Location of solar panel

ovsa · 11-01-2021, 07:31 PM

If I am mounting only one 100W panel (42" x 20") where would be the best location on the roof of my 2003 Chevy Roadtrek 170P?

Front or back of van, side to side orientation or front to back?

Don't know if it makes a big difference but I hate to put it up and then realize I should have put it somewhere else.

Also consider wind forces. Just looking for input.

Thanks

Rlum · 11-01-2021, 09:52 PM

Quote:

Originally Posted by ovsa

If I am mounting only one 100W panel (42" x 20") where would be the best location on the roof of my 2003 Chevy Roadtrek 170P?

Front or back of van, side to side orientation or front to back?

Don't know if it makes a big difference but I hate to put it up and then realize I should have put it somewhere else.

Also consider wind forces. Just looking for input.

Thanks

Considering the panels require sunlight to function. You will parking that portion of the van directly under sunlight or as close to it as you can. This will increase the heat inside the vehicle. So if you speed lots of time in the back, I would install near front area. This way you minimize the heating of area where you will be living.

Just my opinion.

mkguitar · 11-02-2021, 12:01 AM

because of the parking in the sun issue I wouldn't have panels on my van

I do have a small freestanding panel which I put out in the sun and kick it to follow the sun throughout the day

we try to camp where we have shade, unless it's winter, to keep the interior temps comfortable

I have a connector at my house battery and about 20' of wire.

mike

hbn7hj · 11-02-2021, 03:43 AM

My 100 watt panel on a 2003 C190P Roadtrek is front to back behind the vent. I have a vent cover which cuts the wind loads. Were I to do it over I’d do 200 watts. The panel feet are mounted with VHB tape. Been there for 10 years with no problems. The controller is on the aft facing cabinet wall on the passenger side.

SteveJ · 11-02-2021, 12:37 PM

Quote:

Originally Posted by hbn7hj

My 100 watt panel on a 2003 C190P Roadtrek is front to back behind the vent. I have a vent cover which cuts the wind loads. Were I to do it over I’d do 200 watts. The panel feet are mounted with VHB tape. Been there for 10 years with no problems. The controller is on the aft facing cabinet wall on the passenger side.

I would agree with at least 200 watts. A single on the roof, especially at the low solar gain at Canadian latitudes will be severely compromised for output. I would urge using a portable setup, whether framed or flex panels. You will get more output, especially "up north".

Disclaimer: I'm on my second solar setup. Parking in the shade while still collecting solar is the bomb.

ovsa · 11-02-2021, 03:38 PM

Good idea with the vent cover.. That must help with cutting wind resistance.
As the 190 is longer than my 170 i have the issue of the back feet resting on top of the A/C housing which is higher than the roof around it. So i either have to lift up the front of the panel about 4 inches to keep it level or install it at slope with the back being higher. Not sure if that's a good idea.
I'm just going to go with the 1 x 100w for now see how it goes, I can always add more later or add the portable type. i overized the cable and controller just in case.
I'm not a big energy consumer.
Thanks

GeorgeRa · 11-02-2021, 03:43 PM

I have 300W of solar panels on under 20’ long Sprinter. I could push to 400W but found 300W sufficient. I designed my roof from scratch which included vent, awning and solar panels.

A few rules:
1. Panels in series could lose all output if one of them is partially shaded.
2. Panels in parallel will lose shaded panel only.
3. Keep about an inch gap between the roof and the panel for cooling (hot panels are less efficient)
4. Keep panels away from shading structure
5. Don’t cut holes in panels for vents or other reasons (I wouldn’t mentioned it if I wouldn’t see it).
6. With high voltage panel >20V use MPPT charge controller, with lower voltage PWM charge controllers are OK
7. Draw the diagram with shading structures, see attached drawing.

ovsa · 11-02-2021, 04:03 PM

thanks.. that's a really nice mounting system. In your opinion do you think there is a big difference in wind resistance factor (noise and fuel economy) between mounting them in the front of the van versus rear? I know you didn't have the room in the back but from a theoretical point of view. Although the aerodynamics are a bit different on the Roadtrek with that 3 window step up.
Thanks again

booster · 11-02-2021, 04:05 PM

Quote:

Originally Posted by ovsa

Good idea with the vent cover.. That must help with cutting wind resistance.
As the 190 is longer than my 170 i have the issue of the back feet resting on top of the A/C housing which is higher than the roof around it. So i either have to lift up the front of the panel about 4 inches to keep it level or install it at slope with the back being higher. Not sure if that's a good idea.
I'm just going to go with the 1 x 100w for now see how it goes, I can always add more later or add the portable type. i overized the cable and controller just in case.
I'm not a big energy consumer.
Thanks

We have 190 and also have 300 watts (3X100) crosswise behind the fan and over the AC housing. There is on need to go overly high with the panels. It would actually be the rear that has to be higher as the roof slopes, to be level, at least on the newer roof style.

All I did was progressively step the panels down as the go to the rear, with each panel on their own 4 supports. They are level, lower, more aero, that way don't shade each other. I have a thread on here I will try to find and link.

booster · 11-02-2021, 04:12 PM

Re the portable panels vs roof mount. It is a personal decision, but for us the idea of carrying and storing the panels and long cable, having to set it up or put it outside every time we stop and camp, plus make it theft proof is a non starter.

Probably 80% of the time we can turn the van around in the site during the day to get enough sun, or even park it in overflow lot while we go hiking from the park. If even that isn't feasible, we can go at least 5 days on batteries and if want longer will just drive 20 minutes to the dump site and get another day or two.

GeorgeRa · 11-02-2021, 04:16 PM

I couldn’t detect any difference regarding noise but my van is well insulated with sound deadening Thinsulate.

Regarding gas mileage, for my setup the difference was unmeasurable, but I drive 65MPH or below.

See my set-up. https://photos.app.goo.gl/NaDXquJwAigYuTBw1

I use monocrystalline, back contact panels, very efficient, they charge in light clouds condition. I would suggest to mount as many panels as you can.

ovsa · 11-02-2021, 04:19 PM

Yes .. i feel the same way. I was leaning towards the portable type because of better efficiency and parking in the shade bonus , but with the lack of extra room in the 170P I couldn't see it.

to each their own.

booster · 11-02-2021, 06:25 PM

Here is the thread that shows our 300 watts of solar put on in a stepped way to keep them closer to the roofline but still horizontal.

https://www.classbforum.com/forums/f...olar-3407.html

Bobow · 11-07-2021, 04:21 PM

Portable works best. Park in the shade and put panels in the sun with cable to van. They may get in the way at times but many ways to work around this. Bob

ovsa · 11-07-2021, 05:57 PM

Can someone have a quick look at this wiring sketch and tell me if it looks o.k.?
Just wondering if taking the controller leads to the terminal block instead of directly to the battery is ok?
Even with the ground shunt there.
I don't have much room in my battery compartment for extra wiring hence the terminal blocks. Just makes everything alot neater.

Thank you
03C170P

hbn7hj · 11-08-2021, 03:20 AM

Quote:

Originally Posted by ovsa

Can someone have a quick look at this wiring sketch and tell me if it looks o.k.?
Just wondering if taking the controller leads to the terminal block instead of directly to the battery is ok?
Even with the ground shunt there.
I don't have much room in my battery compartment for extra wiring hence the terminal blocks. Just makes everything alot neater.

Thank you
03C170P

Looks good to me. Ready for the smoke test.

GallenH · 11-09-2021, 02:48 AM

I understand the roof vs portable arguments. Doesn't @michael have a system where he can supplement rooftop solar with portable? Seems as though you would benefit from the rooftop in sunny locations (parking at trailheads, etc.) and park your RV in shade with portable when in campground.

I've only had suitcase but will eventually add some rooftop so I'm especially interested in this approach. BTW: I put a box with a covered outlet under the rear bumper that's directly wired to the battery to easily plug the suitcase into and carry several lengths of cable which can be combined. I also have a chain and locks so I can lock the suitcase to the RV trailer hitch or to a tree or picnic table in the campsite if I leave. On my 97PW with the spare on the rear door, the suitcase in its case fits nicely between the tire mount and the door (strapped securely to the tire mount).

ovsa · 11-10-2021, 11:20 PM

Well looks like I answered my own question regarding the location of the a 100w panel on the roof of a 03C170P.
There is only one place it will fit. And that is just in front of the roof vent.
The A/C cover on those units comes up too high to close to the rear of the vent to give me anything level.

Easy choice

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