Rollable/stowable Solar Panels

[marujosortudo]

Turns out those thin flim panels I found are discontinued (still a few in stock), so I'm not too excited there.

Brian, I would totally run solely on solar if I felt like I had the space for it. Unfortunately, for my power budget and climate that would be about 340W of panels that would take up way too much space for my taste (we're talking a 32' boat with lots of sail). Heck, I can't even imagine where I'd put all that! If I throw a Duogen on (lots on pro/cons here, not the least of which is price), I could drop that down to about 180W which is starting to seem reasonable with a couple of 60W panels off the stern and another one forward somewhere. All of which would be getting shaded somewhere. I may even just go with 120W of solar and expect to run the diesel to top off from time to time.

Safety is certainly a big concern. That's one of the reasons I'm willing to pay more for the Duogen as it seems much safer than several of the other windgens, and MUCH easier to retrieve than the other towed gens while also having less drag.

I do worry about safety even with solar though. What if one of those panels breaks loose or simply breaks? The thoughts of broken glass or flying panels in a storm is scary. Presumably overbuilt mountings and/or stowability should address this.

Solar is actually my first choice, too, but I'm hoping some great new thin film panels might be coming out in the next few years, so, I'm tempted to wait and see. Solar definitely has the best price per Amps generated per day even in my climate, although some of the cheaper wind gens come close. Still, there are many other considerations when living on a boat.

Cheers, Colin

[marujosortudo]

Just found another interesting one. Uni-solar PVL-68's are thin film, no glass, adhesive, and made for roofing with a good warranty (80% at 25 years). No mention of marine stuff, so that would probably void the warranty, and the dimensions are weird 112.1" x 15.5". But thin film might actually perform on a cabin top (if you can fit it) with no windage, no mounting hardware, and no glass. 68W for $265 is pretty good deal, too, especially if you consider that thin film outperforms crystalline in cloudy/shady conditions. Could even make a bimini cover out of these, but I'm sure the regular flexing would toast them eventually. Of course, the watts/ft^2 is less than half of a crystalline panel, but still might work well for some boats. They don't really advertise the step-ability of these, so I'm sure that would degrade performance over time, too. Still, at this price, replacing these might not be the end of world compared to other power gen options.

[marujosortudo]

Well, Brian, your points have been sinking in and they are good ones. After wrestling with my power budget, I'm hoping I get get away with about 180W of solar and maybe the occasional engine recharge, and NO wind or towed gen. It'll be close, but I'll just have to try it and see. In the end, the maintenance argument is always a strong one with me, not so much because I don't like maintenance, but because I'd rather be sailing. Also, my amp-hour generation estimates mean that even expensive solar panels pay for themselves WAY faster than a Duogen, and they don't make any noise. Now, if I can just find somewhere to put them....

I still don't feel like there are good places for me to mount them around the stern, though. Most permanent mounting hardware doesn't appeal to me, either. It would seem that shading is almost certainly going to be an issue (for me). I'd like them to be highly mobile so I can easily put them where it makes the most sense and stow them when I need to. With my wattage and shading, I think the Morningstar Sunsaver-MPPT-15L makes a lot of sense. I can have three 60 or so watt panels on there each with separate power peak tracking which should be very useful with the shade factor. I'm guessing this will let me max out power generation even with mixed shade conditions.

I also still am deeply curious about thin film vs. crystalline performance on actual sail boat conditions. So, here's my crazy idea. I could get one Kyocera KC65T ($339, 29.6x25.7, 13.2#) and one Global Solar P3-62 ($859, 52.5x30, 3.1#). The MPPT controller can actually log data to my laptop, so I could actually gather some real data about the performance of these different types of panels on sailboats (which seems to be totally tacking) and post it online. Naturally, I could note mounting position, shading/weather observations, etc. This way we would have some real data to go off of in these comparisons. It seems our community is small enough that we just need to do our own research if we want real answers, and I'd be glad to contribute there. Then, when I have the answers, I can by one or two more of the one I like and sell off the extra if need be.

Cheers, Colin