Rocketbox and solar

[Stalking Light]

I've got an Eagle on order to go on my Tacoma quad cab and have been thinking additional storage options. It looks like a Yakima Rocketbox would at best block about 9" of the rooftop solar. Does anyone have this setup and does it significantly reduce you solar charging capacity?

 

[DesertDave]

I don't have that setup, but I would think that amount of shading would cause you issues. A single Yakima bar about 5" above my solar panel reduced the output 20% when I was testing in bright overhead sunlight. The yakima bar shadow was at most a 1" wide strip across the panel.

A small portion of the nose of a white water kayak, which varies in the amount of shading depending on the direction of the sun, from say 20% to zero % of the panel, basically eliminates any effective charging while driving in total sun on the interstate.

Guides on solar panel placement for RV's often mention the need avoid any shading from roottop AC units or refrigerator vents, for this reason.

 

[MarkBC]

As DesertDave suggests, the effect of shading on solar panels is way more (way worse) than the % of panel in shade.
It's a result of how cells work and how they're wired together...something like that. A shaded cell blocks current from unshaded cells from flowing through it...something like that.
One source says: "The cells in a module are all connected in series. Shading a single cell causes the current in the string of cells to fall to the level of the shaded cell."

 

[Stalking Light]

Thanks all the more reason to travel light. ;-)

 

[Beach]

Yes it will have a significant effect. You could have the panel mounting offset to one side and mount the rocket box opposite side, still would have some effect with the box blocking at a low sun angle. Another option would be to install larger panel(s) to compensate for the loss.I am toying with installing a remote panel plug now so I can keep a portable panel in optimum position while parked in the shade. I would recommend adding a remote plug in if you didn't ordered it.

 

[Stalking Light]

I did order the remote plug too, I have a 60w foldable panel I used with my AT Chaser that I will also use with the 4WC. I'll probably just stop thinking about rooftop storage and just try and minimize the junk I haul with me. I have been spoiled by all the room inside the Chaser, ;-)

 

[MarkBC]

I don't carry anything on the roof (other than solar panels), so I can't offer my experience...
BUT, I know quite a few folks do carry stuff on the roof AND have a solar panel. Sometimes big long things like kayaks...
I wonder how they do it? Maybe they are blocking their panels but don't know about it...or don't worry about it...?

 

[DrJ]

I don't carry anything on my roof either - except solar panels. I can affirm the problem of shading your panels - it greatly reduces solar output.
Maybe the next generation of solar panels will overcome this, but for now it's a significant issue.
You'd have to plan out your panels and rack to avoid this to really make it all work.

 

[Stalking Light]

I don't carry anything on the roof (other than solar panels), so I can't offer my experience...
BUT, I know quite a few folks do carry stuff on the roof AND have a solar panel. Sometimes big long things like kayaks...
I wonder how they do it? Maybe they are blocking their panels but don't know about it...or don't worry about it...?

I'll haul my SOT kayak from time to time but it will mainly be off the roof when I am parked at a campsite.

 

[BFH4N]

My understanding is that not all solar panels behave as described above when partially shaded. I don't remember the different types, but I believe there are some for which the output when partially-shaded is approximately equal to the ratio of light to shade. It's something about how the cells are hooked up and I think it has to do with extra diodes in the circuit somehow. Might be worth looking into before you buy. I'll try to look up where I read about it when I get home next week.

- Bernard

 

[Stalking Light]

Thanks. I ordered my Eagle with the 100w rooftop solar plus a plug I can use for my 60w Powerfilm foldable panel. Not sure what brand the 100w is.

 

[brianjwilson]

I feel like global solar claims to have great results in partial shade or low sun angles. I think there is one member here who has them on a fwc fleet camper?

 

[jha6av8r]

I carry a kayak that blocks about 1/3 of my panel. When we're driving everyday I don't worry about it. If we're going to be stationary the kayak is unloaded.

 

[camper101]

I feel like global solar claims to have great results in partial shade or low sun angles. I think there is one member here who has them on a fwc fleet camper?

Jonathan Hanson has 2 on his JATAC. There are also at least one or 2 others at Expedition Portal who have them.

I have a GS panel but haven't stuck it on the roof yet - slowly getting the parts together and refining my plans.

My understanding is the same: that the CIGS panel is supposed to do a little better when you don't have direct overhead sun (at least that's the marketing claim). That's why they're bigger (per watt) and less "efficient."

 

[brianjwilson]

Jonathan Hanson has 2 on his JATAC. There are also at least one or 2 others at Expedition Portal who have them.

I have a GS panel but haven't stuck it on the roof yet - slowly getting the parts together and refining my plans.

My understanding is the same: that the CIGS panel is supposed to do a little better when you don't have direct overhead sun (at least that's the marketing claim). That's why they're bigger (per watt) and less "efficient."

Yeah that's right. I haven't read any specific reviews but it would make more sense in theory. I wanted to have a fleet built with yakima racks and two global solar panels, but FWC will no longer build a roof with the vents centered like Hanson has. I don't know if 100 watts will be enough for my use. It sure is frustrating to see them do some custom work and then tell you "no" to the exact same thing. If it weren't for ATC's 70's style interior I'd use them instead.

 

[camper101]

I also haven't seen GS reviews and I don't have any technical knowledge (but I haven't seen negative reviews... and the few people I asked had no regrets about installing them). I figured if there's any truth to the CIGS hype it'll be better than nothing because winter is when I need the most power.

Yes, the panels are big and there aren't many layout options up there when you try to work around everything else...

I think there's another technology that's similar (does a little better in low light or shade?) -- possibly amorphous but I really don't know how much truth there is to any of that. The OP could also try something that'll stick on top of the rocketbox so it doesn't get blocked.

 

[Stalking Light]

I think I have concluded the box would cause more problems than it would solve.