Temporary solar mountings for roof.

[Tasemu]

Hi all, i'm living on a narrowboat at the moment but I do not own it. I'm planning on finding my own boat in the near future but want some solar in the meantime. Does anyone have a recommendation for fitting 2-3 100w panels from bimble (https://www.bimblesolar.com/solar/small-panels/12v-bimble-100w) onto the roof with the ability to take them with me when I leave and not drilling holes into the roof?

 

Thanks in advance for any and all advice!

[Alan de Enfield]

How about 4 of these for each panel.

 

https://www.screwfix.com/p/double-cup-suction-lifter/6299P?

 

 

 

Screw the corner of the panel down onto the handle and rotate then so they are across the diagonal (so each sucker is clear of the panel and you can operate the levers)

 

It will not be theft-proof, but then no 'temporary' fixing will be.

 

 

[Tasemu]

Just now, Alan de Enfield said:

How about 4 of these for each panel.

 

https://www.screwfix.com/p/double-cup-suction-lifter/6299P?

 

 

 

Screw the corner of the panel down onto the handle and rotate then so they are across the diagonal (so each sucker is clear of the panel and you can operate the levers)

 

It will not be theft-proof, but then no 'temporary' fixing will be.

 

 

That's a decent option, i'm a little worried that it won't get much suction out of the old paint job on the roof of this boat. These things are for glass right?

[Mad Harold]

3 minutes ago, Tasemu said:

That's a decent option, i'm a little worried that it won't get much suction out of the old paint job on the roof of this boat. These things are for glass right?

lI think silicone sealer (the domestic type) will hold the feet of the panels securely enough.Removal will need a Stanley knife and rubbing the residue with your fingers.

[matty40s]

24 minutes ago, Alan de Enfield said:

How about 4 of these for each panel.

 

https://www.screwfix.com/p/double-cup-suction-lifter/6299P?

 

 

 

Screw the corner of the panel down onto the handle and rotate then so they are across the diagonal (so each sucker is clear of the panel and you can operate the levers)

 

It will not be theft-proof, but then no 'temporary' fixing will be.

 

 

 

Wont work on non slip or rough surfaces.

Try magnet mounts....unless it's a GRP.

[TheBiscuits]

Do you have raised round handrails on the boat?  My solar panel is mounted on a car roof rack clamped and locked to the bars.  This also gives a raised cover that junk like brushes can be stored under.

 

[Tasemu]

Just now, TheBiscuits said:

Do you have raised round handrails on the boat?  My solar panel is mounted on a car roof rack clamped and locked to the bars.  This also gives a raised cover that junk like brushes can be stored under.

 

Yep we got rails, this looks excellent. Car roof aye, an adjustable one yeah?

[TheBiscuits]

Just now, Tasemu said:

Yep we got rails, this looks excellent. Car roof aye, an adjustable one yeah?

 

£28 from Lidl I think.  I had to trim the roof bars a bit so they didn't stick out too far, but they are aluminium so cut easily with a hacksaw.

 

It was a quick temporary fix when I got the solar panel 5 years ago ... 

[Tasemu]

Just now, TheBiscuits said:

 

£28 from Lidl I think.  I had to trim the roof bars a bit so they didn't stick out too far, but they are aluminium so cut easily with a hacksaw.

 

It was a quick temporary fix when I got the solar panel 5 years ago ... 

This looks like exactly what I need, can I ask what you used to fix the panels to the roof rack? (being very brain lazy right now)

[TheBiscuits]

5 minutes ago, Tasemu said:

This looks like exactly what I need, can I ask what you used to fix the panels to the roof rack? (being very brain lazy right now)

 

That's a full size house panel at 260W, but you can now get 300W+ panels in the same size.  That's cheaper than the little panels and gives you more power in limited roof space.  It also gives you a more substantial frame than the little panels.

 

You can either drill through the roofrack bars and bolt into the panel frame or you could use a U-bolt to clamp round the roofrack and bolt both ends into the panel frame.  A bit fiddly though!

[David Mack]

I have used these mounts, stuck onto the roof with stixall. I'm sure they'd come off with a bit of work with a knife and a scraper. 

[Tasemu]

Just now, David Mack said:

I have used these mounts, stuck onto the roof with stixall. I'm sure they'd come off with a bit of work with a knife and a scraper. 

I was talking to the guys at bimble solar about these and was told they would not work with the curved roof of a narrowboat. Is your roof curved, if so that would be great!

[David Mack]

19 minutes ago, Tasemu said:

I was talking to the guys at bimble solar about these and was told they would not work with the curved roof of a narrowboat. Is your roof curved, if so that would be great!

Yes the mounts are at an angle due to the roof curvature, so the panel doesn't sit quite flat in them. But it all works fine.

Full size panel set longways on the roof with 4 corner mountings and the straight mountings half way down the long sides.

I assembled it all dry on the roof, then jacked up the panel slightly on timber offcuts so I could get the mounts out one by one, apply stixall to the underside then put them back in place. Left the stixall to set, then put self tapping screws into the panel surround the next day.

[Jen-in-Wellies]

Magnets. I use rare earth magnets, around 20mm diameter and 5mm thick. The panels have four 2" long lengths of steel angle attached with a single bolt through each to allow them to rotate slightly and cope with the curve of the roof. Two magnets to each bit of angle iron, eight per panel. Have this on my boat and it has survived numerous storms without movement.

Jen

Edited June 9, 2020 by Jen-in-Wellies

[WotEver]

1 hour ago, matty40s said:

Try magnet mounts....unless it's a GRP.

 

3 minutes ago, Jen-in-Wellies said:

Magnets. I use rare earth magnets, around 20mm diameter and 5mm thick

 

These sound like the best suggestion to me.  Ebay or Amazon for the magnets - plentiful and cheap.

[matty40s]

33 minutes ago, Tasemu said:

I was talking to the guys at bimble solar about these and was told they would not work with the curved roof of a narrowboat. Is your roof curved, if so that would be great!

They wont work on a Liverpool/Collingwood roof, but there are boats built properly with roofs flat enough to mount those on.

[Tasemu]

Off-topic perhaps, but it recommends me to put a DC breaker between my solar controller and batteries. In my head this sounds bad, as if the breaker trips, would it not disconnect the battery and possibly fry my controller being connected to the panels?

[Alan de Enfield]

5 minutes ago, Tasemu said:

Off-topic perhaps, but it recommends me to put a DC breaker between my solar controller and batteries. In my head this sounds bad, as if the breaker trips, would it not disconnect the battery and possibly fry my controller being connected to the panels?

 

The BSS specifically allows for Solar panels (via the controller) to be connected directly to the batteries and NOT routed thru any 'switches'. A fuse should be used as close as possible to the battery so maybe they are considering the breaker as a replacement for the fuse.

[Tasemu]

1 minute ago, Alan de Enfield said:

 

The BSS specifically allows for Solar panels (via the controller) to be connected directly to the batteries and NOT routed thru any 'switches'. A fuse should be used as close as possible to the battery so maybe they are considering the breaker as a replacement for the fuse.

In that case would the same potential controller frying happen with a fuse? i've heard from a few sources not to have the solar panels attached to the controller without the batteries connected.

[Alan de Enfield]

2 minutes ago, Tasemu said:

In that case would the same potential controller frying happen with a fuse? i've heard from a few sources not to have the solar panels attached to the controller without the batteries connected.

Potentially yes, but would you prefer a potential full on 'boat fire' (batteries melt, all wiring melts etc etc etc, or a potential controller frying ?

 

If you get a short (without a fuse) and your cables melt, then the controller will be disconnected anyway.

 

Doesn't make sense not to fuse the cables.

[Richard10002]

9 minutes ago, Tasemu said:

In that case would the same potential controller frying happen with a fuse? i've heard from a few sources not to have the solar panels attached to the controller without the batteries connected.

My understanding is that this applies to controllers which automatically detect battery bank voltage, (12V or 24V). If you connect the panels before the battery, the controller may choose the wrong voltage, and damage can ensue.

 

There are several opportunities for panels to be supplying a controller with the batteries not connected, such that it would be hard to think there wouldn't be protection in all/most controllers? I'm no expert, merely logical, (mostly), so could easily be wrong.

 

In the route that power takes from my controller to the batteries, there are 2 fuses to protect the cables, so 2 opportunities for the above scenario to occur.

Edited June 9, 2020 by Richard10002

[WotEver]

34 minutes ago, Tasemu said:

In that case would the same potential controller frying happen with a fuse? i've heard from a few sources not to have the solar panels attached to the controller without the batteries connected.

The fuse or breaker rating should be chosen to protect the cable, and if that cable is sufficiently large then the fuse should never be stressed by the controller's output. Therefore it shouldn't ever blow in the absence of a fault.  Not fitting some protection for the cable risks a fire in the event of a catastrophic fault such as a direct short between the cables.

[Tasemu]

Great, that makes sense to me. Cheers!

[Dave 2]

I've just fitted 2 x 175w panels using the black plastic feet, I found the best way way was to put the feet on the roof then the Panel then drill the holes it took care of the curve of the roof, then stick them down using Soudal Soudaflex. 

[RufusR]

On 09/06/2020 at 11:02, Jen-in-Wellies said:

Magnets. I use rare earth magnets, around 20mm diameter and 5mm thick. The panels have four 2" long lengths of steel angle attached with a single bolt through each to allow them to rotate slightly and cope with the curve of the roof. Two magnets to each bit of angle iron, eight per panel. Have this on my boat and it has survived numerous storms without movement.

Jen

This best option. By far . Currently have 2 x big inefficient Solar’s on 30 degree tilt mounts held by 6 x neomyedium (six ) 9.1 kilo magnets and didn’t move an inch in recent high winds even when from behind . Have 6 x 270 watt panels coming tomorrow and they will be held by 6x 12 kilo magnets each on tilting frames . Cost from amazon is 12 quid delivered per six . Job done ✅