[marcosdumay]

Interesting. That's 0.20$/W on launch costs, what is actually not a showstopper.

I still doubt it will happen any time soon, because by the time we have enough launch capacity to use on things like this, the 0.2$/W will be a sizeable fraction of the costs of solar on the ground. The advantage is that you don't need batteries, but like photovoltaics, the floor on the costs of batteries is very low.

[giantrobot]

Their math is wrong. The ISS solar panels plus supporting truss elements mass about 60t or 2KW/t. At the fantastical (unbelievable) $20/kg to LEO that's $10/W. That doesn't include the mass of thermal control elements, maneuvering systems, power conversion, or power transmission system.

Also that's only to LEO which is useless for an SPS since the system wouldn't dwell over any receiver on the ground long enough to transmit a useful amount of power. You'd need all that mass in a geosynchronous orbit which trebles or quadruples that cost.