Doing some research at Arizona Wind and Sun... (http://www.windsun.com/) on 6 Jan 2002
Looks like generally, $5/watt for the usual panels. The flex panels from Solarex are as low as $4.39/watt, but the Unisolar ones are $12/watt. Output is around 120 W/square meter for the fixed panels, 47W/square meter for the flex panels (a heck of a lot less efficient!)
The real problem seems to be that the bigger panels (75W plus), are all 1.2 meters long or bigger. No problem when bolting it to your roof, a big problem on a 1 meter long rover....
I wonder if you can redesign the panels a bit.....
|Rated I||Rated V||Voc||Isc|
|Siemens SP75(single crystal solar electric panel with 36 cells)||409||
|Siemens SP100 (discontinued!)||478||1498x594x56||10.9||100||5.9||17.0||21.6||6.5|
|Unisolar USF11||149, 2/280||554x424||0.91||11||0.62||16.5||27.1||0.78|
|Solarex Millenia 43W||189||?||?||43||?||?||?||?|
Astropower (http://www.astropower.com/) has a eval kit for $185 that has 20 AP105 cells (5" single crystal, 2.1 W) which is: 40W, or about $4.60/watt (pretty high, considering you can get a whole panel already assembled for about the same..)
The Solar Cell Company (http://www.solarcell.net/) sells 4" cells, 0.9W for $1.95, or 36/$64.75 (which is about $2/Watt). Kind of a cheesy web site, but heck, they're in the business of selling solar cells, not web design. (114W/square meter of cell area)
http://www.solarbotics.net/library/pieces/parts_elect_semic_solar.html has some interesting analysis and a handy calculator showing that All Electronics cells SPL-22, which are 10 for $5 are not such a bad deal. 20mm square, .45Voc 100mA Isc (the catalog shows V@I (simultaneous), but hah, we know better). ANyway, they're up in the big 0.12 mW/mm2 clump (120W/m2..), and give 90mW/$. Interestingly, this is $10/W... The SolarCell company selling the $2/0.9W cells is a much better deal on a W/$ basis,
There's a fair amount of literature on the web about using a concentrator with a cell. Even a flat plate mirror can increase the output (never as much as the whole area), especially when you have a fixed orientation panel. And, mirrors are a heck of a lot cheaper than cells.