4 ms·

Also watches? I'm skeptical on the idea but the math seems to be reasonably close as to justify hope. Suppose the notebook's lid is 20cm x 30cm, direct sun lig

by DenisM 17y ago

Also watches? I'm skeptical on the idea but the math seems to be reasonably close as to justify hope. Suppose the notebook's lid is 20cm x 30cm, direct sun light is 1000wt/m^2, so we're getting 60 watts of energy per lid. Best solar cell efficiency available today is 20%, with 40% in the works (it takes very long time to make stride though). So, we're looking at 12w today and 24w in the future. This is not entirely outlandish. Moving parts can be removed and silicon parts can be optimized for smart power management (e.g. sleep some regions of RAM, some parts (cores) of CPU, shutdown some SSD controllers while keeping others etc). The only big thing left is the screen. Latest 2.2" OLED screen works at 100mw. http://www.treehugger.com/files/2008/08/tmdisplay-oled-screen-world-best-efficiency-lifetime.php http://www.treehugger.com/files/2008/08/tmdisplay-oled-scree... So this screen is, (2.2 * 2.54)^2 * sqrt(3)/4 = 13.5 cm^2 and to cover a big 20x30cm screen we need 600/13.5 = 44 such small screens, and they should consume 4.4watts total. So the screen problem is manageable in the long run. This can be made to work, at least in sunnier climates. I would probably expect cell phones to get there first, however. the technology is expensive (both OLEDs and solar cells) and ARM&cell phone companies have better expertise in deep power management.

ryanwaggoner 17y ago
But this assumes you're letting this thing sit in direct sunlight for hours at a time...who does that? I really doubt that cell phones or laptops will ever be solar powered, at least as their primary power source, because if they're not in use, they sit in a bag or a pocket.
- DenisM 17y ago
  You're right, that's why I'm sceptical. I think it may work as a last resort (e.g. I forgot my power adapter at home), when camping/traveling or in poor countries with no electricity grid. The problem is with such marginal and cost-sensitive usage scenarios who will be compelled to develop it in the first place? In poor countries they use simple dynamo machines to power the cell phones afaik. I think realisticaly there is a point for a special traveler's cellphone - take one with you when going hiking and know that you will be able to call help no matter what happens. That sort of thing.
- DenisM 17y ago
  Hey, take a look at this! http://www.voltaicsystems.com/bag_generator.shtml http://www.voltaicsystems.com/bag_generator.shtml 15w solar laptop briefcase.
  - electromagnetic 17y ago
    That's even more useful to the urban thief. Not only will they know they have a laptop, but they'll know they've got everything they need in a convenient briefcase. I'm not saying these things aren't a good idea, I'm just saying most people live in highly urbanized areas where leaving stuff like this in the sun will get them stolen. If you want to take a laptop with you on a fishing trip or into cottage country, then this is ideal.
  - netsp 17y ago
    On a slightly more serious note, a good playground for developing thses kinds of things might be products for developing countries. Specifically, those parts that are not on grids. A lot of things you make must be cheap, must have own power source & must be useful enough to (a) justify spending money in a place without much (b) worth the hassle of putting panels on your roof or whatever. What seems relatively sensible is a solar powered desktop to start with.

by DenisM 17y ago

ryanwaggoner 17y ago

But this assumes you're letting this thing sit in direct sunlight for hours at a time...who does that? I really doubt that cell phones or laptops will ever be solar powered, at least as their primary power source, because if they're not in use, they sit in a bag or a pocket.

DenisM 17y ago
You're right, that's why I'm sceptical. I think it may work as a last resort (e.g. I forgot my power adapter at home), when camping/traveling or in poor countries with no electricity grid. The problem is with such marginal and cost-sensitive usage scenarios who will be compelled to develop it in the first place? In poor countries they use simple dynamo machines to power the cell phones afaik. I think realisticaly there is a point for a special traveler's cellphone - take one with you when going hiking and know that you will be able to call help no matter what happens. That sort of thing.
DenisM 17y ago
Hey, take a look at this! http://www.voltaicsystems.com/bag_generator.shtml http://www.voltaicsystems.com/bag_generator.shtml 15w solar laptop briefcase.
- electromagnetic 17y ago
  That's even more useful to the urban thief. Not only will they know they have a laptop, but they'll know they've got everything they need in a convenient briefcase. I'm not saying these things aren't a good idea, I'm just saying most people live in highly urbanized areas where leaving stuff like this in the sun will get them stolen. If you want to take a laptop with you on a fishing trip or into cottage country, then this is ideal.
- netsp 17y ago
  On a slightly more serious note, a good playground for developing thses kinds of things might be products for developing countries. Specifically, those parts that are not on grids. A lot of things you make must be cheap, must have own power source & must be useful enough to (a) justify spending money in a place without much (b) worth the hassle of putting panels on your roof or whatever. What seems relatively sensible is a solar powered desktop to start with.