Illustrated Guide to Solar Installations on Boats

[aybabtme]

Figured I'd answer in the requested format.

Type and model and size of boat.

Hunter Legend 37.5

Total Panel Output (How much power can be generated?)

915W

Panel Size: How big are the panels? Individual? Total area required?
each: 1500x1000mm
total: 3000mm x 1500mm
so about 10ft wide, for a beam of 12.9ft

Age of Panels: When did you install the panels?
Installed this week. Panels were second hand, so no idea of their age. Maybe 10y?

Panel Location: Where is the panel located and does it cause problems there? Does it cause problems with any other gear or while sailing? Does it cause windage problems? Has shading of the panels been a problem due to location of the panels and surrounding rigging or equipment?

Panels are above the back section of the cockpit, over the stern. It's out of the way of all the gear. I haven't tested them while sailing yet, but I expect they'll create a decent amount of windage. There's no shading so far while at the dock. The panels have stood just fine in strong gusts, so I'm not too worried about them flying away in weather. In any case, the frame allows for easily dismounting the panels, and otherwise is made of Al instead of SS, so it should break /be sacrificial.

Type and Brand of Panel: Who made the panel? What type of panel is it? Marine or Domestic (land) panel? Origin?

Sunpower 305W, mono. Come from an old large domestic/industrial install.

Total Cost: How much did it cost to build the system? How much was each panel?
Paid 90$ for each on Craiglist. Metal to build the arch was ~700$. Tooling was maybe ~1000$ (started with no tools). Charge controller was 350$. Wiring was 100$.

Total Efficiency: Do you consider the installation efficient? Please any comments that may help another improve efficiency, based on your experience.
I didn't take the most efficient panels money can buy, just the biggest I could get for cheap. I can alway shell out top $ to go get another 180W by buying fancy 365W LG panels.

Damage? Has the installation been damaged by wind or corrosion or breakage?
Too early to tell.

What would you do differently next time? Tips? Different type of panel?
Not sure. I think I did as well as I could. Maybe next time I'd pay someone to build the arch, but the learning process was worth it, and labor in the SF Bay Area is way too expensive.

Any problems? Disappointments? Surprises? Disatisfaction? Issues? Weaknesses of gear or system?
I find the arch is pretty big and looks a bit funny. But it's so convenient that I don't care. My wife is happy to have a lot of electric gear onboard, and so am I. I don't care if the line of the boat is "ruined", it's not that fancy of a boat anyways and the convenience is well worth the odd look.

How has adding the solar affected your sailing or cruising?
Too early to tell.

[RickG]

Originally Posted by RickG

Thanks to Steady and the folks who contributed to this post. It was helpful to follow this while I worked my project.

Beneteau 423 42' sloop with two Panasonic 330 watt hard panels installed 2018 above the bimini. Panels do not add noticeable windage, and do not look unnatural. The solar portion of the system was under $2,000. There is a bit of shading from our radar emitter on the arch, but not enough to make use want to move the radome.

Here's the text from a blog post I wrote on the subject:

https://dinghylife.wordpress.com/201...arger-upgrade/

Quick update, we hauled our boat for hurricane season at Puerto del Rey Marina in Fajardo Puerto Rico. We took down our big Panasonic panels and stored them on the boat. Taking the panels down was trivial and took less than half an hour. It sure was easier than putting them up!

Cheers, RickG

[FredVeroMakani]

Sorry, I know it is an old post thread. How are you Firefly working for you so far?
I had 4 unit that are being replaced under warranty, they lost more than 50% of capacity within less than 2 years (and plenty of charge) . I have the same set up as you do with less solar panels.
Thank you for your feedback.

[RickG]

Our Fireflys are great. We have seven. After two months on the hard they are holding charge with minimal losses. Game changer for us after moving from FLA GCs. Our 800ah bank has never gone below 50% DOD and is fully charged from solar most days by noon. I'm thinking about putting a 12V heating element in our hot water heater for this excess solar power generated.

Cheers, RickG

[SailingKiss]

I saw some realy nice installations here - thank you for sharing!


We have a 36' catamaran and thus plenty of space for solar panels. As we want to start cruising next year from Germany to the Caribbean we're discussing which panels to go for. Basicly I found the special marine grade panels which come at a high price and are lighter. Or I can go for the domestic 300 to 400 Wp panel which costs way less than the marine grade. I could go for Canadian Solar 330 Wp for 130 € or for fancy LG 400 Wp for 310 €.



What I did not find on the forum was a longtime experiance with domestic panels onboard. Do they suffer from corrosion? Or do you recomend to go for domestic panels and replace them after 5 years which still would be cheaper than the special marine grade panels?

[Copacabana]

Originally Posted by SailingKiss

I saw some realy nice installations here - thank you for sharing!


We have a 36' catamaran and thus plenty of space for solar panels. As we want to start cruising next year from Germany to the Caribbean we're discussing which panels to go for. Basicly I found the special marine grade panels which come at a high price and are lighter. Or I can go for the domestic 300 to 400 Wp panel which costs way less than the marine grade. I could go for Canadian Solar 330 Wp for 130 € or for fancy LG 400 Wp for 310 €.



What I did not find on the forum was a longtime experiance with domestic panels onboard. Do they suffer from corrosion? Or do you recomend to go for domestic panels and replace them after 5 years which still would be cheaper than the special marine grade panels?

I have found my Canadian Solar panel to be fantastic, and you can't beat the price. I'm not sure there is such a thing as a "marine" solar panel (except in marketing). Panels made to sit on the roof of a house in the sun, rain, sleet, snow, wind and salt air will certainly stand up to boat use, especially when you consider that boat panels get a lot more TLC (cleaning, checking connections etc.) than a panel on the roof of a house.

[Mr B]

I ran an Anodising plant for Aluminium in my early days during a recession when there were no jobs for any one,
So I got to learn a lot about the process of anodising aluminium,
The aluminium has different structural grades,
The Anodising is the same process for all of it,
Engineering Blacksmith and Boilermaker/welder jobs were non existant, Which I am,
Anodised aluminium is like a chrome plated cover on aluminium,

Aluminium corrodes internally from the exposed ends of the anodising where there is no coating from being cut to length,
Anodised aluminium is coated to with stand all environments,
It holds the windows in, In tall buildings,

How often do they strip all the aluminium window frames out of a 25 story building,
Same goes for stainless window frames,
They are usually there for the life of the building,

There is no Marinised version of Anodised aluminium,
Same as stainless steel, There is no Marinised version, Its stainless and thats it,

But it is a good marketing ploy to charge extra, Its Marinised, Hahahaha

[SailingKiss]

Thank you - that was what I was hoping for, that's another tick in the box


I will go for the domestic panels and post my installation (next spring).

[Svan]

I have removed three old Siemens solar panels of a 2003 vintage with two slightly larger Renogy panels. I bought an Epever solar charge controller sized 40 amp. This came with a useless Ethernet cable remote box with a friendlier display which I am not sure whether I will mount. Probably.

My advice to anyone who buys these panels to also buy a wrench so you can bust open the connectors cleanly and a collection of male female blanks. We reused the existing wiring as it was also 10 ga.

My problem is in mounting to the roof. Don’t want to just knock a new hole and use the “z clips”. I am thinking to install with a tilting mount to tilt upwards From centre with a possible rig involving the boom on calm days. My impression of this mount is that it can also be secured level, suitable for travel.

Anyone with input on these mounts?

[Svan]

I don’t know why it posted everything a bunch of times. Follow up question. Our boat has outboard auxiliaries. I have an automatic charge relay planned to sit between the house and outboard starter battery so that the 10 amps available on each goes into the house if we are motoring a while. Is it a good plan to lead the “house” leg of the ACR to the panel side of the charge controller? This would bring around 13.5 volt approx 20 amp.

This is partly why I got a 40amp charger.

[rgleason]

Originally Posted by Mr B

Same as stainless steel, There is no Marinised version, Its stainless and thats it, but it is a good marketing ploy to charge extra, Its Marinised, Hahahaha

Small quibble. It makes a big difference where the stainless steel is made and how it is made! There are different grades of stainless steel ie 316 and 304.


https://continentalsteel.com/stainless-steel/grades/

[a64pilot]

304 and 316 are the most common though, 304 is also know as 18-8, it’s way far and away the most common, almost all kitchen stainless cutlery etc is 18-8 / 304.
316 is almost always labeled as such, if you find stainless that isn’t labeled as to its type just called stainless, it’s almost certainly 304.
People like to think that a magnet can be used or determine quality of stainless, unfortunately that’s not true, stainless can be made magnetic by being cold worked, rolling the threads on a screw or bolt for instance, so the exact same grade of stainless may or may not be magnetic.

Passivating SS goes a long way to help keep it from rusting, passivation takes an acid to “eat” the iron exposed to the surface away, acetic acid can be used to passivate, read and follow directions.

316 is more resistant to rusting, but as they are both 300 series stainless, it’s not unfortunately a huge difference. There are nearly rust proof types of stainless, but it’s not common and of course more expensive.

[Pete7]

I have a couple of pieces of 304 box section supporting the solar panel. There is slight rusting on the surface after two years, but its more like a tea stain rather than thick rust you would see with mild steel after years in the weather.

Can it be polished at home with limited equipment and will it be worth the effort? if so how?

Or is it a case of leave it alone and find something more important to worry about

Pete

[a64pilot]

I would scrub it with barkeepers friend, which has an acid and does a very mild passivation. Very good results for not a whole lot of work.
Polishing stainless pretty much takes a big bench grinder on which you put a leather wheel and likely a cloth wheel on the other side, and this only after it’s been sanded very smooth with very fine sand paper.
It depends on how much work you put into it. I just had a ladder made with a mount that bolted to the hull that had to be polished.

However 304 can be very successfully polished and passivated. Look at Kato Marine davits and Radar pole, they are very highly polished 304 and are know to be a high quality manufacturer.

[Pelagic]

Originally Posted by a64pilot

.

However 304 can be very successfully polished and passivated. Look at Kato Marine davits and Radar pole, they are very highly polished 304 and are know to be a high quality manufacturer.

Exactly, My heavy rub rail on Stargazer is 304 polished to a mirror finish.
Mini grinder, various fine cloth polishing discs and that Green block of wax that you mix with water to apply. Rub rail has held its shine for years