How to make photovoltaic solarpanels to suit our boatdesign

Hmm, very interesting. I shall read more.

 

Yep Bert,

Glad to say we are boatbuilders and tinkerers, not bomb guys.
Just shows ya how finicky customs can be. and I spose for good reason.

 

Another interesting supplier for cells, broken cells and a lot more:
http://www.goldmine-elec-products.com/products.asp?dept=1174

Beware of the guys who offer their cells priced per Watt instead of per piece. You order 50 pcs of 2 watt cells and get only 25!

 

Thanks for the tip CDK, you are right, they are shrewd.

Lets calculate whether it is worthwile to invest all that time and money versus a 90Watt 36 cell solar panel for R3600.00 ( Euro 350) made in RSA

If we consider the 4 Amp at 0,5 Volt = 2 watt @ 8.95 + postage
for 90 watt, we need 45 i.e. 45 x $8.95 = $ 402,75 + postage + glass + aluminium frame + connection strips + silicon layers = ??????

It does not look like a proposition for me and to me. Except if I want a special shape and use resin. I will probably order some monocrystaline cells and play a little with them. Only at end of next month I will have the time to experiment.

 

The 4 Amp cell costs $6.00 for quantities over 4 pcs with free strips. That is $216 plus postage for a 36 cell panel rated at 72 watts.
Not bad....

 

Indeed CDK, not bad at all. I will be off line for a few days, I have to go back to WinXP.
Under Win7, I can't sent an e-mail anymore, If I dial into my service provider, I can read my e-mails, but can't reply.
Under win7 one cannot click on the URL in an e-mail anymore, also not on the boatdesign.net - My Canon scanner does not find the correct driver etc. etc.
I can't even get to the solarcells suppliers anymore.

It is a pity, that we all live so far from each other, otherwise we could make a bulk buying deal and get the price even further down.

What is a better buy today-
a) monocrystaline - price - quality - surface coverage (round, not efficient)
b) polycrystaline - price - quality -surface coverage = square = very good
What is your opinion CDK

 

You are mixing things up Bert.

Only old-fashioned monocrystal was round because wafers were 3" or 4" and cutting squares from them produces too much waste. Modern cells are cut from 6" wafers into squares with rounded corners. They are the most efficient cells, alas the expensive ones. Growing monocrystals is an expensive process and so is laser cutting wafers from it.
The best cells are the dark ones, they reflect less photons.
For low power applications and flexible panels, the cut-off segments are used.

The polycrystalline process yields cheaper, rectangular cells that reflect more photons and have no uniform structure, causing higher leakage currents.
If surface area is not an issue, pc panels are cheaper per watt. For the same output, you need approx 20% more surface, so if space is limited, mc panels are the best choice.

Retail prices are approx. $1.80 for mc cells/watt, $1.20 for pc cells. The really good, almost black mc cells are already sorted out and sold to panel makers working for the satellite industry.

 

No, I am not mixing things up, I am just too long out of that industry to know the latest. That was a very nice explanation and update you gave us. I am off to find prices for hardened glass and resins.

Back on WindosXP again.

Bert

 

interesting thread guys
I liked the reflector suggestion so I gave it some thought

ok
a lid on the panels that has a reflector underneath it and it can operative one of two ways

imagine a frame with two "doors" hinged off of it and reflectors underneath
when the sun is pretty much directly overhead the "doors" open and let the sun in
with the sun at a low angles the frame tilts moving both "doors" to act as a reflector
if you rotated the whole system you could follow the sun at low angles to eek the most out of they daylight

I love the idea of making your own to fit the curvature of the vehicle
really turns it from a cobbled together mess into a piece of art

 

Boston,

The tracking systems and doubling the solar capture with reflectors has been around for awhile. I have seen it on a number of buildings. And I even worked on a solar powered shade house for nurturing young trees. It had a built in 20 minute delay to keep a passing cloud from opening the shade roof.

The problem as I see it would be making the reflector mirror the solar panel as now a convex panel would have a concaved matching reflector and focusing it could become a problem. and with boats turning this way and that the trackeing system could have a real problem keeping up.

Might be best to find the average of all positions and fix it to there.

 

oh Ive seen reflectors but not opening and shutting ones
typically they just follow the sun

the motion of the boat would screw up everything about focusing the angle properly

but I like the idea of a cell you could protect with a cover

I think the Russians used an opening lid on there cells for there moon rover 50 years ago

 

I guess a lot would depend on the type of boat and how it is used. A sailboat on a steady course for hours or days could really benefit but a runabout pulling skiers would not gain much from a tracking system. I like the concept tho and I'm sure its time will come. But for now I suppose having more area would be the cheapest and most reliable way to go. all those moving parts and electronic comtrollers scare me. But I once saw som woodburnings by a guy who did them with a magnifying glass and sunshine and it was pretty impressive.

I wonder how long it will be before they can make solar panels not only formable but flexible. Like sails made of photoreactive materials. The solar shingles are cool and someday as cheap as roofing but for now they are way expensive.

By the way, I worked on a passive solar house in Winter Park, CO some years ago.
worked great on sunny days but all that glass sure lost a lot of heat anytime else.

 

Ya I worked on a bunch of them in the Estes area
I have pictures from years ago that were not lost when my portfolio got stolen/lost
cool house to
Ill try to load em up soon and post them

I was also envisioning a simple reflector shining down a mirrored hole in the deck and the panels are down underneath keeping the weight low
like in a transom overhang or up in the bow were space is hard to use anyway

cheers
B

ps
absolutely no work in the construction industry around here these days
1.9 million jobs reported lost just last year and probably an equal number went unreported

 

Hi Boston, I am so sorry to hear that there is so little construction work. This coupled with the closing down of the 2 Toyota plants, it must be a hardship for many friends and people you know. Lets hope that the downturn will be stopped soon and reversed.

To come back on solar, yes I love to see those pictures
Bert

 

There are many differenet flexible solar panels already available on the market. Refer to CDK reply a few days back. His is understood to be 15 years old and still working.