Travel:

Power for the JATAC

 

[Bwht4x4]

I'm really attracted to the Global Solar panels, but the idea of adhering them to the roof scares me a little bit. What happens if they are damaged or short out and need to be replaced? What is the efficiency of them compared to a rigid solar panel that is mounted above a roof with air flowing under it?

Lots of questions about these units...?

 

[craig333]

Are the cable clamps glued down or screwed? I do like the low profile. Very nice.

 

[JHanson]

The GS panels can be removed if needed, although they're certainly not coming off on their own. I can't remember the last time I heard of a PV panel failing - I have no doubt they do, but the technology is so simple and reliable the chance must be scant. I imagine you could damage flush-mount semi-rigid panels if you tried really hard, but I'm convinced they're less susceptible to harm than a rigid panel mounted above the roof on a bracket.

Air circulation? I suppose the lack of it might hamper efficiency to some very slight degree (I've seen no figures regarding this), but for us the advantages of zero wind resistance, better overhead clearance, and a nearly invisible profile to thieves far outweighs any such concerns. I can tell you that if the sky is clear we'll be floating at 13.5 volts within an hour of sunrise with our 200-watt system, and even on high overcast days we've kept up with demand. Brian DeArmon has no lack of power with his single 100-watt GS panel.

Craig, I don't remember if the clamps are screwed down (the truck isn't where I am right now). I'll try to remember to look next time.

 

[Bdold]

That is a really slick system. What amount of weight does this add to your roof? I've also read about keeping airflow but, this does not appear to be an issue for you.

My panel sits below the enclosure 1" so, it's somewhat protected from me moving kayaks up there.

 

[ntsqd]

There is a performance loss if the backside of the PV's isn't cool. Pretty much the same temp related loss as with a rigid I would expect. How much the GS panels are affected by this I've no idea. I'm considering drilling a series of vent holes in around the frame of my Grape panels so that there isn't a captured air volume under them.

 

[JHanson]

Bdold, if I recall correctly the panels weigh about 20 pounds each.

I would think that under many circumstances the back of a panel secured to the roof of a camper might be cooler than if it were exposed to air. But that's sheer speculation. In any case I think the tradeoff is well worth it.

 

[jbahr]

Are the cable clamps glued down or screwed?

They are glued!

 

[JHanson]

Thanks Jason! I figured they must be.

 

[Jack]

I mounted a 120 W solar panel to the front luggage rack bar (FWC's luggage rack), mounted crosswise with stainless steel hinges, I also mounted 2" rubber pads to the rubber pads to the side of the panel away from the luggage rack bar such that they rest on one of the roof ribs. A bungee cord to the jack mounts keeps the panel from bouncing on rough roads. The hinges let me push a box under the panel to prop it up for better angle. I've not propped it up very often, but the hinges make it easy to remove. (We have shipped the camper across country, and getting under 80" is critical - but that's another two stories).

 

[The Next Adventures]

Hi Long horn,
I have two 65 watt unisolar mats on my roof that stick on. I have the wires running down the outside of the camper and drilled no holes in the roof. I got the two mats with all wiring a fuse box and morningstar mppt controller for $340.00. I did the install myself, was very simple just take your time. I live full time in my camper and never plug into shore power. I charge multiple tablets, laptops, camera batteries, my shaver well just about everything daily because I live full time in my camper. You can see the workings of this project on my post just click here

 

[longhorn1]

Longhorn, as Brian mentioned, we had FWC install two 100-watt Global Solar semi-rigid panels on our camper. We wanted the extra capacity to charge camera batteries and run our laptops for working in the field. FWC moved the roof vents on our camper to the center to accommodate the panels:

We're extremely happy with the system - plenty of power, essentially zero wind resistance, and just two holes through the roof. We also used the GS charge controller, which has been operating perfectly.

Solar power is frighteningly expensive to install, but it's a lifetime investment, so it's worth it to do it right the first time. For most applications I think a single 100-watt panel would be sufficient. I think the ultimate setup would be a single GS panel on the roof, plus a portable plug-in panel with a strut that would allow you to park in the shade and run a panel out into the sun (and would also allow you to exploit very early and late sunlight).

Here's a link to the writeup I did on Overland Tech and Travel:

Power for the JATAC

Jim and to all that have been adding to my Solar post thank you. I suggested that FWC go to the Global Solar Mats since there would only be penetrations through the roof for the wires and less wind resistance. I have been working with Terry Budd at FWC. I even mentioned the JATAC article. He said that FWC engineers were researching different solar companies. Last week he got back to me and said that moving forward FWC would be offering Zamp Solar in a 100W panel on the roof, a wall plug for an additional portable 80W panel. As a building envelope consultant, when it comes to roofing, the fewer penetrations through the roof, the less chance of a leak. They were also looking at cost. The new costs for the 100W and portable 80W are now on the web site. I'm not sure what the cost difference to use 2 Global Solar 100W adhered panels would be. I do like the option of the portable panel, which can be adjusted to the sun. I suppose, if one has clout it may be easier to get FWC to install other systems. When I place my order during the next year, I will find out.