Solar Mounted on roof rack

[rafa]

Hi All.

I am fixing my 145W solar panel to roof rack today. Just chasing mounting tips n pics if you can be bothered.

I will be mounting mine flat as I don't use roof rack much at all and bought a much higher wattage to compensate for the not ideal angle. Seems to be ok so far at 7am this morning the PV was 13.2 and PAmps 1.7 so happy so far.


Cheers.

Marty.

[threedogs]

You can buy Panel specific mounting brackets , but invert some angle iron and
cut some rubber to isolate it and give it abit of shock absorbing .Avoid aluminium angle and pop rivets they WILL
rattle loose over time, and not ideal for outback conditions, over engineer it with what you have available.

[P4trol]

Here's a cheap n dodge tip that was done on mine before I bought it.

A thin layer of foam stuck to the back, then a black cable tie on each corner. You need to replace the cable ties every now and again. Cabling comes up behind the snorkel.

[rafa]

Ok. Quick trip to Church oops I meant Bunnings.

Panel now mounted and has foam around frame between panel and roof rack.

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[threedogs]

KISS love your work Rafa , failsafe

[DX grunt]

G'day Marty.

I think these pics are pretty useless, but the wife's got the camera and she's away for another 2 weeks.

I've got mine angled a bit to allow for rain run off and a bit of wind deflection.

Make sure you check the tightness of the nuts, regularly.

Rossco

http://i1015.photobucket.com/albums/af279/DXgrunt/024800x600_zps43774db0.jpg (http://s1015.photobucket.com/user/DXgrunt/media/024800x600_zps43774db0.jpg.html)

http://i1015.photobucket.com/albums/af279/DXgrunt/0ab51a8c-d9f3-4f09-b7eb-cf05ad207b9b_zpse16d1ee5.jpg (http://s1015.photobucket.com/user/DXgrunt/media/0ab51a8c-d9f3-4f09-b7eb-cf05ad207b9b_zpse16d1ee5.jpg.html)

http://i1015.photobucket.com/albums/af279/DXgrunt/023800x600_zps681e9e84.jpg (http://s1015.photobucket.com/user/DXgrunt/media/023800x600_zps681e9e84.jpg.html)

http://i1015.photobucket.com/albums/af279/DXgrunt/DX%20grunt/Solar/ExtraMoreDXgrunt003.jpg (http://s1015.photobucket.com/user/DXgrunt/media/DX%20grunt/Solar/ExtraMoreDXgrunt003.jpg.html)

[AB]

My brother has recently done this using 2 x panels.

He mounted them under the roof rack using channel and a lock so they can be slid out easily and set up at camp to position better but...

Mounting them under the rack is no good for a permanent set up. The rack itself does block out a bit of the sun so as both of you have done is better.

My brother's idea does have It's advantages though...

1) You can still use the rack to carry things
2) Having the channel system to easily remove and position better at camp.

Food for thought anyway. Have a think about your type of usage (Drive directly to camp sit at camp and do nothing or more touring regularly) and decide the best mounting for ease of removal but secure.

Maybe torx bolts and key on your keyring could be a good option to take them out easily and be "semi" and I mean "SEMI" secure from theft.


P.S.....Love the dual bag holders Rossco....Very SEXY....lol

[megatexture]

We use our roof rack a fair bit and I've considered mounting it under the rack on a slide to pull out the back once set up camping but again haven't decided if it would be with the effort. ATM I just strap on top the gear up there

[rafa]

Thanks all. I use this for work. Remote trips for week at a time. Just want fridge to run 24/7 without touching dual battery on car. So far so good. Added warm carton this morning to give it work out. 13V in battery at sundown and Cold beer. Gotta be happy with that.

[rafa]

The 145 w on the roof has generated 38.6 aH today so far :)

[Skyhawk]

You have some good pics here.
I like these all very much and wish to have a such installation of my own.
I love to have good stuff.


Platinum Construction & Design Pty Ltd
"Gold Coast QLD Australia?
+61 404 354 284, platinumconstructiondesign.com.au"

[Cuppa]

Just a word of caution about mounting solar panels either as Rafa or AB's brother has done.

Before doing this it would be worthwhile to test the panel(s) for shade tolerance. Some are MUCH worse at this than others. I have found that just the shadow of a hand on some panels can reduce total output to next to nothing, whilst others a similar shadow reduces output only negligibly. Unfortunately it is difficult to predict which will behave in which way without trying them out. Buying expensive branded panels is no guarantee, any more than expecting that eBay cheapies will suffer this problem. AB's brother presumably doesn't have this issue, or he would get virtually no input. In Rafa's case hopefully all will be well, but there is a possibility of reduced daily output, due to shadows caused by the raised sides of the roof rack during early morning & late afternoon. If you have enough, you have enough, & such 'loss' is of no concern, but if you need all the panel can provide raising the panel might make a difference.

Cuppa

[megatexture]

Arnt polycrystalline panels better in a shaded scenario?

[rafa]

Good points Cuppa. For that very reason I went "overboard" with the watts. I am only running a 40L engel and today it cranked 41 a/H so I guess all is well. Being up here in the sun helps too I guess.

In the three days its been on the 3rd battery is back 13V by mid morning

Marty.

[Cuppa]

In the three days its been on the 3rd battery is back 13V by mid morning



Sounds good. :)

[rafa]

We will see how it stands up to some of these top roads and tracks though. Will report back after rugged bush trip. :)

[Cuppa]

Arnt polycrystalline panels better in a shaded scenario?

Hi MT,
All of my panels, 11 of them from various different manufacturers, are monocrystalline. I tested them one day by having my wife cast a shadow with her arm over a small section of each panel. Some it made very little difference to output, whilst with others output dropped immediately by up to 90%. Depends on how the panel's internal connections are laid out, more than the type of panel. The panels often touted to be better in partially shaded situations are the amorphous (unisolar) panels but they have their own problems (http://www.exploroz.com/Forum/Topic/4577/Uni-Solar_panelA_word_of_caution.aspx) (as well as having a larger area to output ratio, significant when available space is limited.

Not sure about better shade tolerance on poly panels. Historically mono panels have been more efficient (how much of available sunshine is converted to electricity, expressed as a percentage, with 18% being at the high end) than poly, but used to be more expensive. In more recent times panel prices have dropped so much this difference is small, often no difference. Poly have become far more common since solar house installations became popular, partly because it was easy to compensate for lower efficiency by adding another panel or two. Plenty of roof real estate on most houses, but this is not so in most mobile situations, hence the generally continued preference for mono by travellers. That all said the arguments that used to rage between mono & poly advocates no longer occur, because the difference between them these days is not worth worrying about.

Cuppa

[rafa]

Just thought i was due to update this post. One month on. Covered some pretty crappy roads/tracks. Panel still in place and never dropped below 12v by lunch everyday back at 13+v

Loving it.

Marty.

[DX grunt]

The 145 w on the roof has generated 38.6 aH today so far :)

I love my roof mounted panels, too (2 x 125 watt BP Solar Panels, hinged together in the middle and held together with angle iron all around).

Got a power drain somewhere, and the regulator dropped down to 65% battery power, the other day.

Left the truck out in the sun, and by the end of the day it was up to 95%. Remembering it's still spring and the sun isn't really hot.

In summer over here, in the middle of the arvo, I can leave my long range Codan HF radio and UHF CB on scan, car radio on and still run my 95lt Evakool fridge, and the power doesn't drop below 100%.

Can't remember who told me, but somebody said I'd need 120w to run my fridge. So I got a 2nd panel to run my 'accessories', lol

I'm one little happy chappy too.

Rossco.

PS. Not that it matters now, but I'll post some pics of how mine's secured to the roof - once it stops raining.

Rossco

[Cuppa]

Left the truck out in the sun, and by the end of the day it was up to 95%. Remembering it's still spring and the sun isn't really hot.



Just to split hairs & clarify a possible misconception. Solar panels give their best performance on clear sunny but cool days, as the temperature rises their output actually reduces.
BTW Rossco, I still think that your solar panel wattage was a good choice, plus it gives you a 'tropical roof' to help keep the inside of your pod a bit cooler. :)

Cuppa

[Cuppa]

Got a power drain somewhere, and the regulator dropped down to 65% battery power, the other day.



Just a thought, do you have an inverter? An inverter left on in standby mode will drain your battery like that.

Cuppa

[AB]

An update on my brothers set up with panels under roof rack. It's crap to be honest and as Cuppa mentioned with the bars blocking portions of the panel makes a huge difference!

Even the smallest of shadows can make a huge difference.

[DX grunt]

Just a thought, do you have an inverter? An inverter left on in standby mode will drain your battery like that.

Cuppa


I do, but it's tucked away in the wardrobe at the moment. lol

I spoke with a Telstra technician and his former trucks never had this problem, so it's off to the auto leccie

[rafa]

40.9 A yesterday from my panel, how's that stack up?

Marty

[Cuppa]

Sounds pretty reasonable Marty.

Mounted flat, in good sunny conditions your 145w panel should be pushing out about 8.45 amps provided the battery was 'empty' enough to accept it &/or a load switched on (eg. Fridge running & had been running overnight). 40.9 Ah divided by 8.45 = 4.8 (peak sun) hours. Sounds about right to me at this time of the year & bearing in mind it's possible you might be getting a bit less than 8.45amps due to roof rack shading. The important thing is that it is meeting your needs & keeping your battery topped up.

Cuppa

[rafa]

Battery has been + 12.5v everyday by 12.30!

Not a deep cycle either. Also hasn't dropped under 12v yet

Cheers cuppa