Anybody ever set up solar power on their boat? Any ideas what would be needed?

About powering boats with electricity

Moderator: BruceDow

Post Reply
JvilleJeff
Posts: 2
Joined: Tue Mar 26, 2019 7:49 am

Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by JvilleJeff »

Hello,

Hope all is well, gents.

I am wondering if anybody has had any experience setting up solar power / panels on their boat?

I am considering powering the following:

-Light, Small fans

-Small water heater, small hub

-Little wonder watermaker - 5 - 6 gph

-Small AC unit - 5,000 - 6,000 BTUs

-Small laptop, WiFi cell booster, router

Looking at possibly purchasing a Go Power solar kit (or more than one) to set it up: https://citimarinestore.com/en/384-go-p ... r-products. How many panels (watts) do you think will be necessary to power these appliances?

Also, if you have experience, how dependable is it running things on solar power? I can imagine during cloudy days the power is greatly reduced. Considering purchasing a small gen set as well, for this purpose.

Thank you.

JimmY
Posts: 1043
Joined: Sat Jul 30, 2016 11:08 am
Location: Brighton, MI

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by JimmY »

I just have a small panel setup to trickle charge my small 12V starting battery while the boat is on the lift. The panel is approximately 6" x 12" and has a regulator to prevent draining the battery when the sun isn't shinning. This works great and I don't have to worry about charging the battery out of the boat.

I do belong to a R/C airplane club and we have a large solar array (24" x 36"?) that charges 3 deep cycle marine batteries (for recharging airplane Li-Po packs), and also provides Wi-Fi and internet connection for a small weather station. The IT guy working on had us move a windsock because for 3 hours a day the shadow of the sock was enough to greatly reduce (~50%) the power output of the solar array. Also, here in Michigan during the winter it had trouble keeping up with load with the available sun light. Bottom line, make sure you have clear line of sight to the sun to get the rated power out of the array. I would over size the array if possible (~25% or more) if you are going to depend on it, and I wouldn't depend on it too much! :lol:
-Jim
Nothing says poor craftsmanship like wrinkles in your duct tape!

rleete
Posts: 149
Joined: Sun Sep 18, 2016 9:22 am
Location: Rochester, NY

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by rleete »

The link you posted has WAY overpriced stuff. Search on the web some more, you'll find the same stuff for about 1/4 the cost.

Heck, even the Harbor Freight kit is better and cheaper than that.

JvilleJeff
Posts: 2
Joined: Tue Mar 26, 2019 7:49 am

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by JvilleJeff »

Hi JimmY, thanks for the feedback on your experience with the panels. Seems technology hasn't come far enough to rely too much on it yet. Will keep in mind the direct line of sight to the sun when setting up the panels. Should not be a problem.

rleete, thanks for the suggestion about Harbor Freight. When it comes to saving money, I'm always for it!

User avatar
CaptDave
Posts: 217
Joined: Wed Aug 20, 2014 8:09 pm
Location: Columbus, OH

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by CaptDave »

Thinking about solar? What is your daily load in kilo-watt-hours?
Lets say you have 2- 100 watt solar panels. On a clear summers day let us assume you will have 8 hours of good sunlight and you are optimistically able to produce an average of 80 percent of peak power over that period. 200 watts x 80% x 8 hours =1280 watt hours that you put into your batteries. If your 5000 BTU AC draws 650 watts,you will generate enough electricity during the course of the day to run it for 2 hours. This will probably be a little less because your inverter efficiency is likely to be only a little better than 90% On my boat 1.2 KW hours will run my boat at 5 mph for about an hour and 45 minutes. So for me I can charge a completely dead battery bank in 3 days or give myself almost 9 more miles of range.
So calculate your total power need in KWH's and calculate the number of panels you need based on some simple calculations. I wouldn't try for all the comforts of home on a small boat from solar.

200 watts of Solar is what I have purchased to charge the batteries on the Aquatron.
Capt. Dave
Builder of the Amp Eater Aquatron

gpcramins
Posts: 10
Joined: Sat Sep 07, 2019 1:57 pm

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by gpcramins »

The (2) items on your list which are going to be the most problematic are the water heater and A/C.

Even a 6 gallon water heater will pull 1500 watts when being used, even at 100% efficiency, it will pull 125 amperes off the battery. Theoretically, you may have a battery which can provide this for the time necessary to heat the water, but you will need to immediately charge the battery afterwards. I suspect two (2) 31 group batteries at 105 ah could handle this, just not sure how long it would take to charge them after one heck of a hit...

The 5,000 btu A/C, I assume you are referring to a window unit, will pull 4 amps for the most efficient models, which comes out at 460 amperes. Don't forget there is an initial startup current draw which will exceed this. I've heard various figures thrown around but don't suspect it would be excessive. This would be 38 amps at 12 volts, very high as well, just not as bad as the water heater.

Solar panels typically deliver 15 watts per square foot AT BEST and usually much less. So let's assume to run both the panels are supplying their rated output on a nice sunny day. One would need 130 square feet of panels to power these loads... To put this in perspective, you would need AT LEAST 6 panels sized a little over 5 x 3 feet. Mind you, contrary to much of what you may have seen, the average panel is less than 20% efficient! Go figure...

The first question is, what kind of boat is this? If it is an inboard, gasoline or diesel, you are in the best position! A second alternator can be added and the existing one upgraded to provide the sort of power you are looking for via an inverter....

If you are like me and configuring these loads for a sailboat, you could still provide for these loads via shore power or generator unless you have an installed diesel in which case you could run them 24/7 provided you have fuel.

kathyoc2
Posts: 4
Joined: Sun Jan 19, 2020 9:02 am

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by kathyoc2 »

I read about Jim Greer. He’d built a makeshift boat, about eight feet long, and set sail on a mid-American river in what he says was a search for Tom Sawyer — a fictional character he was convinced was real. He made it as far as the Mississippi River before a sheriff rounded him up and took him back home. :D

User avatar
Locutus
Posts: 125
Joined: Thu Feb 26, 2015 9:23 am

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by Locutus »

Everything you ever wanted to know about solar power (and some opinions you can probably live without) can be found on "Handybob's" blog. His posts are geared toward RVs and Off-Grid home systems but much of the information can be applied equally well to marine use.

https://handybobsolar.wordpress.com/

As for your A/C, I think you'd need a huge solar panel array, and equally huge battery bank, to power any A/C unit. Better to power it with a second engine alternator and inverter set-up, or a generator rated for at least 4000 watts.

There are some marine-specific A/C units that use sea or lake water in the cooling process. They may consume less power or not, I don't know anything about those though. May be worth researching.

My two cents.

Edit: I think your cheapest option (by far) for A/C would be a window A/C unit plugged directly into a contractor's generator. You can probably pick up a 4000 or 5000 watt generator for about $400 and a window A/C unit for another $150. These types of generators tend to be quite noisy though. Double the money for a quieter inverter type generator. I say this option is cheapest even though a second alternator on your engine might be cheaper than a generator, because the alternator route would be more involved in terms of wiring and peripheral hardware like a suitable DC to AC inverter.

kathyoc2
Posts: 4
Joined: Sun Jan 19, 2020 9:02 am

Re: Anybody ever set up solar power on their boat? Any ideas what would be needed?

Post by kathyoc2 »

Thank you for advise, my friend. I read blog and would to say its nice info for me. By the way I found better blog aboutWill Solar Panels Get Cheaper - Blog About Solar Energy | Websolarguide

Post Reply

Return to “Electric Power”