Solar Panel Lift, Drag and Noise

[Brianna]

The magical interweb is loaded with technical info, videos and stories (both professional and amateur) about every aspect of RV Solar.

There is every possible installation scenario, from small and compact to something massive--approaching a subdivision's electrical substation.

But there is very little content about drag, lift and noise. Obviously the most important of the 3 concerns is lift.

On a typical 30-40' motorhome going down the road at 50-60mph is this not a real concern as long as the panels are not close to the leading edge of the vehicle?

All I see in discussions is people reporting that their panel have not come loose. Do we know the actual likelihood of this happening, or is it all anecdotal?

[DirtRider]

Originally Posted by Brianna

The magical interweb is loaded with technical info, videos and stories (both professional and amateur) about every aspect of RV Solar.

There is every possible installation scenario, from small and compact to something massive--approaching a subdivision's electrical substation.

But there is very little content about drag, lift and noise. Obviously the most important of the 3 concerns is lift.

On a typical 30-40' motorhome going down the road at 50-60mph is this not a real concern as long as the panels are not close to the leading edge of the vehicle?

All I see in discussions is people reporting that their panel have not come loose. Do we know the actual likelihood of this happening, or is it all anecdotal?

Good question, and I'm interested to see the answers. I'd think there would be minimal lift since the angle-of-attack is zero. There is the question about wind speed differences above and below the panel--if the speed below was much lower than the speed above, that actually should create some lift. Maybe the 2" or so they're mounted above the roof fixes that?

But I do agree that I wouldn't want to mount one too close to the front of the RV.

*This is based off zero experience with solar panels, just thinking it through.

[whalepirot]

Noise would be caused by turbulent airflow.



Lift was discussed.


Drag would be minimal given the frontal cross-sectdion of the huge RV.


The OEM panels on ours have hno discernable effect on all three.

[Old Scout]

...can't imagine an issue with any of potential wind resistance related problems posed....having said that, and even though I realize there are any number of "space-age" adhesives, EHB tapes and sealants on the market, I still opted to use screws on the leading edge roof brackets of my panels....belt and suspenders I guess....

[Alpine36]

We still have the original Siemens panels on ours. WRV mounted them with steel screws which rusted out. I reattached them with stainless screws and Dicor, not an issue even when they were ready to fall off.
I can't believe the original panels still work, but they do!

[Old Scout]

Curious--"still working".....but how much output?

[RVPioneer]

Lift is definitely possible. Don’t think for a second that it can’t happen because the panel is horizontal. Put one on the roof with no screws or adhesive and see what speed you can reach before it blows off. Make sure they’re properly secured.

Drag. Unless your operating in a vacuum, drag will exist. It will probably be insignificant as far as fuel economy goes. Drag could conspire with lift (and vibration) to separate a poorly secured panel from the coach.

Noise. Probably. Also, probably won’t hear it from the drivers seat.

[Lv2Roam2]

We have 8 160W panels mounted for about 40,000 miles of travel at speeds up to 65 mph. The panels are double-sided tape and dicor sealed to a fiberglass roof. We've never experienced any noticeable noise or drag. My roof checks every 3 months show no evidence of lifting on the leading edge panel mounts.

In 5+ years as a full-timer I've never read or heard of an incident where a panel broke loose.

[Alpine36]

Originally Posted by Old Scout

Curious--"still working".....but how much output?

Not much lol.
Enough to keep the house batteries at 12.9v for a few days with the inverter charger off...at home with little DC load of course.
This seems to keep the battery watering to a minimum.
Not sure if a solar upgrade makes sense in our location on the O.P., where we spend 80% of our time.
We like our propane and Honda EU2000i for those rare extended times spent off grid. Onan for the roof AC, also a rarity in the PNW. Suppose we could invest big bucks in solar/battery improvements, but would it improve our quality of time spent RV'ing? For us, the answer is not really.
We're usually "plugged in" somewhere anyhow, with few exceptions.

[Woo10-210]

The majority of the lift will be at the first several feet of the coach. Beyond that it will equalize. The higher the velocity the further back that point will be.

[Brianna]

Originally Posted by Woo10-210

The majority of the lift will be at the first several feet of the coach. Beyond that it will equalize. The higher the velocity the further back that point will be.

Thanks Woo, that makes a lot of sense.

[Bobby F]

Originally Posted by Brianna

All I see in discussions is people reporting that their panel have not come loose. Do we know the actual likelihood of this happening, or is it all anecdotal?

I do know that I (and many other people) have attached a 1/16" SS cable through mounting holes on each panel and looped it to the A/C frame, so that I don't kill a motorcyclist if a panel does come loose. (You can screw and glue, but if you're working with a rubber membrane over a luan panel, "apocryphal" just means "it hasn't happened to me yet.")

[paul65k]

Originally Posted by Alpine36

Suppose we could invest big bucks in solar/battery improvements, but would it improve our quality of time spent RV'ing?

The answer is YES......It has to be YES........I've spent way too much money on mine for it to be anything other than YES........so I'm sticking with YES!!!

[Brianna]

Originally Posted by paul65k

The answer is YES......It has to be YES........I've spent way too much money on mine for it to be anything other than YES........so I'm sticking with YES!!!

Perhaps a different thread, but I enjoy tweaking the Alpine just as much as I enjoy driving it around.

I owned a 30' sailboat for about 12 years and did a ton of upgrades and modifications and beautifications. When there was nothing left on my self-imposed to-do list it got a little boring. It turns out I was more of a remodeler than a hardcore sailor.

So, adding solar or flooring or slipcovers or battery- boost solenoids is all part of the fun and excitement for me.