solar panels on roof but dismount as portable on site? is this a practical option?

mixedup · Veteran Member

solar panels on roof but dismount as portable on site? is this a practical option?

PeterD · Guru

All the rigid panels are suitable. You just have to add some bits (eg brackets) to the sides and suitable mounts on top of the van to connect the panels to the roof. If you look around the forums way back you will even see some that have been hinged on both sides so one side can be detached and props connected to tilt the panels. It's just the flexible/stick-on panels that will provide more of a challenge.

mixedup · Veteran Member

thanks - trying to google to see some examples now. Do you think I need to have the solar mounting supported by steel frame, or can it attached to 3mm sign white sheeting?

In fact, I'm building the frame now and wondering whether I need to have specific steel frames at appropriate points, or extend frame on top for "roof racks". In other words could I just finish off my frame and sheet with 3mm aluminium composite (sign white) and then come back later to mount the solar panels?

Jaahn · Guru

Hi mixedup smile

Just some thoughts for your consideration.

A lot of people just stick some angle brackets to the roof nowadays using Sikaflex to hold the panels. I would think that over a frame support would be best so mark where they are.

I would find that getting up on the roof to take panels on and off would be very difficult and I would not personally consider it. Also risky for an oldie cry However if you do then buy smaller panels say 60-80w, that can be easily handled. The current standard wiring plugs are designed for permanent installations and are difficult to unplug on a regular basis. Replace with something easier and better.

Buy standard panels from the internet, not a retail shop. I have bought quite a few and they all worked well at good prices, with delivery to my door. Cheep and cheerful, not dear and oh dear. hmm

Good luck Jaahn

-- Edited by Jaahn on Saturday 30th of July 2016 08:45:52 AM

mixedup · Veteran Member

Jaahn wrote:
Replace with something easier and better.

Thanks for the advice Jaahn - wondering what you had in mind here?

Aus-Kiwi · Guru

Yep $7 alloy L angle from Bunnings. Some stainless steel screws, sikoflex . Mainly Se seal ., I found the new connectors can come apart if wanted quite easy .. I have used solar to house via inverter to run the pool pump . Hey .. It's better than being on trickle charge doing bugger all !! Lol

iana · Guru

cargo tie down 1.jpg I was considering the same idea, or just doing something similar so the panels could be tilted at an angle. What I had in mind was using cargo tie down track and quick release fittings. You can buy the same tie down as the heavier unit that is threaded to take a bolt from the states for about $3.80 each.

Jaahn · Guru

mixedup wrote:
Jaahn wrote:
Replace with something easier and better.
Thanks for the advice Jaahn - wondering what you had in mind here?

Hi mixedup smile

I have used several types of plugs over the years for portable panels. Some by chance as i acquired the hardware cheap or from a sale. Having arthritis in my hands I found the late style panel plugs were difficult to use regularly having to press the tabs in evenly to seperate them. You might find it OK. But they will wear out IMHO as they are not designed for constant use. hmm

The old fashioned type of two flat pin polarised plugs and sockets for low voltage DC, pins in a T arrangement. Easiest to use but not water proof. Latest plastic plugs are crap.

Marine waterproof two round pin polarised, threaded locking plug to socket. Ackward to use but good and you can leave them lying around.

Merit plugs are my current favourite if I had to buy some more. They are double pole connection in a simple push in plug and socket design that holds in place. Not water proof.

In my system I used a lead with a "box" on the far end with the sockets for the panels. The lead needs a connection to the vehicle with a higher rating and I have used an anderson plug there. Having a decent length lead and size gives more options for positioning the panels ! Also repositioning during the day.

I also have a marine stainless steel cable, 5mm with an eye each end crimped on, for security for the panels. Perhaps for my peace of mind as much as anything. wink Drilled a hole through the panel frames and a modest lock.

Jaahn

PS just for information if useful for someone else. I used the above system for a 24v motorhome and had the 12v panels wired at the plugs in the "box" as pairs of 24v.

mixedup · Veteran Member

thanks for the info guys - some more ideas

Actually....since I'm doing it DIY I wondering why not build in a way to after unleashing/unlocking the panels from the driving position to then be able to rotate and elevate them whilst on the roof. Would need a central rotation bearing/device upon which to rotate them. Any ideas what sort/type of part could be used here? Almost like a mini-version of the large bearings that diggers pivot/rotate around.... I'll do some googling...

mixedup · Veteran Member

perhaps this could be part of a design...

https://www.bunnings.com.au/prestige-155mm-150kg-swivel-assembly_p4013194

Jaahn · Guru

Hi mixedup, smile

My thoughts again on your new ideas.

Panels are relatively cheap. My time is precious and my energy more so. I would just buy more panels and put them on the roof flat and fixed. Then a couple of portable ones stored away for the bad days. That is more or less what I do. hmm

Life is too short now for a lot of mucking around and I am not up to it either ! The easy life is my aim when I get on the road biggrin

Jaahn

PS I've been playing with panels and power for 15 years. In the old days people had trackers to maximise the expensive panel power. All the problems they entail. Hardly see them now as people just put more panels up instead as it is cheaper, easier and more reliable.

-- Edited by Jaahn on Tuesday 2nd of August 2016 08:57:11 AM

-- Edited by Jaahn on Tuesday 2nd of August 2016 09:07:30 AM

iana · Guru

I agree, carried away with complexity. If you are parked in the shade, panels on the roof of the van will be useless. Better to have fixed on the roof and some portable as stand by.

robol · Veteran Member

Panels also keep a lot of sun off the roof, good insulation. I also connected my 200w x 35amp panels in groups of two so that if one group is shaded then the whole system doesn't suffer, also MPPT controller helps. 24v system.

Cheers Rob.

mixedup · Veteran Member

Jaahn wrote:
Panels are relatively cheap. My time is precious and my energy more so. I would just buy more panels and put them on the roof flat and fixed. Then a couple of portable ones stored away for the bad days. That is more or less what I do.

I agree that sounds more intelligent :)

swamp · Senior Member

HI

Mixed up

Yes it can be achieved but at greater complexity in bracketry and engineering .This is great but not ideal unless u absolutely have to ,such as a foldout camper that covers the panels when unpacked .

To do this the panels have to be very secure otherwise vibration will damage them .

Solar is now more affordable go fixed mount 200-300watt fixed to roof .

Use 160-200watt foldouts for the portable set .Trifolds are easier to carry

The sun does not always reach the roof or the portable unit in the same amount . Having both ensures you get some solar at least .

300-400 watts is a great starting point

200watts per 100ah of agm is also good target to aim for if not exceed .

swamp

mixedup · Veteran Member

Ok - thanks swamp - I'll have 2x220AH AGMs - was thinking of putting 2 panels on the roof for the moment - haven't decided what power/size for these yet..

Jaahn · Guru

mixedup wrote:
Ok - thanks swamp - I'll have 2x220AH AGMs - was thinking of putting 2 panels on the roof for the moment - haven't decided what power/size for these yet..

Hi mixedup smile

We have answered your questions as asked, however there is another that you have not asked yet that I will address. How are you going to utilise the tug alternator to charge the batteries. That is the best source of charging you have. It might charge in an hour what the panels will do all day. Depends on what the tug is and the age and the type of alternator fitted.

???

Jaahn

mixedup · Veteran Member

Hi Jaahn, yes I will. Planning to run with a BMS that allows alternator/240V/Solar...

macka17 · Guru

Hi.

Mixedup.... Says it all.
Don't know where to go next hey ! ! ! (only kidding).

After 40 odd yrs of panels on all sorts of things.
It's honestly not worth the trouble.

Unless you want every miliamp or have nothing better to do.

When we started Solar originally. I remember paying around $600 for a 20w panel
The largest you could get. (originally they were 5/10w )
The 2 x 40w on carport cost me just under $700ea. over 34yrs ago
and still going fine.

Nowadays. Just buy a couple exra, I bought a 200w recently for around $220 del..

bolt them down. Gives security from thieves. Heat reflective proofing for interior of van.
it really does. Them and heat reflective paint combined.

IF you have to have a mobile.
Pick one up around 80w and carry it around for a while.
Bigger outputs are heavier again.
Think about lugging.bolting lifting. each one EVERY time you move.

Nah...Not in our age group mate.

How old are you??.

I did one on ute for a while but never used it.

S/S hinges one side.
Lift up legs. adjustable, other side. Works,
but in 6 months on ute used twice. (The two times I tried to make sure it worked and locked.)

Another one. I made similar to fridge slides. coming out forwards and propping on front bar.
Out of ally angle.
Can do sideways as well.

Same thing. never used them. Both on mates utes now,
They Just kept panel under deck or roof bars so you can carry other stuff too.
Have fun

mixedup · Veteran Member

ok thanks - yes, I'm pretty much converted and onboard with you now smile

voyaginator · Newbie

In terms of electric connectors for the panels what are the easiest to connect/disconnect, sturdy and weather (water, UV) proof ?

robol · Veteran Member

Google " Energy Matters " and then look at " quick connect cables, MC4 ". I have had these on solar panels permanently mounted to roof rack on car for about 10 years and no problems. The connectors have been clipped up underneath the solar panels. I did make up a small tool to release the connectors although they can be purchased. I have also used the same connectors for the panels on the bus. So far I am very happy with them.

Cheers Rob.

mixedup · Veteran Member

Hi robol, how does this compare to Andersson connectors?. I'm looking at using Andersson connectors for the 12V from car to caravan fire example.

Dick0 · Guru

Got a couple of these fixed permanently to the roof of a pop-top, by using angle aluminium and sikaflex from Bunnings. Adds about 30kg to van weight. Solar power through mppt controller feeding 2 x 110ah batteries. Batteries also charged from tug via Dual VSR and Anderson plugs. Batteries always fully charged by end of day journey. When camped I couldn't care less which way panels face...batteries still get charged if sunny & close to charged on duller days. Never run out of 12v supply yet.

robol · Veteran Member

Hi mixedup , I know the MC4 connectors have an o-ring to seal against moisture etc. but I don't think the Anderson plugs are sealed as well.

Cheers Rob.

Hi Dicko, Yes you can't have enough solar, they make life a lot easier when camped. They also help keep a fair bit of sun off the roof itself. I have just enough roof space left for two more 80w panels. Mine are set up in two separate lots, front and rear so that if one lot are shadowed then hopefully the other end will still get some sun. It also helps with voltage drop.

Cheers Rob.

-- Edited by robol on Sunday 21st of August 2016 07:30:55 AM

Jaahn · Guru

robol wrote:
Google " Energy Matters " and then look at " quick connect cables, MC4 ". I have had these on solar panels permanently mounted to roof rack on car for about 10 years and no problems. The connectors have been clipped up underneath the solar panels. I did make up a small tool to release the connectors although they can be purchased. I have also used the same connectors for the panels on the bus. So far I am very happy with them.

Cheers Rob.
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Voyaginator
In terms of electric connectors for the panels what are the easiest to connect/disconnect, sturdy and weather (water, UV) proof ?

Hi I did make some comments on my experience with connectors for portable panels in the 7 or 8th reply in this thread.

The MC4 connectors are ok for fixed panels as you fit and forget them. But I found they were hard to disconnect when you did it regularly. My hands are a bit worn out ! My wife could not do it either. So I would only use something easier. The old T two pin low voltage plugs are the easiest, just like using your 240 plugs at home. Wife used these easily for years even without my being there at 'the block'. Here is a link to show the style of plug and socket. This site is not necessarily recommended. confuse

http://www.ebay.com.au/itm/12-volt-PowerSocket-Extention-T-Plug-Caravan-Boat-Marine-4WD-Low-voltage-2-pin-/291499620878?hash=item43debb3a0e:g:8V0AAOSwDNdVih~E

Being waterproof may not be necessary if you put the connection in a place which is protected. I have used a flap of rubber hanging over them, or underneath a side battery door etc. Anderson plugs have no protection as supplied. The low voltage does not require to be waterproof as it will not short out, more to do with contact corrosion and dirt IMHO. hmm

Do also take notice of Macka and my comments about the weight of portable panels !

Jaahn

-- Edited by Jaahn on Sunday 21st of August 2016 11:44:22 AM

Dick0 · Guru

robol wrote:
Hi Dicko, Yes you can't have enough solar, they make life a lot easier when camped. They also help keep a fair bit of sun off the roof itself. I have just enough roof space left for two more 80w panels. Mine are set up in two separate lots, front and rear so that if one lot are shadowed then hopefully the other end will still get some sun. It also helps with voltage drop.
Cheers Rob.

-- Edited by robol on Sunday 21st of August 2016 07:30:55 AM

Hi Rob, true, my panels shade the roof quite well in the heat and when free camping I can run 2 large 12v fans to move a lot of air in the cabin (pop top).

Colin Penrose · Senior Member

Hi. I have just returned from two weeks free camping. I have a 200w solid panel Sikaflexed to the roof using the 6 plastic mounts. I have a 105amp 12v battery that never got below 12v. Granted I did install a new diesel heater and use gas for fridge. Perfect set up for me plus no one can steal my solar panel and I don't have to stow it when leaving camp.

Aus-Kiwi · Guru

Although permanent panels may not be 100 % directed at sun ? They are working while sun is out and while driving . Portable solar needs to be moved every hour or so .. Often end up shaded by trees, campers etc also .. Oh yes the sun moves too ! Lol

Cruising Cruze · Guru

@ Mixedup

You can always make it that way that you can stand the panels up on either side like what I did on my ute

Cheers John