Timeline for Imagining a Solar-Powered Economy
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Aug 14, 2015 at 8:12 | comment | added | ctravisuk | Secondly, solar cells do not work by heating. The incident photons from the light induce a current in a semiconductor by exciting electrons from the valence band into the conduction band where they are free to move and are accellerated by chemical and other potentials in the medium (Photovoltaic effect). As an example of their suitability for space, consider that almost all satellites and space stations feature many solar cell arrays to recharge their batteries. | |
| Aug 14, 2015 at 8:08 | comment | added | ctravisuk | Firstly, it is a parabolic mirror in space that is reflecting gathered light from space down to Earth (or elsewhere) in a cone. This means that (arbitrary numbers) a 1km^2 mirror is focusing the light from the sun that would fall on that area down to a solar cell of 10m^2, representing a massive increase in gathering efficiency. It would not light up the night sky as the light is focused down to that point. In the same way that focusing light by a magnifying glass does not present a bright beam to an outside viewer unless they are directly in its path. | |
| Aug 12, 2015 at 19:27 | comment | added | SJuan76 | I do not see it... either you propose that mirrors point to the solar station back in Earth (but many people will have issues with such a bright night) or to a solar station in space. The problem with such a space solar station is that to get electricity you need a temperature differential, but that is not easy to get in space (you may get the tower very hot, but all of it will be so, because cooling in space is quite difficult). | |
| Aug 12, 2015 at 15:08 | comment | added | ctravisuk | The mirror in space can be made out of foil, so it can be ultra lightweight while being huge. The problem with that is that the lower its weight the easier it is for it to be moved from position by solar radiation pressure as it becomes similar to a solar sail. | |
| Aug 11, 2015 at 17:26 | comment | added | Adam D. Ruppe | Mirrors can be pretty light weight... or you might build them in space with space materials. Big up front cost in building the infrastructure, but then the marginal cost goes way down as the materials no longer have to eb launched. | |
| Aug 11, 2015 at 16:33 | comment | added | user3652621 | But wouldn't launch costs be prohibitive? | |
| Aug 11, 2015 at 15:26 | comment | added | ctravisuk | I should have added that the major benefit of this is that the concave mirrors in space focus the light from a large area down to a small point on earth, and that solves one of the major hurdles of solar energy generation: the amount of space the solar farms take up on Earth. | |
| Aug 11, 2015 at 15:24 | history | answered | ctravisuk | CC BY-SA 3.0 |