> The cause becomes circular: orbital power only works once space industry is cheap, and space industry only becomes cheap if orbital power already pays for itself.

I'm still hoping (but not expecting) some kind of magical material suitable for space-elevators and skyhooks. The half-n-half idea of launching rockets from big balloon structures is also interesting.

> [At a level where it won't injure people] a gigawatt-class space beam needs a rectenna covering tens to hundreds of square kilometers. [...] The same footprint could host conventional photovoltaic panels that would quietly produce the same or greater power without any orbital complexity.

Also if one wants to make the "beam" more intense, that gets into concerns about military use or accidents.