I need a Solar System! Do you like yours?

[FLWestCoast]

I've used Hamilton Ferris products on my boat and my RV. The boat had two 135W panels mounted on the davits and a nice controller with a flat screen for the many readouts. The system maintained the four golf cart batteries indefinitely in good weather with the fridge running 24/7. I could also keep the lithium battery for my Torqeedo outboard motor charged. With the boat in her berth, I shut off the onboard charger since the Ferris system did a better job of maintaining the batteries. The RV has a 100W flex panel and a 30A mppt controller that does a good job of helping to keep the house battery charged on a sunny day. Eric or Hamilton are great to talk to about any solar system questions.

Interesting idea to rely on teh panels rahter than shore power to maintian the chanrge at the dock. There are times when getting her plugged in is half the work of closing her up to leave for the week. Skipping that step and letting the panels do the work is a great idea.

 

[kappykaplan]

Interesting idea to rely on the panels rather than shore power to maintain the change at the dock.

This is what I do.

 

[heritage]

I would not limit your search for solar panels to marine or RV stores. Panels meant for homes and large solar farms are less expensive and provide a greater choice in size and wattage. I bought eight Jinko panels from A1solarstore.com and am very satisfied. The Jinkos are assembled in Jacksonville, Fl. (The panels I bought were for my house..)

 

[fred1diver]

Haven't thought of using magnets. Any problem with high winds? I assume you remove them and store them below at the end of each day's sail or whenever you leave the boat?

Amazon has magnets with studs on them, I use those on the panels, and regular round magnets on the other side of the fabric.
I put them on in spring and take them off when I put the boat away, crazy strong

 

[colemj]

I'm not seeing those prices so I'll keep looking. I also like the idea of bi-facial bc I assume reflection of sunlight off the water adds watts. Is that how bi-facials work, or am I assuming facts not in evidence?

Thank you.

Just search for panels on google - don't buy "marine" panels, or rely on marine retail stores for them. Here is where I got the bifacial ones I mentioned we have now: https://www.platt.com/p/2174312/hyundai/solar-module-410w-66-cell-b-b/hynhiss410yhbk

You can find larger ones cheaper like here: JA Solar 16BB N-type Solar Panel Bifacial 580w 575W 570W Solar Energy System

Solar is very cheap right now. If you pay more than 50cents/W, you are getting a bad deal.

Yes, bifacial panels work by harvesting reflected sunlight on their backsides. However, it isn't like having two panels in one, and water isn't a good reflector of sunlight.

We had for several years two 400W panels from the same manufacturer next to each other on an arch overhanging the water. One panel was a traditional one, and the other was that exact panel only bifacial. While we would on occasion see up to 35% extra gain from the bifacial, the overall yearly average increase during all conditions of the bifacial panel over the non-bifacial was 12%. This could even be measured instantaneously by placing towels over the tops of the panels, when one panel would stop producing, while the bifacial still produced current.

So they do work to harvest more light, but don't expect miracle production. However, 12% on average is significant. It turned that 400W panel into a 450W panel for no extra money or space.

Our bifacials (we now have four of them) are mounted over the water on an arch. You would think water is a good reflector of light since it blinds you, but it actually is very poor at that. Ironically, we get more output from the backside of our panels when the dinghy is in the davits blocking the light from the water, but reflecting light from its white floor and grey tubes. I've toyed with the idea of throwing a white sheet over the dinghy, or putting a reflector below the panels.

Mark

 

[colemj]

I didn't even know Kyocera made panels. I'll look for them. Thank you for the response

Kyocera used to be the top name in solar panels, and the 130W model was universally popular. We had 4 of them and they were great.

However, you can do much better than Kyocera nowadays - in performance, size, and price. Kyocera has pulled out of the US market, although some places still import them. They aren't a big player, or even competitive today - likely can't compete on price and innovation as they did in the past. Other large manufacturers of high end panels like LG and Panasonic have also exited production.

Mark

 

[Tom J]

Interesting idea to rely on teh panels rahter than shore power to maintian the chanrge at the dock. There are times when getting her plugged in is half the work of closing her up to leave for the week. Skipping that step and letting the panels do the work is a great idea.

The reason I used the solar charger at the dock is that the onboard charger that was original to my boat was a dumb charger that tended to overcharge the batteries, whereas the solar charger would go through the proper stages of charging; bulk, absorption and float. This helped maintain a healthy charge on the golf cart batteries I finally installed. I still used shore power for things like the water heater, etc.

 

[dlochner]

Hello: I am shopping for a solar system for my Hunter 33. I calculate that I need about 300 Ah and would like to meet that need with 600W solar panels and 400 Ah of LiFePo. Now I just need to decide on a brand (or brands). Do you like your system? Why or why not.

Thank you!

Let's do some math. Since solar panels are marketed in terms wattage, it is easiest to us watts as a measure to calculate your energy needs. A watt is equal to Volts x amp. The estimate of 300ah of daily consumption is equal to 3.6kWh at a nominal 12v. That is a lot of consumption.

A solar panel can be expected to provide about 3 times its nominal wattage per day. Somedays when conditions are perfect there will be more, on days that are cloudy there will be less. Better quality, higher efficiency panels will do better. After about 2 years on solar, that fits with my experience.

To generate the 3.6kWh you will need about 1200 watts of solar. If you have the real estate for 2 600 watt panels placed in clear sun without shading, then you will have adequate solar power for your daily needs.

However, your battery bank is woefully inadequate as there is no reserve or cushion for a few bad days. If you only get 50% efficiency on a cloudy day, you will not make enough power for one day and your battery will down to 25% SOC. Two bad weather days and your bank is pretty much depleted.

The real estate for solar panels on a boat is limited. While panels can be placed on the deck or dodger their efficiency goes down because of the shading inherent in those locations. It doesn't take much shading to significantly reduce the panel's output. Instead of 3x the nominal wattage, dodger panels may only produce 1 or 2 times the nominal wattage. A while back Delos looked at the energy production of their solar system and shared it on their YouTube channel. The performance differences are interesting.

One other note, panel output is rated based on standard conditions which allow for fair comparisons between different panels and manufacturers. Those conditions are rarely attainable on a sailboat, which means the panels will rarely produce their nominal wattage.

For a deeper dive into what makes a good panel, take a look at this article from Nigel Calder. It is a few years old, however it still relevant.

Advances in Onboard Solar - Professional BoatBuilder Magazine

Advances in onboard marine solar technology improved efficiency and lowered the cost. But they also introduced more complexity.

www.proboat.com