Solar Panel Review .. After reading the postings

[Jasper Windvane]

If .. I purchase the boat. I will need to update the electric.
And I'd love to have a solar panel. The idea of free electrons.

I read the many postings here. The cost of the panel
and regulator, the return in electrons, the placement
on the boat, fold up panel as opposed to flat hard panel.

I also wonder; what exactly is a genset. I'm assuming it is
a generator to charge the batteries, right? Are there very
small gensets, that can be stored somewhere out of the way
when not in use? The generators I am familiar with, the
kind folks up my way have for backup power, are loud, and
use a heck of a lot of fuel.

The solar panel again: there are a couple different types, right?
The book I have recommends an Amorphis [ spelling? ] panel
because of shadowing. But then I looked on line and the
Kyocera panel gives the most electron for the size..

Can you explain to me the different types of crysal? Or panel?

The fold ups are sweet, but after reading about the problems
and how the panels start to lose their ability .. no thanks.

What about a hard panel that can be stored on board someplace?
When docked or anchored? The panel could be brought out,
attached by stretch cord, run the wire to a clip connection,
through a regulator, to the batteries.. As the day ends, and the
sun fades, take it down, put it away.

Does this make sense?

The panels I saw for sale on Ebay seem good, but the panel frame
looks weak. For a panel that comes out and goes back in a
frame .. I'd think a strong frame .. right?

I'd like something in the 50-90 watt range. The little mini watt
chargers don't make much sense to me..

Any more info .. ??

Thanks.

[roline]

Mono-crystalline have the highest output from sunlight, but are the most expensive. The pure silicon wafers are cut from an ingot, polished, cleaned and then subjected to dopants and high temperature P, and N to form the P-N junction that is excited by photons. The aluminum interconnects are vacuum vapor sputtered on the surface and then etched to reveal the connect pattern. The silicon cells are very brittle, thus protected from flex.
Polysilicon versions are many and can be flexed; the down side is less power density.
There are many new thin film polysilicon version in development. A company in Colorado is working on vacuum deposition on mylar to made low cost, durable cells that perhaps some day could be installed like shingles on houses for independent power…
I have a couple smaller polysilicon panels hinged together to protect them when in storage with a connect cord that plugs into a 12 volt connector. I did have an AGM engine battery fail last year and I had run the house battery down to where it would not spin the 2GM20. After an hour in the sun, I was able to start the engine....

[BubbleheadMd]

Roline is spot-on when he describes the different panels. I think mono-crystalline would be better in a stationary application, like a home. A sailboat is a heaving, vibration-prone platform and the matrix could fail prematurely.

It's a bummer to give up the extra output, but I'd rather have more forgiving, reliable panels. Buy a set of small panels, and stack them with foam or a towel in between each one. Don't forget, you can also put up a small wind-turbine for extra power.

These kinds of devices only make sense on a vessel powered by the wind.

[Jasper Windvane]

Thanks.. can you go on .. be more specific.. such as make a recommendation of a certain panel. That way I can look at it, and read up on it, and why that panel is the best to use. I did find a place that speaks about the Uni Solar panels.. but so far, I am would not feel comfortable buying any panel .. I just don't know enough yet.

[BubbleheadMd]

I'm still doing my own research and cannot recommend a particular brand or model of panel yet. I'm sure some of the long-haul cruisers can.

[nickmerc]

I am an engineer at a solar panel manufacturing plant. I concentrate on cutting the silicon into wafers. However I am pretty familiar with all of the processes. I am not sure what else you want to know. The reccommendations about the different panels are correct. In most applications the point of failure is the electrical connections on the panel, not the cells themselves. I would look for the length of the manufacturer's warrenty. We have 20 or 25 year warrenties on our panels. Also look at what is covered under the warrenty. Over time the power output will reduce. Check what is "acceptable loss" for each manufacturer and model of panel.

Also keep in mind that many manufacturers are vendors of components to thier competitors. For example, Comany A will buy silicon ingots or bricks from Compnay B. Company A will then cut them into wafers and sell them to Comany C. Company C will turn them into cells and sell them back to Company A and/or Company C and keep some for themself. Then all three companies will contract out the final panel assembly to Company D. It gets very confusing. That said, look for warrenty and power loss over time.

I, of course, am biased to my brand.
________
LIVE SEX

[mitiempo]

Jasper
Here's a good primer on solar for boats written by Sailingdog. Good info.
Solar Power on Boats | Adrift at Sea