So you have orbiting panels that will do what? Beam the energy back to earth? Isn't the sun beaming energy to earth directly? What problems do orbiting panels solve?
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.
> 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 […]. 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.
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.
Ground based solar has a capacity factor of about ~25% depending on location, while a space based installation would have nearly a 100% capacity factor. So to generate the same amount of energy per year you need about 4x as many panels on the ground. I probably should not have said power but instead something like exajoules/year.
Another important issue is that in space, PV can be extremely thin. The actual active layer of semiconductor can be maybe 50 microns (for silicon) or less than 1 micron (for CdTe). This also suggests solar-powered electric propulsion in space can have high acceleration, limited by heat dissipation in the engine.
* 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.