Using the Sun as a Space-Based Power Source
Posted: Thu Aug 05, 2004 1:31 pm
Recently, I've been discussing the issue of building a power-collecting space station
with my colleagues. Based on the figure that the Earth receives about 1.3kw/m^2 of
sunlight, we've calculated that a power output of 130kw/m^2 would be received at
0.1au, and that the temperature would rise from 300K to 900K.
My suggestion was to put a space-station at 0.1, which is solar panel surface of
109.73x48.78 meters (the exact dimensions of a football field). Such a surface area
would receive nearly 700MW of power. Unfortunately, the panels would only be about
20% efficient, and would suffer from the heat. Also, the station would have to rotate
fairly quickly to prevent too much heat buildup on its outer surface.
How realistic do you guys think a large Stirling space-station would be? One side
would have a black football-field sized surface that absorbs heat, and the other side
would bleed the heat off. In between, our Stirling engine(s) would be cooling the front
surface, heating the back surface, and generating power in between. Using a
guesstimate that the rear surface would experience about 100K temperatures or
lower, I came up with an 88% efficiency rating.
Other than building and transporting such a station (that's another discussion), what
problems do you see in making something like this work? Would one large engine or
an array of smaller Stirling engines be about to absorb and generate electricity from
the 700MW of power heating the surface? How difficult would the engineering be?
Thank you for your opinions.
with my colleagues. Based on the figure that the Earth receives about 1.3kw/m^2 of
sunlight, we've calculated that a power output of 130kw/m^2 would be received at
0.1au, and that the temperature would rise from 300K to 900K.
My suggestion was to put a space-station at 0.1, which is solar panel surface of
109.73x48.78 meters (the exact dimensions of a football field). Such a surface area
would receive nearly 700MW of power. Unfortunately, the panels would only be about
20% efficient, and would suffer from the heat. Also, the station would have to rotate
fairly quickly to prevent too much heat buildup on its outer surface.
How realistic do you guys think a large Stirling space-station would be? One side
would have a black football-field sized surface that absorbs heat, and the other side
would bleed the heat off. In between, our Stirling engine(s) would be cooling the front
surface, heating the back surface, and generating power in between. Using a
guesstimate that the rear surface would experience about 100K temperatures or
lower, I came up with an 88% efficiency rating.
Other than building and transporting such a station (that's another discussion), what
problems do you see in making something like this work? Would one large engine or
an array of smaller Stirling engines be about to absorb and generate electricity from
the 700MW of power heating the surface? How difficult would the engineering be?
Thank you for your opinions.