It seems like the stuff of a science fiction book, but space-based solar power, at least theoretically, could eliminate the need for fossil-fuel energy production altogether.
Earth-based solar power is as far as we’ve gotten, and some studies suggest that solar power could supply the entire world’s energy needs without huge disruptions of living space. For example, using even a small area of the Sahara Desert, just ≈500,000 km2 (≈200,000 mi2) in Northern Africa, could supply the entire world’s energy needs. There are very few people roving the Sahara, as well as limited numbers of wandering wildlife, which would make a desert solar power station an excellent idea. There’s only a couple problems with such a plant. First, the sun doesn’t shine 24 hours per day on land, and then there’s the atmospheric problems.
Of course, atmospheric problems might include clouds, as well as sandstorms, but the air itself introduces a certain amount of inefficiency in even the most-efficient solar power plants. Come to think of it, this is why the Hubble Telescope was put in orbit, because there is no atmosphere to interfere with getting a clear view of the heavens. Additionally, there’s none of that pesky planetary rotation, requiring telescope tracking and having to stop viewing the stars when dawn rolls around. Interestingly, these are the exact same issues that space-based solar power would solve, but how feasible is it?
Space-based solar power might be capable of unprecedented efficiency, as well as 24-hour power production, but it would be insanely expensive. Some basic math and rocket economics tells us that putt enough photovoltaic solar panels in orbit would cost some $320 billion, but that doesn’t include assembly or operation, possibly hundreds of billions of dollars more. Additionally, keeping the solar power stations in their orbits requires propulsion technology that we just don’t have right now. Finally, “beaming” the collected energy back down presents another whole slew of challenges. For now, I believe space-based solar power is going to stay in the science fiction realm.