solar panel cover up

[kenpatterson]

Hi
I am about to fit a flexable solar panel to my boat. I have come to the conclusion the best hassle free place to put it would be on top of my sprayhood. I was thinking of getting a clear pvc envelope sown into the sprayhood to keep it in place but will the pvc cover reduce the output of the panel. Any ideas.

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[Rohorn]

Hi....First thoughts are more about the effect of sprayhood flapping and highspeed oscillations on the panel connections. Also semi rigid plastic fatigues in those conditions. If the spray hood is really rigid, should be OK.
I'm told that the panels deliver current in diffused light as well as direct sunshine, so having a transparent cover may be ok. I'm too far away from mine at the moment to run a quick check. Mine are mounted further back on the Portique (radar arch with no radar) to get out from under the mainsail.
Cheers....R

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[kenpatterson]

Hi R
thanks for advice. Can't see any problem with movement. The hoods fairly firm. Only other place I can put it would be forward of the mast. to run cable back to batteries would be a nightmare. I would be happy to take a reasonable drop in output to avoid this. Still waiting for panel to arrive by post otherwise I could test beforehand.

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[anchorhandler]

Hi Ken
Dont worry too much about covering up the panel.....Technically there has to be a slight drop in output as you are in effect putting a restriction on the sunray's (what are they ?) making contact with the solar panel but i would be surprised if, after connecting a current meter, you would even notice it!
My solar panel is rigged up inside my cabin relying on sunlight shinning through the window to develop a charge.....I measure the current output outside =.38 amps and then measured it inside = .37 amps (its a 5watt flexible panel) so as you can see the difference is negligeable.
Regards
Simon


<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!

 

[kenpatterson]

Hi simon
You have made my mind up. ps. Will there be a diode with the panel. I ordered from compass. D does'nt say what make it is.

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[anchorhandler]

yep,
99.9% of all solar panels i have seen have blocking diodes fitted so yours should be no exception.

Raises in interesting question though.....on a dull, dreary typically British day, could you remove the blocking diode, plug the panel into your battery bank, then sit back with a beer and promptly get a sun tan from the solar panel?

Must try this out!
Simon



<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!

 

[Johnjo]

Just recently bought a flexy Uni-Solar USF11, this make has a blocking diode installed.

But did notice when looking to purchase that not all have one fitted , but they can be purchased separately, think they are called "Schottky Diode" if i remember correctly !

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[simonfraser]

every surface you add on top will reduce the light received by the panel by at least 9% plus the loss due to lack of transparancy.
tie, nail, screw the thing down, don't put anything on top.
Simon

p.s. and you might get condensation in between

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by simonfraser on 19/03/2004 19:19 (server time).</FONT></P>

 

[anabel]

If possible don't cover it with anything. In these latitudes there is little enough sun. On top of hood sounds ok if you can make it really secure. I bought a UNI Solar one in US some years ago. Still working fine. Have fitted it just forward of hatch. Can be walked on with no damage (sailing shoes) Try to have it where it will get whatever sun there is no matter what direction the boat is pointing. Most of them are fitted with diodes. Absolutely necessary otherwise battery will discharge i to solar panel as soon as it gets dark. Incidently during reasonably bright sunshine there will be an open voltage reading of about 18 volts. However as soon as you colnnect it to the battery or any load this drops to about 12.5 or very slightly higher. Mine is a 10 watt model and it is connected to starter battery only. This means the engine battery will always be fully charged when I arrive to go sailing. Larger models 15 or 20 watts & above need to have a regulator otherwise they will over charge the battery during our long hot summer !!!
The shorter the wire going tothe battery the better. Also don't have too light (thin) a wire as this would rfeduce the charge delivered to the batt.

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[anabel]

If possible don't cover it with anything. In these latitudes there is little enough sun. On top of hood sounds ok if you can make it really secure. I bought a UNI Solar one in US some years ago. Still working fine. Have fitted it just forward of hatch. Can be walked on with no damage (sailing shoes). Try to have it where it will get whatever sun there is no matter what direction the boat is pointing. Most of them are fitted with diodes. Absolutely necessary otherwise battery will discharge into solar panel as soon as it gets dark. Incidently during reasonably bright sunshine there will be an open voltage reading of about 18 volts. However as soon as you connect it to the battery or any load this drops to about 12.5 or very slightly higher. Mine is a 10 watt model and I have it connected to starter battery only. This means the engine battery will always be fully charged when I arrive to go sailing. Larger models 15 or 20 watts & above need to have a regulator otherwise they will over charge the battery during our long hot summer !!!
The shorter the wire going to the battery the better. Also don't have too light (thin) a wire as this would reduce the charge delivered to the batt.

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[Rabbie]

I have a Unisolar panel which I have tied down flat on the top of the hatch garage. I quote from the Unisolar instructionbook - 'Do not allow the charger to flap in the wind.Tie or mount against a supportive surface, slightly convex if possible to shed water. DO NOT shorten the cable as this is hazardous'.

<hr width=100% size=1>A day not spent on my boat is a day in my life wasted.

 

[Benbow]

<blockquote><font size=1>In reply to:</font><hr>

DO NOT shorten the cable as this is hazardous

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Are you shure that's not 'short' the connection ?!

If not I would bet its a bad translation or transcription somewhere along the line. The connections can be any length you like, but shorter is better. Quality of connection is important as any ammount of resistance will cause a significant voltage drop.

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[Dave1258]

A little tip I can offer is if ever you need to do any work with the leisure batteries, then cover up the solar panels with a towel or similar first before diconnecting them.

<hr width=100% size=1> A man should have two things in life, a boat and a wife willing to let him have one.....

 

[Ric]

You will get a loss, and I fear it may be quite significant. I have one of my panels on the coachroof and when I open the sliding perspex hatch it slides over the panel and output is significantly reduced. I also suspect that you will get lots of problems with condensation in the envelope.

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[Rabbie]

Apologies. Slip of typing finger. My end quote should have been after 'water'. What I should have then said was do not CUT cable (ie shorten) as instructions said this was hazardous.

<hr width=100% size=1>A day not spent on my boat is a day in my life wasted.