I'm thinking $21 billion / (30 years * 1GW) is a little less than $80/MWh [1], which between two and three times the market price [2].
The way to look at this is that the electricity produced is expected to refund one third to half of the investment. I'd imagine the IP created will be worth a lot more.
Those are just watts at peak power, which are probably roughly 10x average power produced by panels, at least on the earth.
But perhaps I was too hasty in that the major hit against solar panel production is the earth obscuring the sun at night. On the other hand, I would expect cells in space to heat up substantially, given that they have no air to conduct away the heat.
If I could, I'd edit my comment to clarify that my comparison was not fair-- I was comparing two systems with different capacity factors as if they were the same.
How did you get this number?
I'm thinking $21 billion / (30 years * 1GW) is a little less than $80/MWh [1], which between two and three times the market price [2].
The way to look at this is that the electricity produced is expected to refund one third to half of the investment. I'd imagine the IP created will be worth a lot more.
1. http://www06.wolframalpha.com/input/?i=%2421+billion+%2F+%28...
2. http://www.bloomberg.com/markets/commodities/energyprices.ht...