An interesting response

[Dan M]

>Takes 10 200 ton payload
> rockets each flying once a day to do it and with a blank check
> perhaps under 5 years to work up to this production rate and 6-7
> years from start to get to a $50 billion a year revenue stream
> increasing at $25 billion a year.
 
OK, let's do the math on that.  At the present time, the cost of lift to
geosynchronous orbit is $20,000 per kg or $20M per metric ton. Ten 200 ton
payloads would be about 40 billion per day or 14.6 trillion per year.
That's roughly the GDP of the US.

The trick is, as it always has been, to lower launch costs.  Unfortunately,
even in inflation adjusted dollars, launch costs haven't dropped much over
the past 40 years.  

The income stream (which you estimate at 25 billion/year) would also have to
support ground receivers, safety mechanisms, transmission lines, etc.  Plus,
it costs money to build the actual arrays.  If you can find a way to drop
launch costs a factor of 100 to 500, then space based solar becomes a
player.  There is nothing like that on the horizon.

Dan M.