Illustrated Guide to Solar Installations on Boats

[Pelagic]

Luther's experience with blowing out panels has me worried and wondering about best storm perpetuation.

My vinyl/polyester Bimini usually stays on if anchored for a typhoon, as it has bar tight lacing and wraps around all the stainless structures. You can walk on material.... side covers come off

The clearance above the Bimini is zero inboard, about 2" outboard
My sense is if prepping for storm at anchor, I would leave as is

However should i put some padded athwartship strapings across panels to help?

I chose to install a large structured Bimini for tropical live aboard that wraps around mast to cover entrance to pilothouse

If necessary it can come off in about 1 hour if offshore conditions were threatening

But having experienced 50 knot gusts, it heels a little quicker than before but steadies to same heel

I won't know until the added weight and windage of panels is tested, but on a 48 ton boat, I am not too worried

[PaulinOz]

Type and model and size of boat. Lagoon L450F

Total Panel Output (How much power can be generated?) 1,962 watts

Panel Size: How big are the panels? Individual?aprox 1500 x 1000mm

Total area required? 9 square meters

Age of Panels: 2 1/2 years

When did you install the panels? 2014

Panel Location: Across back of boat at Fly bridge level



Does it cause problems with any other gear or while sailing? No

Does it cause windage problems? No

Has shading of the panels been a problem due to location of the panels and surrounding rigging or equipment? The boom will shade at some sun angles.

Type and Brand of Panel: Sunpower E327 watt

Origin? Panels purchased from Floating Impressions in Oz
How much did it cost to build the system?

6 x Panels E327 $640 each = $3,840 AUD
2 x Flexmax 80 $700 each = $1,400 AUD
S/S and Aluminum Framework $3,900 AUD
Cabling, switches, fuses connectors etc $1,795 AUD

Total for Solar system $10,935 AUD




Total Efficiency: Theoretical o/p 160 amps best observed output 131 amps

Do you consider the installation efficient? Yes

Please any comments that may help another improve efficiency, based on your experience. Keep panels clean

Damage? Has the installation been damaged by wind or corrosion or breakage? No

What would you do differently next time? Tips? Different type of panel?

Only thing I would change is panels currently 6 x 1 so 6 meters x 1.5 meters, should have mounted 3 x 2 so 4.5 meters x 2 meters
How has adding the solar affected your sailing or cruising? No need to run generator or engines to charge batteries while at anchor. Once batteries up above 90% SOC, heat hot water via 240 volt inverter and one hour electronic timer. (Thanks to Rolf for that idea).


The best thing about a large array is not the 130 amps in full sun it's 30 to 40 amps on an overcast day with some misty rain.

Parting advice nobody ever said "I wish I had less power on my boat"

[Pelagic]

Great post Paulinoz

[mitiempo]

Originally Posted by PaulinOz

Total Panel Output (How much power can be generated?) [/I]1,962 watts

Total Efficiency: [/I]Theoretical o/p 160 amps best observed output 131 amps[I]

Yes, great post. But your theoretical max output is 136 amps, not 160. Panel wattage divided by the bulk charging voltage of 14.4.

[Pelagic]

Double post

[Pelagic]

Originally Posted by mitiempo

Yes, great post. But your theoretical max output is 136 amps, not 160. Panel wattage divided by the bulk charging voltage of 14.4.

Mitiempo, trying to understand your calculation

Here is the 327w Sun power Specs same as Paulinoz.

He has 6, I have 4 installed.

How did you come up with your number for Paul?

Where do you find "bulk charging"?

[noelex 77]

327x6 /14.4=136A

So if the solar panels were putting out their rated STC output and the battery voltage was 14.4v the current would be 136A.

It is very likely that when accepting a high current the battery voltage would climb to around 14.4V so it is a realistic number. Certainly better than using 12V. However, it is possible that the voltage could be lower if there was a heavy load, for example, the inverter was running an electric hotplate. In this case the voltage would be lower and current would be higher for the same output.

The Outback regulator will remember the maximum wattage input from the panels. This removes the voltage from the equation so this number will provide a better indication of how close the panels are performing to the 1962W (327x6) in the specifications.

Don't forget if the controller starts regulating (ie batteries hit absorption voltage or float voltage once they have finished the absorption stage) the controller will start not utilising all the power from the solar panels. Thus only numbers seen without regulation are relevant when comparing the actual verses theoretical output.

[a64pilot]

Rethink panels blowing out, they are a huge area and at least mine I think I had rather lose the panels as opposed to losing the structure they are attached to.
Mine have taken a 45 kt or so gust that knocked us down with no issue and with us laid on our side, the wind was very much more under the panels than I would expect in a storm.

[Mike OReilly]

Originally Posted by a64pilot

Rethink panels blowing out, they are a huge area and at least mine I think I had rather lose the panels as opposed to losing the structure they are attached to.
Mine have taken a 45 kt or so gust that knocked us down with no issue and with us laid on our side, the wind was very much more under the panels than I would expect in a storm.

I built my solar panel bimini with the idea of being able to remove them in the case of a major approaching storm. It won’t be easy, but I can do it. So far though, it hasn’t been an issue.

[a64pilot]

I had thought about removal also, I can remove mine in maybe an hours work, I used the MC4 connectors it's it just unplug and unbolt, I would leave the frame.
My issue is once removed, where will I put them?

[kas_1611]

a64 - would they lie flat in the cockpit area? or could you manage to get them down the companionway into the cabin?

Just voicing some ideas

[a64pilot]

I could get them into the cabin I think , but they are big, and not sure where to put them.
I guess it all depends on the size of the storm, the time I have to prepare and whether I have to ride it out in the boat or not.
My preference would be to remove everything and take it ashore and store it. I would not want them in the cockpit, air think they would ride it out better mounted where they are.
Panels are pretty tough, we just had a Tornado come through Albany Ga a week or two ago and it walked through the Marine Base here, that has a Solar Farm, I mean acres of panels. It seemed the only ones damaged were from flying debris, or that is what it look like when I fly over and look.

[Mike OReilly]

Originally Posted by a64pilot

I had thought about removal also, I can remove mine in maybe an hours work, I used the MC4 connectors it's it just unplug and unbolt, I would leave the frame.
My issue is once removed, where will I put them?

Guess you have to get a bigger boat

My two 150 W panels will fit down below pretty easily. My other two 50 W panels can be tied tightly down to the deck. But I sure hope I don’t have to do it quickly. I had originally planned to make the whole set up very easy to remove. This changed to ‘relatively easy.’ Certainly can do it, but would probably take me a couple hours of cursing and swearing.

[Pelagic]

Originally Posted by noelex 77

327x6 /14.4=136A

So if the solar panels were putting out their rated STC output and the battery voltage was 14.4v the current would be 136A.

Thanks Nolex, so to confirm on my 24v system...when testing in the next few weeks I should see something below:
327 x 4 / 28.8 = 45 amps @ 24V

[Pelagic]

[QUOTE=a64pilot;2324752
......Panels are pretty tough, we just had a Tornado come through Albany Ga a week or two ago and it walked through the Marine Base here, that has a Solar Farm, I mean acres of panels. It seemed the only ones damaged were from flying debris, or that is what it look like when I fly over and look.[/QUOTE]


That was my impression also and when I checked the Sun power specs it shows a Max wind loading rating (above and below) of 245kg/sqm

For the engineers out there, how many MPH does that equate to per sqm?

I think the key question in Luthar's case ....Was it the panels that failed, or the attachments to the boat?

My own Bimini is made of stainless pipe (not tube) with 12 flanged attachments to the integral steel...
No flex or harmonics in high winds.

Perhaps this is not an issue if attached properly.