Solar Panel Sailing Lifestyle Choices

[Kenneth K]

I added solar last year . The rigid 100 watt panels were a little big for my personal taste, so I opted for two 50 watt panels. They store nicely below deck if I don't want one (or both) out.



My boat sits on a buoy year-round, so it's always floating in a different orientation. I liked the dual panel / dual controller idea rather than having the possibility of a single panel being aimed away from the sun for much of the time.

My post about it here: https://ericsonyachts.org/ie/ubs/battery-systems-upgrade.921/

 

[debonAir]

I added a 100W flexible panel on top of the dodger. It was a fantastic upgrade. Battery is always 100%. I don't have refrigeration (yet) so 100W is fine for current needs. You would want more like 200W to keep a fridge running, but you also need full Sun to really get the power.

My feeling is having to pull a panel out, connect it, then reverse every time you want to use it seems like a pain. Getting the fold-out kind you can put over the cockpit life-lines seems a decent choice if you have no dodger/bimini to work with.

Upgrading the house bank to large LiFePo (like 400AH) might be a convenient but coslty way to extend your anchoring for a few days. For people like me on moorings or anchored all the time there's nothing better than permanent mounted solar.

 

[Pete the Cat]

TK, Yes…I realize that one 100 watt panel will probably not meet all of my needs but that is not really my intent. I want to supplement charging by shore power/engine power to extend my time at anchor. I don’t want to replace shore power/engine power. To do that I’d need at two or more 100 watt panels that would need to be permanently mounted and that’s something I’d like to avoid because that what I don’t need. Most of the time I day sail. The rest I go out for about a week or more stopping at marinas and anchoring. I’d like to anchor a bit more. I’m leaning more now towards buying one 100 watt flexible panel that can be easily stored below when not in use. Then I might buy a second one and deploy them around different parts of the boat as the sun direction changes. I suppose I could even add a third or more as long as the controller can handle it. So the two big issues for me are flexibility and storage of the panels. As for battery power I have, or had, two large group 24 “house” batteries that were 7 years old and are being replaced this spring. Then there is a third smaller starter battery under that Nav station seat used solely to start the engine. The house and starter batteries each have their own 120 volt chargers. All three batteries are control with two large battery switches which, depending on how they’re set, can deliver power to the boat or engine from all three, from just one of the batteries or a combination of either one of them. The system was designed and built by the previous owner and it works well. The other purpose for having temporary solar panels is for use in the winter months when the boat is on the hard. Every other year I have the boat pulled that have the bottom inspected and painted, along with any other required maintenance. While On the hard the boat cannot be plugged in the keep the batteries charged. The temporary panel(s) can then be laid out on the deck, bimini or hung to take advantage of the sun’s angle depending on where the boat is placed.

I agree with your direction here. I just installed a single 100 watt panel ($120) with a 10 amp Renogy PWM controller (I highly recommend this company--$20) and a cam seal to get the wire. through the deck to my batteries. I used standard 12 g double wire. So my whole set up was about $150. I attached it to my dodger with rare earth magnets which do not interfere with the compasses for reasons I cannot explain. I chose this system because I do the kind of sailing with this boat that you do and my daily electrical budget is really not much--I have a wheel pilot, nav gear, radios and instruments--no refrigeration or windlass-- but probably use less than 20% of my 200 ah capacity in any 24 hour period. I agree with others that having a battery monitor would be a very good investment. I have cheap Chinese one I bought on EBay for about $40 that works as well as my Xantrex Link Lite on my Tartan that I paid $200 for.

I have a much older system of just 65 Watt panel on my Tartan 37 that I have used for 15 years to keep my batteries topped off in Maine. I use that boat for much longer trips to Nova Scotia and the whole coast of Maine and I have a lot more power needs with refrigeration and a below deck autopilot at such. Still I am not inclined to put more panels on the boat because I generally move to another anchorage every couple days and charge the batteries as I am taking up and deploying anchors (at least) and generally motor a bit just to get out to good wind or when the wind abandons me. So unless I was going out into some long passages in the tradewinds, I would be unlikely to need more. I spent a couple years sailing this boat from San Francisco to Maine (I was moving every couple days) and never had an electrical shortage. It was nice to be able to leave the boat for a period and not worry about flattening the batteries.

As you may know, Nigel Calder outlines the simplicity that most of us should follow in his books and then mostly writes about very sophisticated systems that most of us will just end up spending a lot of time installing, maintaining and fixing. As someone pointed out, solar can be a rabbit hole if you let it. But you seem to have already figured that out. The advice to have a good idea of your actual usage, have a battery monitor and build around that is spot on in IMHO.
FWIW.

 

[Geoff W.]

I did two 100W panels on my pushpit. It's maybe a bit of cruisier look but I don't find that it's overall too impactful to sailing or the aesthetics. And they've been an absolute godsend on some of our longer cruises! We've got a hungry fridge, cell booster, charging laptops, you name it.... "work from home" necessitated some more power.

 

[toddster]

I did two 100W panels on my pushpit. It's maybe a bit of cruisier look but I don't find that it's overall too impactful to sailing or the aesthetics. And they've been an absolute godsend on some of our longer cruises! We've got a hungry fridge, cell booster, charging laptops, you name it.... "work from home" necessitated some more power.

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Cool. I had decided on that exact installation as being the most expeditious. I don't recall now why I abandoned it - maybe it would interfere with my swim ladder? Or I thought it wasn't enough support - my pushpit is probably a bit smaller. Then I decided to add a solid rail between the pushpit and the lifeline gate, and hang the panels there. But I couldn't get the material due to COVID shortages. Meanwhile, I found an aluminum arch that might be made to fit, and allow expansion to three panels. But I'm afraid that it may end up being so monstrous that I'll circle back to the first option again.

 

[Pete the Cat]

I guess if you have refrigeration and big needs and spend a lot of time at anchor you would benefit from multiple panels. I find that a single 100w panel (I do not have refrigeration and I move around enough to use the engine almost daily when cruising). seems to be just the thing to keep batteries topped off. Seems that smart or dumb alternator regulators always leave a bit of a deficit in charge as they approach 100%. I don't bother with the cord in the marina any more and that is a nice thing. FWIW.

 

[dhill]

Solar panels are particularly good for the absorption (typically 80% to 95% charge) and float (typically 95%+ charge) portion of the charge cycle when the charging rate to the battery is slower. Bulk charging (up to 80% charge) is quickest, most efficient, and better matched to an engine-driven alternator since you can get a lot of charge without running your engine for hours (solar panels can also fill this need as well, if you have enough solar capacity). Once the battery reaches an 80% charge, you need to run your engine for a much longer period of time to get to 100%. The solar panels are "on" all during the day, so they can complete the absorption and float portion of the charge in obscurity and silence, while saving on diesel fuel and engine hours.

Here is some more information about battery charging: https://www.pysystems.ca/resources/...inar-charging-your-batteries-episode-3-of-12/.

Pacific Yacht Systems shares a lot of content on electrical systems from past boat show sessions and via their Boating Tech Talk series on YouTube, which I have found very helpful as I review, clean up, and upgrade my electronics. I don't work for or have any relationship with them - I just find their content useful.

Dave