The REAL obstacle to SPSS

The real obstacle to building solar power satellite systems is
diplomatic, and international. Any solar power satellite system that
can deliver power reliably to the ground can also deliver power
reliably to a "target", i.e. it can be used as a weapon.

The economics of the situation aren't obstacles, they're just
timers... sooner or later the price of energy will rise high enough,
and the price of technology will drop low enough, that it will make
/economic/ sense.

The problem is, that unless the world gets a HECK of a lot more
peaceful, it won't make DIPLOMATIC sense. No one country can afford
to piss off the whole rest of the world by developing and deploying
yet another weapon of mass destruction; Nuclear, biological, and
chemical weapons pale in comparison to the threat of ORBITAL weaponry.