| I actually don't think space based solar to beam it back to Earth will ever really be practical short of a space-elevator style tether to transmit the electricity down. But some of the pros would be as follows. * Capable of 100% capacity - power generation can be 24/7/365 if in orbits around the sun or stationed at the Earth-Sun Lagrange points. * Greater panel efficiency - less energy lost to the atmosphere that can be captured by the panels, closer orbits will increase efficiency even more due to more power/area * Surface area - minimum 1x10^20 square kilometers of area you can build panels There are of course many cons - but it could be a vital part to a space based industry - you need a lot of fuel or power to really do anything in space, and the power from space based solar could to be used to kickstart a fuel production facility off Earth. Fun stuff but not very terrestrially relevant. EDIT: Some more numbers: You get about 40% more power/area in space vs on the ground.
You need about ~22 TW to "power" humanity. So you need about 70,000 km^2 of space based solar assuming 25% end to end efficiency, which might be a generous estimate. So lets round it to 100,000 km^2. But thats a significantly smaller area than the terrestrial equivalent of about 500,000 km^2. Right now it costs about $1B installed for a square kilometer solar installation, so we if can build solar panels on the Moon or something anywhere close to the same cost as on Earth (very very BIG if), potentially a difference of $400T dollars at todays terrestrial prices. |
Those number are inconsistent with each other. Seems you calculated with 400% more power/area in space vs on the ground. That seems incorrect to me, as it would make space solar convert close to 100% of incident solar energy to electricity.