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.....
| Make/Model | Price | dimensions | Mass (kg) |
Output (W) |
Rated I | Rated V | Voc | Isc |
|---|---|---|---|---|---|---|---|---|
| Siemens SP75(single crystal solar electric panel with 36 cells) | 409 |
1200x527x56mm |
7.6 | 75 | 4.41 | 17 | 21.7 | 4.8 |
| Siemens SP100 (discontinued!) | 478 | 1498x594x56 | 10.9 | 100 | 5.9 | 17.0 | 21.6 | 6.5 |
| UnisolarUSF32 Flexible | 298 | 1430x424 | 2.14 | 32 | 1.94 | 16.5 | 27.1 | 2.4 |
| Unisolar USF11 | 149, 2/280 | 554x424 | 0.91 | 11 | 0.62 | 16.5 | 27.1 | 0.78 |
| Solarex Millenia 43W | 189 | ? | ? | 43 | ? | ? | ? | ? |
| Kyocera KC80 | 389 | 976x652x52 | 9.6 | 80 | 4.73 | 16.9 | 21.5 | 4.96 |
| Kyocera KC120 | 598 | 1425x652x52 | 11.9 | 120 | 7.1 | 16.9 | 21.5 | 7.45 |
| BP/Solarex SX-120 | 598 | 1456x731x50 | 12.8 | 120 | 3.56 | 33.7 | 42.1 | 3.87 |
Individual Cells
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,
Reflectors
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.